KI Open Archive Karolinska Institutet
Not a member yet
10598 research outputs found
Sort by
Omics-based immune profile in first-episode psychosis : revealing biomarkers for understanding schizophrenia pathophysiology
No full textSchizophrenia is a lifelong, severe mental health disorder characterized by significant disability, disrupted psychosocial functioning, and premature mortality. Typically emerging in early adolescence, schizophrenia imposes a substantial healthcare burden worldwide. This thesis provides a comprehensive examination of fluid biomarkers and metabolic pathways during the onset and progression of psychosis, with a particular focus on first-episode psychosis (FEP).The pathophysiology of schizophrenia is linked to neurotransmitter activities such as dopamine, glutamate, and γ-aminobutyric acid, giving rise to several theories including those of dopamine, glutamate, kynurenic acid, and neuroinflammation. There is an urgent need to identify new drug targets to develop more effective medications that goes beyond symptomatic management of psychosis, emphasizing the limitations in current treatments. Omics studies, including proteomics and metabolomics, could revolutionize schizophrenia treatment by offering a more systematic approach to identifying drug response markers and minimizing adverse effects in therapies. Through metabolomics and proteomics analyses of cerebrospinal fluid (CSF) and serum metabolites, this research identifies crucial alterations that indicates the potential of these biomarkers in diagnosing and monitoring schizophrenia and related disorders. Collectively, these studies deepen our understanding of the biological underpinnings of psychosis and support the development of biomarker-based diagnostic and therapeutic strategies. This research highlights the intricacy of schizophrenia, which involves a complex interplay of metabolic, genetic, and inflammatory factors.List of scientific papersI. Shang, Pei, Ada Man-Choi Ho, Maximilian Tufvesson-Alm, Daniel R. Lindberg, Caroline W. Grant, Funda Orhan, Feride Eren, et al. 2022. ‘Identification of Cerebrospinal Fluid and Serum Metabolomic Biomarkers in First Episode Psychosis Patients’. Translational Psychiatry.12 (1): 229. https://doi.org/10.1038/s41398-022- 02000-1. https://doi.org/10.1038/s41398-022-02000-1 II. Eren, Feride, Lilly Schwieler, Funda Orhan, Anna Malmqvist, Fredrik Piehl, Simon Cervenka, Carl M. Sellgren, Helena Fatouros-Bergman, Göran Engberg, and Sophie Erhardt. 2023. ‘Immunological Protein Profiling of First-Episode Psychosis Patients Identifies CSF and Blood Biomarkers Correlating with Disease Severity’. Brain, Behavior, and Immunity. 111 (July): 376–85. https://doi.org/10.1016/j.bbi.2023.04.020. https://doi.org/10.1016/j.bbi.2023.04.020 III. Eren, Feride, Lilly Schwieler, Funda Orhan, Anna Malmqvist, Fredrik Piehl, Simon Cervenka, Carl M. Sellgren, Helena Fatouros-Bergman, Göran Engberg, and Sophie Erhardt. 2023. ‘Preanalytic Handling of Clinical Blood Samples in Assessing Immunological Proteins – Role of Storage Duration’. Brain, Behavior, and Immunity. 114 (November): 163–64. https://doi.org/10.1016/j.bbi.2023.08.013. https://doi.org/10.1016/j.bbi.2023.08.013 IV. Haroon, Humza, Ada Man-Choi Ho, Vinod K. Gupta, Surendra Dasari, Carl M. Sellgren, Simon Cervenka, Göran Engberg, Feride Eren, Sophie Erhardt, Jaeyun Sung, Doo-Sup Choi et al. 2024. ‘Cerebrospinal Fluid Proteomic Signatures Are Associated with Symptom Severity of First-Episode Psychosis’. Journal of Psychiatric Research. February, S0022395624000645. https://doi.org/10.1016/j.jpsychires.2024.02.002. https://doi.org/10.1016/j.jpsychires.2024.02.002 </p
Epithelial alarmins as novel targets for treatment of asthma
No full textAsthma is a chronic obstructive airway disease characterised by episodic or chronic breathlessness due to recurrent bronchoconstriction, mucus production, airway inflammation and structural remodelling of the bronchi. Airway hyperresponsiveness (AHR), i.e. the propensity to get a bronchoconstriction in response to stimuli that do not affect healthy individuals, is a key feature of asthma and a distressing condition. One manifestation of AHR is exercise induced bronchoconstriction (EIB), which is considered to occur when rigours breathing dries the airway epithelium, leading to increased tissue osmolarity and activation om mast cells.Epithelial alarmins interleukin (IL)-33, thymic stromal lymphopoetin (TSLP) and IL-25 are known to participate in the key pathophysiological processes in inflammatory diseases, their role in asthma is not fully elucidated. Using human small bronchi and human lung mast cells in ex vivo experiments, the role of epithelial alarmins in initiating airway hyperresponsiveness was therefore studied with a special focus on mast cell-dependent bronchoconstriction and the release of mast cell mediators.In Paper I, the human small bronchi were exposed to a combination of IL-33, TSLP and IL-25 and contractile responses were measured. The combination of the cytokines enhanced antigen-induced contractions and increased the release of mast cell mediators’ histamine and prostaglandin (PG)D2, while having no effect on contractions evoked by histamine.In Paper II, hyperosmolar-induced contractions in human small bronchi were studied, with the aim to further investigate the role of mast cells in this process and to delineate the contractile prostanoid component of the hyperosmolar- induced response. It was established that hyperosmolar-induced prostanoid component consisted of PGD2 and thromboxane TXA2 released from mast cells, acting on the thromboxane receptor. It was also shown that the use of monensin, a drug that selectively kills mast cells, abolished the hyperosmolar-induced bronchoconstriction.In Paper III, both isolated lung mast cells and human small bronchi were exposed to IL-33, TSLP and IL-25 and activated by hyperosmolar solution or IgE cross- linking (to mimic antigen). In the bronchi, the contractile responses and release of histamine and lipid mediators were assessed, and in the cells, degranulation and the release of histamine and lipid mediators were determined. It was discovered that IL-33, but not TSLP or IL-25, increased the contractile responses and the release of major prostanoids and histamine in response to both stimuli. The effect of IL-33 was then evaluated in the lung mast cells where it was found to increase degranulation, histamine release and release of cysteinyl leukotrienes, prostaglandins and several other lipid metabolites.The findings presented in this thesis propose a specific role for IL-33 as enhancer of mast cell-dependent airway responses, supporting intervention with IL-33 as an attractive target for treatment of asthma and AHR. Furthermore, this thesis adds evidence that mast cells and their mediators have a crucial role in hyperosmolar induced bronchoconstriction.List of scientific papersI. Maria Belikova, Jesper Säfholm, Mamdoh Al-Ameri, Ann-Charlotte Orre, Sven-Erik Dahlén, Mikael Adner. Combined exposure to the alarmins TSLP, IL-33 and IL-25 enhances mast cell-dependent contractions of human bronchi. Clinical and Experimental Allergy. 2023, volume 53, issue 10, page 1062-1066. https://doi.org/10.1111/cea.14367 II. Maria Belikova, Mamdoh Al-Ameri, Ann-Charlotte Orre, Jesper Säfholm. Defining the contractile prostanoid component in hyperosmolar-induced bronchoconstriction in human small airways. Prostaglandins and Other Lipid Mediators. 2023, volume 168, article 106761. https://doi.org/10.1016/j.prostaglandins.2023.106761 III. Maria Belikova, Anna-Karin Johnsson, Johan Kolmert, Craig Wheelock, Willem Abma, Mamdoh Al-Ameri, Axel Dimberg, Erik Sachs, Kasra Vali Jalali, Mikael Adner, Gunnar Nilsson, Sven-Erik Dahlén, Jesper Säfholm. IL-33 enhances responsiveness and mast cell mediator release in isolated human airways. [Manuscript]</p
Prenatal risk factors for severe cardiovascular diseases up to middle-age : a Nordic collaborative study
No full textBackground and objectives: Cardiovascular diseases (CVDs) are major causes of death and disability. However, the established traditional risk factors cannot explain a substantial proportion of CVD cases, prompting investigations into novel risk factors. A growing body of evidence underscores the potential role of suboptimal intrauterine conditions on the development of CVD. Nonetheless, our knowledge about the associations between factors contributing to an adverse intrauterine environment and the risk of developing CVD remains limited. The overall objective of this thesis is to enhance our comprehension of the potential role of prenatal risk factors in developing CVD later in life. More specifically, the thesis aims to study the following research questions: (1) Are negative birth outcomes such as preterm birth, being small (SGA) or large (LGA) for gestational age related to the atrial fibrillation risk later in life (Study I)? (2) Is maternal preeclampsia and its subtypes linked to increased risks of stroke and ischemic heart disease in the offspring (Study II)? (3) Is maternal polycystic ovary syndrome (PCOS) associated with the risks of overall CVD and its major subtypes in her offspring (Study III)? and (4) Is prenatal exposure to maternal severe stress related to the risk of heart failure later in life (Study IV)?Methods: We performed four register-based prospective cohort studies, including all live singletons from Denmark (Study I: 1978-2016, Studies II-IV: 1973-2016) and Sweden (Studies I-IV: 1973-2014), and live births from a randomly selected 90% of all births in Finland Studies I and II; 1987-2014). The size of the study population was 8,012,433 in Study I, 8,475,819 in Study II, 6,839,703 in Study III, and 6,758,560 in Study IV. Information on birth outcomes, maternal and offspring's health and covariates were obtained through linkage to population-based socioeconomic and health registers. Each study participant was followed up until the earliest diagnosis of the CVD of interest, emigration, death, or end of follow-up (Denmark: December 31, 2016; Finland: December 31, 2014; Sweden: December 31, 2020), whichever occurred first. We examined the association between prenatal exposures (including preterm birth, SGA, LGA, maternal preeclampsia, PCOS, and severe stress) and CVD outcomes in offspring using multivariable Cox regression models. Furthermore, we used family- based study designs, i.e. sibling and cousin comparison analyses, to account for unmeasured familial genetic and environmental confounders. Additionally, we investigated the mediating roles of abnormal birth outcomes and congenital heart disease in case of some of the observed associations.Results: In Study I, we found that being born preterm or LGA was linked to an increased risk of atrial fibrillation in both childhood and adulthood. The associations persisted in the sibling comparison analyses. In contrast, SGA was related to an increased atrial fibrillation risk in childhood but not in adulthood. In Study II, we found that individuals prenatally exposed to maternal preeclampsia had higher risks of stroke and ischemic heart disease than those unexposed, and that the associations were more pronounced in cases of severe than milder forms of preeclampsia. The associations of the severe forms of maternal preeclampsia with the offspring's risk of stroke remained in the sibling comparison analyses. In Study III, maternal PCOS was associated with elevated risks of overall CVD, hypertensive disease, stroke, and ischemic heart disease in the population analysis; most of these associations, except that observed in case of stroke, remained in the cousin comparison analysis. When investigating the interaction between maternal PCOS and its prevalent comorbidities, we found that individuals born to mothers with both PCOS and its common comorbid conditions, i.e. diabetes, hypertensive disease, or psychiatric disorders, had higher CVD risks than those born to mothers with only PCOS. In Study IV, we found that offspring exposed to maternal loss of a close family member the year prior to or during pregnancy did not have a higher risk of heart failure than those unexposed. However, the severe forms of maternal bereavement, specifically loss due to unnatural causes and loss of a child or partner, were linked to an increased risk of heart failure in the offspring.When splitting follow-up for Studies I-IV at the age of 18, we found that the association between preterm birth and the risk of atrial fibrillation, maternal preeclampsia and the risk of stroke, and severe maternal stress and the risk of heart failure were stronger during childhood than during adulthood. In the mediation analyses, there was some evidence that the association between maternal PCOS and the risk of CVD in offspring was to a modest extent mediated by preterm birth, LGA, and congenital heart disease. In the case of the link between severe maternal stress and the risk of heart failure, we observed considerable contributions from congenital heart disease and preterm birth.Conclusions: This thesis revealed associations of prenatal risk factors with increased risks of CVD up to early middle-age. Specifically, our findings suggest that preterm birth, SGA, and LGA were related to elevated risks of atrial fibrillation. Additionally, maternal preeclampsia, especially its severe types, was associated with elevated risks of stroke and ischemic heart disease in offspring, while maternal PCOS was associated with increased risks of overall CVD and its major types. Moreover, severe maternal stress was associated with an elevated risk of heart failure in offspring. If subsequent studies confirm our findings, early-life prevention and targeted intervention programs may be developed to inform health policies, eventually resulting in a reduced burden of CVD.List of scientific papersI. Yang F, Janszky I, Gissler M, Cnattingius S, Roos N, Miao MH, Yuan W, Li J, László KD. Preterm birth, small for gestational age, and large for gestational age and the risk of atrial fibrillation up to middle age. JAMA Pediatrics. 2023;177(6):599-607. https://doi.org/10.1001/jamapediatrics.2023.0083 II. Yang F, Janszky I, Gissler M, Roos N, Wikström AK, Yu YF, Chen H, Bonamy AKE, Li J, László KD. Association of maternal preeclampsia with offspring risks of ischemic heart disease and stroke in Nordic countries. JAMA Network Open. 2022;5(11):e2242064. https://doi.org/10.1001/jamanetworkopen.2022.42064 III. Yang F, Wang ZL, Sørensen HT, Janszky I, Gissler M, Yuan W, Miao MH, Roos N, Wikström AK, Li J, László KD. Risk of cardiovascular diseases in offspring of women with polycystic ovary syndrome: a binational cohort study. [Submitted]IV. Yang F, Janszky I, Roos N, Li J, László KD. Severe maternal stress during pregnancy and the offspring's risk of heart failure in the first five decades of life: a binational cohort study. [Accepted] https://doi.org/10.1001/jamanetworkopen.2023.49463 </p
Psychological self-care in chronic conditions : development of digital interventions in type 1 diabetes and atopic dermatitis
No full textBackground: Psychological interventions for somatic conditions have a long history with many successful examples, often based on cognitive behavioural therapy (CBT) However, psychologists are not commonly found in somatic healthcare. Therefore, it is of interest to develop self-guided interventions based on CBT for somatic disorders, for easy dissemination in regular healthcare. In this thesis, intervention in different stages of development were investigated for people with type 1 diabetes mellitus (T1DM) and for people with atopic dermatitis (AD) in both cases based on CBT.Aims: The overall aim in this thesis was to document the development of self-guided psychological interventions for somatic conditions, by a novel intervention for T1DM and a shortened and adapted intervention for AD.Method: The interventions developed for T1DM were inspired by earlier CBT research on T1DM and other somatic conditions. The self-guided intervention for AD was adapted from an evaluated clinician-guided intervention. Study I was a case report describing the treatment of two patients with T1DM who finished an early version of a 10-week CBT programme. Study II was a feasibility study in the setting of a diabetes clinic. Eight participants used two digital tools, focused on problem solving and exposure for four weeks. Study III was a feasibility study about a self-guided CBT-based intervention for AD with 21 participants. Study IV was a report on the secondary outcomes of study III. Study V was a randomised clinical non-inferiority trial with 168 participants randomised to a self-guided intervention for AD or to a clinician-guided intervention.Results: In study I, the 2 participants reported clinically significant improvements. Case 1 reported reduced blood glucose levels and improvements in his health behaviours. Case 2 reported clinically significant improvements in fear of hypoglycaemia. Both cases reported high satisfaction with their treatments and reported no adverse events. In study II, the results did not unreservedly support feasibility. All participants used the problem-solving tool, and three out of eight participants had used the exposure tool. No serious adverse events were reported. Results on feasibility were inconsistent, with credibility generally rated low, and usability below cut-off. However, some participants reported small improvements in outcome measures. As an additional tentative finding, a preliminary analysis of participant’s comments and reported problems suggested two types of users: One that may have more use for a problem-solving tool and one with fear of hypoglycaemia, that may be more helped by exposure. In study III, participants had a significant decrease on AD symptoms at post measurement immediately after intervention with a moderate within-group effect size (d=0.61 95% CI 0.11-1.12) which had improved to a moderate to large within-group effect size at 3-month follow up (d=0.84 95% CI 0.38-1.37) No serious adverse events were reported. The revised intervention consisted of 16 726 words, shortened from 111 142 words. In study IV, secondary outcomes on study III were reported. The intervention was feasible in all measures, except that system usability was rated 67 on average on the System Usability scale (range 0-100), below the scale’s authors’ cutoff of 70. At 3-month follow-up, within-group effect sizes on secondary outcomes were moderate to large. In study V, no significant differences were found between the groups. The estimated mean difference in change of 0.36 points (1-sided 97.5 % CI, −∞ to 1.75) which was lesser than the 3-point noninferiority margin. A clinician administering the clinician-guided group spent on average 50 minutes compared to 16 minutes for the self-guided group.Conclusions: Digital self-guided tools for people with T1DM may work for some people but would need improvements before a larger randomised trial. It’s possible that a general intervention based on problem-solving, and a specific intervention based on exposure for fear of hypoglycaemia would be a way to move forward in the development of interventions for T1DM. A self-guided CBT based intervention for AD was found feasible and effective and could be easily implemented in primary or specialist care. The results also support the feasibility of adapting an existing clinician-guided intervention into a self-guided variant. Self-guided interventions may have the advantage of less time spent by clinicians and therefore less use of resources. An additional possible advantage may be the less time spent by patients on reading written material.List of scientific papersI. Kern, D., Ljótsson, B., Bonnert, M., Lindefors, N., & Kraepelien, M. (2022). Online Guided Self-help Cognitive Behavioral Therapy With Exposure to Anxiety and Problem Solving in Type 1 Diabetes Mellitus: Case Study. JMIR formative research. 6(7), e32950. https://doi.org/10.2196/32950 II. Kern, D., Ljótsson, B., Catrina, S., Lindefors, N., & Kraepelien, M. Digital tools for exposure and problem-solving in type 1 diabetes mellitus: a pilot investigation. [Manuscript]III. Kern, D., Ljótsson, B., Lönndahl, L., Hedman-Lagerlöf, E., Bradley, M., Lindefors, N., & Kraepelien, M. (2022). Optimized User Experience, Efficiency, and Resource Use in Online Self-Management of Atopic Dermatitis. JAMA dermatology. 158(11), 1325–1327. https://doi.org/10.1001/jamadermatol.2022.3434 IV. Kern, D., Ljótsson, B., Lönndahl, L., Hedman-Lagerlöf, E., Bradley, M., Lindefors, N., & Kraepelien, M. (2023). A Digital Self-help Intervention for Atopic Dermatitis: Analysis of Secondary Outcomes From a Feasibility Study. JMIR dermatology. 6, e42360. https://doi.org/10.2196/42360 V. Kern, D., Ljótsson, B., Lönndahl, L., Hedman-Lagerlöf, E., Molander, O., Liliequist, B., Bradley, M., Lindefors, N., & Kraepelien, M. A brief self-guided digital intervention versus a comprehensive clinician-guided online cognitive behavioral therapy for atopic dermatitis: a Randomized Clinical Trial. [Manuscript]</p
Clinical characteristics and treatment outcomes in body dysmorphic disorder
No full textBody dysmorphic disorder (BDD) is an early onset mental disorder characterized by a preoccupation with perceived flaws in physical appearance. Research on the presentation of the disorder is sparse, especially on young people with BDD. Furthermore, the availability of cognitive-behavior therapy (CBT) for the disorder is generally low, despite being recommended in treatment guidelines. The overall aim of this thesis was to further describe the clinical characteristics of BDD and to promote the dissemination of CBT among youth with BDD.In Study 1, 600 individuals with an ICD-10 diagnosis of hypochondriasis or dysmorphophobia (i.e., BDD) (300 each) were randomly selected from the Swedish National Patient Register. Eighty-four medical files of individuals with hypochondriasis and 122 files of individuals with dysmorphophobia were received and used for analyses. Two independent raters assessed the validity and reliability of the diagnosis by performing an evaluation of the clinical charts. The inter-rater agreement regarding the presence or absence of a diagnosis was high for both disorders (95.2% for hypochondriasis and 92.6% for dysmorphophobia), and 80% of the hypochondriasis files and 91% of the dysmorphophobia files were considered ‘true positive’ cases. These results confirmed that the Swedish ICD-10 codes for hypochondriasis and dysmorphophobia are sufficiently valid and reliable to be used in register-based studies.Following up on Study 1, Study 2 was a Swedish nationwide matched-cohort study of 2,833 individuals with an ICD-10 diagnosis of BDD, each matched with 10 unaffected individuals from the general population. During the study period, 466 (16.45%) individuals with BDD and 1,071 (3.78%) unexposed controls from the general population had at least one record of intentional self-harm. In adjusted models, an elevated risk of intentional self-harm was observed among individuals with BDD (IRR=3.37 [95% CI, 3.02-3.76]). Additionally, a total of 17 (0.60%) individuals with BDD and 27 (0.10%) individuals from the general population died by suicide (HR=3.47 [95% CI, 1.76-6.85]). In sum, individuals with BDD showed an increased risk of self-harm and death by suicide, compared to individuals without BDD.In Studies 3 and 4 the aims were to explore the characteristics of a large cohort of adolescents with BDD, to evaluate the multimodal treatment outcomes of this cohort, and to examine potential predictors of treatment response. In our sample, we observed high rates of psychiatric comorbidity (71.5%), self-harm (52.1%), suicide attempts (11.0%), desire for cosmetic procedures (53.7%), and school dropout (32.4%). After receiving multimodal treatment consisting of CBT and medication when deemed necessary, 79% of the participants were classified as treatment responders and 59% as full or partial remitters. Encouragingly, BDD symptoms continued to improve up to one year after the end of the treatment. BDD symptom severity was identified as a predictor of treatment outcomes at post-treatment, but no consistent predictors were found at the one-year follow-up. The conclusion of these studies was that, while BDD in young people can be a serious and disabling disorder, often accompanied with substantial functional impairment and risky behaviors, multimodal treatment is effective in both the short- and the long-term when provided flexibly within a specialist setting.Finally, in Study 5, we transferred the treatment protocol evaluated in Study 4 to an online version. The treatment was considered both credible and satisfactory and was associated with a large reduction in BDD symptoms. At the a priori primary endpoint (3-months follow-up), 74% of the participants were classified as responders and 63% as full or partial remitters, and the results continued to improve up to the 12-month follow-up. Furthermore, the average therapist support time was 8 minutes per participant and week. Nonetheless, risky behaviors typical of this patient group should be carefully monitored during treatment. CBT delivered in an online format with minimal therapist support is a feasible, potentially efficacious, and durable treatment for adolescents with BDD.To summarize, this thesis concludes that BDD can be a severe and impairing mental disorder with several risks, including an elevated risk of intentional self-harm and death by suicide. It further suggests that face-to-face CBT for young people with BDD can be successfully implemented in specialist outpatient settings. To further increase treatment availability, CBT may also be delivered remotely, which has the potential to improve access to evidence-based treatment for youth with BDD.List of scientific papersI. Rautio, D., Vilaplana-Pérez, A., Gumpert, M., Ivanov, V. Z., Linde J, Österman, S., Flygare, O., Isung, J., Isomura, K., Krig, S., Serlachius, E., Högström, J., Rück, C., Mataix-Cols, D., & Fernández de la Cruz, L. (2021). Validity and reliability of the diagnostic codes for hypochondriasis and dysmorphophobia in the Swedish National Patient Register: A retrospective chart review. BMJ Open. 11(12), e051853. https://doi.org/10.1136/bmjopen-2021-051853 II. Rautio, D., Isomura, K., Bjureberg, J., Rück, C., Lichtenstein, P., Larsson, H., Kuja-Halkola, R., Chang, Z., D’Onofrio, B. M., Brikell, I., Sidorchuk, A., Mataix-Cols, D., & Fernández de la Cruz, L. Intentional self-harm and deaths by suicide in body dysmorphic disorder: A population-based study in Sweden. [Submitted]III. Rautio, D., Jassi, A., Krebs, G., Andrén, P., Monzani, B., Gumpert, M., Lewis, A., Peile, L., Sevilla-Cermeño, L., Jansson-Fröjmark, M., Lundgren, T., Hillborg, M., Silverberg-Mörse, M., Clark, B., Fernández de la Cruz, L., & Mataix-Cols, D. (2022). Clinical characteristics of 172 children and adolescents with body dysmorphic disorder. European Child and Adolescent Psychiatry. 31(1), 133-144. https://doi.org/10.1007/s00787-020-01677-3 IV. Rautio, D.*, Gumpert, M.*, Jassi, A., Krebs, G., Flygare, O., Andrén, P., Monzani, B., Peile, L., Jansson-Fröjmark, M., Lundgren, T., Hillborg, M., Silverberg-Mörse, M., Clark, B., Fernández de la Cruz, L., & Mataix-Cols, D. (2022). Effectiveness of multimodal treatment for young people with body dysmorphic disorder in two specialist clinics. Behavior Therapy. 53(5), 1037–1049. *Joint first authors. https://doi.org/10.1016/j.beth.2022.04.010 V. Rautio, D., Andrén, P., Gumpert, M., Jolstedt, M., Jassi, A., Krebs, G., Jansson-Fröjmark, M., Lundgren, T., Serlachius, E., Mataix-Cols, D., & Fernández de la Cruz, L. (2023). Therapist-guided, Internet-delivered cognitive-behaviour therapy for adolescents with body dysmorphic disorder: A feasibility trial with long-term follow-up. Internet Interventions. 34, 100688. https://doi.org/10.1016/j.invent.2023.100688 </p
Defining human adaptive immune gene diversity
No full textThe lymphocytes (B and T cells) of the adaptive immune system undergo variable (V), diversity (D), and junctional (J) gene recombination, resulting in highly diverse antigen receptor repertoires capable of recognizing a wide variety of invading pathogens. The B cell receptor (BCR) contains two identical heavy and light chains. While the T cell receptor (TCR) can either be composed of an alpha-beta (αβ) or a gamma-delta (γδ) chains, utilized by conventional T cells and γδT cells respectively. The chromosomal regions that encode the BCR and TCR loci are highly polymorphic and include both allelic variation and structural variation (deletions and duplications). The diversity within the adaptive immune receptor loci has remained insufficiently explored at the individual and population-level. At the outset of this project, the main currently used database for BCR and TCR germline variation, IMGT (The international immunogentics information system), is composed almost exclusively of alleles from European individuals, and it contains many alleles that have not been independently confirmed. To improve our understanding of BCR and TCR germline gene variation, and to generate improved and more accurate databases representing this variation, we developed laboratory techniques and software programs that allow personalized genotyping of these genes such as IgDiscover, corecount and haplotype analysis, as well as the high throughput technique, ImmuneDiscover, used in this thesis.In paper I, we used an expression-based germline gene inference approach to characterize 45 human volunteers belonging to four different populations: African, European, East, and South Asian. Using the IgDiscover tool we identified 175 novel V and J alleles and we found that a substantial number of these alleles contained coding-changes and several alleles were population restricted. Additionally, we identified three introgressed regions from Neanderthals that were present in presentday Europeans and Asians. Through functional studies of recombinant TCRs engineered to use different TRGV4 alleles, we showed that a highly diverse archaic TRGV4 allele mediated reduced binding to the BTNL3/BTNL8 ligand (butyrophilin-like molecule), which has implications for intraepithelial γδT cells that are known to use TRGV4, critically showing that allelic variation can result in functional differences.In Paper II, we introduce a novel genotyping tool, developed as a part of IgDiscover software known as corecount, for identifying the allelic variants within the BCR and TCR loci. We applied this technique to the 16 IgM libraries and the accuracy of this tool was verified through targeted genomic PCR and Sanger sequencing of all the 65 V alleles, 27 D alleles and seven J alleles present in one European donor. The genomic validation process determined the full length of five known V alleles and two known J alleles, which are truncated at the 3’ end in the IMGT database. We showed that the corecount tool can be used for highly accurate personal TCR (in paper I) and BCR genotyping, including for genes that are present at lower frequency and contain variations at the end of the V gene.In paper III of this thesis, we used IgDiscover and corecount to define germline gene variations within the human heavy chain V, D and J genes in 90 donors from different population groups: African, European, South Asian, and East Asian. We also developed an additional high-throughput genomic sequencing technique, ImmuneDiscover, which enables the analysis of a much greater number of samples, for example from biobanked DNA. We verified the accuracy of this technique by comparing donor genotypes identified from expressed libraries by IgDiscover with those identified from genomic libraries using ImmuneDiscover. We further applied this method to a large sample set of 2485 donors from the 1000 Genomes Project (1KGP), belonging to 25 population groups. We identified 321 novel V alleles, seven novel D alleles and two novel J alleles. Finally, we applied the plotalleles module within the IgDiscover software to four related donors elucidating that the heavy chain locus is continuously evolving.In paper IV, we determined the allelic variation at the human light chain kappa and lambda loci from 82 donors using the IgDiscover and corecount tools. These donors belong to different population groups: African, European, South Asian, and East Asian. In total, we identified 38 and 53 novel alleles for IGKV and IGLV respectively, that are not described earlier. These alleles were confirmed through several approaches, such as targeted genomic PCR and Sanger sequencing, identification of same novel allele in more than one donor and verifying the novel allele in two independent libraries from the same donor. Additionally, we show that some novel IGKV and IGLV alleles are population-restricted, and we identified two novel J alleles, each from different African donors. Finally, we identified alleles that may have archaic ancestry.The findings reported here greatly enhance our knowledge about human TCR and BCR germline gene variation. This will facilitate future studies of human adaptive immune responses in humans from diverse population ancestries.List of scientific papersI. Martin Corcoran, Mark Chernyshev, Marco Mandolesi, Sanjana Narang, Mateusz Kaduk, Kewei Ye, Christopher Sundling, Anna Färnert, Taras Kreslavsky, Carolina Bernhardsson, Maximilian Larena, Mattias Jakobsson, Gunilla B Karlsson Hedestam. Archaic humans have contributed to large-scale variation in modern human T cell receptor genes. Immunity. 2023 Feb. https://doi.org/10.1016/j.immuni.2023.01.026 II. Sanjana Narang, Mateusz Kaduk, Mark Chernyshev, Gunilla B Karlsson Hedestam, Martin M Corcoran. Adaptive immune receptor genotyping using the corecount program. Frontiers in Immunology. 2023 April. https://doi.org/10.3389/fimmu.2023.1125884 III. Martin Corcoran, Sanjana Narang, Mateusz Kaduk, Mark Chernyshev, Christopher Sundling, Anna Färnert, and Gunilla B. Karlsson Hedestam. Ultra-high throughput IGH genotyping reveals individual and population level diversity and provides a comprehensive resource for future adaptive immune analysis. [Manuscript]IV. Sanjana Narang, Martin Corcoran, Mateusz Kaduk, Mark Chernyshev, Christopher Sundling, Anna Färnert and Gunilla B. Karlsson Hedestam. Human immunoglobulin lambda and kappa light chain gene variation in individuals from Africa, Asia and Europe. [Manuscript]</p
Determinants of age-related brain iron accumulation and links to neurocognitive functions
No full textIron is crucial for development and normal functioning of the brain. With increasing age, it accumulates in the cells and can cause irreparable damage, affecting both the structure and function of the brain. Despite these findings, the factors which influence iron accumulates and the longitudinal effects of iron are still poorly understood. This doctoral thesis aimed to explore what influences brain iron accumulation in normal aging, and how this accumulation impacts molecular, and functional properties of the brain, and working-memory.Study I investigated if iron accumulation in striatum and DLPFC affected working memory change in normal aging, and if this accumulation and relationship to performance varied based on availability of dopamine, specified by COMT genotype status. We found that iron accumulated in both striatum and DLPFC. Greater iron accumulation in DLPFC was related to more deleterious change in working-memory performance. In addition, iron accumulation was amplified in older adults with presumably lowest levels of dopamine. These individuals were also driving the link between changes in iron and working-memory performance.Study II investigated if iron was linked to dopamine receptor availability and whether this association affected working memory. The study revealed that more iron was related to lower receptor availability in DLPFC and that this, coupled together with older age, contributed to reduced brain activity during a working-memory task. Additionally, the reduction in brain activity was in turn related to poorer task performance.Study III assessed (1) if brain iron content and accumulation were related to longitudinal changes in in brain activity during working-memory performance in normal aging, (2) potential association with glutamate, and (3) whether glutamate mitigated iron-brain activity relationship. In this study, we found that younger adults with initial elevated iron down-regulated more brain activity over a 3-year period, while performing the task. The results also showed a potential age-dependent relationship between iron and glutamate, such that younger adults with elevated iron content had more glutamate in DLPFC.Study IV explored biological and lifestyle factors that might influence iron accumulation in normal aging. Here, blood iron markers, physical activity, diet, and cardiovascular health significantly influenced brain iron content and accumulation. Furthermore, the associations between these factors and brain iron were influenced by age, highlighting the complexity of these relationships.Collectively, our studies show that age-related brain iron accumulation can be influenced by a number of factors, both modifiable and non-modifiable, such as lifestyle choices and genetic predisposition respectively. The potential to attenuate the accumulation of brain iron is essential, as we have also shown that iron can have deleterious effects on brain function and cognition older age. Finally, the links between iron and the dopaminergic system could partially explain age-related alterations, such as diminished receptor availability. Understanding the role of neurotransmitters on attenuating iron accumulation can pave the way for tailoring interventions in neurodegenerative disorders.List of scientific papersI. Gustavsson, J*., Papenberg, G*., Falahati, F., Laukka, E. J., & Kalpouzos, G. (2022). Contributions of the Catechol-O-Methyltransferase Val158Met Polymorphism to Changes in Brain Iron Across Adulthood and Their Relationships to Working Memory. Frontiers in Human Neuroscience. 16. *Authors contributed equally to this work as first authors. https://doi.org/10.3389/fnhum.2022.838228 II. Gustavsson, J., Johansson, J., Falahati, F., Andersson, M., Papenberg, G., Avelar-Pereira, B., Bäckman, L., Kalpouzos, G., & Salami, A. (2023). The irondopamine D1 coupling modulates neural signatures of working memory across adulthood. NeuroImage. 2023, 279:12323. https://doi.org/10.1016/j.neuroimage.2023.120323 III. Gustavsson, J., Falahati, F., Sitnikov, R., Manzouri, A., Papenberg, G., Salami, A., Persson, J., Kalpouzos, G. Influences of brain iron and glutamate on changes in brain activity during working memory in aging. [Manuscript]IV. Gustavsson, J., Ištvánfyová, Z., Papenberg, G., Falahati, F., Laukka, E. J., Lehtisalo, J., Mangialasche, F., Kalpouzos, G. Lifestyle, biological and genetic determinants of brain iron accumulation across adulthood. [Submitted]</p
Navigating the oligodendroglial chromatin landscape using high-throughput single-cell epigenomics
No full textThe central nervous system (CNS), which includes the brain and spinal cord, is a remarkably complex system composed of billions of cells controlling everything ranging from basic metabolic functions to higher executive processes. This is achieved through the coordinated actions between neurons and glia. Oligodendrocytes, a specific glial population, are the myelinating cells of the CNS and wrap neuronal axons with the myelin sheath to facilitate the action potential and coordinate neuronal circuits. Recent years have shown that these cells, along with their progenitor population – OPCs – are more transcriptionally and functionally diverse than was previously believed. The epigenome acts as a function that converts the conserved genetic code to the diverse phenotypes that are observed, and so studying the epigenome can provide insights into how these states arise. The rise of high-throughput single-cell sequencing technologies has enabled the profiling of complex tissues and unveiled cellular diversity in the epigenome and transcriptome.This thesis aims to broaden our understanding of gene regulation in the oligodendroglial lineage in both healthy and diseased contexts using a range of single-cell epigenomic methods.In Paper I we used single-nucleus ATAC-seq to investigate the chromatin landscape of oligodendroglia in experimental autoimmune encephalomyelitis (EAE), a mouse model of Multiple sclerosis. We sought to understand the regulatory mechanisms that underlie the immune-like transcriptomic states that oligodendroglia exhibit at peak EAE. We found that healthy oligodendroglia exhibit primed chromatin at a subset of immune genes. We then show that these genes are activated in EAE, through a coordinated action involving the Polycomb Repressive Complex 2, and alterations in the histone landscape.In Paper II, we developed scCUT&Tag, a new single-cell technology that enables the profiling of histone modifications and transcription factors (TFs). We applied the method to the juvenile mouse brain targeting the histone modifications H3K27me3, H3K27ac, H3K4me3, and H3K36me3, as well as the chromatin-associated proteins OLIG2 and RAD21. We use scCUT&Tag to delineate regulatory principles such as promoter bivalency, H3K4me3 spreading and promoterenhancer interactions.In Paper III, we used snATAC-seq and nanoCUT&Tag to profile adult human CNS tissue and capture the chromatin accessibility, H3K27me3 and H3K27ac histone landscape in different neural cell types. We unveiled a primed chromatin signature at the development-associated HOX genes in spinal cord-derived oligodendroglia (OLG). Using Micro-C to profile the chromatin architecture, we found that iPSderived human OPCs exhibit a HOX architecture that is compatible both with the primed chromatin state seen in the adult OLGs and with high-grade pontine gliomas. Our results suggest that spinal cord-derived adult OLGs retain epigenetic memory of these genes, which may enable them to promptly transcribe these genes in regenerative contexts but may also make them susceptible to gliomagenesis.In Paper IV, we developed nanoCTAR (pronounced “nano-star”) a 4-in-1 multimodal single-cell technology. We used nanoCTAR to simultaneously capture accessible chromatin, two histone modifications and the transcriptome in single cells from the developing mouse brain. We showcase nanoCTAR as a versatile, easy-to-implement, cost-effective method for high-complexity single-cell profiling.List of scientific papersI. Epigenomic priming of immune genes implicates oligodendroglia in multiple sclerosis susceptibility. Mandy Meijer*, Eneritz Agirre*, Mukund Kabbe, Cassandra A. van Tuijn, Abeer Heskol, Chao Zheng, Ana Mendanha Falcao, Marek Bartosovic, Leslie Kirby, Daniela Calini, Michael R. Johnson, M. Ryan Corces, Thomas J. Montine, Xingqi Chen, Howard Y. Chang, Dheeraj Malhotra, Gonçalo Castelo-Branco. Neuron. 2022. *Equal Contribution. https://doi.org/10.1016/j.neuron.2021.12.034 II. Single-cell CUT&Tag profiles histone modifications and transcription factors in complex tissues. Marek Bartosovic, Mukund Kabbe, Gonçalo Castelo-Branco. Nature Biotechnology. 2021. https://doi.org/10.1038/s41587-021-00869-9 III. Single-nuclei histone modification profiling of the adult human central nervous system unveils epigenetic memory of developmental programs. Mukund Kabbe, Eneritz Agirre, Karl E. Carlström, Fabio Baldivia Pohl, Nicolas Ruffin, David van Bruggen, Mandy Meijer, Luise A. Seeker, Nadine BestardCuche, Alex R. Lederer, Jilin Zhang, Virpi Ahola, Steven A. Goldman, Marek Bartosovic, Maja Jagodic, Anna Williams, Gonçalo Castelo-Branco. bioRxiv. 2024. [Manuscript Preprint] https://doi.org/10.1101/2024.04.15.589512IV. Multimodal single-cell epigenome and transcriptome coprofiling. Mukund Kabbe*, Mattia Zaghi*, Oluwatoba Ajani, Naomi Rijk, Marek Bartosovic, Gonçalo Castelo-Branco. * Equal Contribution. [Manuscript]</p
Major lower extremity amputations : outcomes, complications, and patient perspectives
No full textAn amputation is considered to be one of the oldest surgical procedures; yet, despite advancements in medical care, it continues to be associated with high rates of complications and postoperative mortality. This thesis aims to shed light on the complications, outcomes, and patient perspectives surrounding major lower extremity amputations (LEA).Study I investigated mortality rates following the first-ever transfemoral amputation (TFA) at 1 week and 1 year, focusing on the potential influence of diabetes. A total of 162 individuals who underwent their first-ever TFA between 1996 and 2012 were included. Diabetes was present in 30 patients (19%). Mortality rates were notably higher for patients with diabetes compared to those without at both 1 week (30% versus 8%, p = 0.001) and 1 year (80% versus 57%, p = 0.02). This difference remained significant after conducting a multivariable analysis.Study II examined and compared outcomes after two different reamputation levels following a failed transtibial amputation (TTA) – TFA and knee disarticulation (KD). The primary outcomes were further reoperation and reamputation. A total of 152 patients were included, with 66 cases of KD and 86 cases of TFA. Following KD, the reamputation rate was 36% compared to 15% after TFA (p = 0.004). In the multivariable analysis, TFA was associated with a decreased risk of reamputation, with an odds ratio of 0.31 (95% CI 0.14 – 0.69). The reoperation rate was 22% after TFA, compared to 38% after KD (p = 0.03). Prosthetic fitting was achieved in 30% of KD cases and 19% of TFA cases (p = 0.1), however, this was not statistically significant. Mortality did not significantly differ between the two reamputation levels.Study III analyzed the impact on days to prosthesis after the implementation of a new guideline for transtibial amputations. We included 263 TTA patients after the new guideline was implemented and compared them against 169 patients undergoing TTA before the new guideline. Following the implementation of the new guideline, there was a significant reduction of time to prosthesis compared to before (76 versus 103 days, p Using a qualitative method, Study IV explored patients’ experiences of their care trajectory, the given information, and involvement in care following the implementation of a new guideline. In total, 15 participants were selected and interviewed, all with experience of a TTA within the care under the new guideline. The interviews were analyzed using content analysis, and three themes emerged: (1) The mixed experience of becoming an amputee; (2) The need to be seen during the amputation process; and (3) The importance of being involved in the care. The main discovery is the participants’ desire for increased involvement in the decision-making process, with our interdisciplinary team follow-up serving as an exceptional demonstration of shared decision-making. While participants appreciated the printed information, oral communication was deemed most significant presenting the gravity of the subject. Participants also noted a lack of continuity throughout their care trajectory.In conclusion, the prevalence of postoperative complications following major LEA underscores the need for improved optimization and careful consideration of surgical approaches and treatment for each patient. Nevertheless, there are ways to enhance care for transtibial amputees, as demonstrated by the implementation of a new guideline, which has the potential to reduce the transition time from surgery to prosthetic fitting in a clinical setting. Gender disparities in prosthetic fitting persist as a significant concern, warranting further investigations. Another important enhancement in clinical practice would involve bolstering shared decision-making processes, facilitating greater involvement and information exchange with patients and their families. In this regard, introducing an interdisciplinary pre-amputation meeting and assigning a contact nurse for improved continuity could represent meaningful improvements. Shared decision-making holds particular significance in surgical interventions like amputations, given the elevated risk of complications.List of scientific papersI. Increased mortality among patients with diabetes following first-ever transfemoral amputation. Sjödin L, Enocson A, Rotzius P, Lapidus LJ. Diabetes Res Clin Pract. 2018 Sep;143:225-231. https://doi.org/10.1016/j.diabres.2018.07.016 II. Knee disarticulation vs. transfemoral amputation after failed transtibial amputation: Surgical outcome and prosthetic fitting in patients with peripheral vascular disease. Sjödin L, Ottoson C, Lapidus LJ. Prosthtet Orthot Int. 2024 Jan 1;48(1):25-29. https://doi.org/10.1097/PXR.0000000000000304 III. Shorter time to prosthesis after implementation of a new guideline for transtibial amputees. Sjödin L, Enocson A, Lapidus LJ. [Submitted]IV. Transtibial amputees’ perspectives on information and shared decision-making. Sjödin L, Lapidus LJ, Torbjörnsson E. [Submitted]</p
Automated microfluidic-based production of PET radioligands for clinical and preclinical use
No full textIn recent decades, microfluidic technologies have been explored for PET radiopharmaceutical production. Moreover, radiotracer production models have been gradually transitioning from centralized to decentralized models using custom microfluidic modules. This project aimed to introduce iMiDEVTM, an automated microfluidic synthesis module for the production of radiopharmaceuticals, and to enable dose-on-demand (DOD) or single-dose production based on clinical and preclinical needs.The work done in Paper I introduces the iMiDEV™ microfluidic system, a novel cassette-based automated module designed for the small-scale production of radiopharmaceuticals. This radiochemistry module uses a microfluidic cassette to perform liquid-phase reactions in an automated synthesizer. The user-friendly interface allows for manual and fully automated operations, facilitating efficient synthesis processes.Building on the foundation laid by the work in Paper I, Paper II explores the application of microfluidic techniques in PET radiopharmaceutical synthesis. Specifically, we investigated the use of an iMiDEVTM radiosynthesizer with a microfluidic cassette to produce [11C]flumazenil and L-[ 11C]deprenyl. Through meticulous method development and prep-HPLC integration, Paper II achieved good radiochemical yields (RCYs) and purities for both radiotracers with high molar activity, thus demonstrating the efficacy of the microfluidic synthesis methods.Paper III work concentrated on the production of increasingly demanding 68Ga labeled tracers and emphasized the vital role of microfluidic technology in meeting this rising demand. Specifically, [68Ga]Ga-FAPI-46 and [68Ga]Ga-DOTA TOC were synthesized as crucial tracers in theranostic applications. Through the fine-tuning of multiple parameters, such as 68Ga elution, mixing techniques, and purification methods, this study achieved good RCYs and purities by utilizing 3-5 times less precursor. This achievement highlights the potential of microfluidic based approaches in clinical settings and has been further validated by testing the developed methods in a separate radiochemistry laboratory setting, which has achieved comparable results.Using microfluidic cassettes and the iMiDEV™ module, Paper IV showcases the synthesis of radiotracers, including L-[ 11C]methionine and [11C]choline. By carefully optimizing the precursor amounts and synthesis parameters, high RCYs and purity levels were successfully achieved, confirming the viability of the DOD synthesis approach for clinical applications.This project highlights the transformative impact of microfluidic technology on PET radiopharmaceutical synthesis. By enabling automated, versatile, and efficient synthetic processes along with the DOD approach, microfluidic-based approaches hold promise in advancing research and clinical applications in nuclear medicine.List of scientific papersI. Ovdiichuk, O.; Mallapura, H.; Pineda, F.; Hourtané, V.; Långström, B.; Halldin, C.; Nag, S.; Maskali, F.; Karcher, G.; Collet, C. Implementation of iMiDEV™, a new fully automated microfluidic platform for radiopharmaceutical production. Lab Chip. 2021, 21, 2272-2282. https://doi.org/10.1039/d1lc00148e II. Mallapura, H.; Tanguy, L.; Långström, B.; Meunier, L.L.; Halldin, C.; Nag, S. Production of [11C]Carbon Labelled Flumazenil and L-Deprenyl Using the iMiDEV™ Automated Microfluidic Radiosynthesizer. Molecules. 2022, 27. https://doi.org/10.3390/molecules27248843 III. Mallapura, H.; Ovdiichuk, O.; Jussing, E.; Thuy, T.A.; Piatkowski, C.; Tanguy, L.; Collet-Defossez, C.; Långström, B.; Halldin, C.; Nag, S. Microfluidic-based production of [68Ga]Ga-FAPI-46 and [68Ga]Ga DOTA-TOC using the cassette-based iMiDEV™ microfluidic radiosynthesizer. EJNMMI Radiopharmacy and Chemistry. 2023, 8, 42. https://doi.org/10.1186/s41181-023-00229-9 IV. Mallapura, H.; Tanguy, L.; Mahfuz, S.; Bylund, L.; Långström, B.; Halldin, C.; Nag, S. Advancements in Microfluidic Cassette-Based iMiDEV™ Technology for Production of L-[11C]Methionine and [11C]Choline. Pharmaceuticals. 2024, 17, 250. https://doi.org/10.3390/ph17020250 </p