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The brain rhythms of cognition : investigating the dynamics of cortical plasticity through behavioural analysis and MEG
No full textVisuospatial processing is a fundamental cognitive capacity that underlies functions ranging from eye movements to working memory and even mathematical reasoning. Training visuospatial working memory can enhance performance across many cognitive domains — a phenomenon known as cognitive transfer. Although this effect is well established and holds therapeutic promise, the mechanisms driving transfer remain poorly understood. Measuring transfer is also challenging, as improvements during training may arise from multiple intertwined cognitive processes, as well as task-specific learning that does not generalise.The aim of this thesis was to understand how and why visuospatial working memory training produces cognitive transfer. To this end, we developed methods for quantifying transferable improvements and related these behavioural changes to underlying neural dynamics.To address how, we first combined a large behavioural dataset from an online cognitive training platform with dense longitudinal Magnetoencephalography (MEG) recordings in four participants. In Study 1, behavioural analyses revealed that task-specific gains appeared early in training, whereas transferable improvements accumulated gradually and consistently over time. In Study 2, MEG data showed that transfer was accompanied by a progressive, linear increase in alpha (~ 10 Hz) synchronisation within the dorsal attention network — a spatially selective network central to top-down control.To address why, we analysed the longitudinal MEG cohort alongside data from 83 participants in the Human Connectome Project (HCP). In Study 3, we found that dorsal alpha oscillations were tightly linked to the maintenance of visuospatial information. Using a whole-brain computational model in which low-frequency oscillations modulated high-frequency neural activity, we specifically demonstrated that alpha synchronisation could facilitate information routing in the dorsal attention network.Interestingly, the dorsal alpha network was active during the maintenance of non-spatial information as well. This suggests that the network supports a more general neural state of cognitive stability. Such mechanisms offer a compelling explanation for how training-induced neural plasticity can extend beyond visuospatial abilities, leading to broader improvements in attention and general cognitive function — even over relatively short training periods.List of scientific papersI. Ericson, J., & Klingberg, T. (2023). A dual-process model for cognitive training. Npj science of learning, 8(1), 12. https://doi.org/10.1038/s41539-023-00161-2II. Ericson, J., Palva, S., Palva, M., & Klingberg, T. (2024). Strengthening of alpha synchronization is a neural correlate of cognitive transfer. Cerebral Cortex, 34(2), bhad527. https://doi.org/10.1093/cercor/bhad527III. Ericson, J., Ruiz Ibáñez, N., Lundqvist, M., & Klingberg, T. (2025). Low frequency oscillations - neural correlates of stability and flexibility in cognition. Nature Communications, 16(1), 5381. https://doi.org/10.1038/s41467-025-60821-2</p
Facial nerve palsy and Lyme neuroborreliosis in children : treatment and outcome
No full textBackgroundAcute peripheral facial nerve palsy is a condition where the muscles on one side of the face become weak or paralysed due to impaired function of the facial nerve. Facial palsy affects both adults and children worldwide, causing difficulties portraying emotions with facial movement, which can significantly impact the social well-being of affected individuals. Studies have shown that 20% of children experience incomplete recovery of facial palsy.Idiopathic facial palsy is the most common cause of facial palsy in children in a global perspective. Lyme neuroborreliosis (LNB), a tick-borne infection, is another common cause of paediatric facial palsy, causing up to 65% of cases in children in Borrelia-endemic areas.LNB-associated facial palsy is treated with antibiotics with either oral doxycycline or intravenous ceftriaxone, depending on the children's age. Idiopathic facial palsy in adults is treated with corticosteroids which improves and hastens recovery, but there is a lack of evidence of the efficacy of corticosteroids in children with facial palsy.Various methods are available to evaluate the physical impairment and social impact of facial palsy. These include physician-assessed facial nerve grading systems and patient/guardian-reported questionnaires. Additionally, neurophysiological examinations may be performed to evaluate the function of the facial nerve.ObjectivesThe aim of this thesis was to investigate the aetiology, incidence, epidemiology and long-term outcomes of facial palsy in children in the Borrelia-endemic area of Stockholm, Sweden. The effectiveness of oral versus intravenous antibiotic treatment for LNB was compared with regard to clinical recovery. Furthermore, the detectability of brain-damage markers in serum in children with LNB was investigated, as well as their prognostic value in clinical recovery.Material and methodsStudies I and IV are historical descriptive cohort studies with prospectively collected data. The study populations consisted of children diagnosed with acute peripheral facial nerve palsy at the Astrid Lindgren Children's Hospital in the Borrelia-endemic area of Stockholm, Sweden. The study periods were 2014- 2015 for study I and 2016-2020 for study IV. Study participants were evaluated with Sunnybrook Facial Grading System, House-Brackmann Facial Nerve Grading System, Facial Clinimetric Evaluation Scale, Facial Disability Index, Synkinesis Assessment Questionnaire and neurophysiological examinations consisting of electromyography and electroneurography.Study II is a historical cohort study that compares the effectiveness of oral doxycycline and intravenous ceftriaxone in children with LNB in regard to clinical recovery. The study population consisted of children with LNB from previously conducted prospective studies. Clinical outcome was compared between the treatment groups receiving either oral doxycycline or intravenous ceftriaxone.Study III is a historical case-control study that evaluates the detectability of the brain-damage markers neuron-specific enolase and S100 calcium-binding protein B in children with LNB and non-LNB controls. Children with LNB were identified as cases with age- and gender matched non-LNB children serving as controls. The detectability of the brain-damage markers was evaluated and compared between children with LNB and non-LNB controls. Among children diagnosed with LNB, levels of brain damage markers were compared between those who showed clinical recovery and those who did not.ResultsIdiopathic facial palsy and LNB were the two most common causes of facial palsy in children in the studies I and IV. During 2014-2015 LNB caused 58,4% of facial palsies in children and idiopathic facial palsy accounted for 36,4% of cases. During 2016-2020 idiopathic facial palsy and LNB caused 41,7% and 41,2% of cases, respectively. The estimated incidence for these conditions were 12/100.000 children/year for idiopathic facial palsy and 11,8/100.000 children/year for LNB (studies I and IV).Facial palsy associated with LNB predominantly affected children under the age of ten, with most cases occurring between June and November in both study periods. After a follow-up period of three months, 8% of the children had incomplete recovery of their facial palsy (study I). When evaluating the long- term outcome of idiopathic facial palsy, differences were found in the evaluation according to the methods applied (grading systems, questionnaires and neurophysiological examination) (study IV).Children with LNB showed no difference in clinical outcome when comparing treatment with oral doxycycline and intravenous ceftriaxone when adjusted for relevant variables (study II). The serum levels of the brain damage markers evaluated did not differ significantly when comparing children with LNB and non- LNB controls. The serum levels did not differ when comparing children with complete recovery and incomplete recovery, among those diagnosed with LNB (study III).ConclusionIdiopathic facial palsy and LNB are the main causes of facial palsy among children in the Borrelia-endemic area of Stockholm, Sweden. LNB mainly affects children under the age of ten during June to November. Children may have persistent long-term symptoms of facial palsy, with a discrepancy seen between the evaluation according to physician-assessed grading systems, patient/guardian-reported questionnaires and neurophysiological examinations. Treatment of LNB in children with oral doxycycline seems to be equivalent to intravenous ceftriaxone in regard to clinical recovery. The brain damage markers NSE and S100B where equally detectable in children with LNB and non-LNB controls and cannot be recommended as prognostic biomarkers for clinical recovery in children with LNB.List of scientific papersI. Peripheral facial nerve palsy in children in a Borrelia high-endemic area, a retrospective follow-up study. Arnason S, Hultcrantz M, Nilsson A, Laestadius Å. Acta Paediatrica. 2020;109(6):1229-35. https://doi.org/10.1111/apa.15063II. Effectiveness of antibiotic treatment in children with Lyme neuroborreliosis - a retrospective study. Arnason S, Skogman BH. BMC Pediatr. 2022 Jun 9;22(1):332. https://doi.org/10.1186/s12887-022-03335-wIII. Brain damage markers neuron-specific enolase (NSE) and S100B in serum in children with Lyme neuroborreliosis - detection and evaluation as prognostic biomarkers for clinical outcome. Arnason S, Molewijk K, Henningsson AJ, Tjernberg I, Skogman BH. Eur J Clin Microbiol Infect Dis. 2022 Jul;41(7):1051-1057. https://doi.org/10.1007/s10096-022-04460-1IV. Aetiology of pediatric facial nerve palsy and long-term outcome of idiopathic facial palsy. Arnason S, Upate Z, Laestadius Å, Hultcrantz M, Skogman BH, Marsk E. Submitted for publication in September 2025. [Manuscript]</p
<b>Genetic tools for investigating the lifecycle of extracellular vesicles</b>
No full textMammalian cells ubiquitously release membrane-enclosed vesicles, known as extracellular vesicles. These particles carry a variety of molecules that reflect the status of their cells of origin, making them valuable sources for biomarker discovery. Furthermore, extracellular vesicles deliver their cargo locally and systemically to regulate biological processes, piquing interest in modulating extracellular vesicle biogenesis and developing extracellular vesicle-based therapies. Therefore, a thorough understanding of the extracellular vesicle life cycle, from biogenesis and trafficking to degradation, is essential for unlocking their full potential in biomarker identification and for the design of extracellular vesicle-based therapies. In this Review, we start by outlining the key steps in the extracellular vesicle life cycle and highlight remaining open questions. We then discuss the design and application of genetically encoded systems that can be applied to study extracellular vesicle biogenesis and fate. Finally, we highlight technical challenges that remain to be addressed in the engineering and application of genetically encoded systems to extracellular vesicle research.</p
Safer kids can't wait : evaluating a parenting program to prevent child abuse
No full textBackground: Millions of children across the world are exposed to violence in the home during their upbringing. While behavioral parenting programs are supported by research as effective in preventing child abuse, few trials include families with suspected abuse - particularly with follow-ups extending beyond one year. In routine services, interventions are often delayed, posing risks, as abuse can escalate and lead to long- term harm. Moreover, many parents decline or discontinue available interventions, underscoring the need for approaches that are not only timely and effective, but also acceptable to families.Aim: This thesis evaluated the feasibility, effectiveness, and parental experiences of Safer Kids, a behavioral parenting program designed for rapid delivery following a child abuse report. Study I assessed feasibility and preliminary effectiveness of Safer Kids in preventing outcomes related to child abuse. Study II evaluated short-term outcomes via a randomized controlled trial (RCT), while Study III examined long-term effects. Study IV explored parents' experiences with the program.Methods: Two studies were conducted with families involved in Swedish child welfare services due to suspected emotional or physical harsh treatment or violence against children (in the studies defined as child abuse, regardless of severity). Families were allocated to either Safer Kids or intervention as usual (IAU). IAU consisted of available standard interventions after reported child abuse at the participating child welfare service agencies. Primary outcomes were new official child welfare reports and scores on the Brief Child Abuse Potential Inventory (BCAP), which aims to assess the self- reported risk for abuse. Secondary outcomes included caregiver and child mental health, parental anger, and parent-child relationship quality. Study I employed a non- randomized controlled design with follow-ups at 4, 7, and 18 months. Studies II-III comprised an RCT, with assessments at baseline and at 4, 7, 18, and 30 months. Study II analyzed RCT data up to 7 months, and Study III up to 30 months. Between-group effectiveness was primarily analyzed using multilevel and linear mixed models, and Cox proportional hazards models for new report incidence. Study IV included semi- structured interviews with parents that took part in Safer Kids in the RCT, analyzed using reflexive thematic analysis.Results: Study I enrolled 67 families (104 caregivers). Most caregivers completed Safer Kids. Families assigned to the program had a lower risk for further child welfare reports than those assigned to IAU. Changes in BCAP and secondary outcomes did not differ significantly between groups, except for a larger reduction in parental depression at 7 months for caregivers who received Safer Kids. The RCT (Study II-III) enrolled 112 families (194 caregivers). Both groups showed improvements in self-rated outcomes at 7 months, with no significant between-group differences. Interestingly, a between-group effect in favor of Safer Kids appeared for child mental health symptoms at 30 months, since the control group's levels returned to baseline between 18 and 30 months. No significant group differences were found in the proportion of families re-reported or in the time to the first new report. However, families in the Safer Kids group accumulated fewer total reports over the 30-month follow-up period. Furthermore, satisfaction was higher among parents and social workers in the Safer Kids group compared to IAU. All except one family who started Safer Kids completed. Additionally, 41 of 42 social service agencies that participated in the trials continued using Safer Kids 2-2.5 years after ending study recruitment. In Study IV, fifteen parents were interviewed, who mostly reflected positively on their experiences with Safer Kids. Parents described improved abilities to handle anger, greater emotional presence, and stronger relationships with their children.Conclusions: Safer Kids was not consistently more effective than standard interventions, though some findings suggest modest additional benefits beyond the services typically offered following a report of child abuse in Sweden. The program appeared feasible within the Swedish social service context and well accepted by caregivers and staff. Further research is needed both to confirm its effectiveness and to investigate whether reducing delays between abuse reports and intervention onset can improve outcomes for children.List of scientific papersI. van Leuven, L., Lalouni, M., Enebrink, P., Sorjonen, K., & Forster, M. (2022). Feasibility and implementation of Safer Kids - A parenting program to reduce child abuse. Child Abuse & Neglect. 123. 105434. https://doi.org/10.1016/j.chiabu.2021.105434II. van Leuven, L., Enebrink, P., Ghaderi, A., Sorjonen, K., Lalouni, M., & Forster, M. (2023). A randomized controlled trial of Safer Kids - A program for parents reported for child abuse: Short-term effects on further reports of child abuse and related risk factors. Child Abuse & Neglect. 143, p. 106329. https://doi.org/10.1016/j.chiabu.2023.106329III. van Leuven, L., Enebrink, P., Lalouni, M., & Forster, M. (2025). Preventing Child Abuse Through a Brief, Rapid-Response Parenting Intervention: 2.5 Year Outcomes from the Safer Kids Randomized Controlled Trial. [Manuscript]IV. van Leuven, L., Västhagen, M., Forster, M., & Lindberg, L. (2025). Parents' experiences of parent training after reported child abuse: A qualitative study. Child Abuse & Neglect. 161, p. 107252. https://doi.org/10.1016/j.chiabu.2025.107252</p
Clinical education : exploring digital tools, multi-source feedback, and formative assessment for nursing student learning in EMS
No full textIntroductionClinical education is a cornerstone of undergraduate nursing programs, traditionally situated in hospitals and other care facilities. However, the rising demand for placements highlights the need for alternative learning environments. The Emergency Medical Services (EMS) represents an underutilized, but valuable context that exposes undergraduate nursing students (UNS) to diverse patient encounters, fosters interprofessional collaboration, and strengthens rapid decision-making skills in unpredictable situations. Despite its potential, assessing UNS in EMS is complex due to brief patient interactions, multiple supervisors, and dynamic clinical conditions. Traditional assessment instruments, developed for hospital context, may not capture the unique competencies required in EMS, such as adaptability, rapid clinical reasoning, and teamwork. Moreover, reliance on summative assessments can limit opportunities for ongoing learning. Consequently, there is a need to explore innovative feedback approaches that supports formative assessment, promote objectivity, and ensure alignment with intended learning outcomes (LO`s) and national curriculum standards. This thesis addresses this gap through three studies exploring UNS learning experiences and assessment processes during clinical education in the EMS, focusing on the use of digital assessment tool (DAT) and Multi-source feedback (MSF) to enhance formative and assessment.MethodsA mixed-methods approach was employed in study I were 50 clinical supervisors assessed four simulated scenarios using two different instruments with similar LOs, followed by 28 qualitative interviews. Quantitative data were analysed using descriptive statistics and logistic regression, while qualitative data were analysed using thematic analysis. Study II used a qualitative design, with group interviews including 16 UNS and individual interviews including 13 supervisors, focusing on their experiences using a DAT in EMS for formative feedback purposes. Data were analysed using Graneheim and Landman’s method for content analysis. Study III adopted a qualitative, inductive approach, conducting four focus group interviews with 31 final-semester UNS who received MSF facilitated by a digital tool during EMS placements. Data were analysed using reflexive thematic analysis according to Braun and Clark.ResultsStudy I demonstrated that while the two assessment instruments produced equivalent pass/fail outcomes, supervisors reported challenges with subjectivity, ambiguous phrasing of LOs, and inconsistent grading scales. These factors contributed to arbitrary judgments, limited day-to-day use, and difficulties in providing formative feedback. Supervisors emphasized the potential of team-based assessments and repeated evaluations to improve validity.Study II found that both UNS and supervisors experienced DAT as supportive of learning, reflection, and transparency. The Likert scale enabled visualization of progress, and the digital format facilitated communication compared to traditional paper-based methods. UNS valued its clarity and structure, while supervisors noted improved opportunities for formative feedback. However, participants requested greater integration with university systems and stronger links to course objectives.Study III highlighted UNS positive experiences with MSF in EMS. Feedback from supervisors and peers fostered self-awareness, professional growth, and reflective practice, while input from patients and health care professionals provided diverse perspectives despite contextual and logistical challenges. UNS appreciated the breadth of insights offered through MSF but stressed the need for structured implementation and digital support to ensure relevance and manage workload constraints.ConclusionThis thesis demonstrates that assessment in EMS requires approaches that extend beyond traditional summative instruments and adapt to the unique challenges of the prehospital environment. While existing tools may yield consistent grading outcomes, their formative value is limited by subjectivity, unclear definitions, and contextual constraints. The findings show that DAT can enhance transparency, structure, and communication, offering UNS clearer insight into their learning progress. Similarly, MSF enriches professional development by incorporating diverse perspectives, fostering self-reflection, and supporting collaborative learning, although patient and interprofessional input can be challenging to obtain. Supervisors emphasized the potential of team-based approaches to mitigate subjectivity and strengthen validity, highlighting the importance of structured support in the assessment process. Collectively, the three studies underscore the need for innovative, context-sensitive feedback frameworks that align with curriculum standards while capturing competencies central to EMS practice, such as adaptability, rapid clinical reasoning, and teamwork. By integrating DAT and MSF into EMS education, clinical placements can evolve into structured, high-quality learning environments that not only enhance formative assessment but also prepare UNS for safe, effective, and patientcentred care.List of scientific papersI. Tomas N, Italo M, Eva B, Veronica L. Assessment during clinical education among nursing students using two different assessment instruments. BMC Med Educ. 2024;24(1):852. https://doi.org/10.1186/s12909-024-05771-xII. Nilsson T, Masiello I, Broberger E, Lindström V. Digital feedback during clinical education in the emergency medical services: a qualitative study. BMC Med Educ. 2023 Mar 14;23(1):156. https://doi.org/10.1186/s12909-023-04138-yIII. Nilsson T, Masiello I, Broberger E, Lindström V. Clinical education: nursing students' experiences with multisource feedback using a digital assessment instrument in the emergency medical service - a qualitative study. BMC Med Educ. 2025;25(1):391. https://doi.org/10.1186/s12909-025-06950-0</p
Breast cancer biomarkers : dynamics during treatment and metastatic progression
No full textBreast cancer is a major global health challenge as incidence is increasing, and risk of recurrence remains a significant concern for long-term survivors. In an era of expanding therapeutic options, identifying biomarkers that can inform on prognosis and guide individualized treatment is of critical importance. This thesis explores both established and emerging biomarkers in breast cancer, examining their expression, dynamics over time and across different disease stages. In addition, it investigates key prognostic factors that influence long-term outcomes and factors associated with poor prognosis in the metastatic setting.In Paper I, a systematic review and meta-analysis was conducted to examine PD- L1 expression rates in primary breast tumors and metastatic lesions, including differences in expression according to cell type, metastasis site and the degree of discordance between primary tumors and their recurrences. The meta-analysis included 20 studies and revealed a significant discordance in PD-L1 expression between primary tumors and metastatic lesions, with overall expression rates being higher among primary tumors. Expression rates varied across metastatic sites, with the highest rates observed in lymph nodes and lungs, and the lowest in bone and liver. A substantial bidirectional discordance in PD-L1 status was observed in matched samples. Nearly half of the patients with PD-L1 positive primary tumors exhibited PD-L1 negative metastasis, while approximately one third of those with PD-L1 negative primary tumors converted to PD-L1 positive status in their metastatic lesions. The findings of the study highlight the critical importance of obtaining metastatic biopsies to accurately determine patients eligible for immune checkpoint blockade.Paper II investigated prognostic factors beyond pathologic complete response (pCR) that influence long-term outcomes in patients treated with neoadjuvant chemotherapy (NACT). A retrospective cohort of 2 487 individuals who received NACT for primary breast cancer between 2007 and 2020 in the Stockholm- Gotland region was analyzed using the National Quality Register for Breast Cancer and medical records. While pCR was confirmed as a favorable prognostic marker, it also demonstrated that patients achieving pCR are a heterogenous group with varying long-term risks. Factors independently associated with distant recurrence-free survival (DRFS) included lymph node involvement, tumor stage, estrogen receptor status, age and HER2 status. Furthermore, the study revealed a temporal dynamic of recurrence risk, with the highest risk occurring within the first two years post-surgery, though never entirely disappearing over time. Patients with residual disease consistently exhibited higher recurrence risk. These findings emphasize the importance of considering additional clinical and pathological factors beyond pCR when evaluating long-term risk, guiding treatment decisions, and designing future clinical trials.Paper III explored the distribution, temporal dynamics, and prognostic significance of HER2 status, including HER2-low, in a population-based cohort of patients with breast cancer treated with NACT. The study revealed a discordance rate of approximately 30% between untreated tumors, residual disease and metastatic lesions. HER2-low status was observed to be associated with ER expression. Notably, survival analysis revealed temporal differences in the risk curve between HER2-low and HER2 0 breast cancer. Patients with HER2 0 tumors had a higher initial peak in recurrence risk, which gradually declined over time, eventually falling below the risk observed in patients with HER2-low tumors. The likelihood of detecting a HER2-low status increased with the number of biopsies performed. The findings in paper III highlight the prognostic significance of HER2 status as well as the importance of obtaining repeated biopsies throughout the disease trajectory.In Paper IV women with very poor prognosis following a metastatic breast cancer (MBC) diagnosis were examined. The study showed that almost one in six women diagnosed with MBC died within 90 days. These patients were typically older, had more aggressive primary tumor biology, a higher clinical stage at initial diagnosis, more frequent visceral metastases, and received less chemotherapy in the primary setting. Notably, nearly half of the patients with poor prognosis never received systemic antitumoral treatment. Multivariable analysis identified age, metastasis site, adjuvant chemotherapy, primary tumor grade and period of diagnosis as independent factors of short survival. The study identified a subgroup of MBC patients with extremely poor prognosis and highlights the need for improved understanding and targeted research to enhance long-term outcomes.In conclusion, this thesis underscores the critical importance of performing repeated biopsies throughout the disease trajectory to enable more accurate and individualized treatment. It further highlights the heterogeneity of breast cancer both across time and anatomical sites. Collectively, these findings deepen our understanding of biomarkers in breast cancer and hold the potential to ultimately improve outcomes for patients with breast cancer.List of scientific papersI. Caroline Boman, Ioannis Zerdes, Kira Mårtensson, Jonas Bergh, Theodoros Foukakis, Antonios Valachis and Alexios Matikas. Discordance of PD-L1 status between primary and metastatic breast cancer: A systematic review and meta-analysis. Cancer Treat Rev. 2021 Sep;99:102257. doi:10.1016/j.ctrv.2021.102257. PMID: 34237488https://doi.org/10.1016/j.ctrv.2021.102257II. Caroline Boman, Christian Tranchell, Xingrong Liu, Louise Eriksson Bergman, Maria Angeliki Toli, Jonas Bergh, Theodoros Foukakis and Alexios Matikas. Prognosis After Pathologic Complete Response to Neoadjuvant Therapy in Early-Stage Breast Cancer: A Population-Based Study. J Natl Compr Canc Netw. 2025 Mar 12:1- 7. doi:10.6004/jnccn.2024.7093. PMID: 40073831https://doi.org/10.6004/jnccn.2024.7093III. Caroline Boman, Xingrong Liu, Louise Eriksson Bergman, Wenwen Sun, Christian Tranchell, Maria Angeliki Toli, Balazs Acs, Jonas Bergh, Theodoros Foukakis and Alexios Matikas. A population-based study on trajectories of HER2 status during neoadjuvant chemotherapy for early breast cancer and metastatic progression. Br J Cancer. 2024 Sep;131(4):718-728. doi:https://doi.org/10.1038/s41416-024-02777-6. PMID: 38942987IV. Caroline Boman, Luisa Edman Kessler, Jonas Bergh, Alexios Matikas and Theodoros Foukakis. Women with short survival after diagnosis of metastatic breast cancer: a population-based registry study. Breast Cancer Res Treat. 2022 Jul;194(1):49-56. doi:https://doi.org/10.1007/s10549-022-06591-7. PMID: 35461374</p
Climbing the magic mountain of tuberculosis : host related diagnostic biomarkers in blood may clear the view and get us to the top
No full textTuberculosis (TB) remains a global health challenge, with an estimated 2.6 million undiagnosed cases in 2023. The performance of current microbiological diagnostic methods is inadequate particularly in extrapulmonary and paucibacillary pulmonary TB, and no reliable biomarker is available to monitor treatment response or confirm cure. This thesis investigates host-response derived biomarkers expressed in blood as diagnostic and monitoring tools for TB disease and infection.In Study I and II we identified and validated three plasma protein signatures associated with TB disease. A 12-protein signature was identified in Study I through plasma profiling and network-based analysis. In Study II, the signature was refined into two condensed panels and validated in independent cohorts. The optimized 4-protein panel (CDCP1, VEGFA, IFNy, CXCL9) demonstrated the strongest discriminatory power. The overall AUC for distinguishing TB disease from TB infection was 0.86 (95% CI: 0.80-0.93) in the validation cohort. In the Italian sub cohort with only pulmonary TB, the 4-protein signature achieved an AUC of 0.92 (95% CI: 0.80-0.93) for TB disease in comparison with other respiratory diseases. All three signatures reached the minimum WHO target product profile screening test requirements in the Italian cohort, with sensitivities of 94-97% at a fixed specificity of 70%.In Study III we evaluated the Xpert MTB-Host Response (MTB-HR) assay, based on a three-gene transcriptomic signature comprising an MTB-HR score [(GBP5 + DUSP3)/2 - TBP]. The study included 307 participants with presumed TB disease, out of which 103 were then diagnosed with TB disease. MTB-HR showed equal diagnostic performance in pulmonary and extrapulmonary TB (AUC 0.84 and 0.82,), with high negative predictive values (NPV 94% and 95%, respectively) at separate cut-offs. The MTB-HR score correlated strongly with bacterial burden, with lower scores observed in individuals with positive microscopy and PCR compared to Mtb culture alone. The assay was particularly effective in detecting severe disseminated forms of TB and had a higher sensitivity than sputum microscopy and PCR in pulmonary TB. MTB-HR demonstrated utility as a triage tool and screening test, with potential to reduce reliance on sputum sampling and invasive diagnostic sampling methods. Capillary and venous samples for MTB-HR were highly correlated (r = 0.97, p In Study IV 99 individuals were followed longitudinally during TB treatment. MTB- HR scores increased over time. A tentative reference score for cure (MTB-HRref = - 0.79) was reached by 24% of participants at four months, and some even sooner. Lower bacterial burden at baseline was associated with earlier normalization. Notably, post-treatment MTB-HR scores closely resembled those of non-TB individuals, suggesting immunologic recovery and potential utility in verifying cure. Score dynamics were more closely associated with clinical assessment of treatment response than conventional markers like CRP, indicating MTB-HR as a more specific measure of treatment effect.A graded MTB-HR score may offer greater diagnostic flexibility than a single fixed threshold-especially given the wide clinical spectrum of TB disease. Establishing differentiated reference ranges and thresholds could enable Xpert MTB-HR to be used both for diagnostic, treatment monitoring and screening purposes.In Study V we assessed a multiplex FluoroSpot immune assay detecting combinations of IFNy, IL2 and TNF-secreting T-cells. Triple IFNy/IL2/TNF positive cells showed superior specificity for M.tuberculosis specific immune responses. The assay revealed distinct cytokine secretion profiles across the TB spectrum. TB disease was associated with IFNy/TNF-dominant responses, while TB infection showed an IFNy/IL2 and IL2/TNF predominance. Recent contacts had higher rates of non IFNy-producing cells combined with lower cytokine secretion, suggesting early immune activation. These findings support FluoroSpot's potential to improve differentiation between TB infection stages and enhance early detection of recent TB infection.In summary, these studies demonstrate that host-related biomarkers can complement existing diagnostic methods, particularly needed in extrapulmonary TB and paucibacillary pulmonary TB and for treatment monitoring. Xpert MTB-HR is a non-sputum-based diagnostic test with high negative predictive value and potential utility in screening, triage, and individualized care. The FluoroSpot assay provides functional immune profiling, could improve detection of Mtb specific immune responses and facilitate preventive treatment decisions.Future directions include combining proteomic and transcriptomic signatures to enhance diagnostic precision, establishing reference ranges for Xpert MTB-HR, and exploring biomarkers for incipient TB and post-treatment cure. These approaches could transform TB diagnostics, reduce diagnostic delays, and support global TB elimination efforts.List of scientific papersI. A protein signature associated with active tuberculosis identified by plasma profiling and network-based analysis. Mousavian Z, Folkesson E, Fröberg G, Foroogh F, Correia-Neves M, Bruchfeld J, Källenius G, Sundling C. iScience. 2022 Nov 22;25(12):105652. https://doi.org/10.1016/j.isci.2022.105652II. Optimization and validation of plasma protein signatures for identification of tuberculosis disease. Mousavian Z, Folkesson E, Sousa Silva C, Palmieri F, Vanini V, Cuzzi G, Correia-Neves M, Goletti D, Bruchfeld J, Källenius G, Sundling S. [Submitted]III. Improved Detection of Extrapulmonary and Paucibacillary Pulmonary Tuberculosis by Xpert MTB Host Response in a Tuberculosis Low-Endemic, High-Resource Setting. Folkesson E, Fröberg G, Sundling C, Schön T, Södersten E, Bruchfeld J. The Journal of Infectious Diseases, Volume 232, Issue 1, July 2025, Pages e78-e88. https://doi.org/10.1093/infdis/jiaf110IV. Xpert MTB Host Response is a promising biomarker indicating favorable treatment response in pulmonary and extrapulmonary tuberculosis. Folkesson E, Fröberg G, Sundling C, Zheng X, Schön T, Södersten E, Bruchfeld J. [Manuscript]V. A multiplex Mtb-specific FluoroSpot assay measuring IFNy, IL2, and TNF-secreting cells can improve accuracy and differentiation across the tuberculosis spectrum. Folkesson E, Foroogh1 F, Kleberg L, Kjellgren V, Jakobsson M, Grunewald L, Hellberg J, Ryberg J, Maher Z, Sousa Silva C, Gower M, Grönlund H, Correia-Neves M, Makower B, Källenius G, Bruchfeld J, Sundling C. [Submitted]</p
An anti-CEA affibody showing high-definition staining in human pancreatic cancer tissue sections and selective tumor targeting in vivo
No full textWe report development and characterization of small non-immunoglobulin affibody affinity proteins directed to the highly glycosylated human carcinoembryonic antigen-related adhesion molecule 5 (CEACAM5, CEA), and their use in immunohistochemical (IHC) analyses of human pancreatic cancer samples and for in vivo tumor imaging. A total of nineteen unique anti-CEA affibodies were identified from large phage display libraries constructed using combinatorial protein engineering of a small 58 amino acid three-helix bundle protein domain. Molecular modeling suggested that all enriched clones share a binding surface with several clustered tryptophan residues interacting with a hydrophobic patch in the N1 domain of CEA centered around a phenylalanine residue. One variant, designated as C9, exhibited the highest affinity in biosensor analyses and was reformatted into a 15 kDa homodimer expressed in Escherichia coli. The biotinylated form, C9-C9-Bio, was evaluated for its IHC performance on matched frozen and formalin-fixed, paraffin-embedded (FFPE) sections of human pancreatic cancer samples (n = 7). Compared to clinical-grade monoclonal antibodies II-7 and CEA31, as well as a polyclonal reagent, C9-C9-Bio demonstrated highly sensitive CEA detection with minimal background staining. Statistical analyses including intraclass correlation and Bland-Altman assessments revealed excellent agreement between C9-C9-Bio and the two monoclonal antibodies in FFPE tissue samples. Further, a 99mTc[Tc]-labeled C9-C9 construct showed CEA-dependent binding to human cancer cell lines in vitro, and selectively bound to CEA-expressing BxPC3 xenografts in mice when investigated as a tracer for in vivo imaging, allowing for a visualization of tumors after four hours. In , these findings highlight the potential use of the easily produced CEA-binding C9 affibody for various clinical applications, including IHC and medical imaging, and as a targeting moiety for directing various therapeutic modalities to CEA-expressing tumors.</p
Living matter(s) : exploring the educational use of live animals in learning to manage surgical traumatic injuries
No full textBackground: Live anaesthetised animals are used in many countries for medical professionals to practice surgical techniques. This type of simulation - known as "live tissue training" (LTT) - has been used specifically by military organisations to learn to manage complex traumatic injuries, and criticised by animal rights activists. There is a moral and ethical imperative to reduce live animal use in medical research and education, in accordance with the principles of the 3Rs (replacement, reduction and refinement) of humane animal experimentation. Yet, many advocates argue that there are currently no available simulation models that can replace all which can be achieved by using an anaesthetised pig. One significant component of the debate relates to the perceived realism or fidelity of using an animal in place of a human patient. Although the educational effectiveness of simulation is not in question, the benefit of this specific practice is unclear, in terms of educational outcomes for learners or improved health outcomes for patients.Aim: This doctoral research project aimed to explore how live animals are being used as simulators to educate medical professionals in the context of trauma, with a specific focus on surgeons and surgical teams. By improving our understanding of this type of simulated practice, it may be possible to contribute to an argument for justification of LTT in certain situations or contexts, inform educators on the most optimal way to use live animals for learning, guide technological developments to produce open surgical simulators, and assist with the rational reduction of animals in unnecessary medical training.Methods: A sociomaterial approach was adopted, focusing on how materials interact with social practices. Four sub-studies - a review of the literature and three empirical qualitative studies - were used to explore the research questions. Studies I(a) and I(b) reviewed the literature to understand how live animals are used as a simulation modality and what the associated ethical arguments are. Studies II-IV contributed to understanding how LTT is used in different contexts and for different learner populations. Study II used focus groups of UK military medical personnel to explore the use of LTT in a military environment. Study III involved focused ethnographic observations of seven international military and civilian surgical courses that use a live animal to train in the management of trauma. Study IV used fifteen qualitative semi-structured interviews of the learners and educators involved with LTT to explore how this sort of training could be optimised to maximise educational benefit.Findings: By concept, LTT is simulation, but the observed training is not delivered according to the established practices of simulation-based education. Instead, LTT appears more akin to a traditional surgical apprenticeship. Training is typically orientated toward learning procedural skills with in-situ feedback delivered by expert educators; there is no formal debriefing. Military LTT tends to be more aligned to pre-hospital and surgical team training in an operational context, whereas civilian LTT is typically orientated toward educating surgeons. Most learners and educators apply a consequentialist ethical outlook aligned with 'the end justifies the means'.The animals exist on an ontological spectrum, as a model for training and a patient that needs to be saved, which influences how learning is mediated. The tactile nature of the animal is important for all, but can be interpreted and valued differently. Survival of the animal is critical, at least until the learning objectives have been completed, when the animal is euthanised. During LTT, life and death are interpreted as success and failure. Premature death of the animal is problematic - superficially, as the perceived value for learning diminishes, and on a deeper level, as clear evidence presented to the learner that their actions truly matter in relation to patient outcomes.The experience of participating in live animal training is highly valued because it is considered to be realistic. An authentic learning experience is more likely to be perceived when animals are framed as patients, with a focus on the technical and non-technical skills of surgical practice. This facilitates multimediation of learning and a wider range of both intended, and unintended, learning outcomes.Conclusions: By considering the dual ontological nature of the animal alongside how this training is conceptualised - as simulation or a surrogate clinical experience - pedagogic knowledge could be used to optimise the learning that occurs through this educational event. It is also ethically and morally reasonable for each use of a live animal to be thoroughly considered as to whether the educational value, compared to alternative simulation models, outweighs the ethical cost. This approach would not only comply with the principles of the 3Rs, but ensure training in the context of trauma is the best available to improve patient care.List of scientific papersI. Swain CS, Cohen HML, Helgesson G, Rickard RF, Karlgren K. A Systematic Review of Live Animal Use as a Simulation Modality ("Live Tissue Training") in the Emergency Management of Trauma. Journal of Surgical Education. 2023;80(9):1320-39. https://doi.org/10.1016/j.jsurg.2023.06.018II. Swain C, Rickard R, Karlgren K, Helgesson G. Considering the ethics of live tissue training in trauma surgery. Journal of Medical Ethics. 2025 Mar 5:jme-2023-109761. Epub ahead of print. https://doi.org/10.1136/jme-2023-109761III. Swain CS, Harjani MG, Helgesson G, Rickard RF, Karlgren K. The perceptions and attitudes of British Armed Services medical personnel toward live tissue training for the surgical management of trauma. [Submitted]IV. Swain C, Silen C, Karlgren K. Living matter(s) for learning: an international, multi-sited ethnography exploring how surgeons' learning is mediated through the use of live animal simulation. Perspectives on Medical Education. 2025;14(1):181-193. https://doi.org/10.5334/pme.1762V. Swain C, Cohen H, Routh J, Helgesson G, Rickard R, Karlgren K. Optimising the educational utility of live tissue training in trauma surgery. [Submitted]</p
Aspects of abdominal surgery in children
No full textKnowledge of long-term consequences following abdominal surgery in children and infants is crucial as the child will live and develop with possible risks and adverse effects for a lifetime. Children's postoperative development is challenging to predict as there is a complex interaction with several biological-, psychological- and social functions that can affect each other dynamically for a long time.The overall aim of this doctoral thesis was to improve our understanding of long- term consequences following paediatric abdominal surgery. The studies focused on intra-abdominal adhesions, treatment of adhesive small bowel obstruction (ASBO) and long-term outcomes in the aspects of neuropsychiatric dysfunction. Finally psychiatric illness after childhood appendectomy and a possible link to the gut microbiome was explored.In study I we conducted a retrospective study of 619 individuals with appendectomy before the age of 15. The occurrence of ASBO was compared after open appendectomy (OA) and laparoscopic appendectomy (LA) and risk factors for ASBO were identified. Age, sex and proportion of perforated appendicitis were comparable between the LA and OA groups. Median follow-up time was 11.4 years (2.6-18.4). The risk for ASBO was related to perforated appendicitis and postoperative intra-abdominal abscess and not to the surgical method. Perforation increased the risk for ASBO hazard ratio (HR) 9.03 (95% CI 2.44-33.34; p =In study II we conducted a retrospective study of 101 individuals who were hospitalized for a total of 137 episodes of ASBO before the age of 15. In 58.4% the first surgery was performed during the neonatal period. Median time to the first ASBO was 3.76 months and median follow-up was 11.3 (0.6-19) years. In the cohort 86.6% of the children required surgical treatment for ASBO and the rate of complications following surgery for ASBO was 52%, registered according to the Clavien Dindo Classification of Surgical Complications. A substantial cost was related to the treatment of ASBO.In study III we compared a cohort of 485 individuals who were exposed to abdominal surgery during infancy to a cohort of 4835 unexposed controls matched by sex, age and gestational week in a population-based register study. Median gestational age was 38 weeks (24-44) and median age at surgery was seven days (0-365). Surgery was performed before 44 gestational weeks in 70%. Exposure to anaesthesia and abdominal surgery during infancy was not associated with cognitive dysfunction from the perspective of educational level, disposable income and ADHD in adolescent and adult individuals.In study IV we compared a cohort of 752 individuals from study II who were exposed to appendectomy before 15 years of age to a cohort of individually- matched 3760 unexposed individuals in a population-based register study. Median follow-up time was 15.5 (6-21) years. We found that childhood appendectomy increased the risk of psychiatric illness, HR 1.19 (95% CI 1.04-1.37; p=0.013) in general and for affective disorders HR 1.20 (95% CI 1.01-1.42; p=0.038). The healthcare consumption was also significantly increased following childhood appendectomy.In study V we added microbiome data from faecal samples to national population-based registers on 155 exposed individuals from study IV. A psychiatric diagnosis was found in 56 (36.1%) individuals. The microbiome was compared between individuals with psychiatric illness to individuals without. We identified significant changes in bacterial taxa within each diagnostic subgroup, with patterns of both up- and downregulation. Among these findings, we observed a downregulation of taxa associated with anti-inflammatory processes and an upregulation of taxa previously associated with pro-inflammatory processes. In addition, the microbial profile became less diverse as the number of psychiatric diagnoses increased in an individual.In conclusion, the results of this thesis contributes to both novel and expanded knowledge in aspects of abdominal surgery in children. Highlighting the importance of having both short- and long-term perspectives in paediatric studies. Future studies are needed to develop safe management guidelines for the treatment of ASBO, appendicitis and infant abdominal surgery.List of scientific papersI. Adhesive small bowel obstruction after appendectomy in children - Laparoscopic versus open approach. Cecilia Arana Håkanson, Fanny Fredriksson, Helene Engstrand Lilja. Journal of Pediatric Surgery. 2020;55(11):2419-2424. https://doi.org/10.1016/j.jpedsurg.2020.02.024II. Paediatric adhesive small bowel obstruction is associated with a substantial economic burden and high frequency of postoperative complications. Cecilia Arana Håkanson, Fanny Fredriksson, Helene Engstrand Lilja. Journal of Pediatric Surgery. 2023;58(11):2249-2254. https://doi.org/10.1016/j.jpedsurg.2023.05.017III. Attention deficit hyperactivity disorder and educational level in adolescent and adult individuals after anesthesia and abdominal surgery during infancy. Cecilia Arana Håkanson, Fanny Fredriksson, Helene Engstrand Lilja. PLoS One. 2020;15(10):e0240891. https://doi.org/10.1371/journal.pone.0240891IV. Childhood appendectomy and subsequent psychiatric illness. Cecilia Arana Håkanson, Fredrik Stiger, Nele Brusselaers, Helene Engstrand Lilja. PLOS Mental Health. 2025;2(1):e0000219. https://doi.org/10.1371/journal.pmen.0000219V. Alterations in the gut microbiome following childhood appendectomy and subsequent psychiatric disease. Cecilia Arana Håkanson, Marcela Pereira, Marina Carrera-Dulsat, Fredrik Stiger, Ann-Marie Kassa, Lars Engstrand, Nele Brusselaers, Helene Engstrand Lilja. [Manuscript]</p