1,720,975 research outputs found
SVILUPPO DI UN BIOSENSORE E ANALISI GENOMICHE PER LO STUDIO DELLA RISPOSTA ALL'INFLIXIMAB IN PAZIENTI PEDIATRICI CON MALATTIE INFIAMMATORIE CRONICHE INTESTINALI
No full textLa terapia farmacologica delle malattie infiammatorie croniche intestinali (MICI), ed in particolare l'uso di anticorpi monoclonali contro il fattore di necrosi tumorale alfa (TNFα), come ad esempio l’infliximab e l’adalimumab, ha completamente rivoluzionato il trattamento delle MICI, grazie alla loro capacità di indurre e mantenere la remissione clinica. Il trattamento con agenti anti-TNFα ha successo nella maggior parte dei pazienti affetti da MICI, ma una percentuale di pazienti va incontro ad una perdita di risposta durante l’induzione (10-20%) o nelle fasi più tardive del trattamento (fino al 45%) e allo sviluppo di reazioni avverse al farmaco (20%). Vi sono prove crescenti che suggeriscono che il fallimento del trattamento possa essere associato a livelli di farmaco nel sangue inadeguati, alla comparsa di anticorpi anti-farmaco e/o alla presenza di varianti genetiche. Lo studio dei meccanismi alla base di questa variabilità interindividuale diventa quindi un obiettivo importante nella pratica clinica, con lo scopo di migliorare gli outcomes clinici e ottenere una terapia personalizzata, ad hoc per il paziente.
In questo contesto, questa tesi ha dimostrato:
- l'utilità del point of care come alternativa ai saggi ELISA, per il monitoraggio terapeutico dell’infliximab nei pazienti pediatrici affetti da MICI;
- incoraggianti risultati preliminari nell’utilizzo dell’AFM come metodica innovativa per il monitoraggio dell’infliximab nei sieri di pazienti pediatrici con MICI. È stata infatti dimostrata una buona correlazione tra la variazione di altezza e la concentrazione di infliximab permettendo così di sfruttare in futuro questa tecnica, grazie alla sua capacità di analisi multiplexing, per dosare contemporaneamente infliximab e anticorpi anti-farmaco;
- una correlazione tra livelli più elevati di adalimumab durante l’induzione e la risposta clinica a lungo termine nei pazienti pediatrici affetti da MICI;
- il ruolo del polimorfismo nel gene FCGR3A (rs396991) nei pazienti pediatrici con MICI: questo polimorfismo sembra influenzare la risposta all’infliximab e la suscettibilità alla produzione di anticorpi anti-farmaco. Questi dati supportano l'utilità della genotipizzazione di geni candidati per predire la risposta all’infliximab, riducendo i costi delle terapie ed aumentando l’efficacia del trattamento;
- la validità del modello in vitro di linfociti T CD4+ (Jurkat) per lo studio del meccanismo d'azione dell’infliximab;
- il ruolo del CD69 come marker di risposta all’infliximab.Pharmacological therapy of inflammatory bowel disease (IBD), and in particular the use of antibodies against tumor necrosis factor alpha (TNFα), such as infliximab and adalimumab, has led to a revolution in the treatment of IBD thanks to their capability to induce and maintain clinical remission. Treatment with anti-TNFα agents is successful in a majority of patients with IBD, yet it can fail in a proportion of patients leading to loss of response during the induction phase (10-20%) or over time (up to 45%) and to the development of adverse drug reactions (20%). There is increasing evidence suggesting that treatment failure may be associated with inadequate blood drug levels, the appearance of anti-drug antibodies and/or the presence of genetic variants. Studying the mechanism underlying this inter-individual variability becomes an important research goal to improve clinical practice.
In this context, this thesis has demonstrated:
- the utility of point of care as reliable option for real-time therapeutic drug monitoring of infliximab in children, showing a good agreement with traditional ELISA assays;
- encouraging preliminary results of AFM methodology for infliximab monitoring in sera of pediatric IBD patients. A good correlation was found between signal height variation and infliximab concentration and this technique can be exploited in the future, thanks to its multiplexing capability, to dose infliximab and anti-drug antibodies at the same time;
- the use of therapeutic drug monitoring to predict the efficacy of anti–TNFα agents in order to optimize treatment and minimize side effects. Early treatment modification can avoid complications: higher adalimumab levels during early treatment obtained from non–trough level serum samples predict long-term remission in children with IBD;
- the role of FCGR3A SNP in pediatric IBD patients: this SNP seems to affect infliximab response and influence anti-drug antibodies production susceptibility; these data support the utility of genotyping candidate genes to predict infliximab response in children with IBD, resulting in more cost-effective and safe therapies;
- the validity of Jurkat CD4+ T cells in vitro model for the study infliximab mechanism of action;
- the role of CD69 as marker of infliximab response
Monoclonal antibodies against pediatric ulcerative colitis: a review of clinical progress
No full textIn children, ulcerative colitis (UC) is often more severe and extensive than in adults and hospitalization for acute exacerbations occurs in around a quarter of subjects. There is a need for effective drugs, which could avoid or reduce the use of corticosteroids which, especially in children, are burdened by a number of severe side effects. The introduction in therapy of monoclonal antibodies has completely changed the therapeutic scenario and the prognosis of the disease. Areas covered: In this review, the use of the monoclonal antibodies directed against tumor necrosis factor (TNF)α or other inflammatory targets for the treatment of pediatric UC will be discussed. A search of the literature was done using the keywords ‘pediatric,’ ‘ulcerative colitis,’ ‘inflammatory bowel disease,’ ‘monoclonal antibodies;’ ‘infliximab,’ ‘adalimumab,’ ‘golimumab,’ vedolizumab,” ‘ustekinumab’ and ‘risankizumab.’ Expert opinion: The use of monoclonal antibodies has greatly increased in recent years in pediatric UC, both in patients who did not respond to conventional therapies, and, more often, as initial therapy. Thanks to therapeutic drug monitoring and to the availability of biologics with different targets, therapy has become more targeted and personalized, with a significant improvement in response, in quality of life, and with a good safety profile
Effect of early post-hematopoietic stem cell transplant tacrolimus concentration on transplant outcomes in pediatric recipients: One facility’s ten-year experience of immunosuppression with tacrolimus
Full text linkAcute graft-versus-host disease (GVHD) is a common life-threatening complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT), ranking as the second leading cause of death among recipients, surpassed only by disease relapse. Tacrolimus is commonly used for GVHD prophylaxis, but achieving therapeutic blood levels is challenging, particularly in pediatrics, due to the narrow therapeutic window and the high interindividual variability. The retrospective study conducted at IRCCS “Burlo Garofolo” in Italy aimed to assess the impact of early post-HSCT tacrolimus levels on transplant-related outcomes in pediatric recipients. The population pharmacokinetic model (POP/PK) was set up to describe tacrolimus pharmacokinetics. Elevated tacrolimus (>12–15 ng/ml) levels within the initial weeks post-HSCT are associated with reduced post-transplant infections (p < 0.0001) and decreased incidence of early transplant-related events (p < 0.01), including a lower incidence of acute GVHD (p <0.05 on day 0). High tacrolimus exposure can lead to an increased risk of chronic GVHD (p < 0.0001) and reduced overall survival (p < 0.01). Personalized dosing and therapeutic monitoring of tacrolimus are crucial to ensure optimal outcomes. POP/PK could help achieve this goal, giving us a model by which we can balance immunosuppression while looking at the patient’s general well-being and providing the necessary treatment
Extracellular Vesicles as Innovative Tools for Assessing Adverse Effects of Immunosuppressant Drugs
No full textExtracellular vesicles (EVs) are a heterogeneous family of small vesicles released by donor cells and absorbed by recipient cells, which represent important mediators with fundamental roles in both physiological and pathological conditions. EVs are present in a large variety of biological fluids and have a great diagnostic and prognostic value. They have gained the interest of the scientific community due to their extreme versatility. In fact, they allow us to hypothesize new therapeutic strategies since, in addition to being cell signal mediators, they play an important role as biomarkers, drug vehicles, and potential new therapeutic agents. They are also involved in immunoregulation, have the ability to transmit resistance to a drug from one cell to a more sensitive one, and can act as drug delivery systems
Pharmacogenetics of treatments for inflammatory bowel disease
Full text linkInflammatory bowel disease is a chronic inflammation of the gut whose pathogenesis is still unclear. Although no curative therapy is currently available, a number of drugs are used in induction and maintenance therapy; however, for most of these drugs, a high inter-individual variability in response is observed. Among the factors of this variability, genetics plays an important role. Areas covered: This review summarizes the results of pharmacogenetic studies, considering the most important drugs used and in particular aminosalycilates, glucocorticoids, thiopurines, monoclonal antibodies and thalidomide. Most studies used a candidate gene approach, even if significant breakthroughs have been obtained recently from applying genome-wide studies. When available, also investigations considering epigenetics and pharmacogenetic dosing guidelines have been included. Expert opinion: Only for thiopurines, genetic markers identified as predictors of efficacy or adverse events have allowed the development of dosing guidelines. For the other drugs, encouraging results are available and great expectations rely on the study of epigenetics and integration with pharmacokinetic information, especially useful for biologics. However, to improve therapy of IBD patients with these drugs, for implementation in the clinics of pharmacogenetics, informatic clinical decision support systems and training about pharmacogenetics of health providers are needed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Preanalytical Stability of 13 Antibiotics in Biological Samples: A Crucial Factor for Therapeutic Drug Monitoring
Full text linkThe stability of antibiotic preanalytical samples is a critical factor in therapeutic drug monitoring (TDM), a practice of undoubted importance for the proper therapeutic use of antibiotics, especially in complex management patients, such as pediatrics. This review aims to analyze the data in the literature regarding the preanalytical stability of some of the antibiotics for which TDM is most frequently requested. The literature regarding the preanalytical stability of amikacin, ampicillin, cefepime, ceftazidime, ciprofloxacin, daptomycin, gentamicin, levofloxacin, linezolid, meropenem, piperacillin, teicoplanin, and vancomycin in plasma, serum, whole blood, and dried blood/plasma spot samples was analyzed. Various storage temperatures (room temperature, 4 °C, −20 °C, and −80 °C) and various storage times (from 1 h up to 12 months) as well as subjecting to multiple freeze–thaw cycles were considered. The collected data showed that the non-beta-lactam antibiotics analyzed were generally stable under the normal storage conditions used in analytical laboratories. Beta-lactam antibiotics have more pronounced instability, particularly meropenem, piperacillin, cefepime, and ceftazidime. For this class of antibiotics, we suggest that storage at room temperature should be limited to a maximum of 4 h, storage at 2–8 °C should be limited to a maximum of 24 h, and storage at −20 °C should be limited to a maximum of 7 days; while, for longer storage, freezing at −80 °C is suggested
Azathioprine Metabolites in Erythrocytes and DNA for Therapy Monitoring in Very Early Onset Inflammatory Bowel Disease Pediatric Patients
Full text linkAzathioprine is used for inflammatory bowel disease (IBD) therapy. Patients under 6 years of age (very early onset, VEO-IBD) showed distinctive clinical characteristics, such as increased activity of thiopurine-methyltransferase (TPMT), a crucial enzyme for thiopurine metabolism. TPMT and PACSIN2 polymorphisms were associated with azathioprine efficacy. This study investigated the role of age in thiopurine active metabolites and disease activity. Also, the effects of age, TPMT and PACSIN2 polymorphisms on azathioprine metabolites and disease activity were evaluated. Erythrocytes thioguanine nucleotides (TGN) were measured by HPLC, and leukocytes incorporated deoxythioguanosine (DNA-TG) byLC-MS/MS in 12 VEO-IBD patients (median age 4.13 ± 0.98, 7 females, 6 Crohn’s disease (CD)), 11 IBD children (median age 9.36 ± 1.52, 8 females, 1 CD ), and 73 IBD adolescents (median age 14.92 ± 1.81, 33 females, 37 CD). VEO-IBD subjects required a higher azathioprine dose (p-value = 0.048) and showed a lower DNA-TG/azathioprine dose ratio (p-value = 0.049) and TGN/azathioprine dose ratio (p-value = 0.013). DNA-TG was positively correlated with TGN (p-value = 4.15 × 10-5) and disease score (p-value = 1.54 × 10-4). TPMT rs1142345 (76 wild type, 10 heterozygous) was associated with increased concentrations of DNA-TG and TGN (p-value = 0.024 and 0.00038, respectively), whereas PACSIN2 rs2413739 (37 wild types, 34 heterozygous, 16 homozygous variants) was associated with the disease score (p-value = 0.04). Together, these data confirmed that VEO-IBD patients show enhanced azathioprine metabolism, which can be accurately reflected by both TGN and DNA-TG levels, highlighting their ability to be good biomarkers of azathioprine metabolism
Atomic Force Microscopy Application for the Measurement of Infliximab Concentration in Healthy Donors and Pediatric Patients with Inflammatory Bowel Disease
Full text linkThe use of infliximab has completely changed the therapeutic landscape in inflammatory bowel disease. However, despite its proven efficacy to induce and maintain clinical remission, increasing evidence suggests that treatment failure may be associated with inadequate drug blood concentrations. The introduction of biosensors based on different nanostructured materials for the rapid quantification of drugs has been proposed for therapeutic drug monitoring. This study aimed to apply atomic force microscopy (AFM)-based nanoassay for the measurement of infliximab concentration in serum samples of healthy donors and pediatric IBD patients. This assay measured the height signal variation of a nanostructured gold surface covered with a self-assembled monolayer of alkanethiols. Inside this monolayer, we embedded the DNA conjugated with a tumor necrosis factor able to recognize the drug. The system was initially fine-tuned by testing known infliximab concentrations (0, 20, 30, 40, and 50 nM) in buffer and then spiking the same concentrations of infliximab into the sera of healthy donors, followed by testing pediatric IBD patients. A good correlation between height variation and drug concentration was found in the buffer in both healthy donors and pediatric IBD patients (p-value < 0.05), demonstrating the promising use of AFM nanoassay in TDM
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