Proteomic profiling of extracellular vesicles in synovial fluid and plasma from Oligoarticular Juvenile Idiopathic Arthritis patients reveals novel immunopathogenic biomarkers

IntroductionNew early low-invasive biomarkers are demanded for the management of Oligoarticular Juvenile Idiopathic Arthritis (OJIA), the most common chronic pediatric rheumatic disease in Western countries and a leading cause of disability. A deeper understanding of the molecular basis of OJIA pathophysiology is essential for identifying new biomarkers for earlier disease diagnosis and patient stratification and to guide targeted therapeutic intervention. Proteomic profiling of extracellular vesicles (EVs) released in biological fluids has recently emerged as a minimally invasive approach to elucidate adult arthritis pathogenic mechanisms and identify new biomarkers. However, EV-prot expression and potential as biomarkers in OJIA have not been explored. This study represents the first detailed longitudinal characterization of the EV-proteome in OJIA patients.MethodsFourty-five OJIA patients were recruited at disease onset and followed up for 24 months, and protein expression profiling was carried out by liquid chromatography-tandem mass spectrometry in EVs isolated from plasma (PL) and synovial fluid (SF) samples.ResultsWe first compared the EV-proteome of SF vs paired PL and identified a panel of EV-prots whose expression was significantly deregulated in SF. Interaction network and GO enrichment analyses performed on deregulated EV-prots through STRING database and ShinyGO webserver revealed enrichment in processes related to cartilage/bone metabolism and inflammation, suggesting their role in OJIA pathogenesis and potential value as early molecular indicators of OJIA development. Comparative analysis of the EV-proteome in PL and SF from OJIA patients vs PL from age/gender-matched control children was then carried out. We detected altered expression of a panel of EV-prots able to differentiate new-onset OJIA patients from control children, potentially representing a disease-associated signature measurable at both the systemic and local levels with diagnostic potential. Deregulated EV-prots were significantly associated with biological processes related to innate immunity, antigen processing and presentation, and cytoskeleton organization. Finally, we ran WGCNA on the SF- and PL-derived EV-prot datasets and identified a few EV-prot modules associated with different clinical parameters stratifying OJIA patients in distinct subgroups.DiscussionThese data provide novel mechanistic insights into OJIA pathophysiology and an important contribution in the search of new candidate molecular biomarkers for the disease

Definition and Validation of the American College of Rheumatology 2021 Juvenile Arthritis Disease Activity Score Cutoffs for Disease Activity States in Juvenile Idiopathic Arthritis

Export Date: 16 February 2023; Cited By: 10Peer reviewe

Proteomics and Extracellular Vesicles as Novel Biomarker Sources in Peritoneal Dialysis in Children

Peritoneal dialysis (PD) represents the dialysis modality of choice for pediatric patients with end-stage kidney disease. Indeed, compared with hemodialysis (HD), it offers many advantages, including more flexibility, reduction of the risk of hospital-acquired infections, preservation of residual kidney function, and a better quality of life. However, despite these positive aspects, PD may be associated with several long-term complications that may impair both patient’s general health and PD adequacy. In this view, chronic inflammation, caused by different factors, has a detrimental impact on the structure and function of the peritoneal membrane, leading to sclerosis and consequent PD failure both in adults and children. Although several studies investigated the complex pathogenic pathways underlying peritoneal membrane alterations, these processes remain still to explore. Understanding these mechanisms may provide novel approaches to improve the clinical outcome of pediatric PD patients through the identification of subjects at high risk of complications and the implementation of personalized interventions. In this review, we discuss the main experimental and clinical experiences exploring the potentiality of the proteomic analysis of peritoneal fluids and extracellular vesicles as a source of novel biomarkers in pediatric peritoneal dialysis

Molecular Allergy Diagnostics in Children with Cow’s Milk Allergy: Prediction of Oral Food Challenge Response in Clinical Practice

Background: Cow's milk allergy (CMA) is the most common food allergy in early childhood. Children with CMA require a precise and punctual diagnosis. Oral food challenge (OFC) is the gold-standard procedure for diagnosing allergies, but it is laborious and requires a particular setting. The aim of the study was to identify the cutoff value of serum allergen-specific IgE values able to predict a positive response to OFC. Methods: Children with suspected CMA performed OFC with cow's milk (CM) or derivatives. Total IgE and specific IgE to raw CM, α-lactalbumin, β-lactoglobulin, and casein were measured. Results: Seventy-two children performed OFC, and 30 (41.6%) had a positive response. The significant predictive factors were sensitization to raw CM extract (p = 0.03), α-lactalbumin (p = 0.013), β-lactoglobulin (p = 0.09), and casein (p = 0.019). The cutoff was, respectively: 5.13 kUA/L for raw CM, 1.47 for α-lactalbumin, 1.35 for β-lactoglobulin, and 4.87 for casein. Conclusions: This study allowed us to define a set of cutoff values for CM protein-specific IgE. However, these cutoffs should be interpreted not as a diagnostic tool for CMA but only predictive of response to OFC in a specific territory. Thus, the practical message may be that a value above the cutoff allows a good approximation to identify children to be started on OFC

Proteomic profiling of extracellular vesicles in synovial fluid and plasma from Oligoarticular Juvenile Idiopathic Arthritis patients reveals novel immunopathogenic biomarkers

IntroductionNew early low-invasive biomarkers are demanded for the management of Oligoarticular Juvenile Idiopathic Arthritis (OJIA), the most common chronic pediatric rheumatic disease in Western countries and a leading cause of disability. A deeper understanding of the molecular basis of OJIA pathophysiology is essential for identifying new biomarkers for earlier disease diagnosis and patient stratification and to guide targeted therapeutic intervention. Proteomic profiling of extracellular vesicles (EVs) released in biological fluids has recently emerged as a minimally invasive approach to elucidate adult arthritis pathogenic mechanisms and identify new biomarkers. However, EV-prot expression and potential as biomarkers in OJIA have not been explored. This study represents the first detailed longitudinal characterization of the EV-proteome in OJIA patients. MethodsFourty-five OJIA patients were recruited at disease onset and followed up for 24 months, and protein expression profiling was carried out by liquid chromatography-tandem mass spectrometry in EVs isolated from plasma (PL) and synovial fluid (SF) samples. ResultsWe first compared the EV-proteome of SF vs paired PL and identified a panel of EV-prots whose expression was significantly deregulated in SF. Interaction network and GO enrichment analyses performed on deregulated EV-prots through STRING database and ShinyGO webserver revealed enrichment in processes related to cartilage/bone metabolism and inflammation, suggesting their role in OJIA pathogenesis and potential value as early molecular indicators of OJIA development. Comparative analysis of the EV-proteome in PL and SF from OJIA patients vs PL from age/gender-matched control children was then carried out. We detected altered expression of a panel of EV-prots able to differentiate new-onset OJIA patients from control children, potentially representing a disease-associated signature measurable at both the systemic and local levels with diagnostic potential. Deregulated EV-prots were significantly associated with biological processes related to innate immunity, antigen processing and presentation, and cytoskeleton organization. Finally, we ran WGCNA on the SF- and PL-derived EV-prot datasets and identified a few EV-prot modules associated with different clinical parameters stratifying OJIA patients in distinct subgroups. DiscussionThese data provide novel mechanistic insights into OJIA pathophysiology and an important contribution in the search of new candidate molecular biomarkers for the disease

Paediatric rheumatologists do not score the physician's global assessment of juvenile idiopathic arthritis disease activity in the same way

Objectives To assess the heterogeneity in factors affecting physician's global assessment of disease activity (PhGA) and in PhGA scoring of multiple JIA patient's case scenarios. Methods An electronic web-based questionnaire of factors potentially considered in PhGA was sent worldwide to members of PRINTO and the Pediatric Rheumatology Care and Outcomes Improvement Network (PR-COIN). The respondents were asked to rate from 0 to 100 the relevance of 17 factors possibly affecting PhGA scoring and to derive a PhGA score of 17 detailed JIA patient cases. The median and interquartile range was used to measure the heterogeneity in the scoring. To demonstrate the consistency among the PhGA scores of the patient cases provided by multiple physicians, we assessed the inter-rater reliability using intra-class correlation. Results The questionnaire was completed by 491 respondents. A large individual variation was observed in the impact of different factors on PhGA when assessing JIA. For non-systemic JIA the presence of fever had the largest variation and swollen joint count had the smallest. For sJIA, the largest variation was seen in the presence of erosions and the smallest in the presence of fever. The intra-class correlation of the group for PhGA scoring of patient cases was 0.53 (95% CI 0.38, 0.72). Conclusions In a sample of worldwide respondents, the scoring of the PhGA is divergent. Consensus on PhGA scoring guidelines is required to obtain a consistent assessment of patients.Peer reviewe

Proteomics and Extracellular Vesicles as Novel Biomarker Sources in Peritoneal Dialysis in Children

Peritoneal dialysis (PD) represents the dialysis modality of choice for pediatric patients with end-stage kidney disease. Indeed, compared with hemodialysis (HD), it offers many advantages, including more flexibility, reduction of the risk of hospital-acquired infections, preservation of residual kidney function, and a better quality of life. However, despite these positive aspects, PD may be associated with several long-term complications that may impair both patient’s general health and PD adequacy. In this view, chronic inflammation, caused by different factors, has a detrimental impact on the structure and function of the peritoneal membrane, leading to sclerosis and consequent PD failure both in adults and children. Although several studies investigated the complex pathogenic pathways underlying peritoneal membrane alterations, these processes remain still to explore. Understanding these mechanisms may provide novel approaches to improve the clinical outcome of pediatric PD patients through the identification of subjects at high risk of complications and the implementation of personalized interventions. In this review, we discuss the main experimental and clinical experiences exploring the potentiality of the proteomic analysis of peritoneal fluids and extracellular vesicles as a source of novel biomarkers in pediatric peritoneal dialysis

Oral or subcutaneus methotrexate: comparison of the efficacy in inducing sustained disease remission in children with oligoarticular JIA

Introduction: Methotrexate (MTX) is widely adopted as a first line treatment in moderate to severe forms of juvenile idiopathic arthritis (JIA), when NSAIDs and intra-articular corticosteroid injections are not sufficient to control joint disease. MTX is generally prescribed at 10-15 mg/m2 weekly and its administration can be either oral or parenteral (subcutaneous (SC) or intramuscular). Contrasting evidence is available in the literature about the difference in efficacy and safety of MTX, according to the route of administration. Objectives: Aim of the study is to compare the efficacy of oral versus SC MTX in inducing sustained disease remission in children with oligoarticular JIA enrolled in two prospective cohorts. Methods: Children with oligoarthritis included in 3 prospective studies were considered for inclusion: a) the TRIMECA trial (1), b) the MD-Paedigree study (2), c) the PharmaChild registry. Patient evaluated at the IRCCS Istituto Giannina Gaslini and at the Ospedale Pediatrico Bambino Gesù were included if they had received methotrexate treatment as a first line systemic medication within 6 months after disease onset and if a follow up of at least 12 month after treatment initiation was available. Patients were then grouped according to the route of MTX administration. Baseline demographic and disease features were compared between the 2 groups. Efficacy was assessed by comparing the rate of inactive disease (ID) and clinical remission on medication (CRM) at 12 months, the rate of patients changing the route of MTX administration or requiring a biologic medication due to treatment failure. Safety was assessed by comparing the frequency of treatment interruption due to side effects of MTX. Results: 79 patients were included in the study: 43 received oral MTX, 36 received SC MTX. At treatment initiation, disease duration was not different in the two groups; children receiving SC MTX were older at baseline (4.6 yrs vs. 2.5 yrs) and at disease onset (4.2 yrs vs. 2.3 yrs). Disease activity was comparable in the 2 groups, with a median of 2 active joints in both groups. Median MTX dose was 14.4 mg/m2 for oral MTX group and 15.2 mg/m2 for SC MTX (Mann-Whitney U test, p < 0.01). At 12 months, children receiving SC MTX achieved more frequently ID (84.9% vs 43.8%, Chi squared test p < 0.001) and CRM (54.5% vs 28.3%, p = 0.002). Patients in SC MTX group were more often prescribed a biologic medication (22.9% vs 6.5%, p = 0.024), but none of them were switched to the oral administration while 37% of children in oral MTX group were turned to SC MTX. One patient in both groups had MTX treatment suspended due to side effects. Conclusion: Our preliminary results support the evidence of an increased efficacy of MTX in inducing sustained disease remission when it is administered subcutaneously

Paediatric rheumatologists do not score the physician’s global assessment of juvenile idiopathic arthritis disease activity in the same way

Abstract Objectives: To assess the heterogeneity in factors affecting physician’s global assessment of disease activity (PhGA) and in PhGA scoring of multiple JIA patient’s case scenarios. Methods: An electronic web-based questionnaire of factors potentially considered in PhGA was sent worldwide to members of PRINTO and the Pediatric Rheumatology Care and Outcomes Improvement Network (PR-COIN). The respondents were asked to rate from 0 to 100 the relevance of 17 factors possibly affecting PhGA scoring and to derive a PhGA score of 17 detailed JIA patient cases. The median and interquartile range was used to measure the heterogeneity in the scoring. To demonstrate the consistency among the PhGA scores of the patient cases provided by multiple physicians, we assessed the inter-rater reliability using intra-class correlation. Results: The questionnaire was completed by 491 respondents. A large individual variation was observed in the impact of different factors on PhGA when assessing JIA. For non-systemic JIA the presence of fever had the largest variation and swollen joint count had the smallest. For sJIA, the largest variation was seen in the presence of erosions and the smallest in the presence of fever. The intra-class correlation of the group for PhGA scoring of patient cases was 0.53 (95% CI 0.38, 0.72). Conclusions: In a sample of worldwide respondents, the scoring of the PhGA is divergent. Consensus on PhGA scoring guidelines is required to obtain a consistent assessment of patients