Adverse events of biological agents in pediatric rheumatologic diseases.

OBJECTIVES: To evaluate adverse events (AEs) in pediatric patients with rheumatologic diseases being treated with approved or off-label biologic agents (BAs). METHODS: This observational, retrospective, multicenter study was conducted from 2010 to 2022 in patients under 18 years of age with rheumatic diseases who were receiving interleukin-1 antibodies (Anti-IL1), interleukin-6 antibodies (Anti-IL6), and tumor necrosis factor alpha inhibitors (anti-TNF). Efficacy, AEs, and timing of AEs were collected from electronic medical records. RESULTS: Three hundred and fifteen BAs were prescribed to 237 patients. Fifty AEs occurred in 44 patients (18.6%). Anti-TNF exposure was present in 8 (72.2%) of 11 patients with latent tuberculosis (TB) and in all 7 patients with herpes infections. Four of 6 patients (66.7%) with recurrent upper respiratory tract infections and 7 of 8 patients (87.5%) with local skin reactions were on Anti-IL1. The cutoff value for latent TB development was determined as 23.5 months by ROC analysis (AUC: 0.684 ± 0.072, p = 0.038, 95% CI: 0.54-0.82). In patients who used BA for 23.5 months or more, the risk of latent TB was 5.94-fold (p = 0.024, 95% CI: 1.26-27.97). Drug rash with eosinophilia and systemic symptoms (DRESS) occurred in 2 patients on anakinra, and anaphylaxis occurred in 1 patient on anti-IL6. There were no cases of malignancy or death in any patient. CONCLUSION: The physician should be vigilant for latent TB in patients exposed to BA for more than 2 years. While local skin reactions are more prevalent in patients receiving anti-IL1, severe skin reactions such as DRESS may also occur.

Relationship between biologic modifying agents and development of latent tuberculosis in pediatrics.

INTRODUCTION: Biologic modifying agents are associated with an increased risk for infection with mycobacteria. The aim of this study is to document patients who received different biologic modifying therapies in our pediatric rheumatology department and the possibility of development of tuberculosis (TB). METHODOLOGY: This retrospective study was conducted in Ankara City Hospital. Pediatric patients who were treated with biologic modifying agents between 2010-2020 were documented. Development of TB and the risk factors were assessed in this patient group. RESULTS: There were 72 patients who were treated with different biologic modifying agents. Tuberculin skin test (TST) was positive in 7 (9.7%) patients during follow up. Three patients whose TST was positive had received canakinumab, 2 received etanercept, 1 received adalimumab and 1 received anakinra. Median duration of therapy was 43.5 (16.5-168) months for these patients and the duration was longer than patients who did not develop latent tuberculosis (p = 0.04). Patients who developed latent TB under treatment were significantly older than the patients who did not (p = 0.01). CONCLUSIONS: According to our findings, 9.7% of pediatric patients who received biologic modifying agent therapy developed latent TB. Patients who developed latent TB were older, and the duration of treatment was longer than patients who did not develop latent TB. Although not statistically significant, canakinumab, which is known as an agent less likely to cause TST conversion, was in fact the most common agent that caused TST conversion.

Predictors of relapse in patients with oligoarticular juvenile idiopathic arthritis in remission off medication.

The aim of this study was to evaluate the predictors of relapse in patients with oligoarticular juvenile idiopathic arthritis (oJIA) who achieved clinical remission off medication. This retrospective observational study was conducted between June 2009 and July 2022 in 126 patients with oJIA who achieved remission off medication. The relationships between relapse status and demographic, clinical and laboratory findings, and treatment details were evaluated using electronic medical records. Of the 126 oJIA patients who achieved remission off medication, 85 (67.5%) were female. Relapse occurred in 31 patients (24.6%) with remission off medication after a median of 18 months (IQR 7-26). No statistically significant relationship was found between gender, age at diagnosis, oJIA subtype, number of joints, ANA, ESR, CRP level, initial Juvenile Arthritis Disease Activity Score and relapse in oJIA patients who achieved remission off medication (p = 0.66, p = 0.25, p = 1, p = 0.54, p = 0.29, p = 0.59, p = 0.95 and p = 0.52, respectively). There was a statistically significant relationship between the number of intraarticular corticosteroid injections (IACIs) and relapse (p = 0.01). Patients who underwent IACI 2-3 times had more relapses than those who never underwent IACI and those who underwent IACI only once (p = 0.01, p = 0.02, respectively). A relationship was found between the length of follow-up and relapse in patients with oJIA who achieved remission off medication (p = 0.035).    Conclusion: In oJIA patients who achieve remission off medication, the probability of relapse increases in patients who need ≥ 2 IACI during the period until remission. The length of follow-up period is associated with the probability of relapse. What is Known: • Approximately one-fourth of oJIA patients who are in remission off medication have relapse. • There is a need for markers that can predict the risk of relapse in oJIA patients who achieve remission on or off medication. What is New: • The possibility of relapse should be considered in patients with oJIA who need ≥ 2 IACIs until achieving remission off medication. • The relapse rate may increase as the follow-up period prolongs in patients who achieve remission off medication.

The Effect of Clinical and Genetic Variables of Familial Mediterranean Fever Patients: Real Life Data.

BACKGROUND: The Eurofever/the Pediatric Rheumatology International Trials Organization (PRINTO) classification criteria for familial Mediterranean fever (FMF) include a combination of clinical symptoms and genotype. The pathogenicity of gene variants associated with FMF is categorized by the International Study Group for Systemic Autoinflammatory Diseases (INSAID) classification criteria. OBJECTIVE: The aim of this study was to evaluate the real-life impact and usefulness of the Eurofever/PRINTO classification criteria and the INSAID classification criteria in patients with FMF and their impact on treatment management. METHODS: In this medical records review study, the files of FMF patients who met the Eurofever/PRINTO classification criteria were reviewed. The MEFV (MEditerranean FeVer) variants were grouped according to the INSAID classification criteria. RESULTS: Of the 1062 patients, the female-to-male ratio was 1:1.01. In group 1, there were 150 patients (14.1%) who met the clinical criteria. Group 2 consisted of 912 patients (85.9%) who met the criteria according to genetic variants. The mean ages at symptom onset in groups 1 and 2 were 5.6 ± 3.8 and 1.5 ± 1.2 years, respectively ( p = 0.024). Whereas the mean annual attack frequency was 2.7 ± 3.1/year in group 1, it was 4.1 ± 2.3/year in group 2 ( p = 0.04). The pathogenic variant was higher in the colchicine-resistant group compared with the responders ( p = 0.12). CONCLUSIONS: The Eurofever/PRINTO classification criteria may provide a new perspective on the diagnosis and clinical follow-up of FMF patients. Patients with a pathogenic variant who meet the Eurofever/PRINTO classification criteria including genetic variables have earlier onset of disease and more frequent attacks than those who meet the criteria including clinical variables. These patients need regular and closer follow-ups in terms of attack frequency, colchicine dose adjustment, and colchicine resistance.

The Juvenile Spondyloarthritis Disease Activity Index Is a Useful Tool in Enthesitis-Related Arthritis: Real-Life Data.

OBJECTIVE: To compare enthesitis-related arthritis (ERA) patients with active and inactive disease at 6 months and define baseline predictors for disease inactivity. In addition, to evaluate the demographic, clinical, and laboratory characteristics of ERA patients and to identify the real-life impact of the Juvenile Spondyloarthritis Disease Activity Index (JSpADA) in predicting active disease in ERA. METHODS: This medical record review study was conducted with 56 patients who were diagnosed with ERA at our clinic between June 2009 and June 2022. Demographic and clinical characteristics, laboratory parameters, treatment, and JSpADA were recorded. RESULTS: The patients were divided into 2 groups as active (n = 34) and inactive (n = 22) according to their disease activity at month six. Sex, age at diagnosis, number and type of affected joints, and presence of sacroiliitis were similar in both groups. There was no difference in baseline erythrocyte sedimentation rate, but there was a significant difference in erythrocyte sedimentation rate at the third month ( p = 0.52 and p = 0.018, respectively). The median JSpADA values at disease onset were 3.5 (interquartile range [IQR], 3.0-4.5) and 3.3 (IQR, 2.5-4.0) in the active and inactive groups, respectively ( p = 0.27). At the third month, the median JSpADA values were 1.5 (IQR, 0.5-2.1) in the active group and 0.5 (IQR, 0.5-1.5) in the inactive group ( p = 0.037). The cutoff value for JSpADA at the third month for active disease persisting at the month six was determined as 1 point (area under the curve, 0.662 ± 0.06; p = 0.042; 95% confidence interval, 0.51-0.80) by receiver operating characteristic curve analysis. CONCLUSION: In ERA patients, a persistently high JSpADA value at follow-up is a predictive factor for active disease at the sixth month.

Biological Agent Switching in Patients With Juvenile Idiopathic Arthritis: A Tertiary Center Experience.

OBJECTIVE: The purpose of this study is to investigate the causes and outcomes of switching biological agents in juvenile idiopathic arthritis (JIA) patients using biological agents and compare the characteristics of patients whose biological agents are switched and those whose are not. METHODS: This medical records review study was conducted with 128 patients who were diagnosed with JIA at our clinic between January 2009 and January 2022 and were receiving biologic agents. Factors affecting the biologic agent switching were investigated. RESULTS: The JIA subtype with the most frequent switching in biological agents was systemic JIA (n = 13, 40.6%). Systemic JIA was followed by rheumatoid factor-negative polyarticular JIA and persistent oligoarticular JIA with 5 patients (15.6%), extended oligoarticular JIA and enthesitis-related JIA with 3 patients (9.3%), rheumatoid factor-positive polyarticular JIA with 2 patients (6.2%), and undifferentiated JIA with 1 patient (3.1%). Among the patients, 32 (25%) patients had their biological agent switched once, and 5 (3.9%) had theirs switched twice. The most frequently used biological agent was etanercept (n = 76, 59.3%), whereas the most frequently observed cases of biological agent switching were from an anti-TNF agent to another anti-TNF agent (40.6%). The reason for switching was unresponsiveness to the agent in 22 patients (68.8%), adverse effects in 6 patients (18.7%), drug intolerance in 1 patient (3.1%), and other reasons in 3 patients (9.3%). CONCLUSIONS: The most frequently used biological agent was etanercept; the most frequent cases of biological agents switching were from an anti-TNF agent to another anti-TNF agent.

A case series of intracardiac thrombi and vascular involvement in pediatric Behçet's disease.

To evaluate the general characteristics of pediatric Behçet's disease (BD) patients with thrombus and to present the clinical features, treatment responses and prognosis of patients with intracardiac thrombus. The clinical characteristics and outcomes of 15 patients with thrombus among 85 pediatric BD patients followed in the Department of Pediatric Rheumatology were evaluated retrospectively. Of the 15 BD patients with thrombus, 12 (80%) were male, 3 (20%) were female. The mean age at diagnosis was 12.9 ± 1.1 years. Thrombus was present at the time of diagnosis in 12 patients (80%), while thrombus developed in three patients within the first three months after diagnosis. The most common site of thrombus was the central nervous system (n = 9, 60%), followed by deep vein thrombus (n = 6, 40%) and pulmonary artery thrombus (n = 4, 26.6%). Three male patients (20%) developed intracardiac thrombus. The overall intracardiac thrombus rate in the 85 patients was 3.5%. Two of the three patients had thrombus in the right, and one had thrombus in the left heart cavity. In addition to steroids, 2 of the 3 patients received cyclophosphamide, while the patient with thrombus localized in the left heart cavity was given infliximab. In the follow-up, the two patients with thrombus in the right heart cavity were switched to infliximab because of resistance to cyclophosphamide. Complete resolution was observed in 2 of the 3 patients on infliximab; a significant reduction in the thrombus of the other patient was achieved. Intracardiac thrombus is a rare presentation of cardiac involvement in BD. It is usually observed in males and in the right heart. Although steroids and immunosuppressive agents such as cyclophosphamide are recommended as first-line treatment, favorable outcomes can be achieved with anti-TNFs in resistant cases.

Pediatric mixed connective tissue disease versus other overlap syndromes: a retrospective multicenter cohort study.

Pediatric mixed connective tissue disease (MCTD) is a subgroup of overlap syndromes. We aimed to compare the characteristics and outcomes in children with MCTD and other overlap syndromes. All MCTD patients met either Kasukawa or Alarcon-Segovia and Villareal criteria. The patients with other overlap syndromes had the features of ≥ 2 autoimmune rheumatic diseases but did not meet MCTD diagnostic criteria. Thirty MCTD (F/M = 28/2) and thirty (F/M = 29/1) overlap patients were included (disease onset < 18 years). The most prominent phenotype at disease onset and the last visit was systemic lupus erythematosus (SLE) in the MCTD group; juvenile idiopathic arthritis and dermatomyositis/polymyositis, respectively, in the overlap group. At the last visit, systemic sclerosis (SSc) phenotype was more frequent among MCTD than overlap patients (60% vs. 33.3%; p = 0.038). The frequency of the predominant SLE phenotype had decreased (60% to 36.7%), while predominant SSc phenotype had increased (13.3% to 33.3%) during follow-up in MCTD patients. Weight loss (36.7% vs. 13.3%), digital ulcers (20% vs. 0), swollen hands (60% vs. 20%), Raynaud phenomenon (86.7% vs. 46.7%), hematologic involvement (70% vs. 26.7%), and anti-Sm positivity (29% vs. 3.3%) were more common, while Gottron papules (16.7% vs. 40%) were less frequent among MCTD than overlap patients (p < 0.05). A higher percentage of overlap patients achieved complete remission than MCTD patients (51.7% vs. 24.1%; p = 0.047). The disease phenotype and outcome differ between pediatric MCTD and other overlap syndromes where MCTD may be regarded as a more severe disease. Analyzing these patients could pave the way for early and effective treatment.

Cardiac involvement in a case of juvenile dermatomyositis with positive anti-melanoma differentiation associated protein 5 antibody.

Juvenile dermatomyositis (JDM) is an autoimmune disease characterized by muscle weakness and specific skin lesions, as well as non-muscular involvement such as interstitial lung disease (ILD), cardiac involvement and arthritis. Anti-melanoma differentiation-associated protein 5 (anti-MDA5)-positive JDM patients are typically characterized by the presence of skin ulcers and rapidly progressing ILD (RP-ILD). Although cardiac involvement is not an expected involvement in anti-MDA5-positive JDM cases, it is significant because it can be fatal. In this report, an anti-MDA5 myositis-specific autoantibody-positive JDM case referred with the diagnosis of psoriatic arthritis in whom cardiomyopathy and arrhythmia were detected in follow-up is presented. Since cardiac involvement is associated with mortality, it would be useful to follow up anti-MDA5 positive patients for cardiac involvement in addition to lung involvement. Tofacitinib is a promising treatment option in treatment-resistant JDM.

Factors Associated with the Development of Thrombosis in Pediatric Behçet Disease.

OBJECTIVE: The present study aimed to compare the demographic, clinical, and laboratory characteristics of patients with pediatric Behçet disease (BD) with and without thrombosis to elucidate the factors that may contribute to the development of thrombosis. METHODS: This observational, descriptive, medical records review study included patients with BD (n = 85) who were diagnosed at age younger than 16 years at our clinic between 2010 and 2022. The demographic, clinical, and available laboratory data of patients with and without thrombosis were compared. The potential risk factors for the development of thrombosis were evaluated with multivariable logistic regression analysis. RESULTS: Central venous sinus thrombosis was the most common type of thrombosis. Thrombosis was significantly more common in male patients ( p = 0.002), and regression analysis revealed that being male was a risk factor for developing thrombosis. Genital ulcers were less common in patients with thromboses. Patients with thrombosis had higher erythrocyte sedimentation rates, C-reactive protein, leukocyte, and neutrophil counts, as well as antinuclear antibody positivity. In contrast, mean platelet volume and lymphocyte counts were significantly lower in patients with thrombosis. According to the logistic regression analysis, erythrocyte sedimentation rate value >17 mm/h was a risk factor for developing thrombosis (odds ratio, 1; confidence interval, 1.1-1.8; p = 0.012). CONCLUSIONS: Male sex has been associated with an increased risk of thrombosis in children with BD. Inflammatory parameters may serve as predictive factors for thrombosis in pediatric BD.

What are the factors associated with the duration of remission of intra-articular corticosteroid injection in juvenile idiopathic arthritis?

INTRODUCTION: Intra-articular corticosteroid injection (IACI) is generally used in the management of juvenile idiopathic arthritis (JIA) to obtain rapid relief of active synovitis and functional recovery and to prevent the need for regular systemic therapy. The aim of this study was to investigate the outcome of IACI treatment and the factors associated with remission of synovitis. METHODS: The clinical records of JIA patients who received IACI between January 2014 and December 2020 in two pediatric rheumatology centers were reviewed. The procedure was evaluated in terms of efficacy, factors that may affect the duration of remission, procedural and drug-related complications. RESULTS: During the study period, 134 patients received 227 injections and 37 joints were injected more than once. One hundred and six (79%) patients had persistent oligoarticular disease. At the time of injection, all patients were receiving non-steroidal anti-inflammatory drugs, 74 patients were on methotrexate, and 14 patients were on biologics. The median duration of remission without exacerbation of synovitis treated with IACI was 15 (range 1-64) months. The inactivity rate was 81% at the 6th month after the injection. It has been shown that being less than 7 years old at disease onset and low initial CRP levels were correlated with a long remission period (p < 0.05). Despite the differences were not statistically significant, the duration of remission was longer in boys, in ANA positives, in HLA-B27 negatives, in patients with concurrent methotrexate treatment and in patients not receiving biologic therapy (p > 0.05). Only two patients (1.5%, 95% CI - 0.6 to 3.5) developed cutaneous hypopigmentation and subcutaneous atrophy as side effects of injection. CONCLUSION: Intra-articular corticosteroid injection was more effective especially in patients with low initial CRP levels and younger than 7 years of age. The duration of remission was longer in these patients. Key Points • Intra-articular corticosteroid injection is an effective method for controlling joint inflammation and achieving long-term remission without significant side effects. • Intra-articular corticosteroid injection can be preferred in all forms of juvenile idiopathic arthritis as primary therapy or to relieve the patient while waiting for the effect of systemic agents or to avoid increasing the dose of systemic drugs. • It can be recommended as a treatment option at any stage of the disease, especially in young patients and patients with low initial CRP values.

Delta neutrophil index and C-reactive protein: a potential diagnostic marker of multisystem inflammatory syndrome in children (MIS-C) with COVID-19.

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening hyperinflammation syndrome emerging after COVID-19. The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is evaluated in infection and inflammation. The aim of this study is to evaluate the usefulness of DNI as a diagnostic marker in patients with MIS-C and to assess its role in determining the severity of MIS-C. This retrospective, observational study included 83 patients with MIS-C and 113 patients with COVID-19, and 102 healthy controls. C-reactive protein (CRP), the absolute neutrophil count (ANC), absolute lymphocyte count (ALC), DNI, and the platelet count were recorded. The DNI levels were 4.60 ± 5.70% in the MIS C group, 0.30 ± 0.99% in the COVID group, and 0.20 ± 0.56% in the control group (p < 0.001). According to the severity of MIS-C, the DNI level was found to be 1.22% in mild MIS-C, 4.3% in moderate MIS-C, and 5.7% in severe MIS-C. There was a statistically significant correlation between DNI levels and the severity of MIS-C. The cutoff value of DNI for predicting MIS-C was 0.45%. In the analysis of the diagnostic performance of DNI compared with CRP, ANC, ALC and platelet counts, sensitivity, specificity, positive predictive value, and negative predictive value were found to be 79.5%, 97.1%, 95.7%, and 85.3%, respectively.Conclusions: The delta neutrophil index was identified as a diagnostic marker for MIS-C such as ANC, ALC, platelet count, and CRP. DNI levels in hemogram analysis may guide clinicians in determining the diagnosis and severity of MIS-C. What is Known: • Although CRP, sedimentation, ALC, ANC, platelet count, sodium, and albumin are used as first step tests, there is no specific laboratory marker used in the diagnosis of MIS C. • The serum delta neutrophil index (DNI) reflects the fraction of circulating immature granulocytes and is elevated in infection and inflammation. What is New: • DNI is a promising and easily accessible marker that can be used with other markers in the diagnosis and determines the severity of MIS C. • DNI is an easily accessible, inexpensive, and dynamic marker and its levels in simple hemogram analysis will guide pediatricians in determining the diagnosis and severity in MIS C.

Juvenile Behçet's disease: a tertiary center experience.

OBJECTIVES: Juvenile Behçet's disease is a rare and severe disease of childhood characterized by a chronic inflammatory vasculitis. The aim of the present study is reporting demographic, clinical and therapeutic outcomes of juvenile Behçet's disease in a tertiary center. METHODS: The retrospective study included patients who were diagnosed Behçet's disease before 16 years. The demographic and clinical features, and diagnostic and therapeutic strategies of patients were recorded. RESULTS: Seventy-two patients with jBD were included in this study; 32 were male (44.4%). Thirty (41.7%) patients had BD cases in their family. We observed oral ulceration (100%), genital ulceration (68.1%), joint involvement (36.1%) and cutaneous manifestations (34.7%) as the most common clinical findings, respectively. As severe organ involvements, 20.8% ocular, 18.1% vascular and 15.3% neurologic pathologies were seen. All patients had colchicine. Corticosteroid (20.8%) was used to treat severe cases and acute attacks. Azathioprine (23.6%) was the main immunosuppressive agent and cyclophosphamide (8.3%) was applied initially for life-threatening conditions with pulse methylprednisolone. CONCLUSION: In this cohort, the prevalence of genital ulceration and family history was high, and we observed less ocular involvement, a few permanent neurological morbidities and no death. Key Points • In the present study, there were acceptable permanent neurological involvements as morbidity and no mortality. • It is important noticing and managing jBD in early phase in order to prevent the devastating results. • The awareness of jBD provides timely treatment of patients. • The positivity of family history and HLA B51 should alert the clinician about the incomplete cases.

Is the performance of the international severity scoring system for familial mediterranean fever in children better than other scoring systems?

AIMS: Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterised by recurrent episodes of fever and serosal inflammation with elevated acute phase reactants. Assessing the severity of the disease may be useful in identifying colchicine-resistant patients. The aim of this study is to determine the disease severity of FMF patients according to the Pras, Mor, and International Severity Scoring System for Familial Mediterranean Fever (ISSF) scoring systems and to evaluate the consistency of these three systems. METHODS: The medical records of patients with FMF were retrospectively reviewed. Demographic features, family history of FMF, clinical characteristics at disease onset, laboratory features, Mediterranean fever genetic mutations, treatment regimens, and disease courses were recorded. RESULTS: A total of 205 patients (116 girls) were included in the study. The mean age of the patients was 13.3 ± 4.0 years. The Pras, Mor, and ISSF scores were inconsistent with each other, and there was poor fit between them (generalised Kappa: 0.140 ± 0.029; P < .001). In the receiver operating characteristic (ROC) analysis performed by accepting the clinician's opinion as the gold standard, the ISSF was found to be more sensitive and specific than the other two systems. CONCLUSION: Evaluation of disease severity according to the ISSF in paediatric patients is more sensitive and specific than the Pras and Mor scoring systems.

The importance of lower extremity involvement type on exercise performances, function, and quality of life in peripheral predominant forms of juvenile idiopathic arthritis.

BACKGROUND: Juvenile idiopathic arthritis (JIA) can cause reduced exercise capacity, deterioration in functional activities, and poor health-related quality of life. This study aims to objectively reveal lower extremity involvement in the peripheral predominant forms of juvenile idiopathic arthritis through qualitative evaluations and to determine the effects of these involvements on exercise, function, and quality of life. METHODS: Thirty-two patients with a history of peripheral arthritis and aged between 7 and 16 years participated in the study. Demographics, JIA subtype, disease duration, arthritis and deformities of the lower extremity, disease activity score, 6-min walk test (6MWT), cycling exercise test (CYC-E), childhood health assessment questionnaire (CHAQ), and pediatric quality of life inventory (PedsQoL) scores were recorded. In case of clinical suspicion of arthritis, an ultrasonographic examination was performed for a definitive diagnosis. Regression analyses were performed to explore the most associated lower extremity involvement and patient characteristics for each of the dependent variables including 6MWT, CYC-E, CHAQ, and PedsQoL. RESULTS: Of the total number of patients, with a mean age of 12.91 (SD 2.37) years, 28.1% had knee arthritis, 15.6% foot arthritis, 12.5% hip arthritis, and 37.5% lower extremity deformity. The parameters that were most associated with CHAQ and PedsQoL were hip and knee arthritis, whereas CYC-E was found to be most associated with knee arthritis and height, and 6MWT was found to be most associated with hip arthritis, knee arthritis, and demographic characteristics. CONCLUSION: This study emphasizes the importance of hip and knee arthritis, which are among the determinants of walking endurance, function, and quality of life; and knee arthritis, which is among the determinants of cycling performance in JIA with lower extremity involvement.

Algorithm for the diagnosis and management of the multisystem inflammatory syndrome in children associated with COVID-19.

OBJECTIVE: Although the initial reports of COVID-19 cases in children described that children were largely protected from severe manifestations, clusters of paediatric cases of severe systemic hyperinflammation and shock related to severe acute respiratory syndrome coronavirus 2 infection began to be reported in the latter half of April 2020. A novel syndrome called "multisystem inflammatory syndrome in children" (MIS-C) shares common clinical features with other well-defined syndromes, including Kawasaki disease, toxic shock syndrome and secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome. Our objective was to develop a protocol for the evaluation, treatment and follow-up of patients with MIS-C. METHODS: The protocol was developed by a multidisciplinary team. We convened a multidisciplinary working group with representation from the departments of paediatric critical care, cardiology, rheumatology, surgery, gastroenterology, haematology, immunology, infectious disease and neurology. Our protocol and recommendations were based on the literature and our experiences with multisystem inflammatory syndrome in children. After an agreement was reached and the protocol was implemented, revisions were made on the basis of expert feedback. CONCLUSION: Children may experience acute cardiac decompensation or other organ system failure due to this severe inflammatory condition. Therefore, patients with severe symptoms of MIS-C should be managed in a paediatric intensive care setting, as rapid clinical deterioration may occur. Therapeutic approaches for MIS-C should be tailored depending on the patients' phenotypes. Plasmapheresis may be useful as a standard treatment to control hypercytokinemia in cases of MIS-C with severe symptoms. Long-term follow-up of patients with cardiac involvement is required to identify any sequelae of MIS-C.

Therapeutic plasma exchange: A potential management strategy for critically ill MIS-C patients in the pediatric intensive care unit.

This study aimed to evaluate the effectiveness and the role of therapeutic plasma exchange (TPE) in treatment of children with severe MIS-C. In addition, we assessed demographic data, clinical features, laboratory abnormalities, underlying conditions, treatments, and outcomes. Patients with severe MIS-C who were admitted to the pediatric intensive care unit (PICU) between September 01 and October 05, 2020 were included in this observational, descriptive, retrospective study. The data collected included the patients' demographic data, presenting symptoms, clinical features, laboratory parameters, diagnostic investigations, and medications. Of 27 children with MIS-C, 63 % were male. The median age of the patients was nine years. Intravenous immunoglobulin and corticosteroids were used for treatment in 100 % of the patients, anakinra in 51.8 %, vasopressors in 85.1 %, noninvasive mechanical ventilation in 25.9 %, and invasive mechanical ventilation in 18.5 %. Ten of the 27 patients (37 %) underwent TPE. In the patients who underwent TPE, the median PELOD score was 21 (IQR: 11-30.25) before TPE and 10 (IQR: 10-11) after TPE (p < 0.001). Moreover, their median left ventricular ejection fraction (LVEF) was 52 % (IQR: 49.25 %-55 %) before TPE and median LVEF was 66.5 (IQR: 58 %-68.5 %) after TPE (p = 0.012). The median number of TPE sessions was three (IQR: 2-4.75). The mortality rate of the patients with severe MIS-C admitted to the PICU was 7.4 %. We suggest that TPE should be considered as a therapeutic option in children with severe MIS-C. Early initiation of TPE followed by immunomodulatory therapy in critically ill children with MIS-C may help improve clinical and laboratory outcomes.

Comparison of baseline laboratory findings of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis and multisystem inflammatory syndrome in children.

AIMS: Recently, multisystem inflammatory syndrome in children (MIS-C) has been recognized in association with coronavirus disease 2019 as a cytokine storm syndrome. MIS-C presents with symptoms similar to Kawasaki disease and macrophage activation syndrome (MAS). We aimed to better understand this cytokine storm syndrome by comparing the initial laboratory findings of MIS-C and MAS. METHODS: Patients who were diagnosed with MAS due to systemic juvenile idiopathic arthritis in our clinic between March 2002 and November 2020 and with MIS-C between 20 September and 20 October 2020 were enrolled into the study. The medical files of all patients were reviewed retrospectively. RESULTS: A total of 13 MAS (9 boys, 4 girls) and 26 MIS-C (16 boys,10 girls) patients were included in the study. Hemoglobin, absolute neutrophil and lymphocyte counts, C-reactive protein (CRP), ferritin, fibrinogen and lactate dehydrogenase (LDH) levels showed significant differences between the two groups (P < 0.05). Patients with MAS had lower hemoglobin (10.10 g/dL) and fibrinogen (2.72 g/dL), but higher ferritin (17 863 mg/dL) and LDH (890.61 U/L) at the time of diagnosis. Patients with MIS-C had higher absolute neutrophil count (12 180/mm3 ) and CRP (194.23 mg/dL) values, but lower absolute lymphocyte count (1140/mm3 ) at the time of diagnosis. Left ventricle ejection fraction was significantly lower in the MIS-C group in echocardiographic evaluation (P < 0.001). CONCLUSION: Ferritin, hemoglobin, LDH, and fibrinogen levels were significantly changed in MAS compared with MIS-C. However, patients with MIS-C have more severe signs than MAS, such as cardiac involvement.