The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

A treatment algorithm for familial Mediterranean fever patients with menstruation-associated attacks.

OBJECTIVES: Familial Mediterranean fever (FMF) is characterized by febrile polyserositis attacks. Menstruation could be a trigger for attacks. We aimed to analyze the features of adolescent FMF patients with menstruation-associated attacks and propose a management algorithm. METHODS: All female FMF patients who had menarche and visited the Pediatric Rheumatology Unit between January-December 2022, were included into this study. Demographics, general characteristics, and the features of menstrual cycle and FMF attacks were noted. RESULTS: A total of 151 female FMF patients were included. Thirty-five (23.2%) had menstruation-associated attacks. Fever and arthritis were less frequent during the menstruation-associated attacks than the attacks not associated with menstruation in these patients (65.7% vs 88.6%, p= 0.01 and 2.9% vs 20%, p= 0.04; respectively). Patients with menstruation-associated FMF attacks were younger at symptom onset and diagnosis (2.5 vs 5 years, p= 0.004 and 4 vs 7 years, p= 0.01; respectively), had a higher rate of dysmenorrhea (74.3% vs 38.8%, p< 0.001, respectively) and higher pre- and post-menarche attack frequency (4 vs 2 and 10 vs 0, respectively; p< 0.001 for both) than patients whose attacks were not associated with menstruation. The interventions for menstruation-associated attacks included initiating colchicine, increasing the dose of colchicine, switching from coated to compressed colchicine tablets or anti-interleukin 1 drugs, and on-demand non-steroidal anti-inflammatory drugs, on-demand glucocorticoids, and on-demand anakinra. On-demand therapies were beneficial in controlling menstruation-associated attacks. CONCLUSIONS: This is the largest cohort of adolescent FMF patients with menstruation-associated attacks. Severe FMF may cause tendency to this association. On-demand therapies could be preferred in the management.

Transitioning from pediatric to adult-oriented healthcare in rheumatology: the pediatric side of the coin.

OBJECTIVES: The transition of adolescents and young adults (AYAs) from pediatric to adult-oriented healthcare may be affected by many factors, including the personal and cultural settings. We aimed to analyze the transition readiness and the factors affecting the transition success in rheumatology. METHODS: Patients older than 12 years were included in this prospective study. All filled out the Transition Readiness Assessment Questionnaire (TRAQ) 5.0. AYAs were phone-interviewed after their transfer to adult-oriented healthcare. Drug adherence was evaluated with 4-item Morisky Medication Adherence Scale (MMAS-4). AYAs rated their transitional care experience with visual analogue scale (VAS 0-10; 0, the worst; 10, the best). RESULTS: A total of 504 TRAQs were filled out by 406 patients (F/M = 1.5). The total TRAQ score was positively correlated with age and higher in the forms filled out by girls than boys (4.2 vs 4.0, respectively; p= 0.005). The transition was successful for 78 (83.9%) out of 93 patients transferred to adult-oriented healthcare. The VAS for the transition process was lower and the post-transfer MMAS-4 score was worse (8 vs 9, p= 0.030 and 3 vs 4, p= 0.020; respectively) in patients whose transition was not successful when compared with the successfully-transitioned ones. The best-performing TRAQ cut-off value was >4.0 for predicting transfer readiness in rheumatology. CONCLUSION: A TRAQ score of > 4 could be used while deciding about the transfer readiness of AYAs in rheumatology. Improving the AYAs' experience of the transition process and closely monitoring medication adherence during transition are essential for a successful transition.

Polyarticular juvenile idiopathic arthritis has a distinct co-inhibitor receptor profile.

OBJECTIVES: Juvenile Idiopathic Arthritis (JIA) is the most common rheumatic disease of childhood; the pathogenesis is associated with T cell activation. T cell activation can be counter-balanced by signals generated by inhibitory receptors (IRs) such as CTLA-4, PD-1, LAG-3, and TIM-3. Here, we identify the role of IRs in the pathogenesis of different JIA subtypes. METHODS: In total, we included 67 oligoarticular JIA, 12 IgM-RF negative polyarticular JIA, 17 enthesitis related arthritis, 11 systemic JIA patients and 10 healthy controls. We collected plasma (and synovial fluid) samples from the patients either at the onset or during a flare of their disease. We measured the soluble levels of co-IRs (IL-2Rα, 4-1BB, CD86, TGF-ß1, CTLA-4, PD-L1, PD-1, TIM-3, LAG- 3, Galectin-9) by cytometric bead array kits and their cellular expression (PD-1, CTLA-4, TIM-3, LAG-3) by flow cytometry. We compared the plasma levels and cellular expressions of different co-IRs within different JIA subgroups. RESULTS: The polyarticular-JIA group was different from the three other examined JIA subgroups, having higher levels of plasma sCTLA-4(p< 0.001), sPD-1(p< 0.05), and s4-1BB(p< 0.05) when compared with the other JIA subgroups and healthy controls. We analyzed the cellular surface expression of different co-IRs on the PBMCs of different JIA subtypes. Similar to plasma levels, both the percentage(p< 0.05) and the MFI (mean fluorescence intensity) (p< 0.01) of CTLA4 expression were higher in the poly-JIA subgroup. CONCLUSION: This is the first report studying the expression profile of different co-IRs in different subtypes of JIA. Polyarticular JIA patients had a different co-IR profile, having more CTLA-4, PD-1 and 4-1BB in their plasma than the other subtypes of JIA.

A score for predicting colchicine resistance at the time of diagnosis in familial Mediterranean fever: data from the TURPAID registry.

OBJECTIVES: Colchicine forms the mainstay of treatment in FMF. Approximately 5-10% of FMF patients are colchicine resistant and require anti-IL-1 drugs. We aimed to compare the characteristics of colchicine-resistant and colchicine-responsive patients and to develop a score for predicting colchicine resistance at the time of FMF diagnosis. METHODS: FMF patients (0-18 years) enrolled in the Turkish Paediatric Autoinflammatory Diseases (TURPAID) registry were included. The predictive score for colchicine resistance was developed by using univariate/multivariate regression and receiver operating characteristics analyses. RESULTS: A total of 3445 FMF patients [256 (7.4%) colchicine-resistant and 3189 colchicine-responsive) were included (female:male ratio 1.02; median age at diagnosis 67.4 months). Colchicine-resistant patients had longer, more frequent attacks and were younger at symptom onset and diagnosis (P < 0.05). Fever, erysipelas-like erythema, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, chest pain, comorbidities, parental consanguinity and homozygosity/compound heterozygosity for exon 10 MEFV mutations were significantly more prevalent among colchicine-resistant than colchicine-responsive patients (P < 0.05). Multivariate logistic regression analysis in the training cohort (n = 2684) showed that age at symptom onset, attack frequency, arthritis, chest pain and having two exon 10 mutations were the strongest predictors of colchicine resistance. The score including these items had a sensitivity of 81.3% and a specificity of 49.1%. In the validation cohort (n = 671), its sensitivity was 93.5% and specificity was 53.8%. CONCLUSION: We developed a clinician-friendly and practical predictive score that could help us identify FMF patients with a greater risk of colchicine resistance and tailor disease management individually at the time of diagnosis.

Detection of genetic mutations underlying early-onset systemic lupus erythematosus.

OBJECTIVE: We aimed to investigate the presence of monogenic causes of systemic lupus erythematosus (SLE) in our early-onset SLE patients. METHODS: Fifteen pediatric SLE cases who had early disease onset (≤6 years) were enrolled in this study. All patients fulfilled the Systemic Lupus International Collaborating Clinics (SLICC) criteria. Genomic DNA was used for whole exome sequencing (WES). Pathogenic variants were confirmed by Sanger sequencing. RESULTS: The median age at diagnosis of 15 early-onset SLE patients included in the study was 4 (2-6) years (F/M = 12/3). Significant gene mutations were detected in five of these patients (33.3%). Patients 1 and 2 with homozygous DNASE1L3 mutations [c.320+4_320+7del and G188 A (c.563 G>C) variants] had skin involvement and oral ulcers. One of them (patient 1) had arthritis and nephritis, and another (patient 2) had nonscarring alopecia and thrombocytopenia. They are currently clinically inactive but have positive serological findings. Patient 3 with homozygous pathogenic ACP5 mutation [G109 R (c.325 G>A) variant] had arthritis, nephritis, short stature, and skeletal dysplasia. Patient 4 with a heterozygote novel IFIH1 mutation [L809 F (c.2425 C>T) variant] had skin findings and leukopenia. Patient 5 with novel C1S variant [homozygous C147 W (c.441 C>G) variant] had marked skin findings, oral ulcers, nonscarring alopecia, pancytopenia, and low total hemolytic complement CH50 level. All patients have responded to the treatments and have low Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, on therapy. CONCLUSION: Genetic causes should be investigated in early-onset SLE, for better management and genetic counseling. On the other hand, multicenter studies may help to further define genotype-phenotype associations.

Drug-induced lupus erythematosus in childhood: Case-based review.

BACKGROUND: Drug-induced lupus erythematosus (DILE) is the development of lupus-like syndrome following a drug exposure. DILE has been reported less frequently among children than adults. METHODS: In this study, we present four children with DILE and similar published cases through a systematic literature review. RESULTS: We report four children (three girls and one boy) who developed DILE associated with the use of topiramate, doxycycline, etanercept, and ethosuximide. Three of them were positive for anti-histone antibodies. In all patients, the drug was discontinued and symptoms resolved completely. The literature review revealed 48 articles describing 61 children with DILE. In the evaluation of 65 patients (our 4 patients and 61 patients from the literature), the most frequently reported drugs associated with DILE were ethosuximide (n = 13) and minocycline (n = 12). Fever (n = 33), arthralgia (n = 31), rash (n = 30), and arthritis (n = 29) were the most common clinical manifestations. Antinuclear antibody (ANA) was positive in 93.5% of patients and anti-histone antibodies were detected in 72.2% of the patients. As for treatment, the responsible drug was discontinued in all patients, and corticosteroids were initiated in 53.3%. Improvement was achieved in 92.0% of patients. CONCLUSION: For children presenting with SLE features, proper drug history is crucial since DILE may be more frequent than anticipated. An association of the relevant drug with the symptoms, and resolution of symptoms on drug withdrawal provides evidence for the diagnosis of DILE.

Rhupus syndrome in children: A multi-center retrospective cohort study and literature review.

OBJECTIVE: In this study, we aimed to evaluate the characteristics of pediatric rhupus patients including all the related series in the literature. METHODS: Thirty pediatric patients with rhupus syndrome from 12 different centers in Turkey were included in this study. The literature was also reviewed for pediatric patients with rhupus syndrome. RESULTS: The most prominent phenotype of these 30 patients was juvenile idiopathic arthritis (JIA) (60%) at the disease onset and SLE (73.3%) at the last visit. Major SLE-related organ involvements were skin (80%), hematological system (53.3%), and kidney (23.3%). Arthritis was polyarticular (73.3%), asymmetric (66.7%), and erosive (53.3%) in most patients. Hydroxychloroquine (100%), glucocorticoids (86.7%), and mycophenolate mofetil (46.7%) were mostly used for SLE, while glucocorticoids (76.6%), methotrexate (73.3%), and nonsteroidal anti-inflammatory drugs (NSAIDs) (57.6%) were mainly preferred for JIA. Our literature search revealed 20 pediatric patients with rhupus syndrome (75% were RF positive). The most prominent phenotype was JIA (91.7%) at the disease onset and SLE (63.6%) at the last visit. Major SLE-related organ involvements were skin (66.7%), hematological system (58.3%), and kidney (58.3%). Arthritis was polyarticular (77.8%), asymmetric (63.6%), and erosive (83.3%) in most patients. Glucocorticoid (100%), hydroxychloroquine (76.9%), and azathioprine (46.2%) were mostly used for SLE, while methotrexate (76.9%) and NSAIDs (46.2%) were mainly preferred for the JIA phenotype. CONCLUSION: Our study is the largest cohort in the literature evaluating pediatric rhupus cases. Most of the pediatric patients had polyarticular, asymmetric, and erosive arthritis, as well as organ involvements associated with SLE, including the skin, hematological system, and kidney.

Evaluation of pediatric rheumatologists' approach to rituximab use: a questionnaire study.

Rituximab (RTX) is a chimeric monoclonal antibody that targets the CD20 antigen on B cells and is used in various autoimmune disorders. In this study, we aimed to measure the awareness of pediatric rheumatologists about the use of RTX through a survey. Between February and March 2023, a 42-question survey was sent via email to pediatric rheumatology specialists in Turkey. The participants were questioned for which diagnoses and system involvement they preferred to use RTX, which routine tests they performed, vaccination policy, and adverse events that occurred during or after infusion. Forty-one pediatric rheumatologists answered the survey. They prescribed RTX most frequently for systemic lupus erythematosus (87.8%) and ANCA-associated vasculitis (9.8%). Prior to the administration of RTX, 95% of clinicians checked renal and liver function tests, as well as immunoglobulin levels. The most frequently tested hepatitis markers before treatment were HBsAg and anti-HBs antibody (97.6%), while 85.4% of rheumatologists checked for anti-HCV. Clinicians (31.4%) reported that they postpone RTX infusion 2 weeks following an inactivated vaccine. Sixty-one percent of rheumatologists reported starting RTX treatment 1 month after live vaccines, while 26.8% waited 6 months. The most frequent adverse events were an allergic reaction during RTX infusion (65.9%), hypogammaglobulinemia (46.3%), and rash (36.6%). In the event of hypogammaglobulinemia after RTX treatment, physicians reported that they frequently (58.5%) continued RTX after intravenous immunoglobulin administration. CONCLUSIONS: RTX has become a common treatment option in pediatric rheumatology in recent years. Treatment management may vary between clinician such as vaccination and routine tests. WHAT IS KNOWN: • During the course of rituximab therapy, clinicians should be attentive to specific considerations in pre-treatment, during administration, and in post-treatment patient monitoring. WHAT IS NEW: • There are differences in practice among clinicians in the management of RTX therapy. These practice disparities have the potential to impact the optimal course of treatment. • This study highlights that standardized guidelines are needed for RTX treatment in pediatric rheumatology, particularly for vaccination policies and routine tests.

Subclinical enthesitis in enthesitis-related arthritis and sacroiliitis associated with familial Mediterranean fever.

OBJECTIVES: In our study, we investigated the presence of subclinical enthesitis by ultrasonography (US) in asymptomatic patients with enthesitis-related arthritis (ERA) and sacroiliitis associated with familial Mediterranean fever (FMF). METHODS: A total of 50 patients, including 35 patients with ERA and 15 with sacroiliitis associated with FMF, were included in the study. All patients were evaluated with US by a paediatric radiologist. Enthesis of seven tendons (common extensor and flexor tendons, quadriceps tendon, proximal and distal patellar tendon, Achilles tendon, and plantar fascia) was examined on both sides. RESULTS: Subclinical enthesitis was detected in 10 ERA (28.5%) and three FMF (20%) patients. Enthesitis was radiologically diagnosed in 16 (2.3%) out of 700 evaluated entheseal sites. The most frequent sites of enthesitis were Achilles (37.5%) and quadriceps (31.3%) tendons. All patients were in clinical remission and had no active complaints, and acute phase reactants were within normal limits. Therefore, the patients were followed up without treatment change. However, disease flare-up was observed in three of these patients (23.1%) during the follow-up, and their treatments were intensified. CONCLUSIONS: Our results showed that the US can be particularly helpful in detecting subclinical enthesitis and predicting disease flare-ups.

Impact of serological activity on flare following clinically inactive disease and remission in childhood-onset systemic lupus erythematosus.

OBJECTIVES: To assess the association between serological activity (SA) and clinical inactivity in SLE and to investigate whether SA predicts flare after clinically inactive disease (CID) and remission. METHODS: Longitudinal data of children from 3 paediatric rheumatology referral centres were retrospectively reviewed. CID was defined as clinical SLEDAI = 0 in patients with a prednisolone dose < 15 mg/day. A modified DORIS remission on treatment criteria was used to determine remission. RESULTS: Of the 124 patients included, 89.5% displayed SA at onset. Through follow-up, the rate of SA decreased to 43.3% at first CID and 12.1% at remission. Among patients with CID, 24 (20.7%) experienced a moderate to severe flare before the attainment ofremission. While previous proliferative lupus nephritis (OR : 10.2, p: 0.01) and autoimmune haemolytic anaemia (OR : 6.4, p: 0.02) were significantly associated with an increased odds of flare after CID, SA at CID was not associated with flare. In contrast, 21 (19.6%) patients experienced a flare in a median of 18 months after remission. Hypocomplementemia (OR : 9.8, p: 0.02) and a daily hydroxychloroquine dose < 5 mg/kg (OR : 5.8, p: 0.02) at remission significantly increased the odds of flare. CONCLUSION: SA increases the odds of flare at remission but not at CID. Suboptimal dosing of hydroxychloroquine should be avoided, especially in children with SA in remission to lower the risk of flares.

Feasibility of canakinumab withdrawal in colchicine-resistant familial Mediterranean fever.

OBJECTIVES: There is no consensus on canakinumab treatment tapering and discontinuation strategies in colchicine-resistant FMF patients. In this study, we aimed to establish a treatment management and discontinuation protocol in paediatric FMF patients treated with canakinumab. METHODS: Fifty-eight FMF patients treated with canakinumab were included. Since 2020, we have applied a protocol based on our experience whereby canakinumab is administered monthly in the first 6 months, followed by bimonthly for 6 months, and a final period of every 3 months (for 6 months). The patients were divided into two groups: 2012-2019 (group A) and 2020-2022 (group B). RESULTS: In group A (n = 33), the median duration of canakinumab treatment was 2.5 years [interquartile range (IQR) 1.9-3.7]. A total of 25 of 33 patients discontinued canakinumab after a median of 2.1 years (IQR 1.8-3.4). In two patients, canakinumab was restarted because of relapse. In group B (n = 25), canakinumab was discontinued in 18 patients at the end of 18 months. After a median follow-up of 0.8 years (IQR 0.6-1.1), two patients had a relapse and canakinumab treatment was reinitiated. The remaining 16 patients still have clinically inactive disease and are receiving only colchicine. When we compared the characteristics between groups A and B, there were no significant differences regarding demographics, clinical features, and outcomes. CONCLUSION: This is the largest study in the literature suggesting a protocol for discontinuing canakinumab in paediatric FMF patients. It was possible to discontinue canakinumab successfully in more than half of the patients in 18 months. Thus we suggest that this protocol can be used in paediatric FMF patients.

A new tool supporting the diagnosis of childhood-onset Behçet's disease: venous wall thickness.

OBJECTIVES: The lower extremity venous wall thickness (VWT) of Behçet's disease (BD) patients was reported to be significantly increased in adults, suggesting its use for the support of BD diagnosis. This prospective study aimed to investigate the lower extremity VWT in childhood-onset definite and incomplete BD patients and compare it to healthy age-matched controls. METHODS: Paediatric patients classified with BD according to the 2015 international paediatric BD criteria in our centre were included in the study. Intima-media thickness of the lower extremity veins to evaluate VWT was measured by ultrasonography, including common femoral vein (CFV), femoral vein (FV), vena saphena magna, vena saphena parva and popliteal vein (PV). RESULTS: In this cross-sectional study, VWT was measured in 35 patients (63% male) and 27 healthy controls (55% male). Thirteen (37%) of 35 patients met the criteria for the diagnosis of BD. The remaining 22 (63%) had incomplete BD and met two criteria. The median VWT values of both definite and incomplete BD patients were significantly higher than the control group in all veins on both sides. Regarding the best cut-off values of VWT for all lower extremity veins, the sensitivity rates were between 63% and 86%, while specificity rates were between 71% and 100%. CONCLUSION: Increased VWT was present not only in BD patients with vascular involvement but also in those without. We suggest that VWT may be a new criterion in supporting the diagnosis of childhood BD both in definite and incomplete BD patients.

Rice bodies in children with rheumatic disorders: A case series and systematic literature review.

OBJECTIVES: Rice body (RB) formation is an uncommon inflammatory process seen in systemic disorders. In this study, we aimed to assess characteristic features of RBs in pediatric patients. METHOD: We retrospectively evaluated pediatric patients who underwent joint/extremity magnetic resonance imaging. A systematic literature review was conducted for articles including children with RBs. RESULTS: We found 24 patients (median age 6.1 years; F/M = 2.4) with RBs [23 with juvenile idiopathic arthritis (JIA) and one with arthralgia]. The most prevalent location for RBs was the knee joint (75%). RBs were most frequently seen as diffuse multiple millimetric structures. In three out of five patients with follow-up magnetic resonance imaging, resolution or regression of RBs was observed without surgical intervention. Our literature search identified 13 pediatric patients with RBs. Most (84.6%) had JIA, and the knee joint (71.4%) was the most commonly affected joint. Surgery was preferred in our 3 patients (12.5%) and 10 literature patients (83.3%) in the treatment. CONCLUSION: Our results showed that RBs were most commonly detected in the knee joint, and most cases were secondary to JIA. Although surgery is used as a treatment option, we observed that RBs can occasionally disappear during follow-up without surgical intervention.

Treatment of childhood-onset Takayasu arteritis: switching between anti-TNF and anti-IL-6 agents.

OBJECTIVES: Biologics are new treatment alternatives in Takayasu arteritis (TA), although data in childhood are limited. The aim of this study was to share our experience in seven childhood-onset TA patients who received a TNF-α inhibitor (adalimumab) or an IL-6 receptor inhibitor (tocilizumab) and the effect of switching therapy. METHODS: We retrospectively evaluated the medical treatment records of seven patients with TA, followed between August 2005 and January 2021 at the Pediatric Rheumatology Department of Hacettepe University Faculty of Medicine. RESULTS: The median age of patients was 14 (IQR 4) years, and six were female. All of the patients had severe disease and high acute-phase reactants. The patients initially received only steroids or steroids+CYC. Prednisone was decreased, and biologic agents were started once the acute phase reactants decreased, and the Indian Takayasu Activity Score (ITAS) returned to normal. Initially, four patients received tocilizumab (TCZ) [median 25.5 (IQR 41) months] and three patients received adalimumab (ADA) [median 13 (IQR 31) months]. However, due to the progression of MR angiography findings or persistent elevation in acute-phase reactants, the biologic agents were switched from TCZ to ADA in four patients and from ADA to TCZ in three patients. The patients' median follow-up time after changing was 50 (IQR 77) months, and median ITAS was evaluated as '0' after 2 (IQR 4) months. CONCLUSIONS: In conclusion, both TNF-α and IL-6 inhibitors are effective alternatives in treating patients with childhood-onset TA. However, prospective randomized controlled trials are needed for the comparison of their effectiveness.

IgG4-related disease in pediatric patients: a single-center experience.

OBJECTIVE: Immunoglobulin G4-related disease (IgG4-RD) is a systemic, immune-mediated, and fibroinflammatory disease that can affect almost any organ system. We aimed to present our single-center experience of pediatric patients with IgG4-RD, a rare disease in children. METHODS: Pediatric patients diagnosed with IgG4-RD at the Hacettepe University between June 2014 and September 2020 were evaluated retrospectively. Patients with definite, probable, or possible diagnosis of IgG4-RD were included. RESULTS: A total of eight patients with a median age of 13.4 (IQR 9.5-15.0) years were included in the study. Clinical presentations were IgG4-related ophthalmic disease in six patients, IgG4-related lymphadenopathy in one patient, and IgG4-related sialadenitis and lymphadenopathy of several lymph nodes accompanied by pancreatitis, ulcerative colitis, and pulmonary manifestations in one patient. Elevated serum IgG4 was detected in three of eight patients (37.5%). The main histopathological feature was fibrosis and lymphoplasmacytic infiltrates. Corticosteroids were used as first-line treatment in almost all patients with or without steroid-sparing agents. Azathioprine, methotrexate and rituximab were used as steroid-sparing agents. Relapse occurred in two of seven patients. Radiotherapy was used as the last resort in one patient with severe orbital disease. CONCLUSION: IgG4 RD mainly presents with orbital manifestations in pediatric population but has wide phenotypic clinical variability. Although rare, early recognition and treatment are essential for a better outcome in these patients.

Impact of the COVID-19 pandemic on the frequency of the pediatric rheumatic diseases.

The impact of the COVID-19 pandemic, and implemented restrictions on the frequency of pediatric rheumatic diseases remain unknown, while they have probably prevented common infections in children. We present the effects of the COVID-19 on our pediatric rheumatology practice in a main referral center. We retrospectively reviewed the medical records of patients presenting to pediatric rheumatology department in 4 years before March 2020 and compared it to the pandemic year (March 2020-March 2021). Since there was an overall decrease in patient numbers, we calculated the percentage according to the total number of that year. A total of 32,333 patients were evaluated. The mean annual number of patients decreased by 42% during the COVID-19 pandemic. When follow-up visits (25,156) were excluded, there were 2818 new diagnoses of rheumatic diseases. In the pre-pandemic period, familial Mediterranean fever (FMF) (n = 695, 28.1%) was the most frequent, whereas in the pandemic period multisystem inflammatory syndrome in children (MIS-C) (n = 68, 19.2%) was the most common diagnosis. There were no significant differences in the percentages of juvenile idiopathic arthritis, autoimmune diseases, rare autoinflammatory diseases, and other vasculitides. However, there was a significant decrease in patients diagnosed with FMF, IgA vasculitis (IgAV), acute rheumatic fever (ARF), classic Kawasaki disease (KD), and macrophage activation syndrome (MAS) (all p < 0.05). During the pandemic year, the percentage of most common diseases did not differ. On the other hand, we suggest that the decreases in IgAV, KD (classic), and MAS, which parallels the decrease in ARF, confirm the role of infections in the pathogenesis for these diseases.

The clinical course of SARS-CoV-2 infection among children with rheumatic disease under biologic therapy: a retrospective and multicenter study.

The effects of biological disease-modifying antirheumatic drugs (bDMARDs) in the clinical course of COVID-19 on children with underlying rheumatologic diseases have not been fully demonstrated. To evaluate the course of COVID-19 infection in patients with rheumatic disease receiving bDMARD treatment. This was a retrospective, multicenter study conducted in pediatric patients infected by SARS-CoV-2 and under bDMARDs therapy. The study population consisted of 113 patients (72 female/41 male). The mean age of the patients was 12.87 ± 4.69 years. The primary diagnosis of the cohort was as follows: 63 juvenile idiopathic arthritis, 35 systemic autoinflammatory diseases, 10 vasculitides, and five cases of connective tissue diseases. The mean duration of the primary disease was 4.62 ± 3.65 years. A total of 19 patients had additional comorbid diseases. Thirty-five patients were treated with canakinumab, 25 with adalimumab, 18 with etanercept, 10 with infliximab, nine with tocilizumab, six with rituximab, four with anakinra, three with tofacitinib, and one with abatacept. The median exposure time of the biological drug was 13.5 months. Seventy-one patients had symptomatic COVID-19, while 42 were asymptomatic. Twenty-four patients required hospitalization. Five patients presented with MIS-C. The hospitalized patients were younger and had a shorter duration of rheumatic disease compared to ambulatory patients, although the difference was not statistically significant. Steroid usage, presence of fever, and dyspnea were more common among the hospitalized patients. A worsening in the course of both COVID-19 and current disease was not noticed under bDMARDs, however, to end with a strong conclusion multicentric international studies are required.

Early is superior to late plasma exchange for severe multisystem inflammatory syndrome in children.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) can be life threatening in severe cases because of uncontrolled inflammation and multi-organ failure. In this study, we report the effect of plasma exchange in the treatment of MIS-C and to emphasize the effect of its early application on outcome. METHOD: In this retrospective observational study, the medical records of children with severe MIS-C admitted to pediatric intensive care unit (PICU) between April 2020 and January 2021 were reviewed. Severe MIS-C patients were treated according to protocol consisting of plasma exchange (PE), intravenous immune globulin, steroids, and anakinra which we called the "PISA" protocol referring to the initials. The patients were divided into two groups as early plasma exchange (E-PE) and late plasma exchange (L-PE) according to the elapse time between hospital admission and the administration of PE. Groups were compared in terms of outcome variables. Primary study outcome was 28-day mortality. Secondary outcome variables were acute phase response time, length of immunomodulatory treatment, frequency of patients requiring mechanical ventilation (MV) and inotropic support, length of inotropic support and MV, length of hospital and PICU stays. RESULTS: Eighteen pediatric patients with MIS-C were included in the study. Seventeen (95%) of the patients presented with decompensated shock and required inotropic support. One of the 17 patients needed extracorporeal membrane oxygenation support (ECMO) PISA protocol was used in all patients. There was no mortality in the E-PE group while the mortality rate was 20% in the L-PE group. Acute phase reactant response was faster in the E-PE group and immunomodulatory treatments could be reduced earlier; the frequency of patients requiring inotropic and mechanical ventilation (MV) support was lower in the E-PE group; the duration of inotropic support, duration of MV, and length of stay in hospital and PICU were significantly shorter in the E-PE group. CONCLUSION: We suggest that in selected cases, timely administration of PE is a beneficial rescue therapy for MIS-C related hyperinflammation presenting with severe cardiovascular collapse.

Challenges in diagnosing COVID-19 related disease in pediatric patients with rheumatic disease.

OBJECTIVES: Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe condition associated with coronavirus disease 2019. Here we aimed to raise awareness for the symptoms of MIS-C in patients with rheumatic diseases, emphasizing the challenges of the differential features. METHODS: We retrospectively evaluated the demographic and clinical characteristics, laboratory and imaging findings, treatments, and outcomes of six MIS-C patients with previous rheumatic disease. RESULTS: Three of the patients had familial Mediterranean fever (FMF), one had juvenile dermatomyositis, one had systemic juvenile idiopathic arthritis (JIA), and another patient had oligoarticular JIA. All FMF patients presented with fever and abdominal pain, two also had chest pain. The patient with systemic JIA presented with fever, rash, and myalgia. All patients had elevated inflammatory markers and high d-dimer levels. Chest imaging of two FMF patients showed infiltrations compatible with pneumonia. One FMF patient had mildly decreased systolic functions with a shortening fraction of 48% in his echocardiography. Intravenous immunoglobulin and methylprednisolone were administered to all patients. Anakinra was given to four patients. CONCLUSIONS: Clinical and laboratory signs of MIS-C may overlap with the findings of various rheumatic diseases, and this may cause a delay in diagnosis.