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.

Macrophage activation syndrome in patients with systemic juvenile idiopathic arthritis on anti-interleukin-1 or -6 therapy.

OBJECTIVES: The aim of this study is to investigate the effect of anti-interleukin (IL)-1/-6 biologics on systemic juvenile idiopathic arthritis (sJIA)-associated macrophage activation syndrome (MAS). METHODS: Demographic, clinical, and laboratory data of patients followed up with a diagnosis of sJIA-associated MAS assessed from sixteen pediatric rheumatology centers across the country. The clinical and laboratory features of MAS developing while on biological drugs were compared with those without this treatment. RESULTS: One hundred and sixty-two patients were included in the study. 45 of the MAS events were detected under the effect of anti-IL-1/-6 biologics, while the patients experiencing the remaining 155 events have not received biological treatment in the last three months. Platelet count [128 (72-232) vs 199 (130-371) 109/l], ferritin level on admission [1107 (676-2050) vs 2863 (1193-9562) ng/ml], C-reactive protein level [15.4 (2.9-56) vs 90 (32-160) mg/l], erythrocyte sedimentation rate [13 (3-36) vs 43.5 (13-77) mm/h] and fever duration [5 (4-7.5) vs 10 (7-14.3) days] were found lower in the group under the impact of anti-IL-1/-6 biologics. Among patients treated with biologics, 26.6% did not meet the published 2016 MAS classification criteria at presentation. The rates of hepatomegaly and splenomegaly were relatively lower in the canakinumab-treated group when compared with those receiving other biologicals or to patients, not on biologicals. CONCLUSION: Anti-IL-1/-6 therapies can mask the clinical and laboratory features of MAS, and proposed guidelines for MAS classification criteria may not be met.

Differentiating Multisystem Inflammatory Syndrome in Children from Kawasaki Disease During the Pandemic.

OBJECTIVE: We aimed to delineate the distinctive characteristics that aid in distinguishing between Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) with KD-like manifestations during the pandemic. MATERIALS AND METHODS: We evaluated KD patients and MIS-C patients with KD-like symptoms admitted during the pandemic (between January 2021 and December 2022). RESULTS: Thirty-three MIS-C patients and 15 KD patients were included. Kawasaki disease patients were younger than MIS-C patients (3.4 vs. 7.6 years). Rash (P = .044, 100% vs. 75.7%), oral mucosal changes (P = .044, 100% vs. 75.7%), and cervical lymphadenopathy (P = .001, 93.3% vs. 42.4%) were more common in KD. Multisystem inflammatory syndrome in children: patients had more hypotension (P = .002, 45.4% vs. 0), gastrointestinal (P .001, 72.7% vs. 13.3%), and respiratory symptoms (P = .044, 24.2% vs. 0). Multisystem inflammatory syndrome in children patients also had low lymphocyte and thrombocyte counts and elevated levels of d-dimer, ferritin, and cardiac parameters, unlike KD patients. Multisystem inflammatory syndrome in children patients exhibited a notable reduction in left ventricular systolic function in echocardiography. Another significant difference with regard to management was the anakinra treatment, which was prescribed for MIS-C patients. CONCLUSION: Although MIS-C patients might display a clinical resemblance to KD, several features could help differentiate between MIS-C and classical KD. Specific clinical (hypotension, gastrointestinal, and respiratory symptoms) and laboratory (low lymphocyte and thrombocyte counts with higher C-reactive protein, ferritin, d-dimer, and cardiac parameters) features are characteristic of MIS-C. In addition, divergence in management strategies is evident between the 2 diseases, as biologic drugs were more prevalently employed in MIS-C patients than in classical KD patients.

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.

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.

Chronic non-bacterial osteomyelitis and immune checkpoint molecules.

OBJECTIVE: We aimed to investigate the plasma levels and cell surface expression of two checkpoint molecules, TIM-3 (T cell immunoglobulin and mucin domain-containing protein 3) and PD-1 (programmed cell death protein 1), in pediatric patients with chronic non-bacterial osteomyelitis (CNO). METHODS: Plasma samples of CNO patients were collected at diagnosis or during biologic agent treatment. Plasma levels of TIM-3 and PD-1 were measured using the sandwich enzyme-linked immunosorbent assay method, and the expression of the two immune checkpoint molecules on the cell surface was analyzed by isolating peripheral blood mononuclear cells by density gradient centrifugation technique. RESULTS: Twenty-seven patients with CNO (14 boys, 51.9%) and six healthy controls (3 boys, 50%) were enrolled in the study. There were no age differences between CNO patients and healthy controls (median age 14.5 vs. 13.5 years, respectively, p=0.762). Of the CNO patients, 18 were included at the time of diagnosis while 9 were receiving biologic treatment at enrollment. The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls (p=0.011). However, no significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls (p=0.083 and p=0.245, respectively). There was also no statistically significant difference in plasma TIM-3 levels of the patient and control groups (p=0.981). CONCLUSION: CNO is an autoinflammatory disease, and overall, our results suggest that T cell exhaustion may not be significant in CNO. Further research is needed to find out whether the immune checkpoints are mainly associated with autoimmunity but not autoinflammation. Key Points • The median plasma PD-1 levels were significantly lower in the CNO group than in the healthy controls. • No significant difference was found in the cellular expression of PD-1 and TIM-3 on CD3+CD4+ T cells in patients and healthy controls. • Our results suggest that T cell exhaustion may not be significant in CNO pathogenesis.

Is it possible to predict a disease course prone to macrophage activation syndrome at systemic juvenile idiopathic arthritis diagnosis?

OBJECTIVES: Macrophage activation syndrome (MAS) is a severe complication of systemic juvenile idiopathic arthritis (SJIA). We aimed to compare the characteristics of SJIA patients who developed MAS in the disease course to those who never experienced MAS. METHODS: Patients with SJIA were included. The features of the patients at the time of SJIA diagnosis were compared. Multivariate logistic regression and ROC analyses were used while evaluating factors associated with MAS. RESULTS: Overall, 126 SJIA patients (M/F:1.17) were included. Eighty-six (68.2%) never had MAS. At the time of SJIA diagnosis, age was younger; the duration of fever was longer; rash, hepatomegaly, and splenomegaly were more frequent and arthralgia/arthritis was less common among patients who had MAS in the follow-up than those who never had MAS. Also, white blood cell, neutrophil, and platelet counts and fibrinogen were lower, while transaminases, lactate dehydrogenase, triglyceride (TG), and ferritin levels were higher among patients with MAS than those without MAS. The multivariate regression analysis disclosed age at symptom onset, duration of fever, platelet count, TG and ferritin levels as independent MAS predictors. For ferritin level/platelet count (F/P) ratio at the time of SJIA diagnosis, a threshold of ≥1.1 performed best to predict a MAS-prone disease course with a sensitivity of 90% and a specificity of 82.6%. CONCLUSION: The F/P ratio at the time of SJIA diagnosis may be a promising biomarker to predict MAS-prone disease course in SJIA. Determining MAS-prone patients at the time of SJIA diagnosis could assist physicians while tailoring SJIA treatment individually. Key points • Systemic juvenile idiopathic arthritis (SJIA) patients with macrophage activation syndrome (MAS) differ from SJIA patients who never have MAS, at the time of SJIA diagnosis. • It could be possible to predict a MAS-prone disease course at the time of SJIA diagnosis. • The ferritin/platelet ratio is a promising biomarker for predicting MAS-prone SJIA disease course.

Comparison of Biopsychosocial Characteristics of Children with Juvenile Idiopathic Arthritis According to Common Disease Subtypes.

OBJECTIVE: In this study, we assessed the functional and biopsychosocial characteristics of juvenile idiopathic arthritis (JIA) patients according to disease subtypes. MATERIALS AND METHODS: Child Health Assessment Questionnaire (CHAQ), Juvenile Arthritis Disease Activity Score-71 (JADAS-71), and Juvenile Arthritis Biopsychosocial Questionnaire (JAB-Q) scales were administered to 304 JIA patients, and the subscale of JAB-Q was administered to their families. RESULTS: The median age of JIA patients at diagnosis was 7.9 (5.5-13) years (female/male = 1.3). Most patients were under treatment (68.7%) and had inactive disease (69.3%). While there was no significant difference between JADAS-71 scores according to the JIA subtypes, total CHAQ scores in polyarticular JIA patients were higher than in systemic JIA patients (P = .005). Enthesitis-related arthritis (ERA) patients had higher JAB-Q fatigue total scores compared to systemic JJIA patients (P = .001). Juvenile Arthritis Biopsychosocial Questionnaire-child psychosocial status scores were higher in polyarticular JIA patients than oligoarticular and systemic JIA patients (P = .004 and P = .003, respectively), and they had higher JAB-Q child form total scores than systemic JIA patients (P = .006). In addition, systemic JIA patients' parents had higher JAB-Q family total scores compared to oligoarticular JIA patients' parents (P = .03). CONCLUSION: Our results suggest that polyarticular JIA patients had higher CHAQ, JAB-Q psychosocial status, and child form total scores, and the JAB-Q fatigue score was higher in ERA patients. Also, JAB-Q-parent scores were higher in systemic JIA patients' parents. Biopsychosocial characteristics should be evaluated in both JIA patients and their parents.

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 30 patients with ERA and 15 with sacroiliitis associated with FMF were included in the study. All patients were evaluated with US by a pediatric radiologist. Enthesis of seven tendons (common extensor and flexor tendons, quadriceps tendon, proximal and distal patellar tendon, Achilles tendon, and plantar fascia) were examined on both sides. RESULTS: Subclinical enthesitis was detected in 10 ERA (33.3%) 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, 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. CONCLUSION: Our results showed that the US can be particularly helpful in detecting subclinical enthesitis and predicting disease flare-ups.

The Effect of Biologics in the Treatment of Multisystem Inflammatory Syndrome in Children (Mis-C): A Single-Center Propensity-Score-Matched Study.

Multisystem inflammatory syndrome in children (MIS-C) is a serious condition characterized by excessive inflammation that can arise as a complication of SARS-CoV-2 infection in children. While our understanding of COVID-19 and MIS-C has been advancing, there is still uncertainty regarding the optimal treatment for MIS-C. In this study, we aimed to compare the clinical and laboratory outcomes of MIS-C patients treated with IVIG plus corticosteroids (CS) to those treated with IVIG plus CS and an additional biologic drug. We used the propensity score (PS)-matching method to assess the relationships between initial treatment and outcomes. The primary outcome was a left ventricular ejection fraction of less than 55% on day 2 or beyond and/or the requirement of inotrope support on day 2 or beyond. We included 79 MIS-C patients (median age 8.51 years, 33 boys) followed in our center. Among them, 50 children (25 in each group) were allocated to the PS-matched cohort sample. The primary outcome was observed in none of the patients in the IVIG and CS group, while it occurred in eight patients in the IVIG plus CS and biologic group (p = 0.04). MIS-C is a disorder that may progress rapidly and calls for extensive care. For definitive recommendations, further studies, including randomized control trials, are required.

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.

Patients Without a Rheumatic Disease Diagnosis in a Pediatric Rheumatology Unit: Retrospective Analysis and Comparison Between Pre-pandemic and Pandemic Periods.

OBJECTIVE: Children with suspicious complaints of rheumatic diseases are generally referred to a pediatric rheumatologist. We aimed to evaluate the profile of patients referred to the pediatric rheumatology unit and were not diagnosed with a rheumatic disease and to assess the impact of the coronavirus disease-2019 pandemic on referral complaints. MATERIALS AND METHODS: All new outpatients who applied to the pediatric rheumatology department between March 2019 and February 2021 and were not diagnosed with rheumatic disease were included. We also compared the frequency of admission symptoms during the pre-pandemic (March 2019-February 2020) and pandemic periods (March 2020-February 2021). RESULTS: A total of 1089 patients without a rheumatic disease diagnosis (568 female, 52.2%; median age 10.0 years) were included in this study. The most common complaint for referral was prolonged or recurrent fevers (13.4%) followed by anti-nuclear antibody positivity (13.1%), arthralgia (13.0%), skin findings (7.5%), and the presence of heterozygous mutations in the Mediterranean fever gene (6.9%). During the pandemic year, the number of patients referred for back pain increased significantly (P = .028). A total of 682 of 1089 patients were consulted from other departments in our center (62.6%). Of these, the most frequent consultation request was from general pediatrics (43.6%). The rheumatic disease was excluded in 11.3% of the patients. CONCLUSION: Prolonged or recurrent fever and anti-nuclear antibody positivity were the most frequent complaints of referrals to a pediatric rheumatology unit in patients who did not have a rheumatic disease. The rate of back pain was more common in children during the pandemic period.

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.

Interstitial lung disease in autoinflammatory disease in childhood: A systematic review of the literature.

BACKGROUND/OBJECTIVES: The lung is one of the target organs in the systemic involvement of autoinflammatory disease (AID), and interstitial lung disease (ILD) is the primary phenotype of lung involvement in AID. In this review, we aimed to conduct a systematic review of the available literature to highlight ILD in AID. METHODS: We conducted a systematic literature search in PubMed/MEDLINE and Scopus from the inception of the databases to January 2022. References were first screened by title and then by abstract by two authors. Eighteen original papers were selected for full-text review. RESULTS: During the literature search, we identified 18 relevant articles describing 52 cases of AID and ILD. Of those, 44 patients had stimulator of interferon genes-associated vasculopathy with onset in infancy (SAVI), six had coatomer protein complex (COPA) syndrome, one had haploinsufficiency of A20, and one had mevalonate kinase deficiency. Pulmonary fibrosis, cyst formation, and ground glass areas were the most common findings in chest tomography of patients with COPA syndrome and SAVI. Janus kinase inhibitors were used to treat most of the patients with SAVI, which stabilized ILD. CONCLUSIONS: ILD should be considered carefully in children with AID, especially those with interferonopathy.

Early-onset juvenile dermatomyositis: A tertiary referral center experience and review of the literature.

BACKGROUND/OBJECTIVES: The aim of our study is twofold: To evaluate the presentation, diagnosis, clinical course, and management of juvenile dermatomyositis (JDM) in children under three years of age, and to compare with older-onset patients. METHODS: Nine patients with early-onset, and 63 patients with older-onset JDM followed between December 2010 and April 2022 are included. We also reviewed the literature on early-onset JDM from the inceptions of the PubMed/MEDLINE and Scopus databases up to April 1st, 2022. RESULTS: Early-onset JDM patients were characterized by longer median diagnostic delay (p = 0.005), calcinosis (p = 0.006), anti-NXP2 antibody (p = 0.049). Diagnostic pathway included muscle biopsy (77.7% versus 50.8%). Muscle biopsy findings were more severe in the early-onset group (p<0.001). Although there was no difference in the partial and complete remission rates, the relapse rate was significantly higher in the early-onset group (p = 0.001), reflected to requirement of intravenous immunoglobulin (p = 0.001), cyclophosphamide (p = 0.011), and biological agents (p = 0.016). Literature search revealed 32 articles reporting 75 patients. The median diagnostic delay was 5 (1-30) months. Calcinosis was present in 29.5%. Twenty-three of the 44 patients (52.3%) had a muscle biopsy. Forty-one patients (64.1%) received second and third-line treatments. Complete remission was achieved in almost half of these patients (48.9%), but relapse was observed in 75%. The mortality rate was 10.2%. CONCLUSION: Diagnosis can be challenging and delayed in early-onset JDM patients. Compared to older-onset JDM patients, this group had higher relapse rate, more severe muscle biopsy findings, and received intensive immunosuppressive treatment.

Report of 2 pediatric cases with atypical Cogan's syndrome and a systematic review.

Cogan's syndrome (CS) is a rare inflammatory disease characterized by interstitial keratitis or uveitis, vestibular impairment, and progressive hearing loss, commonly bilateral. Although glucocorticoids are fundamental treatment options, in most cases, hearing loss gradually worsens. Herein we report 2 pediatric cases of CS who were treated with corticosteroids and methotrexate. One patient had a cochlear implant, and the hearing of the other patient improved with treatment. Also, a systematic literature review was conducted for articles including pediatric CS patients. In the literature, 34 articles describing 44 pediatric patients with CS were identified. Sudden hearing loss (95.3%) and ocular symptoms (92.5%) were the most common manifestations in these patients. Also, aortic involvement was present in 19.5% of patients in the literature. Otorhinolaryngologists, ophthalmologists, and pediatricians should collaborate to diagnose and manage CS to prevent progressive hearing loss and eye involvement.

The pyrin inflammasome, a leading actor in pediatric autoinflammatory diseases.

The activation of the pyrin inflammasome represents a highly intriguing mechanism employed by the innate immune system to effectively counteract pathogenic agents. Despite its key role in innate immunity, pyrin has also garnered significant attention due to its association with a range of autoinflammatory diseases (AIDs) including familial Mediterranean fever caused by disruption of the MEFV gene, or in other genes involved in its complex regulation mechanisms. Pyrin activation is strictly dependent on homeostasis-altering molecular processes, mostly consisting of the disruption of the small Ras Homolog Family Member A (RhoA) GTPases by pathogen toxins. The downstream pathways are regulated by the phosphorylation of specific pyrin residues by the kinases PKN1/2 and the binding of the chaperone 14-3-3. Furthermore, a key role in pyrin activation is played by the cytoskeleton and gasdermin D, which is responsible for membrane pores in the context of pyroptosis. In addition, recent evidence has highlighted the role of steroid hormone catabolites and alarmins S100A8/A9 and S100A12 in pyrin-dependent inflammation. The aim of this article is to offer a comprehensive overview of the most recent evidence on the pyrin inflammasome and its molecular pathways to better understand the pathogenesis behind the significant group of pyrin-related AIDs.