Objectives: This study aimed to evaluate the predictability of the homozygous M694V genotype in paediatric FMF patients and to develop a clinical scoring system to enhance disease management strategies. Methods: This nationwide, multicentre, cross-sectional study included 3981 paediatric FMF patients with biallelic pathogenic variants in exon 10 of the Mediterranean fever gene. Patients were divided into two groups: group 1 (homozygous M694V) and group 2 (other variants). Data were collected from 37 paediatric rheumatology and/or nephrology clinics across Türkiye, covering patients followed between 2014 and 2023. Results: Group 1 had significantly earlier symptom onset (≤3 years: 49.8% vs 43.9%, P < 0.001) and diagnosis (median age: 5 years vs 5.8 years, P < 0.001) compared with group 2. A higher prevalence of family history of FMF was observed in group 1 (P < 0.001). Clinical manifestations, including arthritis (27.5%), erysipelas-like erythema (ELE) (20.3%) and protracted febrile myalgia syndrome (PFMS) (3.6%), were significantly more frequent in group 1 (P < 0.001 for all). Colchicine resistance was also higher in group 1 (18.1% vs 5.1%, P < 0.001). Logistic regression analysis showed that ≤3 years of age at symptom onset, family history, arthritis, myalgia, PFMS, ELE and splenomegaly were independent predictors of the homozygous M694V genotype. A clinical scoring system was proposed based on these findings. Conclusion: This study provides valuable insights into the clinical predictors of the homozygous M694V genotype in paediatric FMF. The proposed scoring system will support clinicians in prognosis assessment and treatment planning, contributing to improved patient outcomes.

Background/aim: Vitamin D levels have been investigated in children with familial Mediterranean fever (FMF), but the relationship between vitamin D status and inflammation/oxidative stress indicators could not be clearly demonstrated. This study aimed to investigate the relationship between subclinical inflammation/oxidative stress and vitamin D status in children with FMF during an attack-free period. Materials and methods: In the cross-sectional study, ninety children with FMF in the attack-free period and 30 healthy children were included. Patients were grouped according to their vitamin D status (< 20, 20-29, and 30-100 ng/mL). The groups were compared in terms of pentraxin 3 (PTX-3), total oxidant status (TOS), and total antioxidant status (TAS). Multivariable linear regression analysis was performed to identify factors associated with vitamin D status. Results: PTX-3 levels were significantly higher in patients with vitamin D insufficiency (20-29 ng/mL) than in the group with vitamin D sufficient (30-100 ng/mL). Patients with vitamin D deficiency (< 20 ng/mL) had higher TOS. A strong negative correlation was observed between vitamin D levels and TOS (p = 0.003). Subclinical inflammation (PTX-3 >= 0.640) and high TOS levels were negatively associated with vitamin D levels. Conclusion: Subclinical inflammation and oxidative stress were negatively associated with vitamin D levels in patients with FMF during an attack-free period. Sufficient vitamin D levels are important in fighting subclinical inflammation and oxidative stress in children with FMF.

Objective: This nationwide, multicenter study was conducted to assess the demographic and clinical features, treatment regimens, and prognosis of primary Sjögren disease (SjD) in childhood. Methods: This retrospective study included a total of 81 patients < 18 years of age from 21 pediatric rheumatology centers. Among these, 51 patients fulfilled the diagnosis of childhood SjD according to the 2016 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria. The remaining 30 patients—who did not fully meet these criteria but exhibited clinical and laboratory findings suggestive of SjD—were categorized as at risk for childhood SjD to highlight diagnostic challenges and the spectrum of early presentations, based on comprehensive clinical evaluation by experienced pediatric rheumatologists. Results: The cohort consisted of 81 patients (85.2% female, 14.8% male) with a median age at symptom onset of 11.4 years and a median follow-up of 24 months. Common clinical manifestations included dry mouth, dry eyes, arthralgia, fatigue, and parotitis. Fifty-one of the 81 patients met the 2016 ACR/EULAR classification criteria, whereas the remaining 30 were classified as an at-risk group. The most common clinical findings in the at-risk group were xerostomia (90%), arthralgia (56.7%), fatigue (50%), and dry eyes (43.3%). Dry mouth and peripheral nervous system involvements were found to be higher in patients categorized as at risk ( P = 0.03 and P = 0.02, respectively). Conclusion: The current classification criteria for childhood SjD appear to be inadequate, highlighting the need for pediatric-specific criteria that more accurately reflect the distinct clinical patterns observed in children.

Background/Objectives: Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disorder characterized by joint inflammation, potentially leading to pulmonary involvement. This study aimed to assess pulmonary function in children with JIA compared to controls and identify potential respiratory abnormalities associated with the disease. Methods: This was a prospective cross-sectional study conducted at the Pediatric Rheumatology, Başakşehir Çam and Sakura City Hospital, İstanbul, Türkiye, between July and October 2024. The study included 70 children with JIA and 60 healthy controls aged 6 to 17. Pulmonary function test parameters, such as forced vital capacity (FVC), forced expiratory volume in the 1st second (FEV1), peak expiratory flow (PEF), and FEV1/FVC ratio, were measured using spirometry. Oxygen saturation (SpO₂) was also measured. Results: There were no significant differences in demographic and clinical characteristics between the JIA and control groups (p > 0.05). FVC and FEV1 values were lower in the JIA group, though not significantly (p = 0.831 and p = 0.711). However, PEF was significantly lower in the JIA group than controls (p = 0.005). Children with moderate or high disease activity had significantly lower FVC, FEV1, and FEF 25–75 than those with low disease activity (p < 0.001). Enthesitis-related arthritis patients had higher FVC and FEV1 than other JIA subtypes (p < 0.05). FVC and FEV1 were positively correlated with BMI (p < 0.001). Conclusions: Although PEF values were significantly lower in children with JIA, overall pulmonary function was comparable between the groups. Regular pulmonary monitoring in JIA patients is recommended for early detection and management of respiratory complications.