Pediatric Immunoglobulin A Vasculitis: Impact of Mediterranean Fever Gene Variants on Clinical Course and Inflammatory Markers.

Objective: The aim of the study is to evaluate the clinical and laboratory features of pediatric patients with immunoglobulin A vasculitis (IgAV) according to Mediterranean fever (MEFV) gene variant status and to identify possible clinical indicators that may guide selective genetic testing. Materials and Methods: A total of 176 pediatric IgAV patients who underwent MEFV gene analysis were retrospectively reviewed. Patients were classified into 2 groups based on the presence or absence of MEFV variants. Demographic, clinical, and laboratory parameters assessed at diagnosis were compared between groups. Results: Among the 176 patients, 75 (42.6%) carried at least 1 MEFV variant. Compared to those without MEFV variants, patients with MEFV variants had a significantly higher rate of family history of Familial Mediterranean fever (FMF) (42.6% vs. 5.9%, P < .001). In addition, arthralgia (76% vs. 58%, P= .02) and arthritis (36% vs. 20.8%, P= .03) were more frequently observed in patients with MEFV variants. Serum amyloid A levels were significantly elevated in patients with MEFV variants (median 15 [IQR 4-150] vs. 5 [2-33] mg/L, P < .001). No significant differences were observed in renal or gastrointestinal involvement between groups. C-reactive protein and erythrocyte sedimentation rate values were higher in patients with MEFV variants but did not reach statistical significance. Conclusion: The presence of MEFV variant in pediatric IgAV patients is associated with increased systemic inflammation and higher rates of musculoskeletal symptoms. Selective MEFV genetic testing and SAA measurement may be beneficial in IgAV patients presenting with marked inflammatory responses, joint involvement, or positive family history of FMF.