Juvenile-onset systemic lupus erythematosus (jSLE) patients typically have a more severe disease course than adults with SLE. We aimed to assess the prevalence and disease course of jSLE patients carrying MEFV variants. MEFV variant analyses were performed in 44 jSLE patients and effect of these variants on disease severity and course was analyzed by SLEDAI score and SLICC/ACR index. Ten of the patients (22.7%) had a MEFV variant. The median (min-max) SLEDAI score and SLICC/ACR index were 2(0-13) and 0(0-3), respectively. Median age at disease onset, disease duration, SLICC/ACR indexes, SLEDAI scores, clinical and laboratory findings of the patients were comparable in carriers of variants and non-carriers. Nineteen patients (43.2%) had biopsy-proven lupus nephritis and four of these patients had MEFV variants. There was no significant difference between patients with and without MEFV carriers in terms of lupus nephritis. Even though not significant statistically, renal involvement was milder in MEFV carriers than non-carriers. The presence of MEFV variants does not increase the overall susceptibility to jSLE in our cohort, while larger number of patients is required to display the protective role of MEFV variants in jSLE.
Keywords: Disease severity; Familial Mediterranean fever; Juvenile-onset systemic lupus erythematosus; MEFV.