The data of 737 patients who were followed up with the diagnosis of IgAV during the study period were reviewed. Forty-five patients with a follow-up period of less than 3 months and 30 patients with missing data were excluded from the study. The remaining 662 patients with IgAV were included in the study.

Three hundred and eleven (47%) of IgAV patients were female. The median age at diagnosis was 7.2 (4.1–17) years. The median follow-up period was 1.2 (0.8–15) years. All IgAV patients had skin involvement. There were gastrointestinal tract involvement in 245 (37%) patients, arthralgia/arthritis in 200 (30.2%), renal involvement in 54 (8.1%), and scrotal involvement in 39 (5.9%). The median PVAS was 2 (1–5).

The patients were subgrouped according to the presence of FMF. Of the 662 IgAV patients, 49 (7.4%) had FMF. The MEFV results of the patients are given in Table 1.

Twelve of 49 (24.5%) IgAV patients with FMF were followed up with a diagnosis of FMF prior to vasculitis. MEFV gene analysis was performed in 107 IgAV patients during vasculitis follow-up. The reason for MEFV mutation screening was widespread rash in 17 (15.9%), severe systemic involvement in 84 (78.5%), and recurrent leukocytoclastic vasculitis in 6 (5.6%). As a result, 35 (32.7%) patients who met Eurofever genetic classification criteria and 2 patients who met Eurofever clinical classification criteria were diagnosed with FMF at the time of IgAV diagnosis. Of the 107 patients who were analyzed for MEFV gene, 70 patients were not considered as FMF because 43 patients had no mutation and 27 patients had heterozygous mutation but no clinical symptoms.

Demographic characteristics, clinical and laboratory findings, PVAS, and treatments of IgAV patients with and without FMF are given in Table 2. The rate of gastrointestinal tract and renal involvement, median PVAS, median C-reactive protein (CRP), and need for steroids, cyclophosphamide, intravenous immunoglobulin (IVIG), and plasma exchange therapy were significantly higher in IgAV patients with FMF (p = 0.01, p = 0.03, p < 0.001, p < 0.001, p = 0.04, p < 0.001, p = 0.01, p < 0.001, respectively). When patients who were carriers of the MEFV mutation but did not show clinical features of FMF were compared with patients without the mutation, no significant difference was found in terms of laboratory findings, clinical features, and vasculitis activity scores (Table 3).

According to MEFV gene mutations, patients with FMF were subdivided into those with homozygous/compound heterozygous mutation in exon 10 (n = 24), those with heterozygous mutation in exon 10 (n = 20), and those with mutation in exon 2 or without mutation but clinically diagnosed with FMF (n = 5). The rate of gastrointestinal tract involvement, median CRP and PVAS, and need for pulse methylprednisolone, cyclophosphamide, IVIG, and plasma exchange therapy were significantly higher in patients with homozygous/compound heterozygous mutation in exon 10 compared to IgAV patients without FMF (p = 0.04, p < 0.001, p = 0.01, p < 0.001, p = 0.01, p < 0.001, p < 0.001, respectively). When patients with heterozygous mutations in exon 10 were compared with those without FMF, renal and gastrointestinal tract involvement rates, median CRP and PVAS, and the need for steroids, pulse methylprednisolone, and cyclophosphamide were significantly higher (p = 0.03, p = 0.04, p = 0.04, p = 0.01, p = 0.01, p < 0.001, p = 0.02, respectively). In the group including patients with exon 2 mutation and patients without MEFV mutation, the rate of joint involvement and median CRP values were significantly higher (p = 0.02, p = 0.03, respectively), while no significant difference was found in terms of other organ involvement rates, median PVAS, and treatment options. The comparison of patients with FMF between subgroups according to MEFV mutations is shown in Tables 4 and  5.