Evaluation of familial Mediterranean fever patients concomitant with juvenile spondyloarthropathy

Familial Mediterranean fever (FMF) may present with various concomitant diseases. This study aims to evaluate the clinical characteristics of patients with FMF with Juvenile Spondyloarthropathy (jSpA).

Thirty-two patients diagnosed with FMF/jSpA, sixty-four with FMF, and fifty-four with jSpA were included in this retrospective study. Three patient groups were compared in terms of clinical and laboratory features.

The mean ages of patients in the FMF/jSpA, FMF and jSpA groups were 15.75(11.50-19.83), 15,41(6.83-21.50), and 16(9-22) years, respectively. Chronic arthritis (OR: 0.11, p = .049), erythrocyte sedimentation rate values (OR:1.07, p = .011), and C-reactive protein values (OR:1,08, p: .039) of the patients in remission period were found higher, the international severity scores for FMF (ISSF) before and after colchicine treatment (OR: 1.16, p: .021, OR: 2,21, p: .012) were higher in the FMF/jSpA group compared to FMF. Plantar fasciitis was more common and HLA-B27 positivity rate was lower in the FMF/jSpA group (OR:0.08, p = .024), (OR:4.71, p = .002) compared to jSpA. FMF/jSpA patients were divided as previous diagnosed FMF and jSpA.The diagnosis of jSpA was at a younger age(p = .002), Juvenile arthritis damage index-articular(p = 0.022) and extraarticular(p = .026), and the rate of biologic drug usage(p = .015) were higher in the previous jSpA group. The number of FMF attacks before colchicine was lower in the previous jSpA group(p = .02).

Our findings suggest that both classical FMF and jSpA findings were lower in patients with FMF/jSpA. Patients who were diagnosed with jSpA at an early age and who had enthesitis and plantar fasciitis should also be evaluated in terms of FMF.