Clinical and genetic characteristics of familial Mediterranean fever-associated vasculitides in children of Armenia

Abstract

Family Mediterranean fever (FMF), or a periodic disease, is the most common hereditary disease among Armenians. FMF manifests mainly in childhood, presenting a significant problem for the pediatric health care system in Armenia. The clinical presentations of FMF have much in common with that of vasculitides: fever, abdominal pains, arthritis, myalgias, and skin damage. The data available in the literature indicate the high incidence of vasculitides in patients with FMF in the ethnically significant groups compared with the general population. Objective: to investigate the clinical and genetic characteristics of FMF-associated vasculitides in children of Armenia. Subjects and methods. The National Pediatric FMF Center, Arabkir Medical Complex, Institute of Child and Adolescent Health, examined a group of 715 children (438 boys, 277 girls; mean age, 8.64+0.17 years) with FMF. The diagnosis of FMF was confirmed using the Tel-Hashomer criteria and the MEFV gene mutation analysis. The Epi-Info 2000 program was used for statistical analysis. Results and discussion. The rate of vasculitides was 4.3% (n=31), being generally higher than expected. In particular, the diagnoses made were Henoch-Scho nlein pirpura (HSP) in 11 (1.5%) children, protracted febrile myalgia (PFM) in 20 (2.7%), and Behcet’s disease (BD) in 1 (0.1%) patient. The patients were characterized by early-onset FMF (at an average of 3 years) with a moderate/severe course, frequent episodes, a predominance of articular syndrome, more commonly acute relapsing arthritis, with the addition of clinical presentations of vasculitis on average 5—6 years after the onset of FMF, and genetically by the M694V homozygous genotype (M694V/M694V). HSP and PFM were observed in 2.9 and 4.6% of patients with the M694V homozygous genotype, respectively (p<0.02). Conclusion. The rate of FMF-associated vasculitides in the children of Armenia was 4.3%: HSP, PFM, and BD were diagnosed in 1.5, 2.7, and 0.1% of patients, respectively. The findings allow HSP and PFM to be considered as additional markers for the severe course of FMF and the M694V homozygous genotype as a risk factor for PFM. They also indicate the feasibility of the MEFV gene mutation screening in children with vasculitides in Armenia for an association with FMF for early diagnosis of the disease, timely administration of colchicine, and prevention of complications.