Background Familial Mediterranean fever (FMF) is a periodic autoinflammatory disease presenting with recurrent episodes of fever, abdominal pain, chest pain and arthritis. The MEFV gene encoding the protein pyrin is though to be responsible from the clinical features. It is known that interferon-γ produced by Th1 cells increase the expression of MEFV and promote inflammation while inhibiting IgE dependent Th2 response.
Objectives There are only few studies regarding the prevalance of atopy in FMF patients and their results are conflicting. In this study children with the diagnosis of FMF were evaluated for the presence of atopy by comparing with the controls.
Methods To this study, 118 children diagnosed as FMF according to Tel-Hashomer criteria and 50 healthy age and sex matched controls were enrolled. None of the children from the control group had taken antihistaminics or other medications 4 weeks before the study and they were not diagnosed for any inflammatory disease. Both of the groups were evaluated for the presence of rhinitis, atopic dermatitis, urticaria and asthma. Laboratory assessment was done by measuring IgA, IgM, IgG, IgE levels, total eosinophil count and by performing skin prick test (SPT) panels for common allergens to children with FMF and healthy controls. Most of the patients had a MEFV gene analysis.
Results One hundred eighteen children (61 girls and 57 boys) diagnosed as FMF with a median age of 120 months (range 36-204 months) were compared with 50 healthy controls (31 girls and 19 boys) having a median age of 126 months (range 48-192 months). The median age of onset of symptoms was 54 months (range 4-180 months), median age of diagnosis was 84 months (range 18-192 months) and the median duration of disease was 24 months (range 18-192 months). All the patients were under colchicine treatment. Although there is no statistically significant difference between the personal history of rhinitis, dermatitis, urticaria and asthma between patients and controls, both urticaria and rhinitis were found to be more common in controls. Presence of SPT positivity was not significantly different between patients and controls. While IgA levels were higher in children with FMF, IgE levels were significantly higher in controls (p<0.05).
Conclusions FMF is mostly a Th1 driven inflammatory disease while atopy is a Th2 response predominant one. A reduction of atopy had been shown in some inflammatory diseases like rheumatoid arthritis and Behçet's disease. Few studies with conflicting results were carried out in patients with FMF. It is important that our study was performed at a larger group of children with FMF. Although statistically not significant, both urticaria and rhinits were found to be less common in children with FMF while atopic dermatitis and asthma were nearly the same in both groups. Lower IgE levels in children with FMF may also mark the role of Th1 in protecting from Th2 driven immune responses. As a last case, significant increase in IgA levels in children with FMF may also be a diagnostic marker for the presence of chronic inflammatory disease.
Disclosure of Interest None declared