Epidemiology of Behçet Syndrome and regional differences in disease expression

Abstract

Behçet syndrome (BS) is more prevalent along the ancient trading route known as the “Silk Road, " extending from the Mediterranean to the countries in the Far East, where the prevalence of HLA-B5 (51) is relatively more frequent in the healthy population. This suggests that the possible causative agent(s), including genetic factors such as HLA-B51, might have had spread along this route. Seven cross-sectional and population-based field studies showed that the prevalence of BS was between 19 and 421 among 100, 000 adolescent/adult population in Turkey. The lower three frequencies (19, 20, and 80/105) come from Thrace, the European part. The disease is less common in Western Europe, the USA, and in the rest of the world but perhaps not as rare as it had previously been thought. A recent study showed that BS was as frequent (7.1/105) as other vasculitic diseases - 9/105 for the combination of polyarteritis nodosa, microscopic polyangiitis, Wegener’s granulomatosis, and Churg-Strauss syndrome - in a suburb of Paris, France. This chapter focuses on the epidemiological features of the field surveys of BS in Turkey and the rest of the globe as well as regional differences in some of the clinical and laboratory features. Gastrointestinal disease is frequent in patients from the Far East (especially Japan), while it is rather infrequent among those from Turkey. Moreover, a high frequency of both pathergy test positivity and being a carrier of HLA-B5 (51) is observed in patients from Japan and the Mediterranean countries, in contrast to the patients from the UK and the USA.