[Epidemiology and pathogenesis of Sjögren's syndrome]

A nationwide epidemiological survey of Japanese Sjögren's syndrome (SS) patients was conducted in 1994 by the Research Committee on Epidemiology of Intractable Diseases and the Research Committee of Autoimmune diseases, Ministry of Health and Welfare, Japan. The total number of patients treated for SS in 1993, in Japan, was estimated as 17,000 (95% confidence interval 15,000-20,000). The estimated crude prevalence rates were 1.9 and 25.6 per 100,000 population in males and females, respectively. The ratio of female to male patients was 13.7. The peak of age distribution was in their fifties. New research trends to explore the pathogenesis of SS are also discussed here.