Primary biliary cirrhosis in Estonia. With special reference to incidence, prevalence, clinical features, and outcome.

BACKGROUND Primary biliary cirrhosis (PBC) is a liver disease of unknown etiology, whose occurrence varies greatly between different regions. For a long time there have been no published data about the incidence and prevalence of PBC from Eastern Europe countries. METHODS The incidence and prevalence of PBC have been investigated in the Estonian population during the period 1973-92. Two sources of information were used: an information circular/questionnaire was sent to all district hospitals and gastroenterologists, and the case histories of all patients with a positive antimitochondrial antibody titer of 1:40 or more were reexamined. RESULTS During this period 69 cases of PBC were diagnosed. The male to female ratio was 1:22; 13% of the patients were asymptomatic. The mean annual incidence was 2.27 per million, and on 31 December 1992 the point prevalence was 26.9 per million. There were differences in prevalence among the various districts of Estonia. Associated autoimmune conditions were reported in 32% of the patients. Mean survival from the time of diagnosis was 52.5 months. CONCLUSIONS The incidence of PBC in Estonia is at the lower end of the range reported in the world literature. This has probably partly been caused by a low percentage of asymptomatic and male patients.