Incidence of adult form of autoimmune hepatitis in Valencia (Spain)

There is little information on the incidence of autoimmune hepatitis (AIH) because on many occasions the disease can progress asymptomatically, different diagnostic criteria have been proposed during the last 20 years, and many epidemiological studies are based on retrospective clinical series. The aim of this study was to determine the incidence of AIH in the province of Valencia, Spain, during the year 2003.

The Services of Gastroenterology of eight acute-care reference hospitals in the province of Valencia, Spain, covering 1,774,736 inhabitants over 14 years of age, participated in a prospective study. All newly diagnosed patients with AIH between January 1, 2003 and December 31, 2003 were eligible. The diagnosis was based on criteria of the International Autoimmune Hepatitis Group revised in 1999.

There were 19 new cases of AIH, 18 females and 1 male [mean (SD) age of 54.3 (11.2) years, range 23-73]. Incidence peaked in the 45-54 year age group. Eighteen cases were classified as AIH type 1 and one case as AIH type 2. The incidence rate of AIH for the year 2003 in people older than 14 years of age was 1.07 new cases per 100,000 inhabitants, with 1.96 cases per 100,000 inhabitants in females and 0.12 cases per 100,000 inhabitants in males.

The 2003 annual incidence of AIH in Valencia, Spain, was similar to that reported in other European countries. AIH occurred more frequently in women and in the 45-54 year age group, type 1 being the most common.