Distinctive clinical phenotype and treatment outcome of type 1 autoimmune hepatitis in the elderly.

Autoimmune hepatitis is classically a disease of young women. Our aims were to determine its occurrence, clinical phenotype, and outcome in elderly patients and contrast findings to young adults. Two-hundred-and-five white North American adults with definite type 1 autoimmune hepatitis were grouped according to age at presentation and the groups compared. Forty-seven patients (23%) were aged > or = 60 years (median age, 68 years), and 31 patients (15%) were aged < or = 30 years (median age, 25 years). The patients > or = 60 years had a higher frequency of cirrhosis at presentation than the patients < or = 30 years (33% versus 10%, P = .03). They also had thyroid or rheumatic diseases more commonly (42% vs. 13%, P = .006). HLA DR3 occurred more frequently in the patients < or = 30 years than in those > or = 60 years (58% vs. 23%, P = .004), and HLA DR4 occurred more often in the patients > or = 60 years (47% vs. 13%, P = .003). Patients aged > or = 60 years failed corticosteroid treatment less commonly than those aged < or = 30 years (5% vs. 24%, P = .03). Autoimmune hepatitis occurred in patients aged 18-30 years (15%), 31-39 years (15%), 40-49 years (21%), 50-59 years (25%), and > or = 60 years (23%). Differences in age distribution, HLA frequencies, and treatment outcome occurred after age > or = 40 years. In conclusion, elderly patients have a greater frequency of cirrhosis at presentation and HLA DR4 than patients < or = 30 years, and they have a lower occurrence of treatment failure. Transitions in clinical and genetic phenotypes occur after age > or = 40 years. Genetic susceptibilities may favor etiologic factors that are age-related.