Epidemiology and the initial presentation of autoimmune hepatitis in Sweden: a nationwide study.
OBJECTIVE
Autoimmune hepatitis (AIH) is a chronic liver disease, which if untreated can lead to cirrhosis and hepatic failure. The aim of the study was to investigate the incidence, prevalence, diagnostic tradition and clinical initial presentation of AIH.


METHODS
Analyses were performed in 473 patients identified as having probable or definite AIH.


RESULTS
The incidence of AIH was 0.85/100,000 (95% CI 0.69-1.01) inhabitants, which is somewhat lower than reported previously. The point prevalence amounted to 10.7/100,000 (95% CI 8.8-13.1), and 76% of the cases were females. The age-related incidence curve was bimodal but men were found to have only one incidence peak in the late teens, whereas women had a peak after menopause. AIH was presented as a spectrum of clinical settings from detected "en passant" to acute liver failure. Almost 30% of patients already had liver cirrhosis at diagnosis. Autoantibodies indicative of AIH type 1 were found in 79% of cases. Other concomitant autoimmune diseases were frequently found (49%).


CONCLUSIONS
The incidence and prevalence figures confirm that AIH is a fairly uncommon disease in the Swedish population. Symptoms at presentation were unspecific, but almost half of the patients were jaundiced, with around 30% having liver cirrhosis. The majority of Swedish AIH patients had AIH type 1.
Werner
Mårten
M
Department of Medicine, Umeå University Hospital, Umeå, Sweden. marten.werner@vll.se
Prytz
Hanne
H
Ohlsson
Bodil
B
Almer
Sven
S
Björnsson
Einar
E
Bergquist
Annika
A
Wallerstedt
Sven
S
Sandberg-Gertzén
Hanna
H
Hultcrantz
Rolf
R
Sangfelt
Per
P
Weiland
Ola
O
Danielsson
Ake
A
D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology