Characteristics of autoimmune hepatitis in the Asia-Pacific Region: historical review.
BACKGROUND
Autoimmune hepatitis (AIH) has been considered a relatively rare disease in Asia, including Japan, where there is a high frequency of infection with hepatitis viruses.


METHODS
We reviewd the ethnic differences of clinical features of autoimmume hepatitis by reported paper.


RESULTS
Immunogenetic predisposition, especially differences in human leukocyte antigens (HLAs), has been pointed out as one of the factors for the occurrence of AIH. In other words, HLA-DR3, which is the first disease-susceptibility gene for AIH discovered in UK and the USA, is extremely rare in Asia including Japan. Moreover, HLA-DR4, which is more frequent than HLA-DR3 in Asia, is associated with a favorable response to treatment and improved prognosis. This also explains why diagnosis and treatment of AIH have not drawn as much attention as viral hepatitis. However, as a survey conducted in Japan shows, the number of patients diagnosed with AIH is increasing. However, the number of elderly patients positive for HLA-DR4 is also increasing in UK and the USA.


CONCLUSIONS
In the era of genome-wide association studies, further progress of studies on AIH, a typical disease model for immunological liver cell damage, is expected.
The Jikei University Graduate School of Medicine Gastroenterology, Tokyo, Japan. zeniya@jikei.ac.jp.
Mikio
M
Zeniya
The Jikei University Graduate School of Medicine Gastroenterology, Tokyo, Japan.
Hiroki
H
Takahashi