Similarities and Differences in Autoimmune Hepatitis Epidemiology between East and West: Autoimmune Hepatitis in East Asia, Southeast Asia, and South Asia

Abstract

Background: Autoimmune hepatitis (AIH)is a relatively rare disease that can develop regardless of age or ethnicity. However, its clinical features differ between eastern and western populations due to several heterogeneous genetic and environmental factors. We herein report the clinical characteristics of AIH patients in East Asia, Southeast Asia, and South Asia. Summary and Key Messages: The prevalence of AIH in eastern countries is considered to be lower than in western countries. Although a few young patients with type 2 AIH have been observed in South Asia, most patients in Asia are middle-aged women with type 1 AIH who respond well to steroid-based immunosuppressive therapy. Human leukocyte antigen DR4 is suggested to be an influential factor in the genetic background of AIH patients in Asia, particularly in East Asia. Notably, AIH may be induced by some societal- or culture-associated medicines, including herbal medicines. The IAIHG (International Autoimmune Hepatitis Group) scoring systems are generally accepted as the standard diagnostic methods for AIH in Asian countries. The results of repeated nationwide surveys in Japan suggest that the clinical features of AIH patients in East Asia are changing, with IgG levels and rates of anti-nuclear antibody positivity decreasing.

Autoimmune Hepatitis in the East and the West

“…It is interesting to note that the incidence and prevalence of AIH are consistently reported as lower in the East than in the West as summarized by Enomoto et al [6] . In the West, the prevalence of AIH was reported as 15-25 cases per 100,000 inhabitants, whereas much lower rates of 4-5 cases per 100,000 inhabitants were reported in the East [9] .…”

“…The current working model postulates that environmental triggers, a failure of immune tolerance mechanisms, and a genetic predisposition collaborate to induce an uninhibited T cell-mediated immune attack upon hepatocytes [5] . In this issue, Enomoto et al [6] have provided an excellent summary of the similarities and differences in the epidemiology of AIH between the East and the West.…”

“…Enomoto et al [6] have shown that, while there are many similarities between AIH in the East and the West, differences exist. The prevalence is lower in the East than in the West, and genetic differences may have contributed to some of the observed differences.…”

Systematic review and meta‐analysis on the incidence and prevalence of autoimmune hepatitis in Asian, European, and American population

“…This may be partly due to the wide spectrum of clinical presentation and lack of specific biomarkers and simple diagnostic criteria. Recently, several researches demonstrated that the incidence and prevalence of AIH were increasing, not only in Europe and Northern America but also in some Asian countries . A systematic review on the incidence of AIH published in 2015 described AIH occurrence all over the world but did not conduct a meta‐analysis .…”

“…Recently, several researches demonstrated that the incidence and prevalence of AIH were increasing, [9][10][11][12] not only in Europe and Northern America 9,11,12 but also in some Asian countries. 10,13 A systematic review on the incidence of AIH published in 2015 described AIH occurrence all over the world but did not conduct a meta-analysis. 14 Therefore, in this study, we conducted a systematic review and meta-analysis with the aim to pool the global incidence and prevalence rate of AIH and characterize the population difference.…”