KASL clinical practice guidelines for management of autoimmune hepatitis 2022

DRB1*0405 or DQB1*0401 were significantly increased in patients with AIH type 1 compared with the control (odds ratio [OR], 3.74 & 3.95), and AIH type 1 was associated with the QRRAA motif at position 70-74 of the HLA-DRB1 molecule. 16Summary 1.The annual incidence of AIH was reported as 1.07 per 100,000 persons, and the prevalence as 4.82 per 100,000 persons in Korea.AIH occurs 6 times more frequently in females than in males.2. The incidence of AIH presented one peak in the sixties in Korea, which was in contrast with a bimodal peak in the late teens and sixties in Western countries. CLINICAL MANIFESTATIONSAIH usually develops insidiously; however, the spectrum of symptoms and clinical manifestations are broad, ranging from asymptomatic to acute hepatitis, and it may also develop as fulminant hepatitis (Figure 2). 17In addition, liver fibrosis has already progressed at the time of the AIH diagnosis, and cirrhosis may be already present, or it may even appear as an acute exacerbation of cirrhosis. 18In a Korean population study, 31-37% of patients were asymptomatic at the time of diagnosis, and 13-32% of patients had cirrhosis as well. 19Therefore, AIH should be considered as a differential disease in most liver diseases regardless of the degree of activity or fibrosis.Typical AIH is a form of chronic hepatitis with autoantibodies, hypergammaglobulinemia, and interface hepatitis in liver biopsy.Nonspecific fatigue is the most common symptom and may include anorexia, weight loss, muscle and joint pain, jaundice, and amenorrhea.Low-grade fever and rash are rare. 20 Asymptomatic AIHPatients who met the diagnostic criteria for AIH but showed no symptoms with elevated liver enzyme accounted for 25-37% of patients with AIH. 19,21In patients with asymptomatic AIH, liver enzyme elevation can improve spontaneously, and in a previous study, symptoms presented in 25.8%, and the average period until symptom onset was 2.00 ± 2.46 years. 22,23Compared to symptomatic AIH patients, asymptomatic AIH patients showed no difference in terms of age, sex ratio, disease progression, and histological findings, however, significantly lower level of liver enzyme elevation and immunoglobulin G (IgG). 24In a Canadian study, asymptomatic AIH patients had no significant difference in 10-year survival when compared with AIH patients with symptoms (80% vs. 83.8%,P=0.8). 22