What is the prevalence of autoimmune hepatitis (AIH) in the general population?

Prevalence of Autoimmune Hepatitis

The global prevalence of autoimmune hepatitis is approximately 17.44 per 100,000 persons, with substantial geographic variation ranging from 4 per 100,000 in Singapore to 42.9 per 100,000 in Alaskan Natives. 1

Global and Regional Prevalence

• Global prevalence is estimated at 17.44 per 100,000 persons (95% CI: 12.01-22.87) 1
• Regional variations show:
  • Asia: 12.99 per 100,000 persons 1
  • Europe: 19.44 per 100,000 persons (range 15-25 per 100,000) 1
  • North America: 22.80 per 100,000 persons 1
  • United States specifically: 31.2 per 100,000 persons 2

Population-Specific Prevalence

Geographic and Ethnic Disparities

• Alaskan Natives demonstrate the highest documented prevalence at 42.9 per 100,000 persons, with characteristically acute icteric presentations 1, 3
• South Korea reports a prevalence of 4.82 per 100,000 persons (2009-2013 data), which increased from 3.9 per 100,000 in 2009 to 5.76 per 100,000 in 2013 1
• Singapore shows the lowest reported prevalence at 4 per 100,000 persons 1, 3

Gender Distribution

• Female predominance is marked, with women comprising 71-95% of adult cases and 60-76% of pediatric cases 1
• In South Korea, gender-specific prevalence is:
  • Females: 8.35 per 100,000 persons 1
  • Males: 1.30 per 100,000 persons 1
• Female-to-male ratio is approximately 6:1 in most populations 1

Age-Related Patterns

• Peak prevalence occurs in the 60s age group for females (8.35 per 100,000) and in the 70s for males (1.30 per 100,000) in South Korean data 1
• Elderly patients (>65 years) show higher prevalence compared to younger adults, with an odds ratio of 2.51 2
• The disease affects all age groups, from children to the elderly 1

Pediatric Prevalence

• Children demonstrate lower prevalence rates:
  • Non-native Canadian children: 2.4 per 100,000 persons 1
  • Native Canadian children: 9.9 per 100,000 persons 1

Temporal Trends

• Increasing prevalence has been documented over recent decades, with nearly 50% increases reported in Spain, Denmark, Sweden, and the Netherlands since 2000 1
• The incidence in Denmark doubled from 1994 to 2012, reaching a point prevalence of 24 per 100,000 (35 per 100,000 for females) by 2012 1

Clinical Context for Prevalence Interpretation

Important caveat: These prevalence figures likely represent underestimates, as 25-37% of AIH patients are asymptomatic at diagnosis and may remain undetected 1, 4. Additionally, 13-32% of patients already have cirrhosis at diagnosis, suggesting delayed recognition 1. The true prevalence may be higher than reported, particularly in populations with limited access to specialized hepatology care or autoimmune serologic testing.