Autoimmune hepatitis refers to chronic and progressive inflammation of the liver from an unknown cause. The proposed mechanism for the development of autoimmune hepatitis is thought to be the interplay of genetic predisposition, an environmental trigger, and failure of the native immune system resulting in chronic inflammation of hepatocytes and subsequent fibrosis of the liver.
There are two known types of autoimmune hepatitis.
Type 1 is distinguished by the presence of anti-smooth muscle antibodies (ASMA) with or without anti-nuclear antibodies (ANA).
Type 2 autoimmune hepatitis presents with positive anti-liver/anti-kidney microsome (anti-LMK) type 1 antibodies or anti-liver cytosol (anti-LC) type 1 antibodies.
Etiology
There is no specific evidence of the cause. Sixty percent of patients have chronic hepatitis but without serologic evidence of a viral infection. The disease is associated with anti-smooth muscle autoantibodies
Pathogenesis
The current proposition for pathogenesis is thought to be secondary to a failure of immune tolerance in a genetically susceptible individual leading to a T-cell mediated inflammation caused by various environmental triggers. Common triggers include infections, medications, and toxins. Certain human leukocyte antigen (HLA) haplotypes are more susceptible to the development of autoimmune hepatitis. Susceptible alleles are different in different ethnic groups. Among White North Americans and Northern Europeans, susceptible alleles are located on the short arm of chromosome 6, specifically within the region of DRB-1. Nitrofurantoin and minocycline are well-documented culprits of drug-induced autoimmune hepatitis. Tumor necrosis factor-alpha drugs have been more recently linked to autoimmune hepatitis.
There is no specific evidence of the cause. Sixty percent of patients have chronic hepatitis but without serologic evidence of a viral infection. The disease is associated with anti-smooth muscle autoantibodies
The current proposition for pathogenesis is thought to be secondary to a failure of immune tolerance in a genetically susceptible individual leading to a T-cell mediated inflammation caused by various environmental triggers. Common triggers include infections, medications, and toxins. Certain human leukocyte antigen (HLA) haplotypes are more susceptible to the development of autoimmune hepatitis. Susceptible alleles are different in different ethnic groups. Among White North Americans and Northern Europeans, susceptible alleles are located on the short arm of chromosome 6, specifically within the region of DRB-1. Nitrofurantoin and minocycline are well-documented culprits of drug-induced autoimmune hepatitis. Tumor necrosis factor-alpha drugs have been more recently linked to autoimmune hepatitis.
Autoimmune hepatitis refers to chronic and progressive inflammation of the liver from an unknown cause. The proposed mechanism for the development of autoimmune hepatitis is thought to be the interplay of genetic predisposition, an environmental trigger, and failure of the native immune system resulting in chronic inflammation of hepatocytes and subsequent fibrosis of the liver.
There are two known types of autoimmune hepatitis.
Type 1 is distinguished by the presence of anti-smooth muscle antibodies (ASMA) with or without anti-nuclear antibodies (ANA).
Type 2 autoimmune hepatitis presents with positive anti-liver/anti-kidney microsome (anti-LMK) type 1 antibodies or anti-liver cytosol (anti-LC) type 1 antibodies.