Autoantibody profiles in autoimmune hepatitis and chronic hepatitis C identifies similarities in patients with severe disease

To determine how the auto-antibodies (Abs) profiles overlap in chronic hepatitis C infection (CHC) and autoimmune hepatitis (AIH) and correlate to liver disease.METHODSLevels of antinuclear Ab, smooth muscle antibody (SMA) and liver/kidney microsomal-1 (LKM-1) Ab and markers of liver damage were determined in the sera of 50 patients with CHC infection, 20 AIH patients and 20 healthy controls using enzyme linked immunosorbent assay and other immune assays.RESULTSWe found that AIH patients had more severe liver disease as determined by elevation of total IgG, alkaline phosphatase, total serum bilirubin and serum transaminases and significantly higher prevalence of the three non-organ-specific autoantibodies (auto-Abs) than CHC patients. Antinuclear Ab, SMA and LKM-1 Ab were also present in 36% of CHC patients and related to disease severity. CHC cases positive for auto-Abs were directly comparable to AIH in respect of most markers of liver damage and total IgG. These cases had longer disease duration compared with auto-Ab negative cases, but there was no difference in gender, age or viral load. KLM-1+ Ab CHC cases showed best overlap with AIH.CONCLUSIONAuto-Ab levels in CHC may be important markers of disease severity and positive cases have a disease similar to AIH. Auto-Abs might have a pathogenic role as indicated by elevated markers of liver damage. Future studies will unravel any novel associations between these two diseases, whether genetic or other.

Historical reflections on autoimmune hepatitis

Autoimmune hepatitis(AIH),initially known as chronic active or active chronic hepatitis(and by various other names),first came under clinical notice in the late 1940s.However,quite likely,chronic active hepatitis(CAH) had been observed prior to this and was attributed to a persistently destructive virus infection of the liver.An earlier(and controversial) designation in 1956 as lupoid hepatitis was derived from associated L.E.cell test positivity and emphasized accompanying multisystem features and immunological aberrations.Young women featured prominently in early descriptions of CAH.AIH was first applied in 1965 as a descriptive term.Disease-characteristic autoantibodies were defined from the early 1960s,notably antinuclear antibody(ANA),smooth muscle antibody(SMA) and liver-kidney microsomal(LKM) antibody.These are still widely used diagnostically but their relationship to pathogenesis is still not evident.A liver and disease specific autoantigen has long been searched for but unsuccessfully.Prolonged immunosuppressive therapy with predisolone and azathioprine in the 1960s proved beneficial and remains standard therapy today.AIH like many other autoimmune diseases is associated with particular HLA alleles especially with the "ancestral" B8,DR3 haplotype,and also with DR4.Looking forwards,AIH is one of the several enigmatic autoimmune diseases that,despite being(relatively) organ specific,are marked by autoimmune reactivities with non-organ-specific autoantigens.New paradigms are needed to explain the occurrence,expressions and pathogenesis of such diseases.