Reassessement of the histological features of autoimmune hepatitis.

AIH is considered "likely" when there is a predominantly portal lymphoplasmacytic hepatitis with more than mild interface activity and/or more than mild lobular hepatitis and in the absence of histological features suggesting other liver diseases. Criteria for lobular hepatitis may be less stringent than those for portal hepatitis, as the differential diagnosis for severe lobular hepatitis besides acute AIH would include DILI and idiopathic hepatitis, for example, seronegative acute liver failure, conditions that often have lymphoplasmacytic infiltration at least focally and may easily meet the criteria of likely AIH. For the "portal hepatitis pattern", they include the degree of interface hepatitis, the degree of lobular hepatitis and the presence of histological features suggestive of other liver diseases; for the "lobular hepatitis pattern", they include lymphoplasmacytic infiltrates, interface hepatitis, portal-based fibrosis and histological features suggestive of other liver diseases. Autoimmune hepatitis (AIH) is a progressive inflammatory disease characterised by a female preponderance, elevated transaminase and immunoglobulin G (IgG) levels, non-organ-specific autoantibodies, inflammatory histology and a dramatic response to corticosteroids. [Extracted from the article]