ABSTRACT
Autoimmune hepatitis [AIH] is an unresolving inflammation of the liver of unknown cause associated with interface hepatitis on histological examination, hypergammaglobulinemia and presence of circulating autoantibodies. Antibody-mediated tissue injury might be responsible for tissue injury in AIH therefore; a number of studies have been focused on the complement system in these patients. The aim of the study is to estimate the level of complement [C3 and C4] in different types of Autoimmune hepatitis [AIH]. The study was performed on 73 Iraqi patients with autoimmune hepatitis [AIH], attending the teaching hospital for gastroenterology and liver disease in a period between November 2003 and July 2004: Anti- soluble liver ANA, SMA.LKM-1, and LC-1 Abs were detected using Enzyme-Linked Immunosorbent Assay [ELISA] technique. Anti-SLA/LP was detected using the Euroline method. Quantitation of serum C3 and C4 of the study groups were carried by single radial immudiffusion [SRID] test. Equal volume. Significant differences was observed between AIH patients and healthy control group in the mean level of C3 and C4. In addition, level of C4 in the sera of patients with type 2 was lower than those of type 1 and 3. It was concluded that patients with AIH do not have abnormal catabolism of complement or increased level of cleavage products of C3, whereas, the depression of complement level may reflect decreased hepatic synthesis