Autoantibodies associated with autoimmune liver diseases

Serum autoantibody (auto-Ab) testing is useful for diagnosing autoimmune hepatopathies (AIH). This test is performed by indirect immunofluorescence (IFI) on triple substrate, and may be supplemented by other techniques. Among 167 requests for testing for auto-Ac associated with HPAI, triple substrate IFI was positive in 19 cases (11.4%), with anti-mitochondria Ac detected in 14 cases (8.4%) and anti-smooth muscle Ac in 5 cases (3%). IFI on VSM47 identified anti-actin F antibodies in 3/5 cases. Immunodot confirmed the positivity of anti-mitochondria Ac in all 14 cases detected by IFI, with or without identification of other associated auto-Ac. What’s more, immunodot, performed despite IFI negativity in 43 cases, was positive in 13 cases/43. Thus, at least one Ac was positive in 32/167 patients (19.2%), 17 of whom had a serological profile in favor of primary biliary cirrhosis, and 9 of whom had a profile in favor of type 1 autoimmune hepatitis. The positivity of these auto-Ac should be interpreted according to the clinical context. Liver biopsy may be indicated to confirm the diagnosis of one of the HPAI entities.