ANTIBODIES TO SINGLE-STRANDED AND DOUBLE-STRANDED DNA IN ANTINUCLEAR ANTIBODY-POSITIVE TYPE 1-AUTOIMMUNE HEPATITIS

To determine the significance of antibodies to single-stranded (anti-s sDNA) and double-stranded DNA (anti-dsDNA) in antinuclear antibody (AN A)-positive type 1 autoimmune hepatitis, sera from 53 patients were te sted by enzyme immunosorbent assay (ELISA) and indirect immunofluoresc ence using the Crithidia luciliae substrate. Anti-dsDNA were detected in 18 patients (34%) by ELISA and 12 patients (23%) by the Crithidia-b ased assay. Twenty patients with anti-dsDNA by either assay (38%) had higher serum levels of immunoglobulin G (3971 +/- 270 mg/dL vs. 3201 /- 247 mg/dL, P =. 05) than seronegative patients. They also had human leukocyte antigen (HLA) DR4 more commonly than other patients (83% vs . 41%, P = .006) and normal subjects (83% vs, 30%, P = .00007), In con trast to patients seropositive by the Crithidia-based assay, those ser opositive by ELISA failed corticosteroid therapy more commonly (24% vs . 3%, P = .04). Anti-ssDNA were found in 45 patients (85%) and they di d not distinguish patients with different clinical features or outcome s. We conclude that anti-dsDNA are common in ANA-positive type 1 autoi mmune hepatitis. HLA DR4 is associated with their production, and sero positivity by ELISA characterizes patients who have a poorer immediate response to corticosteroid treatment. Anti-ssDNA are common but they do not have important clinical implications.