P-19 ANTI-RIBOSOMAL P (ANTI-P) ANTIBODIES IN AUTOIMMUNE HEPATITIS PATIENTS

Abstract

Few studies have investigated the occurrence of anti-ribosomal P antibody (Anti-P) in autoimmune hepatitis (AIH) with controversial results. The rational to evaluate this occurrence is based on the partial overlap of clinical and pathological features of AIH and systemic lupus erythematosus (SLE), for which anti-P is a diagnostic biomarker. In face of the controversial results obtained, this study aimed to contribute by evaluating the frequency of anti-P determined by two different immunoassays in a cohort of AIH patients. One-hundred seventy-seven patients with AIH confirmed diagnosis were screened, and 142 were evaluated for the presence of anti-P antibodies. Samples were analyzed by two different immunoassays, namely enzyme-linked immunosorbent assay (ELISA) and chemiluminescence (CLIA). Positive samples were submitted to western blot assay (WB). A comparison was done with a group of 60 SLE patients. Anti-P was found in 5/142 AIH patients (3.5%) using CLIA. No AIH patient was anti-P-positive using ELISA. Among the five positive AIH samples, one was negative, two weakly positive, and two were anti-P-positive in WB. Anti-P was found in 10/60 SLE patients (16.7%) and presented higher CLIA units than AIH samples. Anti-P antibody was confirmed to occur in AIH at a low frequency and serum levels were lower than those observed in SLE. This marker seems not to be useful as a diagnostic tool for AIH patients.