Clinical Significance of Cytoplasmic Staining in Antinuclear Antibody Tests Using HEp-2 Cells

Baek, Hyun Moon; Nahm, Chung Hyun; Song, Jung Soo; Park, Won; Moon, Yeon Sook; Kim, Jin Joo

Abstract

BACKGROUND
Cytoplasmic stainings in antinuclear antibody tests using HEp-2 cells are usually undetermined and the significance has not been fully understood until now. Hence, we evaluated their clinical characteristics and also the coexistence of other autoantibodies in the sera with cytoplasmic stainings in antinuclear antibody tests. METHODS: We reviewed clinical records retrospectively in 53 sera showing cytoplasmic stainings among 3, 610 sera that were tested antinuclear antibodies from January to September, 2002 and performed antimitochondrial antibodies (AMA) tests using indirect immunofluorescence (IIF) and antibodies to antiribosomal P and extractable nuclear antigens (ENA) tests using enzyme immunoassay (EIA). RESULTS: Among 53 sera with cytoplasmic stainings, 31 sera showed an AMA pattern and 15 sera showed an antibody to ribosomal P pattern. Three cytoskeletal and one golgi complex patterns were also observed. The most common diagnosis was autoimmune disorders (32, 60.4%) and hepatic disorders (excluding autoimmune hepatitis) (6, 11.3%). Hepatic disorders including autoimmune, drug-induced, and alcoholic hepatitis were most commonly observed (32.3%) in sera with an AMA pattern. On the other hand, various autoimmune disorders such as SLE, systemic sclerosis, dermatomyositis, and polymyositis were observed (86.7%) in sera with a ribosomal P pattern. Of 31 sera with the AMA pattern, the corresponding antibodies were confirmed in three by IIF and of 15 sera with a ribosomal P pattern, only one was confirmed to have this antibody by EIA. All the confirmed sera showed high titered (>1: 320) cytoplasmic stainings. Antibodies to ENA were positive in sixteen (RnP, 5; Sm, 4; Ro, 5; La, 2) and anti-DNA in three of the sera. CONCLUSIONS: Although cytoplasmic staining patterns are not disease specific, it is suggested that continuous high titer stainings be followed up since they could provide diagnostic help.