서울중앙병원에서 시행된 항핵항체와 가용성 항원 검사 결과의 비교 분석

Abstract

Antinuclear antibodies(ANA) have high sensitiivity for the diagnosis of systemic rheumatologic diseases, but have low specificity relatively. Recently, we have used antibodies to extractable nuclear antigens(ENA) additionally, which enabled us to determine what the ANA detected really were. The purpose of this study was to examine frequencies of autoantibodies and clinical significances of them by analyzing results of ANA, anti–ENA and anti–dsDNA tests. From January，1997 to March, 1998, the sera of 339 patients who were suspectedthat they have systemic rheumatologic diseases and 54 ones diagnozed as systemic lupus erythematosus(SLE) were analyzed by performing ANA, anti–ENA(anti–RNA⁄Sm, anti–SS – A⁄SS – B, anti–Scl70) and anti-dsDNA tests. In 339 patients with suspicious systemic rheumatologic diseases, the concordance rate of positivity between ANA and anti–ENA was 23.6% and that of negativity was 23.3%. The positivity rate of anti-ENA among patients with negative ANA was 0.9%. We detected anti–SS – A⁄Ro in the rate of 41.0%, anti–RNP 16.9%, anti–Sm 2.4%, anti–SS – B⁄La 1.2% and anti–Sc170 14.5% among patients with positive anti–ENA. Among 42 patients with positive anti–dsDNA, there were 32 cases with positive anti–ENA. 17 patients had anti–SS – A⁄Ro, 4 ones anti–Scl70, 3 ones anti–RN⁄jSm. In 54 patients with SLE, the concordance rate of positivity between ANA and either anti–ENA or anti–dsDNA was 72.2%. Among patients with either positive anti–ENA or positive anti–dsDNA, we detected anti–SS – A⁄Ro in the rate of 12.5%, anti–SS – A⁄ dsDNA 32.5% and anti–dsDNA 17.5%. When the titer of ANA is above 1:160 and anti–ENA is negative, the accurate identification of ANA specificity would be essential by using enzyme immunoassay or immunoblotting methods. The 1.9% positivity of anti–ENA among ANA negative SLE patients suggests the possibility of presence of ANA–negative SLE in spite of performing ANA test using HEp–2 cells.