RA-33抗体检测在类风湿性关节炎和系统性红斑狼疮中的意义

Anti-RA33 Antibody in Patients with Rheumatoid Arthritis and Systemic Lupus Erythematosus

抗RA－33抗体其抗原表位在拼接小体异质性核RNPC（hnRNP）多肽的A2蛋白上，可见于类风湿性关节炎（RA）、系统性红斑狼疮（SLE）和混合性结缔组织病（MCTD）。用免疫印迹法检测88例RA和73例SLE患者血清，发现其抗RA－33抗体的检出率分别为36．49％和21．90％，两者统计学上有显著差异性（P＜0．05）。在SLE患者抗RA－33抗体和抗U1－RNP抗体及Sm抗体密切相关（P＜0．001），而RA患者无此相关性。因此抗RA－33抗体单独出现对RA的诊断有特异性，伴随U1－RNP和（或）Sm抗体同时出现，提示患有SLE或MCTD。并发现RA－33抗体和RA患者手指的畸形（P＜0．001）及SLE患者滑膜炎严重程度相关（P＜0．01）。

Anti-RA33 antibody was first found in patients with rheumatoid arthritis (RA) by Hassfeld (1989). The epitope of the antigen was in the A2 protein of the heterogeneous nuclear ribonucleoproteins (hn RNP) particle, which was one of the particles of spliceosome. The anti-RA33 antibody can also be spotted in patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD). Sera from 88 patients with RA and 73 patients with SLE investigated by immunoblotting showed that the incidence was 36. 49 % and 21. 9 % respectively (P<0. 05 ). The antiRA33 antibody in patients with SLE correlated closely with U1-RNP antibody (P<0. 001 ) and Sm antibody (P<0. 001 ). But this correlation was not found in patients with RA. This study indicated that the presence of anti-RA33 antibody in the absence of anti U1-RNP and Sm antibody was still specific for RA. RA33 antibody with the concomitant occurrence of U1-RNP and Sm suggest diagnosis of SLE and MCTD. The anti-RA33 antibody also correlated with finger deformities of RA (P<0. 001 ) and severe degree of inflammatory synovitis of SLE (P<0. 001 ).