为了研究 IgA 亚型的抗-v-raf murine sarcoma viral oncogene homologue B1 (BRAF) 抗体，检测类风湿性关节炎（RA）患者的血清样品，以探究其在 RA 中的临床意义。从61名RA患者、21名骨关节炎（OA）患者、16名全身性红斑狼疮（SLE）患者、16名痛风患者、16名干燥综合征（SS）患者和22名健康对照中获得血清样品。采用酶联免疫吸附试验（ELISA）检测血清中的 IgA 亚型的抗-BRAF 抗体水平。评估 RA 患者中 IgA 亚型的抗-BRAF 抗体水平与年龄、病程以及红细胞沉降速率（ESR）、C-反应蛋白（CRP）、类风湿因子（RF）、28关节疾病活动评分（DAS28）、抗环瓜氨酸肽（anti-CCP）抗体、免疫球蛋白和 BRAF 蛋白水平等实验室指标之间的关联。数据分析使用 SPSS 19.0 软件进行。RA 患者血清中的 IgA 亚型抗-BRAF 抗体水平显著高于SLE、痛风、OA 患者和健康对照组，分别的P值分别为0.011、< 0.001、< 0.001 和 < 0.001。SS 患者血清中的 IgA 亚型抗-BRAF 抗体水平也显著高于SLE、痛风、OA 患者和健康对照组，分别的P值分别为0.029、0.004、0.001 和 < 0.001。然而，RA 和 SS 患者之间没有差异（P=0.762）。在没有RF、anti-CCP 抗体或抗角蛋白抗体（AKA）的 RA 患者中，可测量到 IgA 亚型的抗-BRAF 抗体。 RA 患者中的 IgA 亚型抗-BRAF 抗体水平与年龄、病程以及ESR、CRP、RF、DAS28、anti-CCP 抗体、免疫球蛋白和 BRAF 蛋白水平等临床特征及实验室指标之间没有相关性。与年龄、病程、ESR、CRP、RF、DAS28、anti-CCP 抗体、免疫球蛋白或 BRAF 蛋白水平在正常和升高的 IgA 亚型抗-BRAF 抗体组之间的比较中，RA 患者并无显著差异。升高的 IgA 亚型抗-BRAF 抗体水平表明 IgA 亚型抗-BRAF 抗体可能在 RA 的发病机制中起到一定作用。此外，对血清阴性的 RA 患者进行 IgA 亚型抗-BRAF 抗体检测，可能对血清阴性的 RA 患者的诊断有帮助。

To detect serum IgA isotype of anti-v-raf murine sarcoma viral oncogene homologue B1 (BRAF) antibody levels in the rheumatoid arthritis (RA) patients in order to investigate their clinical significance in RA.Serum samples were obtained from 61 RA patients, 21 osteoarthritis (OA) patients, 16 systemic lupus erythematosus (SLE) patients, 16 gout patients, 16 Sjögren's syndrome (SS) patients and 22 healthy controls. IgA isotype of anti-BRAF antibody levels in the sera were examined by enzyme-linked immunosorbent assay (ELISA). The associations between IgA isotype of anti-BRAF antibody levels and the clinical features including age, disease duration and laboratory parameters including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), disease activity score in 28 joints (DAS28), anti-cyclic citrullinated peptide (anti-CCP) antibody, immunoglobulin and BRAF protein levels in the RA patients were evaluated. Data analyses were performed by using SPSS 19.0 program.The serum IgA isotype of anti-BRAF antibody levels in the RA patients were significantly higher than in the SLE, gout, OA patients and healthy controls, the P value was 0.011, < 0.001, < 0.001 and < 0.001, respectively. The serum IgA isotype of anti-BRAF antibody levels in the SS patients were also significantly higher than in the SLE, gout, OA patients and healthy controls, the P value was 0.029, 0.004, 0.001 and < 0.001, respectively. However, there was no difference between the RA and SS patients (P=0.762). IgA isotype of anti-BRAF antibody was measurable in the RA patients without RF, anti-CCP antibody or anti-keratin antibody (AKA) antibodies. The levels of IgA isotype of anti-BRAF antibody in the RA patients did not show any correlation with clinical features such as age and disease duration or laboratory parameters including ESR, CRP, RF, DAS28, anti-CCP antibody, immunoglobulin and BRAF protein levels. Compared with the clinical features and laboratory indexes of normal and elevated levels of IgA isotype of anti-BRAF antibody groups in the RA patients, there was no significant differences between the two groups in age, disease duration, ESR, CRP, RF, DAS28, anti-CCP antibody, immunoglobulin or BRAF protein levels.The elevated level of IgA isotype of anti-BRAF antibody in the RA patients showed that IgA isotype of anti-BRAF antibody might play a role in the pathogenesis of RA. Furthermore, detection of IgA isotype of anti-BRAF antibody in the serum negative RA patients showed that it might be helpful for the diagnosis of the serum negative RA patients.