[Significance of the detection of anti-v-raf murine sarcoma viral oncogene homologue B1 antibodies in the diagnostic practice of rheumatoid arthritis].

OBJECTIVE

To clarify the clinical significance of the antibody against v-raf murine sarcoma viral oncogene homologue B1 (BRAF) in the diagnostic practice of rheumatoid arthritis (RA).

METHODS

In the study, 112 patients with RA, 112 patients with other rheumatic diseases,and 73 healthy individuals were recruited . With recombinant human BRAF protein as antigen, we examined the level of anti-BRAF antibody in all the patients by enzyme-linked immunosorbent assay(ELISA), The clinical data of the RA patients were collected simultaneously, and analysed statistically by using SPSS 13.0.

RESULTS

The positive rate of anti-BRAF antibody was 53.6% in the RA patients, which was significantly higher than that of the normal control group (4.1%,P<0.01)and other rheumatic diseases groups (P all<0.01)except osteoarthritis group. The titer of anti-BRAF antibody was also notably higher in the patients with RA than in other rheumatic diseases and normal control groups(P all <0.01).The diagnostic sensitivity and specificity of anti-BRAF antibody for RA were 53.6% and 84.3% respectively. The positive rate of anti-BRAF antibody in rheumatoid factor, anti-cyclic citrullinated peptide antibody, antikeratin antibody,antiperinuclear factor negative groups were 52.6%,38.2%, 30.3% and 31.0%respectively. It showed significant negative correlation between the titer of anti-BRAF antibody and patient's age, disease duration and the level of CRP.

CONCLUSION

The anti-BRAF antibody contributes to the diagnosis of RA, and may act as a supplement of other autoantibodies.