Abstract
OBJECTIVE: To determine the value of HLA DR beta 1 disease associated epitope (DAE) and erythrocyte sedimentation (ESR) in predicting the need for major joint replacement in rheumatoid arthritis (RA). METHODS: Sixty five RA patients who had undergone hip, knee or shoulder arthroplasty within 15 years of disease onset and 65 who had not. HLA DR beta 1 genotype was determined by polymerase chain reaction. ESR at first hospital visit was noted. RESULTS: Significantly more patients with two DAE required surgery, (32% v 9%), chi 2 = 13.9, p = 0.001, odds ratio = 5.4 (95% CI: 1.8, 16). Sensitivity was poor, 32%, specificity high, 91%. Presentation ESR was higher in surgery patients compared with non-surgery patients, 52 mm 1st h v 25 mm 1st h, p < 0.001, but was independent of DAE status. Sensitivity of an ESR of 30 mm 1st h was 75%, specificity 53%. CONCLUSION: The presence of two DAE is a risk factor for major joint surgery in RA and is independent of ESR, whereas in those with one or no DAE, a high ESR is an important predictor.