[Correlation between C reactive protein and erythrosedimentation rate with rheumatoid arthritis disease activity]

To compare the correlation between C reactive protein (CRP) and erythrosedimentation rate (ESR) with rheumatoid arthritis (RA) activity.

Cross-sectional study, in patients with RA. All were assessed by a rheumatologist who evaluated the RA disease activity according to the American College of Rheumatology score. Blood sample was dropped to test CRP and ESR levels. The correlation between CRP and ESR with RA disease activity was estimated using rho Spearman coefficient.

We included 80 patients, mean age of 50.5 +/- 11.0 years. 62.5% had some degree of disease activity. We found that CRP had a high correlation with all parameters of disease activity included: number of tenders joins (r = 0.352, p = 0.001), number of painful joins (r = 0.327, p = 0.003), VAS of join pain (r = 0.385, p < 0.0001), VAS of global disease activity estimated by the patient (r = 0.325, p = 0.003), VAS of global disease activity estimated by the rheumatologist (r = 0.486, p < 0.0001), and HAQ score (r = 0.310, p= 0.005). In contrast the ESR only had correlation with the HAQ score (r = 0.310, p = 0.005).

Our results suggest that CRP is a better test to support the clinical evaluation of disease activity in RA.