Background: Despite low-dose gluco-corticoid (GC) treatment, many patients with rheumatoid arthritis (RA) require additional flare therapy with GC at higher doses. Since low dose GC has been suggested to confer resistance to higher doses, we aimed to assess if resistance was detectable on the clinical level in patients with active RA.
Methods: Eighty-nine patients with active RA (Disease Activity Score 28, DAS28>3.2; mean age 54.5 years, mean duration of RA 9.7 years) were consecutively enrolled into a one-week trial of a total of 250 mg prednisolone. We compared improvement of the DAS28 and the Simplified Disease Activity Index (SDAI) in groups of patients with (n=41) and without (n=48) low-dose GC at baseline (by t-test). In addition, we analyzed changes of all individual core set measures of disease activity using multivariate statistics.
Results: All clinical, serological and functional measures improved significantly over one week (p<0.001). Baseline RA activity of patients with and without low-dose GC was on average +/- standard deviation similar among the two groups (DAS28: 4.8+/-1.2 and 4.9+/-1.1; mean SDAI: 26.1+/-14.0 and 25.9+/-13.0, respectively), and likewise there was no difference between the two groups in the final disease activity reached, for both the DAS28 (1.4+/-1.1 vs. 1.1+/-1.0; p=0.14) and the SDAI (11.1+/-13.4 vs. 11.1+/-11.4; p=0.99). Improvement in all individual measures was also not different using a multivariate model (p=0.26).
Conclusion: Pre-treatment with low-dose GC does not appear to portend GC resistance at least clinically, since the responsiveness to GC boosts is unaffected.