Sixth-month remission as a predictor for twelve-month remission in polymyalgia rheumatica

Objectives: To investigate clinical and laboratory prognostic factors of remission after one year of follow-up in patients with polymyalgia rheumatica (PMR) treated with low-dose prednisone. Methods: In this observational study, in a monocentric Italian Rheumatology Unit, we enrolled eighty-one consecutive PMR patients. Clinical and laboratory tests were performed every 3 months. Clinical remission was defined as the lack of symptoms, while laboratory remission was defined as erythrocyte sedimentation rate ≤40 mm/h and C-reactive protein (CRP) ≤0.5 mg/dl. Results: Thirty-eight patients reached complete (clinical and laboratory) remission after 12 months of follow-up. A significant lower percentage of complete remission was seen in female gender compared to male (33.9 % vs. 78.2%, p=0.0001) at univariate analysis. No significant differences were found at baseline according to response to therapy during follow-up, while CRP values at the sixth month were significantly lower in patients who reached complete remission after one year (median: 0.4 mg/dl vs. 1 mg/dl, p=0.017). CRP<0.5 mg/dl at 6 months was independently associated with complete remission at 12 months in the multivariate analysis. Conclusions: The sixth month of therapy is a target for the management of PMR because it can help to identify patients at greater risk of exacerbations, who may benefit from a tighter follow-up and more aggressive therapeutic strategy. Higher CRP values at 6 months appear to be associated with a higher risk of longer steroid therapy.