Patients with early rheumatoid arthritis treated with methotrexate had remaining pain, despite a good response to treatment, according to a study by researchers from the Karolinska Institute in Stockholm.
Researchers studied 1,640 patients with rheumatoid arthritis (RA) from the Epidemiological Investigation of RA cohort who had follow-up data in the Swedish Rheumatology Quality Register (SQR). At the time of diagnosis, 76% of SQR registrants (1,241 patients) were treated with methotrexate as the sole disease-modifying anti-rheumatic drug.
Pain in the prior week was recorded on the VAS at the time of diagnosis and after 3 months following treatment. Researchers obtained patients’ DAS28, patient global assessment (PGA), and health assessment questionnaire (HAQ) scores, smoking status and the presence of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies. A C-reactive protein (CRP) level of 10 g/L or less was used to define low disease activity. Follow-up data at 3 months was available for 1,063 patients who initiated treatment with methotrexate.
A good response to treatment was observed in 40% of the cohort, and a moderate response was recorded in 38% of patients, while 23% had no response. Pain on the VAS of greater than 20 mm at 3 months was present in 29% of patients with a good response, 70% of patients with a moderate response and 83% of patients with no response to treatment.
Analysis showed remaining pain in patients treated with methotrexate was associated with age, higher disability on the HAQ, higher PGA scores, higher tender joint counts, higher CRP levels and higher DAS28 scores at baseline.
The adjusted odds ratio for remaining pain in good responders was 2.2 for patients with more disability at baseline, while current smoking, positive RF or anti-CCP was not.
Low inflammatory activity combined with a VAS of greater than 20 mm at 3 months was observed in 37% of patients, which was associated with high baseline HAQ, CRP, PGA, total joint count and erythrocyte sedimentation rate following adjustments for age and sex. – by Shirley Pulawski
Disclosure: The researchers report funding from the European Union Seventh
Framework Programme (FP7/2007 - 2013) under grant agreement no 602919, the Swedish
Research Council, the Swedish Council for Health, Working Life and Welfare, the Swedish
Rheumatism Association, the IMI supported project BeTheCure and the Swedish Strategic
Foundations for Research. The funders had no role in study design, data collection, and analysis.