Normalisation of physical function by infliximab in patients with RA: factors associated with normal physical function.

OBJECTIVES

We conducted a two-year prospective study to identify possible factors associated with normalisation of physical function by infliximab treatment in 125 patients with rheumatoid arthritis (RA).

METHODS

RA patients who had been scheduled to receive infliximab at 3 mg/kg were registered and prospectively examined for disease activity, joint damage, and physical function for 102 weeks using the Disease Activity Score of 28 Joints (DAS-28) using C-reactive protein, van der Heijde-modified Sharp score (vdH-Sharp score) of hand and foot x-ray, and Health Assessment Questionnaire Disability Index (HAQ-DI). Normal physical function and clinical remission were defined as a HAQ-DI of 0.5 or less, and DAS28 (CRP) <2.6, respectively.

RESULTS

Forty-two of 125 patients (42%) achieved normal physical function at 102 weeks. The percentage of normal physical function at 102 weeks was significantly higher in the patients achieving clinical remission at 102 weeks (60%) than in those without (16%). In the patients with clinical remission at 102 weeks, less structural damage at baseline was correlated with a higher rate of normal physical function, suggesting the critical importance of joint destruction prior to infliximab therapy, in addition to clinical response. Logistic regression analysis further identified HAQ-DI, serum MMP-3 level, vdH-Sharp score, and methotrexate (MTX) dose as baseline factors contributing to normal physical function with 2-year infliximab treatment.

CONCLUSIONS

Treatment with anti-TNF biologics in combination with MTX may achieve the normalisation of physical function in patients with established RA. Critical factors contributing to the normalisation of function were tight control of disease activity and less joint damage.