Smoking Doesn't Influence Rituximab Responses in Rheumatoid Arthritis Save

Alcohol, smoking and obesity have all been shown to influence the risk and activity of rheumatoid arthritis (RA) and may also influence response to therapy. This study assesssed whether smoking would influence response to rituximab (RTX) in RA. 

A cohort of leading European rheumatologists drew data from the CERERRA international RTX cohort receiving the first treatment cycle. The study included smokers (n = 528) and non-current smokers (n = 1953).

The baseline characteristics of the groups were different at baseline as , smokers were more often rheumatoid factor (RF)/anti-citrullinated protein antibody (ACPA) positive and males, had shorter disease duration, lower DAS28 and Health Assessment Questionnaire (HAQ) score, a higher number of prior biological disease-modifying anti-rheumatic drugs, and were more likely to receive concomitant conventional synthetic disease-modifying anti-rheumatic drug (csDMARDs)  (Leads you to think that maybe tobacco or other factors influence a more difficult to reteat cohort).

When analyzing response to RTX at 6 mos., disease activity decreased less in smokers at 6 months (ΔDAS28 = 1.5 vs 1.7, p = 0.006), although the difference was no longer significant after correction for baseline DAS28 (p = 0.41).

EULAR good response rates did not differ between smokers and non-smokers overall or stratified by RF/ACPA status, although smokers had lower good response rates among seronegative patients (ACPA-negative: 6% vs 14%, RF-negative: 11% vs 18%).

Smoking did not predict EULAR good response [odds ratio (OR) = 1.04, 95% confidence interval (CI) = 0.76-1.41]. Yet ACPA, DAS28, HAQ, and csDMARDs use were significant predictors for good response.

In this multinational RA cohort, smokers differed from non-smokers by having shorter disease duration and lower disease activity, and more previous treatments. These results do not support smoking as an important predictor for response in RA patients treated with RTX (after other csDMARDs and biologics).