Incidence of pneumonitis in patients with non-Hodgkin lymphoma receiving chemoimmunotherapy with rituximab.

Rituximab is a monoclonal anti-CD20 antibody that is standard of care for treatment of B-cell non-Hodgkin lymphoma (NHL). The purpose of this study was to quantify the incidence of rituximab (R)-related interstitial pneumonitis (IP) in patients with NHL receiving immunochemotherapy. All patients with NHL who received cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP), cyclophosphamide, vincristine and prednisone (CVP), R-CHOP or R-CVP in Princess Margaret Hospital between June 1998 and August 2009 were retrospectively reviewed. We compared cohorts of patients who did and did not receive R and documented the incidence of IP during and/or post-treatment. In total 560 patients were included in this analysis. The rate of IP in the entire cohort was 2.9% (16/560) with a trend toward a higher rate in the R group (3.95% vs. 1.3% [odds ratio 3.1, 0.84-17.27, p = 0.074]). Baseline pulmonary computed tomography abnormalities in patients with lymphoma are relatively common. The addition of R to chemotherapy does not significantly increase the risk of symptomatic chemotherapy-related IP.