Infections in patients taking Rituximab for hematologic malignancies: two-year cohort study

Background: Rituximab (R) is a chimeric human-murine anti-CD20 monoclonal antibody used to treat B-cell lymphomas. Despite R remarkable activity against malignant cells, there are concerns that R may facilitate the occurrence of infections. This study is aimed to define risk factors for infections, and the potential interaction with time since therapy, in patients undergoing R containing regimens. Methods: The study has been designed as a multiple failure events historical cohort including all patients who received a R contain regimen at London Royal Free Hospital between May 2007 and April 2009. Result: One-hundred-eighty-one infections occurred among the 113 enrolled patients (overall incidence rate 3.30 per 1000 person-days). Multivariate analysis showed that lymphocyte counts at nadir, graft versus host disease, HIV sero-status and the type of malignancy were all independently associated with the risk of infection. In addition the analysis of the interaction with the time since the start of therapy provided evidence that different risk factors may increase risk of infections in different times. Conclusion: This study provides preliminary data to describe the association between several patients' baseline characteristics and infections during therapy with R.