Bethke M, Varga G, Weinhage T, et al. - In this study, researchers focused on patient parameters and response following administration of rituximab in pediatric mature B-cell non-Hodgkin lymphoma. The observed impacts of rituximab use on patient's immune response aid in understanding the biology behind tumor defense mechanisms and effector function.

• Rituximab has been tested for its therapeutic effect in pediatric patients in the current clinical trials, while the mechanism of action in vivo is still not completely understood.

• Prior to and at day 5 following rituximab treatment, effector molecules essential for tumor defense were evaluated using flow cytometry.

• Post-rituximab treatment, there was a decrease of Fcγ receptor (FcγR) II levels in monocyte subtypes, whereas a significant increase was evident in FcγRI expression.

• Post-treatment, serum concentrations of proinflammatory marker proteins S100A8/A9 and S100A12 significantly reduced to normal levels from an overall proinflammatory state prior to treatment.

• A post-treatment reduction of CD57, perforin, and granzyme B expression, comprising a less cytolytic natural killer cell population, was evident.