Serum IgG and lymphocyte counts are useful for the early detection of infection in patients receiving bendamustine-rituximab therapy.

Bendamustine-rituximab (BR) therapy has been established as a highly effective regimen for indolent non-Hodgkin lymphoma (NHL). However, patients who receive BR therapy exhibit persistent hypogammaglobulinemia and lymphopenia, resulting in an increased incidence of infections. As a sustained immunosuppressive state is a risk factor for infections, early predictive biomarkers for infections related to BR therapy need to be identified. We retrospectively analyzed 61 patients with indolent NHL who were followed up for 2 years after the end of BR therapy. Progression-free survival was significantly influenced by the incidence of infections. Patients with infections related to BR therapy exhibited persistent hypogammaglobulinemia and lymphopenia. In addition, we determined the cutoff values of serum IgG values and lymphocyte counts for infections using receiver operating characteristic curve analysis. Minimum serum IgG and lymphocyte counts at the first BR treatment cycle were significantly associated with the incidence of infections during and after BR treatment. Furthermore, the development of skin reactions during BR therapy was significantly associated with the incidence of infections after BR therapy. Our study suggested that these values and symptom are predictive biomarkers for infections related to BR therapy. Based on these findings, better management of indolent NHL patients will be possible.