Late-onset neutropenia following primary treatment of diffuse large B-cell lymphoma with rituximab-containing therapy.

Late-onset neutropenia (LON) following rituximab therapy is a recently recognized adverse effect occurring in various clinical settings. However, the true incidence and pathogenesis of this adverse effect are not fully understood. We retrospectively reviewed the medical records of 160 patients with diffuse large B-cell lymphoma (DLBCL) in complete remission (CR) following first-line treatment with rituximab-containing therapy. The incidence of LON was 26.9% (grade 1, 2, 3 and 4) and the incidence of severe LON (grade 3 and 4) was 7.5%. The risk factors for the occurrence of LON were not identified, and overall survival did not differ between patients who developed LON and those who did not. This study suggests that LON is a quite common complication to rituximab therapy. However, more studies are needed in order to elucidate the true mechanism behind and risk factors for LON.