Abstract
Sixty‐six B‐cell lymphoma patients were treated with a CHOP‐based chemotherapy containing rituximab (R‐CHOP‐like regimen). Immune reconstitution was assessed by measuring lymphocyte subsets and immunoglobulins. Fifty‐five patients (83.3%) underwent six cycles of the R‐CHOP‐like regimen. CD19^+^ and CD20^+^ cells were completely eliminated from the peripheral blood after one cycle of the R‐CHOP‐like regimen; they were detected again 6 months after the therapy. One year after the therapy, B‐cell numbers recovered to their level at diagnosis and almost doubled 2 years after the therapy. The lowest numbers of CD3^+^, CD8^+^ and CD56^+^ cells were seen after three cycles of the regimen, but continued to increase until 1 year after the therapy, remaining stable thereafter. CD4^+^ T‐cells were at their lowest after six cycles of the regimen and recovered slowly for 2 years after the therapy; however, their numbers were still lower than that at diagnosis. Immunoglobulins decreased over six cycles of the R‐CHOP‐like regimen and then recovered gradually for 2 years after the therapy. The percentage of IgG, IgA and IgM 2 years after the therapy compared with those at diagnosis was 93.9%, 90.1%, 76.3%, respectively. Twelve infectious complications occurred which consisted of three febrile neutropenia, three Herpes Zoster, two tympanitis, two Pneumocystis jiroveci pneumonia and two hepatitis B virus reactivation. B‐cells required 1 year and CD4^+^ T‐cells and immunoglobulins needed 2 years to recover after the therapy. Copyright © 2010 John Wiley & Sons, Ltd.