O1–069 - Influence of Rituximab Plus Bendamustine Chemotherapy on the Immune System in Lymphoma Patients

Abstract

Purpose: This research evaluated the influence of rituximab plus bendamustine(RB) chemotherapy on the immune functions in lymphoma patients. Patients and Methods: Twenty one patients with relapsed indolent B-cell or mantle cell lymphoma(MCL) received rituximab 375 mg/m2 on day 1 and bendamustine 60 or 90 mg/m2 on day 2 and 3 intravenously in every 3-4 weeks for 3 to 6 cycles (median 5) between January 2011 and January 2013. Of those, thirteen patients were evaluated in this study. Six were at first relapse and seven were at 2nd or later relapse. All patients had been received rituximab with CHOP (n = 9) or other chemotherapeutic regimens (n = 4) in prior therapy. The median age was 67(53–77) years. Before and after 0, 3, 6, 9 and 12 months periods of RB completion, lymphocyte subsets(CD3, CD4, CD8, CD20 positive cell counts and CD4/8 ratio) and serum immunoglobulin(Ig) G, A, M level were examined. Results: CD4 +, CD8+ cell counts and median CD4/8 ratio before RB were 24-512(median; 201), 14-1310(147) cells/&mgr;l and 1.03(0.23-2.75), respectively. Those were 25-83(53), 24-531(240), 0.22 (0.07-1.01) at completion of RB and 96-275(182), 169-1382(348), 0.53 (0.14-0.85) at 6 months after RB. Although CD4+ and CD8+ cells recovered to 50.6-365.7(131.4) and 128-2715(409) at 12 months after RB, CD8+ cell increased faster than CD4+ cell and the CD4/8 ratio did not reach 1.0. The median IgG level before RB was 625mg/dl. It slightly decreased to 572 mg/dl at completion and 536mg/dl at 12 months after. Conclusion: CD4 + cell recovered to 70% level of pre RB counts and IgG decline was mild in RB chemotherapy. In this small study the influence of RB on immune function seemed to be smaller than those with R-CHOP in patients with DLBCL (reported in the 9th JSMO annual meeting). Larger scale research is required to evaluate an influence on immune function in RB chemotherapy.