Impact of Rituximab Therapy on Response to Tetanus Toxoid Vaccination in Kidney-Transplant Patients

Abstract

Objectives: Rituximab is used after kidney transplant to prevention or treat kidney-allograft rejection. However, the impact of rituximab on the ability of patients to respond to tetanus toxoid vaccination has not yet been studied.

Materials and Methods: The response to tetanus toxoid vaccination was analyzed in 39 kidney-transplant recipients immunosuppressed by corticoids, antiproliferative agents, and/or calcineurin inhibitors. Thirteen patients had previously received rituximab (group 1), 26 patients had not (group 2). Response to control bacterial antigens and immunologic parameters (lymphocyte count, B-cell subsets, serum immunoglobulin level) were analyzed before and at 1 month after vaccination. Thirty healthy blood donors were used as controls for the before-vaccination immunologic parameters.

Results: Before vaccination, neither patient group differed from controls in serum levels of immunoglobulins and antibodies against bacterial antigens, but they did display lower levels of CD4 T cells and B cells compared with controls. Responders to the tetanus toxoid vaccination were slightly fewer in group 1 (4/13) than in group 2 (16/26), but the intensity of the anti-tetanus toxoid response was not significantly different between these 2 groups. None of the parameters studied at the time of vaccination (anti-tetanus toxoid level, peripheral B or CD4 T-cell count, memory B-cell subsets, treatment with rituximab, time since transplant) were associated with an ability to respond to vaccination. The ability to respond to vaccination and graft outcomes were not correlated in each patient group.

Conclusions: Rituximab impaired the secondary immune response after tetanus toxoid vaccination, but did not abolish it in all patients.