Tetanus immunity in autologous bone marrow and blood stem cell transplant recipients

The aims of this study were to assess long-term immunity and reimmunization responses against tetanus toxoid in recipients of autologous stem cell grafts and to compare immune status in patients who underwent ABMT or autologous blood stem cell transplantation (APBSCT). Ninety patients were included in the study; 52 had received ABMT and 38 APBSCT. Thirty of 52 ABMT patients (58%) and 25 of 38 APBSCT patients (66%) had protective antibody levels against tetanus before transplantation (P = NS). The rate of seropositivity had decreased at 1 year after transplantation; 15 of 52 (29%) ABMT patients and 18 of 38 (47%) APBSCT patients (P = NS) were still positive after 1 year. There were no cases of spontaneous recovery in seronegative patients. Most patients were reimmunized with three doses of tetanus toxoid given at 12, 13, 14 and or 18 months after transplantation. All immunized patients had protective immunity against tetanus at 1 year after vaccination. These results suggest that humoral immunity is defective both after ABMT and after APBSCT and in both cases the loss of immunity seems to be similar. Reimmunization of patients who have undergone ABMT or APBSCT is necessary to obtain protective immunity against tetanus.