Cellular immunity to vaccinations and herpesvirus infections after bone marrow transplantation

The cellular immune response to herpesviruses was studied in 46 recipients of marrow grafts (23 autologous, 23 allogeneic). That study was performed in vitro by evaluating the degree of lymphocyte proliferative responses to herpes simplex virus (HSV), cytomegalovirus (CMV), and varicella zoster virus (VZV). No primary infections with any of those viruses were noted after bone marrow transplantation (BMT). The incidence of active infection in seropositive patients was significantly lower after autologous BMT than after allogeneic BMT (HSV, 2/22 vs. 11/22 patients, respectively, P = 0.007; CMV, 4/12 vs. 9/10 patients, respectively, P = 0.02; VZV, 3/23 vs. 11/23 patients, respectively, P = 0.02). After autologous BMT, the restoration of cellular immunity to the three viruses occurred at a clearly faster rate than after allogeneic BMT. That pattern may have contributed to the low incidence of active infections with those viruses after autologous BMT. Recipients of allogeneic marrow from donors with a positive lymphocyte proliferation test to HSV had a significantly increased incidence of active HSV infection post-BMT (8/9 patients) than those who received marrow from donors with a negative test (3/13 patients; P = 0.008). Acute or chronic graft-versus-host disease (GVHD) decreased the cellular immune response to the three herpes viruses, but not significantly. Our program of vaccinations with diphtheria and tetanus toxoids started in the fourth month post BMT. Chronic GVHD patients who were vaccinated had a clearly impaired cellular immune response to both toxoids as compared with those without chronic GVHD.