Immunological recovery following hematopoietic stem cells transplant for leukemia and lymphoma
Division of Research Immunology/Bone Marrow TransplantationChildren’s Hospital Los Angeles, Keck School of Medicine at University of Southern California, Los Angeles, CA, United States
The process of hematopoietic stem cell transplant is invariably associated with immune deficiency in the peri-transplant period. The immune deficiency is of variable severity and duration. The causative factors can be preexisting immune deficiency due to primary disease and therapy prior to transplant, myelo-ablative and immunosuppressive therapy as part of conditioning regimen for transplant, and post-transplant immunosuppressive therapy to prevent graft-versus-host disease and graft rejection. In transplant recipients, immune deficiency in early post-transplant is quite extensive, involving all immunological components including cellular and humoral immunity, and later on can be limited or selective immune deficiency due to a lacunar defect in the immunological repertoire. The recovery of the immune system post-transplant is dependent upon the type of transplant, type of graft, status and function of thymus, severity and therapy of acute and chronic graft-versus-host disease, and intensity of immunosuppression to maintain chimerism with donor type cells. The process of immune recovery is also dependent on recapitulation of normal ontogeny of lymphoid tissue when selective stem cell graft is given. On the other hand, a very prompt immunological recovery may occur in recipients of unmanipulated PBSC or full marrow transplant who do not receive significant post-transplant immunosuppression. A systematic, periodic assessment of these patients for their immune system, in post-transplant period, is necessary to provide appropriate medical care.
Paper presented at the International Symposium on Predictive Oncology and Intervention Strategies; Nice, France; February 7 - 10, 2004; in plenary session 901 (Immunobiology).