Reconsitución inmunológica en niños receptores de trasplantes de progenitores hematopoyéticos
Introduction: Haematopoietic stem cell (HSC) transplantation is a highly efficacious therapy for many onco-haematologic neoplasias and some congenital primary immunodeficiencies and metabolic disorders. Factors which may interfere in post-HSC immunologic reconstitution include: the HSC source (bone marrow (BM), umbilical cord blood (UCB), peripheral blood (PB), type of transplant (autologous or allogeneic), clinical status of the patient prior to transplant, the underlying disease (neoplastic or not), the conditioning regimen used, graft vs. host disease (GVHD) prophylaxis and the development or not of GVHD (acute or chronic) and its therapy.
Objectives: To evaluate the immunologic reconstitution in the different modes of transplants in children and study whether this depends on the underlying disease, type of transplant performed, HSC source and degree of GVHD.
Material and Methods: We studied the reconstitution of lymphocyte T, B and natural killer (NK) subpopulations, T function and humoral response (IgA, IgG, IgM), natural antibody production (antistreptolysine O ASTO) and response to hepatitis B (HBs) and tetanus (anti-toxoid tetanic) vaccines in 61 recipients in the different HSC transplant modalities, at 1, 3, 6, 12, 18 and 24 months post-transplant at the Bone Marrow Transplant Unit of the Hospital Materno-Infantil VallHebron, Barcelona. We analysed the differences in immunologic reconstitution between: a) the three types of sources, BM, PB and UCB; b) autologous and allogeneic transplants; c) patients with neoplastic and non-neoplastic diseases; d) presence or absence of severe or chronic GVHD. The degree of response to vaccines (tetanus and hepatitis B) was studied in relation to immunoglobulin G levels and presence of natural antigens.
Results and Conclusions: UCB and PB are the HSC sources which present the most rapid immunologic reconstitution of lymphocytic subpopulations with respect to BM. No significant differences were observed in the functional recovery of T lymphocytes according to the types of stem cells used, type of transplant performed and the childs underlying disease, although recovery was slower in UCB recipients compared with other sources and in allogeneic HSC recipients compared with autologous recipients. Higher grades (> III) of acute GVHD and chronic extensive GVHD correlated with a delay in immunologic reconstitution due to long-term immunosuppressor treatment. The reconstitution of B lymphocytes was slower than that of T lymphocyte subpopulations. The CD4+/CD8+ ratio appeared inverted throughout the first year of the study due to a reduction in CD4+ T lymphocytes. NK cells always had an early recovery regardless of source used (BM, UCB, PB), type of treatment or underlying disease. Anti-hepatitis B antibody disappeared post-transplant in a greater proportion than anti-tetanus antibodies; furthermore, the post-vaccine response was better after the anti-tetanus vaccine. ASTO production in children over 2 years of age was greater in those who received HSC from BM and PB compared with those who received HSC from UCB and in children who received
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Advisor:Teresa Español Boren
School:Universitat Autónoma de Barcelona
Source Type:Master's Thesis
Keywords:418 departament de pediatria obstetricia i ginecologia
Date of Publication:09/20/2001