Introduction Despite engraftment and function of graft after hematopoietic stem cell transplantation severe immune suppression is a characteristic of early posttransplant period. Primary parameters contributing to posttransplant immunoincompetence include: lack of sustained transfer of donor antigen specific immunity, recapitulation of immunological ontogeny effect of graft-versus-host disease (GvHD) and its therapy and reduction of the recipient's thymic function. Normal immune reconstitution following allogeneic hematopoietic stem cell transplantation (HSCT) Immune reconstitution following allogeneic HSCT depends on the age of recipient initial pathology, degree of HLA and minor histocompatibility antigen mismatches, T-cell depletion and use of anti-T-cell antibodies for conditioning and prevention of GvHD, posttransplant complications such as acute and chronic GvHD, relapse of disease and infectious status of the donor and recipient prior to transplantation. Tests for studying immune reconstitution following allogeneic transplantation most often used are cutaneous tests of delayed hypersensitivity, phenotyping of blood mononuclear cells and investigation of their functions, production of antibodies (IgG, IgM and IgA) and cytokines such as IL-2, TGF-a, TNF-a or IL-10, study of TCR, mixed leukocyte reaction toward allogeneic cells CD4/CD8 ratio and others. New tools for assessment of immune reconstitution after HSCT New methods and techniques for monitoring immune reconstitution are as follows: ELISPOT assay quantifies secretion of cytokines by T lymphocytes, analysis of the T-cell receptor (chain diversity during immune reconstitution by IMMUNOSCOPE/SPECTRATYPING method, and TREC technology that detects recent thymic emigrants in peripheral blood. Conclusion Usage of above-mentioned contemporary techniques makes it possible to assess and monitor the dynamics of immune reconstitution especially reconstitution of T-cell diversity, thymic function and antigen-specific T-cell response following HSCT.
The Different Extent of B and T Cell Immune Reconstitution after Hematopoietic Stem Cell Transplantation and Enzyme Replacement Therapies in SCID Patients with Adenosine Deaminase Deficiency