Study Of NK Cell Receptor Repertoire And Function Reconstitution In Patients With Chronic Myeloid Leukemia Following Allogenetic Peripheral Blood Stem Cell Combined With Bone Marrow Transplantation.

Objective To observe the NK cell receptor repertoire and function reconstitution after allogenetic peripheral blood stem cell combined with bone marrow transplantation (allo-PBSCT+BMT) of chronic myeloid leukemia (CML) patients.Methods Flow CytoMeter was used to measure NK cells and NK cell receptor repertoire reconstitution of 11 patients of CML following HLA 6/6 coincidence allo-PBSCT+BMT in different intervals. PBMCs was collected from the dornors and from patients at engraftment and monthly thereafter in the following year after allo-PBSCT+BMT, NK cell cytotoxicity against K562 cell line was evaluated in a standard 4-hour 51Cr release assay.Results NK cells reached normal level while engraftment and ascended to peak at 30 days after transplantation (+30d) which was about (37.1±7.06) % of lymphocyte. Then the NK cells declined gradually and keep steady after +60d. NKP46 reached (92.1±33.65) % of NK cells and it reached the normal value. NKG2D is (36.7±14.33) % of NK cells when engraftment and it ascended thereafter and it reached normal at +60d. NKG2A was at a high level that was (90.3±15.35) % when engraftment but it descended quickly at +60d that was (48.5±12.36) %. CD158a was at a low level the whole year along after transplantation. CD158b was at a normal level when engraftment and it ascended gradually and reached (58.5±6.58) % at +60d. CD94 maintained a high level in whole year after transplantation. The activity of NK cells achieved normol value at engraftment and exceeded normol at +30d after allo-PBSCT+BMT.Conclusion NK cells and NK cell receptor repertoire may be of much importance after allo-PBSCT+BMT owe to its unique reconstitution rule. NK cell activity recovered promptly after allo-PBSCT+BMT.