Monitoring of hematopoieticrecovery and cytotoxic activity of NK-cells after allogeneichematopoietic cell transplantation.

Overview

Successful allogeneic haematopoietic stem cell transplantation (HCT) requires a rapid recovery ofhaematopoiesis and NK-cell cytotoxicity. The aim of our study was to investigate a dynamic of thisrecovery in 35 patients who underwent HCT in the very first weeks after transplantation. Samples ofperipheral blood were investigated in 6 weeks intervals starting from the day +16 until the release ofa patient from hospital to outpatient care (the day +38). Flow cytometry to investigate subpopulationsof leucocytes and nonradioactive Europium release assay using K562 cell line as target cells toappreciate NK-cell cytotoxicity were used. TheNK-cell cytotoxicity reached the level of healthy personson average in the day +22. No statistically significant differences in the recovery of CD3+, CD4+, CD8+and CD56+ cells were observed when the group of transplanted patients suffering from acute graftversus host disease (GvHD) was compared to that with no signs of post-transplant immune reactions.A significantly higher percentage of CD8+ cells were found in the GvHD group of patients on the day+22 (p = 0.009) and +28 (p = 0.03), respectively compared the non-GvHD group of patients; however,differences in the NK-cell cytotoxicity did not reach statistical significance. By comparing recipientsreceiving a bone marrow with those transplanted with peripheral blood stem cells, a statisticallysignificant faster recovery of theNK-cell cytotoxicity was observed on the day +16 after transplantation.

Key words:
blood and immune cells recovery, graft versus host disease, haematopoietic stem celltransplantation, NK-cell cytotoxicity