CD26+ (dipeptidyl peptidase IV positive) Cells In Harvest Material For Multiple Myeloma Autotransplantation

Dipeptidyl peptidase IV(DDP IV) known as CD26 can play a role in the process of mobilization as well as in regeneration during hematopoietic cells transplantation. As we know from the studies conducted in vitro and in animals models DDP IV inactivates chemokine CXCL12 (stroma direct factor 1) causing interruption the connection between marrow stoma and hematopoietic cells through CXCR4 receptor.In physiological conditions on the surface of hematopoietic cells concentration of CD26 is low.The purpose of this study was to examine a correlation between the number of CD26+ and CD34+ cells collected during mobilization in multiple myeloma (MM)patients (pts) and investigate the expression of CD26+ on monoclonal cells’. The second purpose was to examine whether CD34 cells have expression of CD26 parallel.30MM pts were mobilized in our department between 2011-2013. For harvest intermediate dose of cyclophosphamid and G-CSF were administered. The number of CD26+ cells and CD34+ cells were measured using immunophenotyping method before starting the procedure in peripheral blood and in collected materialResults All pts collected sufficient for AutoHCTnumber of CD34+ cells,the medianwas 3,8 (2,05-11,1x10^6/kgb.w.).Before mobilization 49,65% of blood nucleated cells showed CD26 expression while in collected material -79,95%. The CD34+ cells in peripheral blood showed low expression of CD26 – median 4,5%. In thecollected material the expression of CD26in CD34+ cells did not increase –median 2,5%, but the number of CD34+ cells (p=0,0003)increased. On mononuclear cells (monocytes and lymphocytes) there were demonstrated also the increase ofCD26 expression after mobilization chemotherapy and G-CSF (p=0,0002).Conclusion In MM patients after mobilization chemotherapy (cyclophosphamide+G-CSF) statistically significant increase ofnumber of CD26+ cellswere observed. It will be interesting to investigate the role of CD26+ cells during autotransplantation.