Association of VLA4, 5, 6 and PSGL1 expression levels with engraftment in autologous HPSC transplantation in multiple myeloma patients

The most promising therapy for leukemia is hematopoietic stem cell transplantation. Engraftment of HPSCs mainly depends on some factors such as adhesion molecules, including VLAs. This study tried to delineate the relationship between HPSCs engraftment and expression level of PSGL1 and VLA4, 5, and 6 genes in candidate MM patients for autologous bone marrow transplantation. Firstly, the CD 34+ HPSCs were collected from multiple myeloma (MM) patients after five days of G-CSF therapy through apheresis processes. Then, the patients were categorized into two groups of good and bad prognosis depending on engraftment time (Less or more than 18 days). Followingly, the expression of PSGL1 and VLA4, VLA5, and VLA6 genes were assessed by the qRT-PCR technique in each patient. Finally, the correlation between the genes and engraftment time was investigated to determine the prognostic role of each gene on HPSCs transplantation. Our findings demonstrated that there is a significant correlation between VLA4 (P=< 0.0001) and 5 (P = 0.005) levels and HPSCs engraftment time. As the higher levels of VLA4 and 5, the shorter time HPSCs engraftment occurs. In contrast, there was no significant correlation between VLA6 (P = 0.2) and PSGL1 (P = 0.3) genes levels and engraftment time. So that, the patients with a good prognosis had a higher level of VLA4 and VLA5, but no relation was found between VLA6 and PSGL1. It is concluded that VLA4 and VLA5 expression could be considered a significant prognostic factor for HPSC transplantation.