Evidence of Endothelial Bone Marrow Microenvironment Affection in Poor Graft Function Post Allogenic Stem Cell Transplanration

Abstract Allogeneic hematopoietic stem cell transplantation (HSCT) is considered a curative option for several hematological disorders. The prognosis of patients undergoing allogenic (HSCT) is dependable on various factors that affect bone marrow microenvironment and poor prognosis can results from poor graft function. On of these factors is the numbers of CD31+ endothelial cells that support the hematopoietic stem cells. Aim of the Study The aim of this study was to assess how the bone marrow microenvironment is being affected in patients with poor graft function post allogenic stem cell transplantation targeting the endothelial cells using multiparameter flow cytometric analysis of CD31 antibody. Patients and Methods Forty patients were enrolled in this study with both benign and malignant hematological diseases who underwent allogenic HSCT from matched related donors. Patients were divided into 2 equal groups: poor graft function (PGF) group and good graft function group (GGF). Patients were subjected to full history recording, clinical examination, full laboratory and radiological work-up, tissue typing and chemotherapeutic conditioning before transplantation. After transplant, bone marrow aspirate was obtained and analyzed for CD31+ endothelial cells using Quantitative tri-color Flow cytometric assay. Results PGF group showed significantly lower counts of WBCs, platelets and hemoglobin concentration compared to GGF group. In addition, CD34 dose showed significantly lower concentration in PGF group compared to GGF group. PGF group had statistically significant lower percentage of stem cells total count compared to GGF group in addition, PGF Group had a significantly higher mean fluorescence intensity (MFI) of CD31 on non-stem cells compared to GGF group. Conclusion PGF had significant increase in MFI of CD31+ve on non-stem cells compared to GGF group. In addition, PGF group had statistically significant lower percentage of CD31+ stem cells total count compared to GGF group.