PB2376 AN INNOVATION IN STEM CELL HARVESTING: HEPARIN

Abstract

Background:GCSF and plerixafor inhibit the CXCL12/CXCR4 interaction on the axis of CXCR4/SDF1; and so they stimulate stem cell mobilization from bone marrow to periphery blood. GCSF activates the compleman cascade and thrombolytic pathway. Finally, it cause SP‐1(syphingosine 1) which is chemoattractant for hematopoietic cells, secretion. At the end, adherence molecules like VCAM gets weak, because of the SDF‐1 gradient decreases in stem cell niches (1). Heparin is a sulphated glycosaminoglycated polymer with 12‐15 kDa mass. İts mechanism of action is inhibiting the factorXa and other proteases via binding ATIII. Heparin is competetive inhibitör of sulphate proteoglycane, heparin inhibits the CXCR4/SDF1 axis, like plerixafor (2). In literatüre, there is a study in which heparin is added for increase the stem cell amount because it mimics the stem cell niches, and heparin increase the osteoprogenitor stem cell differantiation is observed (3).Aims:Plerixafor and GCSF are usually used in mobilization regimens for increase the CD34+ product amount. In this study our aim is observe the effect of heparin on stem cell mobilization. We try to answer whether does heparin can take the role of plerixafor in stem cell harvesting.Methods:We have 46 patients who has done bone marrow transplantation between the years of 2018‐2019 at Inonu University Turgut Ozal Medicine Center Stem Cell Transplantation Unit. All the patients had given intravenously 5000 unit unfractioned heparin in 150 cc isotonic sodium chloride solution in additon to mobilization regimen, 15 minutes before the stem cell harvesting process. Mobilization regimens were different depend on kind of transplantation, like autolog or allogeneic, and patients’ other features.Results:We have 46 patients totally. 26 of them are male (57%) and 20 are female (43%). Mean age is 54,5 (min: 20 and max:75). 43 patients had done autologous stem cell transplantation and 3 patients had done allogeneic stem cell transplantation. 25 of them had multiple myeloma, 10 of them had NHL, 5 had HL, 5 had AML and 1 had testicular cancer as a primary disease. All the patients and donors were successfully harvested hematopoeitic stem cells from periphery in a single cycle. No one had given plerixafor or any other kind of drug other than mobilization regimen plus intravenously heparin. Mean CD34+ cell amount is 9,1 × 106 / kg and 1846, 6 for μl. In literatüre, 2.5 × 106 CD34 + cell /kg is accepted minimal number for successful stem cell harvesting in worldwide (4). But, Target is accepted as 4‐5 × 106 CD34+ cell / kg for successfull harvesting (5‐6). So our result is enough for succesfull stem cell harvesting.Summary/Conclusion:Some molecules which act on SDF and CXCR4 and change the hematopoietic stem cell niches, like GCSF and plerixafor, make the essence of stem cell mobilization. We observed 46 patients who had given 5000 unit unfractioned heparin in additon to proper mobilization regimens without plerixafor or any other kind of drug. All of them has been harvested stem cells succesfully in a single cycle of peripheric stem cell apheresis. Heparin is cost effective and it helps to protect from possible thrombotic complications of apheresis itself indirectly. Heparin is a promising agent for stem cell harvesting procedure.