CD200 glycoprotein genotype’s role in the immune response to HLA-identical sibling hematopoietic stem cell transplant: a multicenter retrospective cohort study

Abstract

7 BACKGROUND: Hematopoietic stem cell transplantation is the preferred therapeutic approach with curative potential for several hematological and non-hematological pathologies. CD200 is a glycoprotein part of the immunoglobulin supergene family (IgSF) and its binding to its receptor results in a downregulation of the immune system. There is very little information regarding CD200 polymorphisms, and their biological implications remain unclear. It has been suggested that rs1131199 polymorphism could influence the extent of regulation of the CD200 protein’s function. CD200 polymorphisms association with complications after allogeneic hematopoietic stem cell transplantations for any cause has not been addressed. HYPOTHESIS AND OBJECTIVE: The purpose of this study is to evaluate the association of donor’s CD200 genotype with overall survival in receptors of HLA-identical sibling donor allogeneic hematopoietic cell transplantation during the years 1991-2015 in hospitals where the “Grupo Español de Trasplante Hematopoyético (GETH)” works. Secondary objectives include analyzing the association of donor’s CD200 genotype with acute GVHD development, relapse, transplant-related mortality (TRM) and disease-free survival (DFS) in receptors of HLA-identical sibling donor allogeneic hematopoietic cell transplantation during the same years in the same hospitals. METHODS: For this aim, multicenter retrospective cohort study is designed in which 1091 will be included. Their donors’ CD200 polymorphism rs1131199 (C or G) will be determined via Allelic discrimination. Overall survival and other clinical outcomes will be compared in a group of patients whose donor was homozygous for allele G against a group of patients whose donor was homozygous for the allele C or heterozygous C/G