Genetic diversity among volunteer donors of bone marrow in southeastern Brazil, according to the HLA system

CONTEXT AND OBJECTIVE: Checking the histocompatibility of the molecules of the human leukocyte antigen (HLA) system is vital for performing bone marrow transplantation with allogeneic material. The objective of this study was to characterize bone marrow donors according to gender, age, ethnicity and HLA groups at a regional hemotherapy center in Brazil.DESIGN AND SETTING:Descriptive study on registered donors at a regional hemotherapy center in a public university hospital in the southeastern region of Brazil.METHODS: The records of 66,780 donors who were registered between 2005 and June 2011 were consulted, and the variables studied were tabulated.RESULTS:There were equal numbers of male and female donors and 82.8% of them were under 45 years of age. In terms of ethnicity, 77.3% declared themselves to be white, 15.0% mixed race, 5.7% black and 2% others. In terms of immunogenetic characterization, the most frequent HLA-A allelic group was HLA-A*02, with 39.20% of the donors; in the HLA-B allelic group, the most common was HLA-B*35, with 14.18%; while in the HLA-DRB1 allelic group, the most frequent was HLA-DRB1*03, with 17.03%. Comparison between these results and data from the Brazilian Bone Marrow Donor Registry (REDOME) showed that there were demographic and immunogenetic differences due to the history of immigration in the region of Ribeirão Preto, in southeastern Brazil.CONCLUSIONS: The results reinforce the importance of understanding the demographic and immunogenic profile of regions of Brazil, in order to reduce the waiting time for a histocompatible donor.

背景与研究目的：人类白细胞抗原（Human Leukocyte Antigen, HLA）系统的组织配型检测是开展异基因骨髓移植的关键前提。本研究旨在巴西东南部某公立大学医院附属区域血液治疗中心，基于性别、年龄、种族及HLA分型对骨髓捐献者进行特征分析。
研究设计与场景：本研究为描述性研究，研究对象为巴西东南部某公立大学医院附属区域血液治疗中心的注册骨髓捐献者。
研究方法：调取2005年至2011年6月间登记的66780名捐献者的档案资料，对纳入研究的变量进行制表统计。
研究结果：男女捐献者人数基本持平，其中82.8%的捐献者年龄低于45岁。种族构成方面，77.3%的捐献者自报为白人，15.0%为混血人种，5.7%为黑人，2.0%为其他种族。免疫遗传特征分析显示，HLA-A等位基因中最常见的为HLA-A*02，占比达39.20%；HLA-B等位基因中最常见的为HLA-B*35，占比14.18%；HLA-DRB1等位基因中最常见的为HLA-DRB1*03，占比17.03%。将本研究结果与巴西骨髓捐献者登记库（REDOME）的公开数据对比后发现，受巴西东南部里贝朗普雷图地区的移民历史影响，该区域人群的人口学与免疫遗传学特征存在显著差异。
研究结论：本研究结果证实，掌握巴西各区域的人口学与免疫遗传特征，对于缩短适配组织相容性捐献者的等待时长具有重要意义。