游离缘指甲DNA检测异基因造血干细胞移植后供受者嵌合状态的变化

目的 探讨异基因造血干细胞移植(allogeneic hematopoietic stem cell transplantation,allo-HSCT)后用患者指甲游离缘标本进行短片段重复序列(short tandem repeat,STR)基因分型和供受者嵌合率检测的适用性,并观察移植后患者指甲中供受者嵌合状态变化.方法 选取2009年7月至2011年9月在北京市道培医院行allo-HSCT的25例患者及25名供者.采集患者及其供者外周血、骨髓、指甲游离缘和口腔黏膜标本.提取标本中基因组DNA,进行15个STR位点的基因分型和嵌合状态分析.将患者分为2组:第1组包括12例患者,在接受allo-HSCT后1个月内分别同时采集患者的指甲游离缘标本和口腔黏膜标本,并做嵌合状态的比较；第2组包括13例患者,观察患者行allo-HSCT后3个月指甲标本中的嵌合状态,并对其中3例患者进行多次指甲标本采集和嵌合状态检测.结果 在第1组12例患者中,指甲标本均检测为患者自身的STR基因型；在4份口腔黏膜标本中检测到供受者混合嵌合状态,供者STR基因型所占比例分别为16.7％、32.1％、35.8％和60.7％.在第2组13例患者中,5例患者存在供受者细胞的混合嵌合状态,即受者指甲中出现供者的STR基因型,嵌合率在6.7％至82.6％之间.3例行allo-HSCT后多次检测指甲嵌合率的患者中,1例始终未检测到供者基因型的嵌合,另2例患者中检测到持续存在的供者基因型的嵌合.结论 移植后1个月内采集的指甲游离缘标本可用于患者STR基因型鉴定和供受者嵌合率分析,优于口腔黏膜标本.供者的移植物中具有可以分化成为皮肤组织的细胞,部分患者移植后皮肤中可长期存在供者来源细胞的嵌合状态.

Using recipient free edge fingernails for chimerism analysis following allogeneic hematopoietic stem-cell transplants

Objective To examine whether DNA extracted from free edge fingernails specimens from patient after hematopoietic stem cell transplantation (allo-HSCT) could be used for short tandem repeat (STR) genotyping and chimerism analyzing,and to observe the chimerism status in fingernails after allo-HSCT.Methods Peripheral blood,bone marrow,oral mucosa and free edge fingernail specimens were collected from 25 patients which allo-HSCT were performed in Beijing Dao-pei Hospital during Jul.2009 to Sep.2011 and their donor.Genomic DNA was extracted and 15 STR loci genotyping and chimerism analysis were performed.For the first group which including 12 patients,pairs of fingernail and oral mucosa specimens were collected within one month after allo-HSCT and were comparative analyzed.For the second group which including 13 patients,chimerism status in fingernail samples were analyzed 3 months or longer after allo-HSCT,and 3 patients underwent repeated testing at different times.Results For the first group,4 oral mucosa specimens showed donor chimerism with varying degrees,but no donor chimerism was detected.in all of 12 fingernail specimens.For the second group,6.7％ to 82.6％ donor chimerism was detected in fingernail specimens in 5 out of 13 patients.For the 3 patients underwent repeated testing,donor chimerism was continued negative in one cases,but continued positive in the other 2 cases.Conclusions Free edge fingernail samples of patients within one month after allo-HSCT can be used for STR typing and chimerism analysis,and it is better than oral mucosa samples.There are cells in allo-HSCT donor graft can differentiate into skin cells,donor derived skin cells chimerism can be formed and persist in some patients.Med,2012,35:23-26)