参照链介导的构象分析策略在人类白细胞抗原-A基因位点分型中的临床应用

Clinical application for reference strand mediated conformation analysis system in HLA-A genotyping

目的 建立并稳定人类白细胞抗原 (HLA)分型新策略—参照链介导的构象分析 (RSCA)系统 ;以HLA A位点为靶标 ,鉴定RSCA分型策略的优劣。方法 采用国际RSCA协作组提供的 2 0例标准分型DNA首先确定RSCA系统的稳定性、准确性及可复性。然后分别提取 84例拟进行造血干细胞移植病人及家系成员的外周血DNA ,采用RSCA和序列特异性引物体外基因扩增 (PCR SSP)法平行对照对HLA A基因位点进行分型。结果 对 2 0例标准分型DNA的分型结果显示 ,所获分型结果与国际RSCA协作组的完全一致 ,准确性及重复率均为 10 0 %。在全部 84例移植病人及家系成员标本中 ,有 82 /84例 ( 97.6 %)标本可明确判定结果 ,其中有 33/84例 ( 39%)可直接指定等位基因型别 ;此外 ,还有 2 /84例 ( 2 .4%)标本因PCR扩增结果太弱 ,致使RSCA法未能获得分型结果。随机选择 2 0例移植标本进行RSCA重复性实验表明 ,前后结果完全一致 ,然而在PCR SSP分型中 ,约有 10 %的标本需要重复 1～ 3次方能判定结果。结论 RSCA与PCR SSP分型结果相比 ,具有灵敏、特异、分辨率高、重复性好、可发现变异基因及新的等位基因、高通量和低成本的优点 ,非常适合于对拟进行非血缘异基因造血干细胞移植供 受体进行HLA分型。

Objective To establish and stabilize a new HLA typing strategy, reference strand mediated conformation analysis(RSCA), and to conform its advantages by using HLA-A as target gene. Methods 20 standard DNA samples from international RSCA cooperative team were used to establish and stabilize RSCA. 84 DNA samples of related hematopoietic stem cell transplant donor-recipients were extracted from peripheral blood cells. HLA-A loci were typed both by RSCA and PCR-SSP. Results RSCA results of 20 standard samples were identical to those of international RSCA cooperative team, and the accuracy and replication rate were both 100%. Among the 84 samples, 82/84(97.6%) cases could be designated definitely, and 33/84 (39%) cases could be typed to allelic level. In addition, 2/84 (2.4%) cases could not be detected by RSCA for their poor PCR results. 20 samples were randomly selected to identify the replication rate of RSCA, and the results demonstrated that the replication rate was 100%. Among the PCR-SSP typing results, there were about 10% samples needed to be typed for 1～3 times to confirm their types. Conclusion RSCA has some advantages compared with the PCR-SSP typing method, which are high resolution,high sensitivity, high accuracy, high replication, capability to find new alleles, high throughput, low cost and suitability for unrelated hematopoietic stem cell transplant donor-recipient HLA typing. But there are still some defects in this new strategy, which are time-consuming for only one sample a time and higher DNA quality requirement. In addition, RSCA database needs to be further improved.