Gene frequencies of platelet‐specific antigens in Croatian population

The human platelet antigens (HPA) are genetically defined polymorphisms expressed on platelet membrane glycoproteins. As platelet antigens are very important in several clinical situations and in population genetics, we used the polymerase chain reaction with sequence‐specific primers (PCR‐SSP) to investigate HPA‐1, ‐2, ‐3 and ‐5 allele frequencies in the Croatian population. The HPA frequencies obtained in 219 Croatians were: 1a–0·854, 1b–0·146, 2a–0·890, 2b–0·110, 3a–0·575, 3b–0·425, 5a–0·895 and 5b–0·105. These data are similar to the frequencies reported in most European studies with some significant differences in HPA‐2 when compared with the Dutch and German population, in HPA‐3 when compared with the Swiss population and in HPA‐5 when compared with the Finnish population. The three most common condensed HPA genotypes in the Croatian population were: HPA‐1a/a, ‐2a/a, ‐3a/b, ‐5‐a/a (0·283), HPA‐1a/a, ‐2a/a, ‐3a/a, ‐5‐a/a (0·137) and HPA‐1a/b, ‐2a/a, ‐3a/b, ‐5‐a/a (0·087). Data obtained in this study can be used for better understanding and treatment of immune‐mediated platelet disorders in our population.     

Human platelet antigen polymorphisms (HPA‐1, ‐2, ‐3, ‐4, ‐5 and ‐15) in major ethnic groups of Pakistan

Objectives: Gene frequencies of human platelet antigens (HPA) determine the magnitude of platelet immunological disorders like neonatal alloimmune thrombocytopenia, platelet refractoriness and ease of availability of particular HPA‐typed platelet donors in a given community. Background: However, the pattern of HPA in Pakistani population is not known. Aim: The aim of present study was to determine the gene frequencies of HPA (HPA‐1 to ‐5 and ‐15) in individuals belonging to major ethnic groups and castes of Pakistani population. Materials and Methods: HPA genotyping was done in 593 individuals belonging to all ethnic groups of Pakistan, by polymerase chain reaction‐sequence specific primers with detection on polyacrylamide electrophoresis. Results: The gene frequencies of the ‘a’ and ‘b’ alleles of HPA‐1 to ‐5 and ‐15 in Pakistanis were as follows: HPA‐1a/b, 0·885/0·115; HPA‐2a/b, 0·92/0·08; HPA‐3a/b, 0·69/0·31; HPA‐4a/b, 1/0; HPA‐5a/b, 0·9/0·1; HPA‐15a/b, 0·59/0·41. Except for significant difference regarding gene frequency of HPA‐3 between Pathans and Sindhis, there was no significant difference of HPA‐1 to ‐5 and ‐15 between major ethnic groups of Pakistan. The estimated mismatch probability regarding platelet antigens 1–5 and 15 in Pakistanis, after transfusion of random donor platelets, is from 14 to 37%. The expected incidence of neonatal alloimmune thrombocytopenia due to anti‐HPA‐1a in Pakistani pregnant females is < 1 of 1000 pregnancies and 8–12 of 1000 in case of anti‐HPA‐5b. Homozygosity of HPA‐1b, ‐2b and ‐5b genotypes ranged from 1 to 2% in the Pakistani population, whereas homozygosity of HPA‐3b and ‐15b was 11 and 18%. Conclusions: There is a need to establish donor registries typed for HPA in the transfusion centres of the country.     

Genotyping of HPA-1 to -7 and -15 in the Thai population using multiplex PCR

Background : Different polymerase chain reaction (PCR) techniques for human platelet antigens (HPA) genotyping have been implemented, in order to diagnose the clinical syndromes of patients with thrombocytopaenia and provide effective HPA‐matched platelet donors. Objectives : The aim of this study is to develop an in‐house multiplex PCR for HPA‐1 to ‐7 and ‐15 genotyping in the Thai population. Methods : One hundred DNA samples of known HPA genotyping by the PCR with sequence‐specific primers (PCR‐SSP), as previously described, were tested with the multiplex PCR. Additionally, 300 DNA samples of group O donors were tested for HPA‐1 to ‐7 and ‐15 genotyping using multiplex PCR. Results : The comparison of HPA‐1 to ‐7 and ‐15 genotype results between multiplex PCR and PCR‐SSP technique was in 100% concordance. Interestingly, HPA‐2b2b genotype was found in two samples; however, other low‐incidence genotypes such as HPA‐1b1b, HPA‐5b5b, HPA‐6b6b and HPA‐7b7b were not found in this study. Moreover, 30 samples were randomly tested twice for HPA genotyping using the multiplex PCR and demonstrated reproducible results. Conclusions : This study shows that the in‐house multiplex PCR is simple, cost‐effective and suitable for HPA genotyping for routine laboratories in other developing countries. Nevertheless, a large‐scale evaluation of this technique through multicentre analysis is suggested.     

Mass-scale high-throughput multiplex polymerase chain reaction for human platelet antigen single-nucleotide polymorphisms screening of apheresis platelet donors

BACKGROUND: Treatment with human platelet antigen (HPA)‐matched platelets (PLTs) is the optimal therapy for bleeding secondary to neonatal alloimmune thrombocytopenia. Recent advances in high‐throughput DNA‐based blood group and PLT antigen genotyping have made it possible to screen plateletpheresis donors for potential HPA‐matched PLT transfusion. STUDY DESIGN AND METHODS: This prospective study evaluated genomic DNA from plateletpheresis donors for single‐nucleotide polymorphisms (SNPs) associated with HPA‐1, ‐2, ‐3, ‐4, ‐5, and ‐15 to determine whether high‐throughput multiplex genomic DNA PCR and oligonucleotide extension technology can be used for mass‐scale PLT antigen genotyping. Genotyping using SNP technology was confirmed using sequence‐specific polymerase chain reaction (SSP‐PCR). RESULTS: Of the 748 donors screened, 277 were found to be negative for antigens implicated in alloimmune thrombocytopenia. In addition, two donors were homozygous for HPA‐1b/b and ‐2b/b, six donors for HPA‐1b/b and ‐3b/b, one for HPA‐2b/b and ‐3b/b, one for HPA‐1b/b and ‐5b/b, 10 for HPA‐1b/b and ‐15 b/b, four for HPA‐5b/b and ‐15b/b, and one for HPA‐2b/b and ‐15b/b. Retesting using SSP‐PCR was conducted for 60 donors. Discrepant results occurred between SNP and SSP‐PCR in less than 20% of samples for HPA‐1b/1b/HPA‐3b/3b, HPA‐5b/5b, and HPA‐15b/b. DISCUSSION: High‐throughput multiplex PCR SNP and confirmatory molecular genotyping are useful for mass‐scale screening of apheresis PLT donors to provide antigen‐negative genotypes. Refinements to mass‐scale multiplex analysis technology would reduce further the confirmatory testing needed.     

盐城地区汉族人血小板抗原HPA-1～17，Caba基因多态性分析

目的：研究盐城地区汉族人群血小板特异性抗原人类血小板同种抗原1～17（HPA1～17）,Caba的基因分布,建立本地区固定机采血小板供者 HPA数据库。方法应用序列特异性引物聚合酶链式反应（PCR‐SSP）技术,对盐城市中心血站200名汉族固定血小板献血者的血液进行HPA1～17,Caba基因分型。用χ2检验统计分析各 HPA血型系统基因分布的期望值与观察值,验证其是否符合 Hardy‐Weinberg平衡定律,并与国内外人群相比较。结果盐城地区200名汉族血小板献血者的HPA‐1a、2a、3a、4a、5a、6a、15a的基因频率分别为0．9950、0．9375、0．5725、0．9925、0．9850、0．9875、0．5425,呈多态性分布,HPA7～14、16～17及Caba呈单线性分布;不配合率大于10％的HPA系统有HPA‐2～3、15。结论本研究已确认盐城地区200名固定血小板供者 HPA基因分布特征,与国内其他地区、其他国家相比有本地区人群特点;在此基础上建立本地区已知 H PA基因型固定机采血小板供者数据库,为临床血小板HPA血型配合性输注提供可能。     

中国牡丹江地区献血人群HPA基因分布特征的研究及数据库的建立

本研究旨在探讨中国牡丹江地区献血人群HPA基因及其多态性分布特征,判断HPA抗原不配合比率,确定有临床意义的抗原系统,建立已知HPA基因型血小板献血者数据库。采用PCR-SSP方法对154名无血缘关系的献血者做HPA基因分型,计算基因频率与基因型频率,并与国内外不同人群进行比较。结果表明,154名健康、无血缘关系的献血者均表达出HPA-a基因中的1a-17a基因;仅表达HPA-b基因中的1b、2b、3b、5b、6b和15b,未表达HPA4b、7b-14b、16b和17b;在基因型中主要以aa纯合子表达为多,具有最高杂合度的为HPA15,其次为HPA3。HPA基因组合型有23种组合型,其中5种频率>10%,其余18种频率<8%,经χ2检验验证本地区HPA基因频率分布符合Hardy-Weinberg遗传定律。结论:本研究已确立牡丹江地区154人的HPA血型分布遗传特征,与其他地区和国家相比具有本地区人群特点,由此建立了牡丹江地区已知HPA基因型的血小板供者数据库,可为临床血小板输注无效者提供相匹配的供者,在临床上具有重要的免疫学意义。     

Human platelet antigen allele frequencies and new mutations on platelet glycoprotein genes in the Chinese Han population

Background and Objectives: The frequencies of human platelet antigens (HPAs) vary between different populations. In this study, we determined the HPA allele frequencies in the Chinese Han population and identified situation of incompatibility possibly leading to alloimmunisation. Methods: A total of 750 volunteer blood donors of the Chinese Han population were genotyped for HPA‐1 to ‐17w systems. HPA genotyping was determined by polymerase chain reaction sequence‐based typing. Results: Among the 17 HPA systems, the allele frequency is different from other populations. We noted the absence of HPA‐7bw to HPA‐14bw, HPA‐16bw and HPA‐17bw alleles in the population. The estimated incompatibility probabilities regarding platelet antigens 1 to 6w and 15 systems after transfusion of random donor platelet were from 0·004 to 0·373. Thirteen glycoprotein alleles were observed in the population. In addition, we identified 16 novel mutations on the glycoprotein genes separated from HPA polymorphisms, including GP1BA (517‐525delAAC), ITGA2B (2722C>T and IVS26+85T>C), ITGA2 (1521C>T, 2474T>G and IVS20+10 G>C), ITGB3 (1476G>A, IVS10+19C>A, 1813G>A, IVS11+21G>A, IVS11+152A>G and IVS11‐104T>C), GP1BB (IVS1‐79G>A, IVS1‐27C>T and 129G>A) and CD109 (2139A>G). Five of them could lead to amino acid deletion, substitution or premature stop codon in corresponding glycoprotein. Conclusions: There was a high degree of polymorphism of the membrane glycoprotein genes related to human platelet alloantigen‐1 to ‐17w systems in the Chinese Han population. These data could have some impact on the diagnosis, prevention and treatment of alloimmune thrombocytopenia.     

应用PCR—SSP方法进行人类血小板抗原1～6系统的基因分型

目的研究采用PCR—SSP技术，建立人类血小板抗原1．6系统（HPA—1，2，3，4，5，6）的基因分型方法。方法合成18条序列特异性引物，通过调节引物浓度、Mg^2＋离子浓度和探索最佳PCR扩增条件．建立HPA—1．6系统同步基因分型技术。对第10届及第11届国际输血协会（ISBT）血小板基因定型协作组送检的考核样本进行盲检来验证。并应用该技术对198名深圳地区健康的血小板志愿捐献者进行基因分型。结果应用本研究的方法，对第10届及第11届ISBT送检的考核样本进行基因分型，结果与ISBT公布的结果完全一致，符合率达100％。对198名随机的血小板志愿捐献者观察到的基因频率分别是：HPA—1a和1b为0．9924和0．0076，HPA-2a和2b为0．9545和0．0455，HPA-3a和3b为0．5556和0．4444，HPA-4a和4b为0．9975和0．0025，HPA-5a和5b为0．9848和0．0152，HPA-6a和6b为0．9798和0．0202。结论本研究建立的HPA基因分型技术具有简便、快速、准确的特点，适合于常规HPA基因分型，具有广泛的应用前景。     

Establishment of platelet donor registry improves the treatment of platelet transfusion refractoriness in Guangzhou region of China

Platelet transfusion refractoriness (PTR) is the major complication of long‐term platelet supportive care. To improve the effectiveness of platelet transfusion therapy in PTR patients, we aimed to establish a platelet donor registry in our region (Guangzhou, China) by typing the human leukocyte antigen (HLA) and human platelet antigen (HPA). Blood donors (n = 864) from our population were genotyped for HLA‐A, HLA‐B and HPA systems by polymerase chain reaction amplification with sequence‐specific primer(PCR‐SSP) techniques. Using this cohort, we compared the results of platelet transfusions (matched vs. random) in 23 patients with PTR. Matched platelets were selected either by HLA antigen matching or by HLA antibody matching, as predicted by antibody specificity prediction (ASP) analysis. Significantly higher platelet recovery (PPR) values were obtained with HLA‐matched platelets in comparison with random platelets. No significant difference in PPR was observed between HLA matching and ASP methods. In two patients, platelet‐specific alloantibodies (alloabs) (anti‐HPA‐3b and anti‐HPA‐5b) were detected besides HLA class I alloabs. Transfusion with HLA‐ and HPA‐compatible platelets in both the patients resulted in significantly higher PPR when compared with HLA‐compatible platelet transfusion alone. In this study, we demonstrated that the establishment of an HLA‐ and HPA‐typed platelet aphaeresis donor registry is useful to improve the treatment outcome of PTR patients and to maintain a long‐term platelet transfusion strategy.     

献血者血小板1-16抗原基因遗传多态性分析及已知HPA型供者数据库的建立

本研究的目的是分析人类血小板抗原（human platelet antigen,HPA）基因多态性,根据分布频率来判断HPA抗原不配合比率以及抗体产生的机会,确定有临床意义的血小板抗原系统,并建立邯郸地区血小板基因频率数据库和供者库.采用SSP-PCR方法对邯郸地区148名随机献血者进行HPA1-16抗原32个等位基因的检测分析,并与不同人群的分布频率进行比较.结果表明：每个样本均检测到HPA-1a、2a、4a-14a、16a基因;HPA-4a、7a-14a、16a呈现单态性,未检测出相应的等位基因HPA-b;对于HPA-1、-2、-5、-6主要以a/a纯合子为多,a/a基因型频率分别是0.9595、0.8108、0.9865、0.9797,没有b/b纯合子出现.在HPA1-16中,具有最高杂合度的是HPA-15,基因型HPA15a/15a、HPA15a/15b、HPA15b/15b频率分别是0.2230、0.5270、0.2500;HPA-3在其次,基因型HPA3a/3a、HPA3a/3b、HPA3b/3b频率分别是0.3851、0.5135、0.1014.经x2检验,结果符合Hardy-Weinberg遗传平衡定律.邯郸地区随机献血者HPA1-5系统基因频率与石家庄地区相似（P＞0.05）;与我国台湾人群进行HPA1-13、HPA-15的比较,HPA-1、-2、-6具有明显的不同（P＜0.05）,其它相似（P＞0.05）;与韩国人群进行HPA1-8的比较,除HPA-3具有明显不同外（P＜0.05）,其余均相似（P＞0.05）;与美国黑人进行HPA1-5的比较,HPA-1、-2、-5具有明显的差异（P＜0.05）;与英国人进行HPA1-11的比较,HPA-1、-5具有明显的不同（P＜0.05）.结论：北方地区中国人群HPA-2、-3、5、-15系统具有多态性,且HPA抗原分布不配合比率较高,这必然造成免疫暴露的机会增加,提示在临床上可能具有重要的免疫学意义.同时,在此次研究数据的基础上建立了邯郸地区血小板基因频率数据库和血小板已知型供者库.     

Establishment of an HPA-1- to -16-typed platelet donor registry in China

In order to determine gene frequencies of human platelet antigen (HPA) and establish a panel of accredited HPA-1a, -2a, -4a, -5a and -6a-negative donors as well as an HPA-typed platelet donor registry, a total of 1000 Chinese donors of Han nationality (500 from north China and 500 from south China) were typed for HPA-1 through -16 using a DNA-based polymerase chain reaction with sequence-specific primers genotyping method. The gene frequencies of HPA-1b, -2b, -3b, -4b, -5b, -6bw, -10bw and -15b were 0.0060, 0.0485, 0.4055, 0.0045, 0.0140, 0.0135, 0.0005 and 0.4680, respectively. The HPA-7bw, -8bw, -9bw, -11bw, -12bw, -13bw, -14bw and -16bw alleles were not found. The HPA-2b and -5b homozygous donors were detected at low frequencies. The HPA mismatch probabilities potentially leading to alloimmunization in random platelet transfusion vary with a region from 0.1% to 37% depending on the distribution patterns of common and less common alleles in each system. This study provides a useful HPA-typed plateletpheresis donor registry in China and could improve platelet antibody detection and HPA-matched platelet transfusion in alloimmune thrombocytopenic patients.     

Genotyping of Eight Human Platelet Antigen Systems in Serbian Blood Donors: Foundation for Platelet Apheresis Registry

IntroductionThe aim of this study was to investigate the allele and genotype frequencies of 8 human platelet antigen (HPA) systems among blood donors from the Blood Transfusion Institute of Serbia and to compare them with published studies. These data would be useful to establish the basis for a platelet apheresis donor registry.Material and MethodsSeventy-two unrelated male platelet apheresis/blood donors from Serbia were typed for 8 HPA systems (HPA-1 to HPA-6, HPA-9, and HPA-15) via the FluoGene method, based on polymerase chain reaction-sequence-specific amplification (PCR-SSP; PCR using sequence-specific primers) with fluorometric signal detection. Allele and genotype frequencies were estimated by direct counting and compared to the expected genotype frequencies according to the Hardy-Weinberg principle. The transfusion mismatch probability was calculated for every HPA specificity.ResultsThe allele frequencies were: HPA-1a, 0.868; HPA-1b, 0.132; HPA-2a, 0.917; HPA-2b, 0.083; HPA-3a, 0.611; HPA-3b, 0.389; HPA-5a, 0.903; HPA-5b, 0.097; HPA-9a, 0.993; HPA-9b, 0.007; HPA-15a, 0.472; and HPA-15b, 0.528. For HPA-4 and HPA-6 only allele a was detected.DiscussionThe HPA allele frequencies of European populations showed no significant differences in comparison with our results. Statistically significant differences were revealed in comparison with some populations of non-European origin. In the tested donors no HPA-2 bb genotype was detected, but we found 1 donor with the rare HPA-9b allele. The biggest transfusion mismatch probability in the Serbian population is for systems HPA-15 (37.4%) and HPA-3 (36.2%), which means that more than a third of random transfusions could cause mismatch in these systems. This study was enabled by the introduction of molecular HPA typing, and it provides initial results of the HPA allele and genotype frequencies in the population of blood donors in Serbia. They will be used to provide a compatible blood supply on demand for treating patients with alloimmune thrombocytopenic disorders. The successful implementation of PCR-SSP with fluorometric signal detection could be further complemented in the future by the introduction of high-throughput methods, which will largely depend on the available financial resources.     

多重聚合酶链反应用于人血小板抗原-2、-4、-5系统基因分型的研究

目的建立用于检测人血小板抗原(HPA)-2、-4、-5系统基因型的多重聚合酶链反应(PCR)。方法在一个反应体系中同时扩增HPA-2、-4、-5系统特异性目的基因片段。用琼脂糖凝胶电泳确定HPA-2、-4、-5系统基因型;再用多重PCR对75名健康的单采血小板者进行HPA-2、-4-、5系统基因分型,分型结果与PCR-序列特异性引物(PCR-SSP)获得的结果进行比较。结果HPA-2、-4、-5系统分型的结果为:70名为2 a/2 a型,5名为2 a/2b型;73名为4 a/4 a型,2名为4 a/4b型;66名为5 a/5 a型,9名为5 a/5b型。未发现2b/2b、4b/4b及5b/5b纯合子个体。多重PCR结果与PCR-SSP方法获得的结果一致。结论多重PCR具有操作简便、快速、准确等特点,可以用于血小板血型抗原基因分型。     

青岛地区汉族人群HPA-1—5,15多态性分布研究

目的研究青岛地区汉族人群人类血小板抗原(HPA)1-5,15抗原分布多态性。方法采用PCR-SSP方法对青岛地区918名无血缘关系固定血小板无偿捐献者进行HPA1-5及HPA-15系统的基因分型.结果各被检系统等位基因频率分别是1a=0.9940,1b=0.0060,2a=0.9319,2b=0.0681,3a=0.5822,3b=0.4178,4a=0.9897,4b=0.0104,5a=0.9804,5b=0.0196,15a=0.4913,15b=0.5087;HPA基因频率分布与国内资料比较,HPA-1与北方人群(河南),HPA-2与南方人群(四川)差异有统计学意义;与台湾人群HPA-2,-4,与日本人群HPA-2,-3,-5,与美国黑人HPA-1,-2,-5,与白人HPA-1,-4,-5,-15分别有统计学显著性差异。结论青岛地区汉族人群HPA分布具有本地人群特点。本组HPA数据分布符合Hardy-Weinberg平衡定律,可以作为北方汉族人群HPA基因分布频率数据库和青岛本地化血小板供者HPA资料库。     

The frequency of human platelet antigen (HPA) genotypes in the Polish population

The human platelet antigens (HPA1–5) in the Polish population were investigated using the PCR with sequence specific primers (SSP). The HPA gene frequency was: 1a — 0.874, 1b — 0.126; 2a — 0.898, 2b — 0.102; 3a — 0.592, 3b — 0.408; 4a — 1.00, 4b — 0.00; 5a — 0.937, 5b — 0.063. The HPA2 and HPA5 differed from those observed in some other European populations — German and both German and Austrian, respectively. The HPA5 alleles frequency was most similar to those observed in the Finnish population. The modification of SSP described allowed the genotyping of HPA1–4 under the same PCR conditions.     

Geno‐ and phenotyping and immunogenicity of HNA‐3

BACKGROUND: Alloantibodies directed against the human neutrophil alloantigen (HNA)‐3a are frequently implicated in severe and fatal transfusion‐related acute lung injury (TRALI). The HNA‐3a/3b system results from a single‐nucleotide exchange (461G>A; Arg154Gln) in the choline transporter‐like protein 2 gene. Genotyping may allow identification of blood donors at risk to develop HNA‐3a antibodies. STUDY DESIGN AND METHODS: A polymerase chain reaction using sequence‐specific primers (PCR‐SSP) for genotyping of HNA‐3a and ‐3b alleles was designed. Results of genotyping and phenotyping were compared in 40 randomly selected individuals and in blood donors and recipients of six TRALI cases associated with HNA‐3a antibodies. Phenotyping was performed by granulocyte immunofluorescence and granulocyte agglutination using typing sera for HNA‐3a and two recently found HNA‐3b–reactive sera. Immunogenicity of HNA‐3a was determined by the rate of HNA‐3a alloantibodies in HNA‐3b homozygous parous women. RESULTS: Genotyping and phenotyping results correlated to 100% and were in accordance with alloantibody formation and binding in HNA‐3a antibody associated TRALI cases. Gene frequencies of HNA‐3a and ‐3b were 0.792 and 0.207 in the German population with 64.1% homozygous individuals for the HNA‐3a allele, 5.5% for the HNA‐3b allele, and 30.4% heterozygous individuals, in accordance with the Hardy‐Weinberg equilibrium and the gene frequencies of 0.819 and 0.181 reported in 1964. Immunization rates were estimated to be of 7% for HNA‐3a and 0.5% for HNA‐3b. CONCLUSION: The PCR‐SSP method allows reliable determination of the HNA‐3a and ‐3b genotypes; approximately 7% of HNA‐3b homozygous women develop antibodies when exposed to the HNA‐3a antigen during pregnancy.     

Establishment of a cell line panel as an alternative source of platelet antigens for a screening assay of anti-human platelet antibodies

Background: A panel of platelets expressing various human platelet antigens (HPAs) for a platelet antibody screening assay is difficult to prepare because some antigens are rarely expressed. Therefore, an alternative method without using platelets would be helpful in detecting HPA antibodies. This study describes the establishment of cell lines that stably express specific HPAs and their application for detecting specific antibodies. Methods: Wild‐type β3, HPA‐1b, ‐6b, ‐7b and ‐7 variant cDNA as well as wild‐type αIIb and HPA‐3b cDNA were individually co‐transduced with wild‐type αIIb and β3 cDNA in the K562 cell line. We performed an immunobead monoclonal antibody immobilisation of platelet antigens (MAIPA) assay to evaluate this cell line panel for antibody detection using identified sera containing HPA antibodies, whose specificities had been determined by the mixed passive haemagglutination test. Results and Conclusion: Of the 12 sera containing HPA‐1a (n = 2), HPA‐3a (n = 6), HPA‐6b (n = 3) or HPA‐7 variant (n = 1) antibodies, all antibodies were detected and determined by our new method, except for two HPA‐3a antibodies. One of the two antibodies was also negative for conventional platelet MAIPA, suggesting that the cell line panel might be used as an alternative source of platelet antigens in the MAIPA assay.     

人类血小板抗原1～4系统基因分型

目的 :建立人类血小板抗原 1～ 4系统序列特异性引物 (PCR SSP)分型方法。方法 :合成 14条引物 ,采用PCR SSP方法对 2 5名健康献血者的HPA 1～ 4系统进行基因分型 ;分型结果与采用等位基因特异性寡核苷酸点杂交 (PCR ASO)获得的结果进行比较。结果 :以PCR SSP方法对HPA 4个系统进行分型均取得了明确、满意的结果 ,且与PCR ASO方法获得的结果完全一致。结论 :人类血小板抗原PCR SSP基因分型方法具有简便、快速、准确等优点 ,具有广泛的应用前景。     

New K103 β3 allele identified in a context of severe neonatal thrombocytopenia

BACKGROUND: A new β3 allele was identified in a severe case of neonatal alloimmune thrombocytopenia (<7 × 10⁹/L). STUDY DESIGN AND METHODS: Diagnosis was done by use of monoclonal antibody–specific immobilization of platelet (PLT) antigen for serologic analyses and polymerase chain reaction (PCR)–sequence‐specific primers (SSP) and PCR–restriction fragment length polymorphism (RFLP) for genotyping. Direct sequencing of PCR product was done and mutant αIIbβ3 expressed in HEK‐293 cells. RESULTS: Serologic analysis revealed in the maternal serum an anti‐human PLT alloantigen (HPA)‐1a alloantibody associated to an anti‐α2β1. Anti‐HPA‐1a alloimmunization diagnosis was confirmed by genotyping showing maternofetal incompatibility. However, investigation of rare HPA polymorphisms revealed discrepant HPA‐16b assignation between PCR‐RFLP and PCR‐SSP. Sequencing revealed a new c.385C>A mutation in the β3 coding sequence resulting in a false assignation of the HPA‐16b allele by PCR‐RFLP. This mutation leads to a Q103K substitution in mature β3. The K103‐β3 form of the complex was expressed in HEK‐293 cells but did not react with the maternal serum. CONCLUSION: We have characterized a new rare allele (frequency < 1%) of β3 that yields false HPA‐16b genotyping in PCR‐RFLP. This new case of false typing assignation emphasizes the necessity to use two genotyping techniques in diagnosis. This particularly applies for rare HPA polymorphisms when PLT phenotyping cannot be used.     

HPA配型在免疫性血小板输注无效中的应用研究

目的探讨以HPA配型解决免疫性血小板输注无效的方案。方法 1)建立PCR-SSP方法检测HPA-1～5基因型检测方法,建立机采血小板供者库;2)采用微柱凝胶法和Capture-P法对32名血小板输血无效患者作血小板同种抗体筛查,并对2种方法比较;3)对血小板同种抗体筛查阳性患者采用已知HPA基因型的标准谱血小板作抗体鉴定并采取HPA基因型同型输注的原则寻找供者。结果 1)采用PCR-SSP方法成功检测出HPA-1～5基因型,并对1 000名血小板供者的HPA-1～5基因型定型;2)32例血小板输注无效病例中,微柱凝胶法检测血小板同种抗体阳性率为50%,Capture-P法血小板抗体阳性检出率为40%;3)32例血小板输血无效病例中2种方法同时血小板抗体阳性13例,其中2例鉴定为抗-HPA,分别为抗-HPA-5b(P=1/84)、抗-HPA-1a(P=1/55)。结论对抗-HPA引起的血小板输注无效患者采用HPA基因型相合的方法寻找供者是有效的。