Incidence of abacavir hypersensitivity and its relationship with HLA-B*5701 in HIV-infected patients in Taiwan

OBJECTIVES: To describe the incidence of hypersensitivity to abacavir and frequency of human leucocyte antigen (HLA)-B*5701 in HIV-infected Taiwanese persons. METHODS: Medical records of 337 HIV-infected Taiwanese in whom abacavir-containing combination antiretroviral therapy (CART) was prescribed from 1 May 2001 to 31 December 2006 were reviewed, and HLA typing of the patients was performed in 320 patients (232 receiving abacavir and 88 not receiving abacavir) with available blood samples. HLA class I and II polymorphisms were determined by PCR with specific primers. HLA-B*5701 was further confirmed by sequence-based typing. RESULTS: Of the 337 patients, median CD4 count was 166.5 cells/mm3 (range, 1.0-1914.0) and 83 patients (24.6%) had AIDS-defining opportunistic infections. Thirty-eight patients (11.3%) discontinued abacavir within 6 weeks of starting abacavir-containing CART. Among them, 10 patients had successful abacavir re-challenge and another 11 patients had other specific reasons for abacavir discontinuation. Therefore, 14 patients (4.2%) were classified as cases in whom abacavir hypersensitivity could not be excluded, and 3 patients (0.9%) met the criteria of abacavir hypersensitivity. Of the 320 patients undergoing HLA typing, HLA-A02 was the most common allele and only one individual (0.3%) expressed HLA-B*5701. Along with some differences in allele distributions, there was a significant difference in the genetic frequency of HLA-B57 in our patients compared with those of previous studies in other Chinese populations. CONCLUSIONS: Abacavir hypersensitivity was less frequently encountered in HIV-infected Taiwanese initiating abacavir-containing CART than in Caucasians, which might be explained by the low frequency of the HLA-B*5701 allele.     

PCR-SBT检测HLA-C座位1-7外显子序列鉴别HLA-C~*07:01:01G和C~*07:02:01G组等位基因

本研究旨在探讨区分人类白细胞抗原(HLA)-C*07:01:01G和HLA-C*07:02:01G组内等位基因,并分析其与HLA-B的连锁情况。通过收集HLA-C*07:01:01G组和HLA-C*07:02:01G组标本,采用聚合酶链反应测序分析方法(PCR-SBT)检测HLA-C座位第1-7外显子编码序列,并采用PCR-SBT方法对标本进行HLA-B基因分型。结果表明,13例HLA-C*07:01:01G组标本中,4例(30.8%)标本为HLA-C*07:01:01,9例(69.2%)标本为HLA-C*07:06;连锁分析显示,HLA-C*07:06与HLA-B*44:03高度连锁。102例HLA-C*07:02:01G组标本全部为HLA-C*07:02:01;连锁分析显示,HLA-C*07:02:01与HLA-B*51:01、B*46:01、B*39:01、B*40:01、B*38:02、B*15:02高度连锁。结论:HLA-C*07:01:01G组中发现存在HLA-C*07:01:01和HLA-C*07:06,而HLA-C*07:02:01G组中以HLA-C*07:02:01为主导。     

中国北方汉族骨髓供者HLA-B＊15组基因多态性的PCR-SBT分型研究

为了研究中国北方汉族骨髓供者HLA—B＊15等位基因的分布特征，探讨其可能对临床供体选择的影响，从中华骨髓库陕西分库内随机抽取815名已知低分辨分型结果中国北方汉族骨髓供者，采用聚合酶链反应-碱基序列直接测序（PCR—SBT）方法对其中206例HLA—B＊15阳性样本和另外附加17例样本进行HLA—B位点DNA测序分析，并应用同源模建分子模拟技术对所有结果模拟出三维结构，用计算机软件Swiss—PdbViewer比较模拟结构间的差异大小。结果表明：随机抽取的815例样本HIJA—A、B、DRB1基因分布符合Hardy—Weinberg平衡定律，HIJA—B＊15基因频率为0．1379，总共检出16种HIJA—B＊15等位基因，分属7种血清学特异性，以B＊1501、B＊1511、B＊1502和B＊1518为主，频率分别为0．0485、0．0215、0．0178和0．0160，累计频率构成比占全部B＊15的75．11％，其余12种B＊15等位基因频率均〈0．0100。19例HIJA—B＊15，-测序分析表明，其中10例中低分辨水平上的纯合子中仅4例为真正意义上的B＊15xx，-纯合子，且均由各自优势基因构成。三维结构模拟分析发现同一血清型中既存在结构差异微小的等位基因，如B＊1501、1505、1507、1525、1527、1532（RMSD≤0．02nm），也存在差异较大的等位基因，如B＊1502、1511、1521之间以及B＊1503、1546之间（RMSD均为0．29nm），而一些分属不同血清型的等位基因之间结构却近似（RMSD值≤0．02nm）。结论：本研究应用PCR—SBT，首次取得了中国北方汉族样本量最大的高分辨水平HLA—B＊15基因多态性分布特征，这将有助于临床患者寻找合适供者，并为移植免疫及本地区群体遗传学等方面的研究提供了重要依据，且对于临床选择最适供者，像HLA—B＊15这样血清学特异性及基因亚型高度多态性的家族进行准确的高分辨分型是必要的。     

Rapid genotyping of HLA-B27 among Korean population by real-time PCR melting curve analysis

BackgroundReal-time PCR and melting curve analysis is the relatively recent method for HLA-B27 genotyping, which has advantages of being simple and rapid.MethodsThe accuracy of melting curve analysis for HLA-B27 was assessed in 153 clinical samples and 52 DNA samples from International Histocompatibility Workshop (IHW) cell lines, with sequence-based typing (SBT) as the reference method. We predicted melting reaction for various HLA-B27 subtypes using simulation software.ResultsFor clinical samples, 53 HLA-B27-positive and 100 negative results by melting curve analysis were confirmed by completely concordant SBT results. The B*27:05 allele was found in 50 patients, and the B*27:04 allele in 3 patients. Among 62 known alleles, 21 alleles had differences in the target sequence, including 10 alleles having mismatches in the primer binding site. In these alleles, differences in melting points (T_m) were predicted to be ≤ 1.2 °C. The predicted results were obtained when IHW samples were tested, which revealed slight lower T_m for B*27:06 and negative results for B*27:07.ConclusionsGenotyping of HLA-B27 by melting curve analysis was fast and reliable for routine laboratory testing for frequent alleles. In silico melting simulations provided useful information about the utility and limitation of this method for diverse HLA-B27 alleles.     

Rapid DNA typing of HLA-B27 allele by real-time PCR using lightcycler technology

For clinical diagnostic routine we developed a fast DNA typing of HLA-B27 by PCR and real-time detection using LightCycler technology. The method combines the sensitivity and specificity of PCR with the swiftness of the LightCycler system. The amplification step was performed with a primer set coding for a region in the third exon common to B*2701 to B*2705. The PCR cycles were monitored continuously using the SYBR Green I dye. Beta-globin was used as an internal control. An analysis of 32 samples with one PCR run was completed within 40 minutes. After amplification a melting curve analysis permitted the accurate identification of the PCR amplicons. The mean melting temperatures (Tm) were 90.5 degrees C and 87.3 degrees C, which are characteristic for HLA-B27 and beta-globin, respectively. A comparison of 300 samples which were typed for HLA-B27 with a conventional sequence-specific polymerase chain reaction (SSP-PCR) and with the new method demonstrated a perfect correlation (specificity 100%). In summary, the method described is fast, reliable, cost-effective and well adapted for routine laboratory testing.     

四川骨髓库汉族人群HLA-B~* 15等位基因分布

目的采用聚合酶链反应-序列分析基础上的HLA分型(polymerase chain reaction-sequence based typ-ing,PCR-SBT)方法,研究中国造血干细胞捐献者资料库(以下简称为中华骨髓库,CMDP)四川分库中四川籍汉族人群HLA-B*15组等位基因的分布特点。方法从四川骨髓分库中汉族人群中/低分辨分型HLA-B*15阳性样本中按不同血清学特异性分层抽取107例样本,应用PCR-SBT技术进行测序分型,获得四川籍汉族人群B*15组高分辨分型结果。应用方根法计算HLA-B*15各等位基因频率,同时与其他人群资料进行比较。结果共检测到16种已知HLA-B*15等位基因和1例未知等位基因。本研究中检出的16种等位基因有:B*15010101(B62),B*1502(B75),B*1503(B72),B*1505(B62),B*1507(B62),B*151101(B75),B*1512(B76),B*1513(B77),B*1517(B63),B*1518(B71),B*1525(B62),B*1527(B62),B*1529(B15),B*1532(B62),B*1546(B72),B*1558(B62)。其中以B*1502(36.2%)最常见,其次为B*15010101(21.6%),B*151101(9.5%),B*1518(6.9%),B*1525(6.0%),这5种等位基因占B*15等位基因家族的80%。在B*15等位基因家族中,表达B75抗原的等位基因B*1502和B*151101共占45.7%,但表达B62抗原的B*15等位基因多态性最强,共检出7种等位基因。此外,本研究发现1例未知等位基因,该等基因序列与目前所有已知的B*15或B*46等位基因序列均不相同,在外显子3的116位处存在1个点突变C->T。结论研究表明在四川籍汉族人群中HLA-B*15等位基因水平表现出丰富的多态性和特有的分布特征。     

广东汉族人群HLA-B~* 15等位基因分布

目的了解广东献血者汉族人群HLA-B*15等位基因的多态性。方法从1 691名广东汉族献血者中采用中/低分辨分型获得带有HLA-B*15基因型466例样本,进一步应用PCR-SBT技术进行测序分型,获得广东汉族人群B*15高分辨分型结果。应用PyPop软件计算HLA-B*15各等位基因频率,同时与其他人群资料进行比较。结果共检测到16种已知HLA-B*15等位基因,其中以B*15∶02(64.75%)最常见,其次为B*15∶01(13.26%),B*15∶25(4.554%),B*15∶27(4.158%),B*15∶12(3.960%),这5种等位基因占B*15等位基因家族的90.69%。在B*15等位基因家族中,表达B75抗原的等位基因B*15∶02、B*15∶11和B*15∶21共占67.92%,但表达B62抗原的B*15等位基因多态性最强,共检出6种等位基因。结论广东汉族人群中HLA-B*15等位基因表现出高度的多态性及其特有的分布特征。     

人白细胞抗原B位点基因芯片分型技术研究

目的 探讨基因芯片技术在进行北方汉族人群人白细胞抗原B位点（HLA-B）分辨度分型的价值.方法 根据中国北方汉族人群HLA-B常见基因位点及临床分型分辨度特征,设计特异性寡核苷酸中分辨度分型探针,制成HLA-B基因分型芯片.采用荧光标记引物和不对称聚合酶链反应（PCR）扩增HLA-B 2、3外显子,产物与芯片探针杂交后经荧光扫描,并用特定软件分析判断阳性探针,以确定样品基因型.结果 用中分辨度探针从30份北方汉族人标本中可分出HLA-B 7～83范围的42个B抗原等位基因,与顺序特异引物聚合酶链反应（PCR-SSP）分型方法对比,多检出3个HLA-B14、73和82新等位基因.结论 HLA-B基因芯片具有较高的精确度和特异性,可一张芯片多人份检测,适合用于临床HLA-B抗原分型.     

Workshop Report on the Genotyping of Blood Cell Alloantigens

The immunization against alloantigens present on platelets, granulocytes and red blood cells (RBCs) is responsible for various clinical syndromes. Since the molecular basis of these antigens has become clear during the last decade, genotyping is nowadays used in several laboratories. However, many DNA-based techniques still have to be evaluated. We therefore organized a workshop on the genotyping of the most relevant alloantigens on platelets and granulocytes as well as on selected RBC alleles. DNA was isolated from peripheral blood lymphocytes or from B-lymphoblastoid cell lines (B-LCL). We distributed samples for the identification of platelet (n = 7), granulocyte (n = 6) and RBC (n = 4) polymorphisms, respectively. There were 33 institutions in Germany, Austria and Switzerland, which participated in at least one part of the workshop. Twenty-four laboratories reported results on HPA-1, and 23 laboratories on HPA-2, -3, and -5 typing. In addition, five laboratories typed for HPA-4 and -6. The HNA-1a/b (NA1/NA2) alleles were identified by eight laboratories, one of which also typed for HNA-1c (SH). The most frequent genes of the ABO (A1, B, O) and Rh (D, C, c, E, e) systems were typed by 12 participating laboratories, and an additional four laboratories restricted their RBC typing to the RHD gene. The typing technique mainly used for all three cell lineages was the polymerase chain reaction with sequence-specific primers. Other techniques were restriction fragment length analysis, oligonucleotide ligation assay, enzyme-linked mini-sequence assay or direct sequence analysis. The following typing errors were observed: HPA: 15/1442 (1.0%), HNA: 4/108 (3.7%), ABO: 5/96 (5.2%) RH 1/320 (0.3%). Our workshop demonstrated the existence of a number of reliable techniques for the genotyping of blood cell alloantigens and a high standard in the participating laboratories. In addition, we could show the usefulness of B-LCL as a source of reference DNA. However, the 5.2% rate of mistyping in the ABO system demonstrated that further efforts are needed to improve the precision of the genotyping techniques. Future workshops will have to challenge methods and participants with rare variants of RBC genes to guarantee reliable genotyping, e.g. in prenatal diagnosis of fetomaternal incompatibility.     

Dispermic chimerism identified during HLA typing for stem cell transplantation

BACKGROUND: Chimerism is defined as the presence of two genetically distinct cell populations in an organism. Few cases of phenotypically normal dispermic chimeras have been reported and most showed abnormalities on blood typing. CASE REPORT: A 32-year-old man was diagnosed with acute myelomonocytic leukemia. He clearly typed as group A, D-. No abnormalities of sexual development were identified on multiple physical exams, previous exploratory surgery, or CT scans. Molecular HLA typing (sequence-specific primers) in preparation for stem cell transplant showed the patient to have three HLA-B* and three HLA-Cw* alleles. Initial serologic HLA typing reported two haplotypes, but on subsequent review reactions for a third HLA-B antigen that were initially deemed to be false-positive reactions were identified. Two of 10 microsatellite short tandem repeat (STR) loci also showed three distinct alleles in blood and buccal samples. In all studies the third allele was attributable to a dual paternal contribution. CONCLUSION: This case represents dispermic chimerism, with one maternal and two paternal haplotypes variably distributed throughout body tissues in a phenotypically normal man without abnormalities in blood typing. The presence of additional alleles that may have been undetected or dismissed by serologic typing should be carefully investigated and verified by molecular techniques. Molecular HLA typing may increase the accurate identification of phenotypically normal chimeras and aid in selecting proper donors for transplantation to reduce graft-versus-host disease and transplant rejection in these patients.     

A new approach to safely type for HLA the HIV infected people eligible to abacavir therapy: Saliva or buccal swab as reliable DNA sources

BackgroundIncreasing the safety in Immunogenetics Labs, in the era of antiretroviral pharmacogenomics, represents an imperative goal. To this purpose, we tested saliva and buccal cells as biological sources of DNA, alternative to peripheral blood, for HLA-B*57:01 genomic typing of HIV positive patients eligible to treatment with abacavir.MethodsBlood, saliva and buccal cells of 20 voluntary donors and 20 HIV positive patients were collected. DNA was extracted with a manual commercial kit and an automated platform. Quality and quantity of DNA was evaluated with different procedures. The suitability and reliability of DNAs for HLA-B*57:01 genotyping was checked at low and high resolution level, using PCR-SSP (sequence specific primers PCR), revPCR-SSO (reverse sequence specific oligonucleotides PCR), bead array and SBT (sequence based typing) techniques.ResultsDNA concentrations were qualitatively very good and quantitatively comparable in all the specimens tested with an inferior yield for cotton swabs. Comparing the results of HLA typing with different methodologies, the 100% of reproducibility was achieved.ConclusionsThe viral load of buccal epithelial cells or saliva is extremely low. Here we demonstrated that the DNA from these alternative sources is appropriate for HLA-B*57:01 typing. We strongly recommend the use of this procedure to increase the safety in the lab when dealing with infectious samples.     

Cytokine profiling in abacavir hypersensitivity patients

BACKGROUND: Abacavir hypersensitivity in genetically susceptible individuals implicates an abacavir-specific T-cell response to either the parent drug or a metabolite generated in vivo. We have analysed the cytokine profile in antigen-presenting cells and the T-lymphocytes that are involved in the pathological immune response to abacavir. METHODS: In this study, we compared abacavir-specific cytokine responses in cultured peripheral blood mononuclear cells (PBMCs) from HIV-infected abacavir hypersensitive, tolerant and naive individuals. Cells were cultured in the presence or absence of abacavir. Cytokine expression was determined by microarray analysis, enzyme-linked immunosorbent assays and flow cytometry. RESULTS: We demonstrated using in vitro models of immune activation that the production of interferon-gamma was specifically induced by abacavir treatment in PBMCs obtained from hypersensitive patients carrying the HLA-B*5701 allele (median 123.86 compared with -30.83 for tolerant controls, P=0.001). CONCLUSION: These results provide further insight into the immunological and metabolic basis of abacavir hypersensitivity syndrome. In vitro assays could assist in the identification of susceptible loci by providing a surrogate marker for the hypersensitivity reaction. Such a marker could be studied in unexposed individuals to shed further light on the immunopathogenesis of the abacavir hypersensitivity syndrome.     

山东地区强直性脊柱炎患者 HLA-B27 基因高分辨分型结果分析

目的研究山东省强直性脊柱炎(AS)与亚型水平的HLA-B27等位基因的相关性。方法应用序列特异性引物聚合酶链反应(PCR-SSP)技术进行山东省AS患者HLA-B27基因高分辨分型。结果30例AS患者HLA-B27高分辨分型均为B*2704或B*2705,其中B*2704阳性11例,B*2705阳性19例,构成比分别是36.67%、63.33%。结论不同地区、不同人群的AS患者,HLA-B27各亚型分布频率存在差异性;山东地区AS患者HLA-B27等位基因以B*2704和B*2705为主,且B*2705最多见。     

Incidence of abacavir hypersensitivity reactions in euroSIDA

BACKGROUND: The aim of the study was to investigate the incidence of abacavir-related hypersensitivity reaction (HSR) and associated deaths in EuroSIDA HIV-1-infected patients. METHODS: Poisson regression models were developed to compare incidence of abacavir discontinuation according to the line of therapy within which abacavir was received, geographical regions, calendar time and drug formulation (abacavir/lamivudine combination tablet versus abacavir as a single drug or abacavir/zidovudine/lamivudine combination). RESULTS: Of 3,278 patients that started abacavir, 2,101 (64.1%) discontinued. Of these, 167 (5.1%) discontinued abacavir within 3 months due to HSR with an incidence of 22.1 (95% confidence interval [CI] 18.7-25.4) per 100 person-years of follow-up. After adjustment for gender, prior AIDS, hepatitis C serostatus, baseline CD4+ T-cell count, region and calendar time, HSR incidence was significantly higher in those starting abacavir in a first-line regimen compared with second-line (incidence rate ratio [IRR] 2.04 [95% CI 1.24-3.38]; P=0.005). There was no significant difference between regions. HSR incidence from 2005 onwards was significantly lower compared with 1999-2000 (IRR 0.54 [95% CI 0.32-0.92]; P=0.024). There was a lower observed incidence in patients starting abacavir/lamivudine compared with other formulations (IRR 0.33 [95% CI 0.13-0.88]; P=0.027), however, available data were limited. CONCLUSIONS: Incidence of abacavir-related HSR is higher in patients starting abacavir in first-line therapy, which could indicate increased over-diagnosis. HSR incidence has decreased in recent years, which might reflect the wider availability of genetic screening and improved awareness of symptoms. There were no reported deaths due to abacavir HSR.     

中国汉族人群HLA-B*40组的多态性研究

为了研究中国汉族人群HLA—B^*40等位基因的分布特点，探讨其可能对临床供者选择的影响，从中华骨髓库深圳分库中随机抽取381名志愿供者，用PCR—SSO方法进行HLA—B基因分型；另从已分型的1270例供者中选出低分辨率结果为B^*40纯合子的样本。所有B^*40阳性标本采用PCR—SBT及PCR—SSP方法进行高分辨率分型。结果表明：随机抽取的381例样本通过Hardy—Weinberg平衡检验，HLA—B^*40的基因频率为0．1692。在实验中仅检测到B^*4001，B^*4002，B^*4003，B^*4006，其血清学特异性分属B60，B61。各等位基因相对频率B^*4001为0．1192，B^*4002为0．0154，B^*4003为0．0038．B^*4006为0．0308。B^*40纯合子在高分辨水平上检测，其等位基因表现出一定的规律性，低分辨结果为B^*40XX(B^*4001组)，一，高分辨都是B^*4001；低分辨为B^*40XX(B^*4002组)．一，高分辨则为B^*4002或B^*4006或二者杂合子。结论：中国汉族人群B^*40基因家族中B^*4001占绝对优势。为了选择最适供者，建议临床配型中使用高分辨率基因分型。     

强直性脊柱炎患者HLA-B~* 27基因亚型及序列研究

目的研究已确诊的强直性脊柱炎(AS)患者HLA-B*27亚型的43个等位基因分布情况,为本地区临床诊断AS提供理论和实践基础。方法经HLA-B*27低分辨基因检测阳性的AS确诊患者标本70份应用PCR-SSP检测;在判读结果为B位点杂合子的27份中随机抽取17份,加上因HLA-B位点多态性及试剂盒局限性而无法判定确切结果的3份标本应用PCR-SBT检测。结果 50名患者表达HLA-B*2704阳性(包括纯合子31名,杂合子19名)2,1名患者表达HLA-B*2705阳性(包括:纯合子10名,杂合子11名),其中1名患者同时表达HLA-B*2704/2705杂合。HLA-B*2704合计阳性率为71.42%,占总标本数的70.41%;HLA-B*2705合计阳性率为30.01%,占总标本数的29.59%。通过直接计算法得出B*2704等位基因频率为0.578 6,B*2705等位基因频率为0.285 7。结论上海地区AS就诊患者HLA-B*27基因亚型为HLA-B*2704和HLA-B*2705此2种,以HLA-B*2704为主。配合应用PCR-SSP与PCR-SBT此2种分型方法具有互补意义,可以获得较为准确的分型结果。     

Nondeletional ABO*O alleles frequently cause blood donor typing problems

BACKGROUND: Difficulties in the demonstration of expected isoagglutinins is a common problem in ABO reverse typing. Some nondeletional ABO*O alleles have been shown to encode for the expression of minimal amounts of A antigen, resulting in very weak anti-A activity in some cases. It is unknown whether minor problems with ABO reverse typing are related to specific ABO*O alleles. STUDY DESIGN AND METHODS: Among 2196 blood group O red cell (RBC) donations, the ABO alleles of those donations in which the isoagglutinins were incorrectly identified were analyzed with an autoanalyzer. The presence of nondeletional ABO alleles was determined by sequence-specific priming and sequencing. RESULTS: Fifty (2.3%) of the group O RBC donations tested had to be typed manually because of isoagglutinin detection problems in automated typing: reduced anti-A activity was observed in 45 cases, reduced anti-B activity in 4 cases, and variably reduced isoagglutinin activity in 1 case. The nondeletional ABO*O alleles ABO*O03 and ABO*Aw08 were implicated in 38 of these 50 cases (1.7% of all blood group O donors). The remaining samples, including those with reduced anti-B activities, were homozygous for deletional ABO*O alleles. CONCLUSION: Nondeletional ABO*O alleles are the most frequent cause of isoagglutinin detection problems in blood group O donors.     

Comparison of two anti-hepatitis C virus enzyme-linked immunosorbent assays

BACKGROUND: Third-generation anti-hepatitis C virus (HCV) enzyme-linked immunosorbent assays (ELISA) are now implemented in most laboratories in Europe, but have not yet been fully implemented in the United States. STUDY DESIGN AND METHODS: Two ELISAs (Ortho 3.0 and Ortho 2.0, Ortho Diagnostics, Raritan, NJ) were compared by tests on various serum panels: A) blood donor samples (n = 530) that tested positive in first- or second-generation anti-HCV ELISA; B) samples from persons with chronic non-A, non-B hepatitis (n = 185); C) samples from multiply transfused patients (n = 79); D) samples from patients on hemodialysis (n = 473); and E) samples from Dutch random blood donors (n = 2153). RESULTS: In panels A, B, and C, 247 (100%) of 247 polymerase chain reaction (PCR)-positive and 278 (100%) of 278 second-generation recombinant immunoblot assay (RIBA-2)-positive specimens were detected by Ortho 2.0 and 3.0 (sensitivity, 100%). In the sera of panel D, used to represent a group of patients with a high risk for HCV, no additional positives were found by Ortho 3.0. In panel E, of 2153 blood donor samples, 2 (0.1%) were positive in Ortho 2.0 and 8 (0.4%) in Ortho 3.0. Two samples that were positive in both Ortho 2.0 and 3.0 were also positive in RIBA-2; one was positive on PCR. From the 6 remaining Ortho 3.0-positive (Ortho 2.0-negative) samples, 1 was positive in RIBA-2 (isolated anti-c100) and 3 were positive in third- generation RIBA (1/3 isolated anti-c100, 2/3 isolated NS5). All 6 samples were PCR negative. In first-time donors, no difference in specificity was found. CONCLUSION: The sensitivity and specificity of the Ortho 3.0 ELISA are comparable to those of the Ortho 2.0 ELISA.     

反向PCR—SSOP技术行HLA—AB分型与临床应用

建立快速,准确的DNA分型技术并用于临床移植前HLA-AB配型,以弥补血清学分型技术的局限性。采用反向聚合酶链反应-序列特异寡核苷酸探针杂交技术（反向PCR-SSOP）进行DNA分型,可检出HLA-A（*0101-8001）和B（*07021-8201）等等位基因。结果表明,发现利用反向PCR-SSOP技术对所有样本分型均获成功,无假阳性和假阴性结果出现;美国洛杉矶加州大学（UCLA）质控细胞DNA分型结果与UCLA公布的测序结果一致。血清学与基因分型相比。血甭学结果HLA-A错检率6.4%和HLA-B错检率为7.4%。2例白血病病人分别有一个HLA抗原血清学方法不能检出。结论提示,反向PCR-SSOP技术用于HLA分型分辨率高,简单快速。结果直观、准确。分型结果较血清学方法更加精确,可适用于临床应用。     

HLA-B*5701 screening for susceptibility to abacavir hypersensitivity

The introduction of highly active antiretroviral therapy (also known as combination therapy) has transformed the nature of HIV infection from a severe and ultimately fatal disease to that of a manageable chronic condition. HIV drugs are highly efficacious, but their use comes at the cost of a range of drug-related adverse events, including severe drug hypersensitivity reactions (HSRs) that have been most notably associated with abacavir and nevirapine therapy. This article discusses the issues of pharmacogenetic screening, in the light of the strong genetic association of the HLA-B*5701 allele and the susceptibility to developing abacavir HSRs. It also presents the screening's impact on clinical practice and discusses the practical considerations that influence the introduction and cost-effectiveness of such screening.