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1.
Ann Hematol ; 99(12): 2911-2925, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33000361

RESUMO

Prior studies have suggested that for leukemia patients with high-risk features, haplo-identical-hematopoietic stem cell transplantation (HID-HSCT) has a stronger anti-leukemia effect compared with HSCT using an identical sibling donor (ISD-HSCT). However, it is unclear whether an HID-HSC transplant also augments the graft-versus-leukemia (GVL) effect among refractory/relapsed (R/R) acute myeloid leukemia (AML) patients who are not in remission (NR). We conducted a retrospective analysis of 124 R/R AML patients with NR status who underwent HID-HSCT between April 2012 and December 2016 and compared these to 27 R/R AML patients who underwent an ISD-HSCT within the same timeframe. Among all of the patients, 68 (45.0%) had primary induction failure (PIF) and 83 (54.9%) were relapsed and had failed to respond to at least one cycle of salvage combination chemotherapy. Myeloablative conditioning regimens were administered to all patients. Here, we present a retrospective multivariate analysis of pre-transplantation risk factors and characteristics of all 151 patients and developed a predictive scoring system to predict patient survival. The median period of follow-up was 46 months for all patients. The HID cohort had a higher 5-year overall survival (OS) compared with the ISD cohort (48.6% ± 4.6% vs 25.9% ± 8.4, respectively; P = 0.017) and higher LFS (leukemia-free survival) (41.6% ± 7.5% vs 25.9% ± 8.4%, respectively; P = 0.019). There was no difference in the 5-year cumulative incidence of non-relapse mortality (NRM) (18.0% ± 3.8% and 34.9% ± 12.6%, respectively; P = 0.212) between the two group. However, the 5-year cumulative incidence of relapse (CIRs) was lower in the HID group compared with the ISD group (55.4% ± 8.9% vs 67.3% ± 9.9%, respectively; P = 0.021). Multivariate analysis showed three risk factors associated with OS and LFS: (1) ISD-HSCT, (2) use of a standardized conditioning regimen, and (3) less than 50% proportional reduction of blast cells in the bone marrow (BM). Based on these three risk factors, we developed a predictive scoring system for R/R AML patients undergoing HSCT. Patients who had a predictive score of 0 and 1 had a 66.6% ± 4.5% and 44.1% ± 3.6% OS rate at 5 years, respectively. Patients with a score ≥ 2 had only a 4.4 ± 0.2% OS rate at 5 years. An HID-HSCT had a better anti-leukemia effect among R/R AML patients with an NR status compared with an ISD-HSCT. We also identified pre-transplantation risk factors to delineate subgroups that could derive maximal benefit from HSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/terapia , Doadores Vivos , Irmãos , Transplante Haploidêntico/métodos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas/tendências , Teste de Histocompatibilidade/métodos , Teste de Histocompatibilidade/tendências , Humanos , Leucemia Mieloide Aguda/diagnóstico , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Condicionamento Pré-Transplante/métodos , Condicionamento Pré-Transplante/tendências , Transplante Haploidêntico/tendências , Resultado do Tratamento , Adulto Jovem
2.
Transplant Rev (Orlando) ; 34(2): 100533, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32007300

RESUMO

Human leukocyte antigen (HLA) matching is one of the cornerstones of organ allocation in deceased-donor kidney transplantation. Increased numbers of HLA allele mismatches are associated with a higher risk of immunological rejection, de novo donor-specific HLA antibody development and graft failure. HLA epitopes are defined as the specific portions of HLA molecules to which antibodies and T-cell receptors bind with their paratopes. The same epitope can be present on different HLA alleles. Therefore, HLA matching at the epitope instead of allele level theoretically offers a more precise assessment of donor-recipient HLA compatibility and may more effectively prevent sensitization against foreign tissue. In this review, we describe the different options proposed to define clinically relevant HLA epitopes and critically discuss the potential role of HLA epitope matching in kidney transplantation.


Assuntos
Epitopos/imunologia , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Teste de Histocompatibilidade/métodos , Isoanticorpos/metabolismo , Isoantígenos/imunologia , Transplante de Rim , Epitopos/genética , Rejeição de Enxerto/prevenção & controle , Antígenos HLA/genética , Histocompatibilidade , Teste de Histocompatibilidade/tendências , Humanos , Isoantígenos/genética , Transplante Homólogo
3.
HLA ; 94(6): 471-481, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31515937

RESUMO

The virtual crossmatch (VXM) is gaining acceptance as an alternative approach to assess donor:recipient compatibility prior to transplantation. In contrast to a physical crossmatch, the virtual crossmatch does not require viable donor cells but rather relies on complete HLA typing of the donor and current antibody assessment of the recipient. Thus, the VXM can be performed in minutes which allows for faster transplant decisions thereby increasing the likelihood that organs can be shipped across significant distances yet safely transplanted. Here, we present a brief review of the past 50 years of histocompatibility testing; from the original complement-dependent cytotoxicity crossmatch in 1969 to the new era of molecular HLA typing, solid-phase antibody testing and virtual crossmatching. These advancements have shaped a paradigm shift in our approach to transplantation. That is, foregoing a prospective physical crossmatch in favor of a VXM. In this review, we undertake an in-depth analysis of the pros- and cons- of physical and virtual crossmatching.Finally, we provide objective data on the selected use of the VXM which demonstrate the value of a VXM in lieu of the traditional physical crossmatch for safe and efficient organ transplantation.


Assuntos
Técnicas de Laboratório Clínico/tendências , Biologia Computacional/tendências , Teste de Histocompatibilidade/tendências , Interface Usuário-Computador , Tipagem e Reações Cruzadas Sanguíneas/história , Tipagem e Reações Cruzadas Sanguíneas/métodos , Tipagem e Reações Cruzadas Sanguíneas/tendências , Técnicas de Laboratório Clínico/história , Técnicas de Laboratório Clínico/métodos , Biologia Computacional/história , Biologia Computacional/métodos , Teste de Histocompatibilidade/história , Teste de Histocompatibilidade/métodos , História do Século XX , História do Século XXI , Humanos , Invenções/tendências , Seleção de Pacientes , Valor Preditivo dos Testes
4.
J Clin Neurosci ; 59: 179-184, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30595166

RESUMO

To compare HLA typing between juvenile- and adult-onset myasthenia gravis (MG), we enrolled 101 children (age ≤12 years) and 168 adults (age ≥20 years) with MG. We excluded patients with histories of thymoma, thyroid disease, or other autoimmune disease. We selected 41 seronegative juvenile-onset patients with ocular symptoms only, and 41 seropositive adult-onset patients with generalized symptoms. We used next-generation sequencing for typing and analysis of HLA genes (Loci: A, B, C, DPA1, DPB1, DQA1, DQB1 and DRB1). Haplotypes HLA-A∗02:07:01-B∗46:01:01-C∗01:02:01-DQA1∗01:01:01-DQB1∗03:03:02-DRB1∗09:01:02, HLA-A∗11:01:01, HLA-A∗24:02:01, and HLA-DPA1∗02:02:02 were found to be related to juvenile-onset MG and HLA-A∗01:01:01, HLA-A∗02:03:01, HLA-C∗03:04:01, and HLA-DQB1∗06:02:01 to adult-onset MG. Therefore, our findings suggested that HLA typing might determine the heterogeneity between AChR-Ab negative juvenile-onset and AChR-Ab positive adult-onset Chinese MG patients.


Assuntos
Povo Asiático/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Teste de Histocompatibilidade/métodos , Miastenia Gravis/genética , Adulto , Criança , Feminino , Cadeias alfa de HLA-DP/sangue , Cadeias alfa de HLA-DP/genética , Cadeias beta de HLA-DQ/sangue , Cadeias beta de HLA-DQ/genética , Haplótipos/genética , Sequenciamento de Nucleotídeos em Larga Escala/tendências , Teste de Histocompatibilidade/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/sangue , Miastenia Gravis/diagnóstico , Adulto Jovem
5.
Methods Mol Biol ; 1802: 1-10, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29858798

RESUMO

The HLA region is the most polymorphic genes in the human genome and is associated with an increasing number of disease states. Historically, HLA typing methodology has been governed by phenotypic determination. This practice has evolved into the use of molecular methods such as real-time PCR, sequence-specific oligonucleotides, and sequencing-based methods. Numerous studies have identified HLA matching as a key determinate to improve patient outcomes from transplantation. Solid-organ transplants focus on HLA-DRB1 in renal organ allocation while hematopoietic cell transplants focus on HLA-A, -B, -C, -DRB1 matching. The role of HLA typing in the future will be driven by HLA expression, understanding of HLA haplotypes, and rapid HLA typing.


Assuntos
Teste de Histocompatibilidade/tendências , Transplante , Sequenciamento de Nucleotídeos em Larga Escala , Humanos
6.
BMC Nephrol ; 19(1): 116, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29776389

RESUMO

BACKGROUND: The magnitude effects of human leukocyte antigen (HLA) mismatching on post-transplant outcomes of kidney transplantation remain controversial. We aim to quantitatively assess the associations of HLA mismatching with graft survival and mortality in adult kidney transplantation. METHODS: We searched PubMed, EMBASE and the Cochrane Library from their inception to December, 2016. Priori clinical outcomes were overall graft failure, death-censored graft failure and all-cause mortality. RESULTS: A total of 23 cohort studies covering 486,608 recipients were selected. HLA per mismatch was significant associated with increased risks of overall graft failure (hazard ratio (HR), 1.06; 95% confidence interval (CI), 1.05-1.07), death-censored graft failure (HR: 1.09; 95% CI 1.06-1.12) and all-cause mortality (HR: 1.04; 95% CI: 1.02-1.07). Besides, HLA-DR mismatches were significant associated with worse overall graft survival (HR: 1.12, 95% CI: 1.05-1.21). For HLA-A locus, the association was insignificant (HR: 1.06; 95% CI: 0.98-1.14). We observed no significant association between HLA-B locus and overall graft failure (HR: 1.01; 95% CI: 0.90-1.15). In subgroup analyses, we found recipient sample size and ethnicity maybe the potential sources of heterogeneity. CONCLUSIONS: HLA mismatching was still a critical prognostic factor that affects graft and recipient survival. HLA-DR mismatching has a substantial impact on recipient's graft survival. HLA-A mismatching has minor but insignificant impact on graft survival outcomes.


Assuntos
Sobrevivência de Enxerto/fisiologia , Antígenos HLA/sangue , Teste de Histocompatibilidade/mortalidade , Transplante de Rim/mortalidade , Transplantados , Estudos de Coortes , Antígenos HLA/genética , Teste de Histocompatibilidade/tendências , Humanos , Transplante de Rim/tendências , Mortalidade/tendências
7.
Transfus Clin Biol ; 24(3): 124-130, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28709842

RESUMO

The diversification of potential donors to perform stem cell allografts now enables to propose a compatible graft cell source adapted to the different clinical situations. Transplants with a geno-identical sibling donor, otherwise with the most HLA-compatible unrelated donor, remain the first-line solutions. Alternative transplants allow to graft patients having no donors in international registries, owing to the rarity of their HLA typing. They are carried out with fairly incompatible grafts and are therefore limited by the existence in the recipient of preformed anti-HLA antibodies which predispose to their rejection. The simple prevention of acute Graft-versus-host disease in haplo-identical transplants, as well as the availability of donors, explain why they have very often replaced placental stem cell transplants. These latter remain useful for pediatric patients or in the absence of family donors.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Teste de Histocompatibilidade , Histocompatibilidade , Aloenxertos , Contagem de Células , Consanguinidade , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Seleção do Doador , Doença Enxerto-Hospedeiro/prevenção & controle , Haplótipos , Doenças Hematológicas/terapia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/tendências , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade/tendências , Humanos , Isoanticorpos/imunologia , Doadores Vivos , Irmãos
8.
Artigo em Inglês | MEDLINE | ID: mdl-28687174

RESUMO

Pre-implantation genetic diagnosis (PGD) requires the use of assisted reproductive technology (ART) to create several pre-implantation-stage embryos, followed by biopsy of embryonic cells for genetic testing and transfer of selected embryos to the womb to establish a pregnancy. HLA typing of ART-created embryos was first reported in 2001. The aim is to establish a pregnancy that is HLA-compatible with an affected sibling who requires haematopoietic stem cell transplantation. HLA-typing can be performed with or without PGD for the exclusion of a single-gene disorder. Haematopoietic stem cells collected from the umbilical cord blood or the bone marrow of the HLA-matched donor sibling born, or a combination of both sources, are used for transplantation and cure of the affected sibling. The procedure is multistep and technically challenging. All specialists involved must aim to adequately support and counsel prospective parents. Results have so far been encouraging, with many documented positive outcomes of affected children being cured.


Assuntos
Implantação do Embrião , Doenças Genéticas Inatas/terapia , Transplante de Células-Tronco Hematopoéticas , Teste de Histocompatibilidade/métodos , Diagnóstico Pré-Implantação/métodos , Criança , Feminino , Sangue Fetal/transplante , Aconselhamento Genético , Doenças Genéticas Inatas/diagnóstico , Teste de Histocompatibilidade/ética , Teste de Histocompatibilidade/tendências , Humanos , Recém-Nascido , Pais/psicologia , Polimorfismo de Nucleotídeo Único , Gravidez , Diagnóstico Pré-Implantação/ética , Técnicas de Reprodução Assistida , Fatores de Risco , Irmãos , Fatores de Tempo
9.
Oncologist ; 22(9): 1125-1134, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28546462

RESUMO

Hematopoietic stem cell transplant (HSCT) is potentially curative for a wide variety of malignant diseases, including acute and leukemias, lymphoma, and myelodysplasia. Choice of a stem cell donor is dependent on donor availability, donor compatibility and health, recipient disease type, and recipient condition. Current sources of stem cell donation for HSCT are matched sibling donors (MSDs), matched unrelated donors (MUDs), 1-antigen mismatched unrelated donors (MMUDs), haploidentical donors (haplo), and umbilical cord blood (UCB) units. Historically, preferred donors for HSCT have been human leukocyte antigen (HLA)-matched sibling donors; however, only about 30% of U.S. patients will have a MSD available. The majority of patients referred for HSCT will require an alternative donor graft: MUD, MMUD, UCB, or haplo. The likelihood of finding a MUD varies depending on the ethnicity of the recipient. White Caucasians of European descent have the greatest chance of finding a MUD. Chances of finding a MUD are significantly less for African-American or Hispanic recipients due to HLA polymorphisms. Therefore, MMUD, UCB, and haplo donor graft sources expand the donor pool for recipients who do not have a MSD or MUD available. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic HSCT has a potential donor in 2017. All transplant-eligible patients with hematologic malignancies should be evaluated by a transplant center to determine if HSCT is a viable treatment option for their underlying disease process. IMPLICATIONS FOR PRACTICE: The goal of this review is to increase the awareness of oncology practitioners to the availability of alternative donor stem cell transplants for patients with hematologic malignancies. Despite new agents, stem cell transplant remains the only curative therapy for many patients with acute and chronic leukemia, myelodysplasia, and lymphoma. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic stem cell transplant will have a donor.


Assuntos
Doença Enxerto-Hospedeiro/imunologia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/imunologia , Obtenção de Tecidos e Órgãos/métodos , Adulto , Aloenxertos/imunologia , Antígenos HLA/imunologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/tendências , Teste de Histocompatibilidade/tendências , Humanos , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/tendências , Transplante Homólogo/efeitos adversos , Transplante Homólogo/métodos , Transplante Homólogo/tendências
10.
Ann Transplant ; 20: 424-9, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26218888

RESUMO

Transplantation and transfusion are related and clinically important areas of multidisciplinary expertise, including pre-operative treatment, donor recruitment, tissue matching, and post-operative care. We have seen significant developments in these areas, especially in the late 20th and early 21st century. This paper reviews the latest advances in modern transplantation and transfusion medicine, including several new genetic markers (e.g., major histocompatibility complex class I chain-related gene A, killer cell immunoglobulin-like receptor, and human platelet antigens) for donor and recipient matching, genotyping platforms (e.g., next-generation sequencer and Luminex technology), donor recruitment strategies, and several clinical applications in which genotyping has advantages over agglutination tests (e.g., genotyping of weakly expressed antigens and determination of blood groups and human leukocyte antigen types in multi-transfused patients). We also highlight the roles of population studies and international collaborations in moving towards more efficient donor recruitment strategies.


Assuntos
Teste de Histocompatibilidade/tendências , Transplante de Órgãos/tendências , Doadores de Tecidos , Medicina Transfusional/tendências , Marcadores Genéticos , Humanos
11.
Clin Transplant ; 29(9): 842-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26172275

RESUMO

BACKGROUND: We sought to investigate temporal trends in the methodology of human leukocyte antibody assessment in heart transplantation. METHODS: The United Network for Organ Sharing database was queried from June 2004 to March 2013 to obtain pre-heart transplantation human leukocyte antibody results. The % panel reactive antibody for class I and II antibodies was recorded along with the methodology of assessment. Allosensitization was defined as class I and/or II panel reactive antibody of ≥ 10%. The primary outcome measure was graft survival. RESULTS: During the study period, 12,858 patients with available data underwent heart transplantation. The prevalence of allosensitization increased, with 16.8% in 2005-2006 sensitized at the time of transplantation compared to 23.1% in 2010-2011 (p < 0.001); this occurred in conjunction with an increase in the utilization of flow cytometry (77.2% in 2005-2006; 97.0% in 2010-2011, p < 0.001). Using multivariable analysis, a positive pre-heart transplantation panel reactive antibody by flow cytometry independently predicted graft loss. CONCLUSIONS: There has been a recent increase in flow cytometric assessment of human leukocyte antibodies prior to heart transplantation, which may be associated with an increase in the prevalence of pre-transplant patients being characterized as allosensitized. Flow cytometry may identify patients with the highest likelihood of graft loss.


Assuntos
Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Coração , Teste de Histocompatibilidade/métodos , Isoanticorpos/sangue , Cuidados Pré-Operatórios/métodos , Biomarcadores/sangue , Bases de Dados Factuais , Feminino , Citometria de Fluxo , Teste de Histocompatibilidade/estatística & dados numéricos , Teste de Histocompatibilidade/tendências , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/estatística & dados numéricos , Cuidados Pré-Operatórios/tendências , Estudos Retrospectivos , Estados Unidos
12.
BMC Genomics ; 15: 864, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25283548

RESUMO

BACKGROUND: Unambiguous human leukocyte antigen (HLA) typing is important in transplant matching and disease association studies. High-resolution HLA typing that is not restricted to the peptide-binding region can decrease HLA allele ambiguities. Cost and technology constraints have hampered high-throughput and efficient high resolution unambiguous HLA typing. We have developed a method for HLA genotyping that preserves the very high-resolution that can be obtained by next-generation sequencing (NGS) but also achieves substantially increased efficiency. Unambiguous HLA-A, B, C and DRB1 genotypes can be determined for 96 individuals in a single run of the Illumina MiSeq. RESULTS: Long-range amplification of full-length HLA genes from four loci was performed in separate polymerase chain reactions (PCR) using primers and PCR conditions that were optimized to reduce co-amplification of other HLA loci. Amplicons from the four HLA loci of each individual were then pooled and subjected to enzymatic library generation. All four loci of an individual were then tagged with one unique index combination. This multi-locus individual tagging (MIT) method combined with NGS enabled the four loci of 96 individuals to be analyzed in a single 500 cycle sequencing paired-end run of the Illumina-MiSeq. The MIT-NGS method generated sequence reads from the four loci were then discriminated using commercially available NGS HLA typing software. Comparison of the MIT-NGS with Sanger sequence-based HLA typing methods showed that all the ambiguities and discordances between the two methods were due to the accuracy of the MIT-NGS method. CONCLUSIONS: The MIT-NGS method enabled accurate, robust and cost effective simultaneous analyses of four HLA loci per sample and produced 6 or 8-digit high-resolution unambiguous phased HLA typing data from 96 individuals in a single NGS run.


Assuntos
Antígenos HLA-A/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Cadeias HLA-DRB1/genética , Teste de Histocompatibilidade/métodos , Técnicas de Genotipagem/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade/tendências , Humanos , Sensibilidade e Especificidade , Análise de Sequência de DNA
13.
Eur J Hum Genet ; 22(6): 715-23, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24253860

RESUMO

Recent developments in second-generation sequencing (SGS) technologies provide an avenue for achieving rapid and accurate high-throughput analysis of human and microbial genomic diversity. SGS technologies have the potential to transform existing medical management of complex and life-threatening medical conditions by enabling clinicians to develop disease-targeted clinical care plans for each patient. In this review, we outline how innovative SGS-based approaches can improve the care of recipients of allogeneic hematopoietic cell transplantation (HCT), a life-saving procedure that carries a 1-year mortality risk of over 30%. We specifically evaluate foreseeable applications of SGS-based technology in facilitating rapid, phase-sensitive human leukocyte antigen (HLA) typing, assessment of non-HLA genomic compatibility, identifying patients at high risk for adverse drug reactions, and post-HCT monitoring for engraftment, minimal residual disease and infection. We conclude that innovative SGS approaches have the capacity to revolutionize the HCT recipient risk assessment process, support non-invasive clinical monitoring and improve patient outcomes, thereby setting the stage for a new era of genomically informed patient-centered medicine.


Assuntos
Genômica/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Teste de Histocompatibilidade/métodos , Genômica/tendências , Antígenos HLA/genética , Transplante de Células-Tronco Hematopoéticas/tendências , Sequenciamento de Nucleotídeos em Larga Escala/tendências , Teste de Histocompatibilidade/tendências , Humanos , Pesquisa Translacional Biomédica/métodos , Pesquisa Translacional Biomédica/tendências
14.
Tissue Antigens ; 83(1): 10-6, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24355003

RESUMO

Super high-resolution single molecule sequence-based typing (SS-SBT) is a human leukocyte antigen (HLA) DNA typing method to the field 4 level of allelic resolution (formerly known as eight-digit typing) to efficiently detect new and null alleles without phase ambiguity by combination of long ranged polymerase chain reaction (PCR) amplification and next-generation sequencing (NGS) technologies. We previously reported the development and application of the SS-SBT method for the eight classical HLA loci, A, B, C, DRB1, DQA1, DQB1, DPA1 and DPB1. In this article, we describe the development of the SS-SBT method for three DRB1 linked loci, DRB3, DRB4 and DRB5 (DRB3/4/5) and characterization of DRB1-DRB3/4/5 haplotype structures to the field 4 level. Locus specific PCR primers for DRB3/4/5 were designed to amplify the gene regions from intron 1 to exon 6 [3' untranslated region (3'UTR)]. In total 20 DRB1 and 13 DRB3/4/5 allele sequences were determined by the SS-SBT to the field 4 level without phase ambiguity using 19 DR51, DR52 and DR53 positive genomic DNA samples obtained from Japanese. Moreover, 18 DRB1-DRB3/4/5 haplotypes were estimated to the field 4 level by the SS-SBT method in contrast to 10 haplotypes estimated by conventional methods to the field 1 level (formerly known as two digit typing). Therefore, DRB1-DRB3/4/5 haplotyping by SS-SBT is expected to provide informative data for improved HLA matching in medical research, transplantation procedures, HLA-related disease studies and human population diversity studies.


Assuntos
Cadeias HLA-DRB1/genética , Cadeias HLA-DRB3/genética , Cadeias HLA-DRB4/genética , Cadeias HLA-DRB5/genética , Teste de Histocompatibilidade/métodos , Alelos , Primers do DNA/genética , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Teste de Histocompatibilidade/tendências , Humanos , Reação em Cadeia da Polimerase , Imunologia de Transplantes
15.
Clin Transpl ; : 393-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25095534

RESUMO

The implementation of the solid phase antibody assays has allowed for the detection and characterization of human leukocyte antigen (HLA) specific antibodies with greater sensitivity and specificity. This information can then be used along with the donor's HLA typing to predict crossmatch results (a virtual crossmatch). Using these data and the level of immunological risk assessed to the antibodies detected, the determination of unacceptable antigens can be made. The calculated panel reactive antibody (CPRA) provides for a means to determine the frequency of these unacceptable antigens in the donor population and thereby predict the probability of a positive crossmatch. In 2009, the Organ Procurement Transplant Network administered by the United Network for Organ Sharing adopted the CPRA as the means to define sensitization and to assign allocation points. Follow-up studies have shown that the number of organ offers refused due to a positive crossmatch has decreased significantly and has saved money through the elimination of unnecessary testing. An additional benefit has been the increased number of sensitized patients being transplanted successfully. Through technical improvements and the refined interpretation of the solid phase antibody assays, continual progress is being made in the definition of the unacceptable antigens and the ability to transplant sensitized patients.


Assuntos
Antígenos HLA/imunologia , Teste de Histocompatibilidade/métodos , Transplante de Órgãos , Obtenção de Tecidos e Órgãos , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/tendências , Citometria de Fluxo/métodos , Citometria de Fluxo/tendências , Teste de Histocompatibilidade/tendências , Humanos , Alocação de Recursos , Sensibilidade e Especificidade , Doadores de Tecidos , Estados Unidos
16.
Tissue Antigens ; 80(1): 1-11, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22651253

RESUMO

The human leukocyte antigen (HLA) class I and class II loci are the most polymorphic genes in the human genome, with a highly clustered and patchwork pattern of sequence motifs. In the three decades since the first HLA gene was isolated by molecular cloning (a cDNA clone of HLA-B7), thousands of alleles have been identified and the names and sequences of all known alleles have been curated in the IMGT/HLA database. This extensive allelic diversity made and continues to make high-resolution HLA DNA typing very challenging. The first attempt at HLA DNA typing involved restriction fragment length polymorphism (RFLP) analysis, but this approach had many limitations. The development of PCR in 1985 allowed for the amplification of the polymorphic exons of the HLA class I and class II genes and the analysis of the polymorphic sequence motifs with sequence-specific oligonucleotide (SSO) hybridization probes. The immobilization of these probes on membranes and later on beads, along with primer sets for sequence-specific priming (SSP), gave rise to the current set of HLA typing reagents. Sanger sequencing has provided high-resolution typing but, in many cases, genotyping 'ambiguity' remains an issue. In the past few years, the introduction of next-generation sequencing, with the critical properties of massively parallel and clonal sequencing, has significantly reduced HLA genotyping ambiguity. Here, our lab's efforts to develop high-resolution and high-throughput HLA DNA typing using the 454 Sequencing System are reviewed, and the potential future developments and applications of HLA DNA typing are discussed.


Assuntos
DNA/análise , Antígenos HLA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Teste de Histocompatibilidade/tendências , Humanos , Patologia Molecular , Polimorfismo Genético
17.
Exp Clin Transplant ; 10(3): 209-18, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22631055

RESUMO

Sensitized candidates for heart transplant usually end up on a long waiting list and have an increased risk of rejection, graft loss, and incidence of cardiac allograft vasculopathy. An increasing number of studies have demonstrated the negative effect of preformed and posttransplant antibodies on graft survival. Thus, in sensitized patients, the combination of new, appropriate, desensitization protocols, and monitoring of posttransplant development of donor-specific antibodies may improve short-term and long-term outcomes. Introduction of more-sensitive and more-specific techniques for antibody detection provides a valid tool for assessing the degree of pretransplant HLA histocompatibility, and, therefore, predicting the results of crossmatch in sensitized patients, which are difficult to transplant. Currently, there are no accurate and standard methods to determine the functional characteristics of antibodies detected by solid-phase assay and, therefore, to predict their clinical relevance. Therefore, the future of heart transplantation requires a better understanding of tissue typing techniques and the effect of anti-HLA antibodies on clinical outcome to prevent discrimination against sensitized patients at the time of organ allocation.


Assuntos
Rejeição de Enxerto/prevenção & controle , Transplante de Coração/imunologia , Teste de Histocompatibilidade/tendências , Histocompatibilidade/imunologia , Anticorpos Anti-Idiotípicos/sangue , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Humanos , Doadores de Tecidos , Obtenção de Tecidos e Órgãos
18.
Hum Immunol ; 73(3): 291-7, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22244919

RESUMO

For the detection of microchimerism, molecular methods detecting donor-specific HLA-DRB1 alleles in the recipient are most commonly used. Nested polymerase chain reaction sequence specific primer (nested PCR-SSP) methods widely used to increase the sensitivity of detection have been reported to give frequent false-positive reactions. We have developed a new method combining nested PCR with single-strand conformation polymorphism analysis (nested PCR-SSCP) and tested the 1 to 0.00001% level of microchimerism for 27 different HLA-DRB1 alleles. For most (26/27) of the HLA-DRB1 alleles tested, this method could detect 0.01 to 0.001% of microchimerism and its sensitivity was equal to or better than that of nested PCR-SSP tested in parallel. Its specificity was verified by visualizing particular DRB1-specific SSCP bands under test. Nested PCR-SSP indicated frequent false-positive reactions, mainly caused by nonspecific amplification of DRB3/B4/B5 alleles present in the major (recipient) DNAs. We have compared a real-time quantitative PCR for non-human leukocyte antigen (HLA) target (insertion/deletion marker) using a commercial kit (AlleleSEQR Chimerism assay), and its microchimerism detection sensitivity (around 0.1%) was 1 step (10 times) lower than that of nested PCR-SSP or -SSCP methods for HLA-DRB1 alleles. We validated that the newly designed nested PCR-SSCP affords good sensitivity and specificity and may be useful for studying microchimerism in clinical settings.


Assuntos
Quimerismo , Cadeias HLA-DRB1/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo Conformacional de Fita Simples , Alelos , Reações Falso-Positivas , Estudos de Viabilidade , Teste de Histocompatibilidade/métodos , Teste de Histocompatibilidade/tendências , Humanos , Sensibilidade e Especificidade
19.
Tissue Antigens ; 78(1): 1-7, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21658007

RESUMO

Antibodies against human leukocyte antigens (HLAs) have long been associated with transfusion-related acute lung injury (TRALI). In contrast to febrile transfusion reactions and refractoriness to platelet transfusions in immunized patients, the causative antibodies in TRALI are present in the transfused blood component, i.e. they are formed by the blood donor and not by the recipient. Consequently, blood components with high plasma volume are particularly associated with TRALI. In addition to antibodies against HLAs, antibodies directed against human neutrophil antigens (HNAs) present in the plasma of predominantly multiparous female blood donors can induce severe TRALI reactions. Especially, antibodies to HLA class II and HNA-3a antigens can induce severe or even fatal ALI in critically ill patients. Over the last decade, the clinical importance of TRALI as major cause for severe transfusion-related morbidities has led to the establishment of new guidelines aimed at preventing this condition, including routine testing for HLA and -HNA antibodies for plasma donors with a history of allogeneic sensitization. This, in turn, poses new challenges for close collaboration between blood transfusion centers and histocompatibility and immunogenetics laboratories, for sensitive and specific detection of the relevant antibodies.


Assuntos
Lesão Pulmonar Aguda/etiologia , Lesão Pulmonar Aguda/prevenção & controle , Teste de Histocompatibilidade/tendências , Histocompatibilidade/fisiologia , Imunogenética/tendências , Reação Transfusional , Transfusão de Sangue/métodos , Transfusão de Sangue/normas , Transfusão de Sangue/tendências , Feminino , Antígenos HLA/imunologia , Teste de Histocompatibilidade/métodos , Humanos , Imunogenética/métodos , Modelos Biológicos , Medicina Regenerativa/métodos , Medicina Regenerativa/normas , Medicina Regenerativa/tendências
20.
Hum Immunol ; 72(9): 723-6, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21663780

RESUMO

Alleles of the C*07:01/07:06/07:18 group is distinguished by polymorphisms in exons 5-6. In a previous study, we focused on exons 2-3 of the gene and showed that 6.8% of Koreans express alleles in this group. In this study, we identified allelic and haplotypic diversities of the C*07:01/07:06/07:18 group in Koreans. Among 118 C*07:01/07:06/07:18-positive, unrelated, healthy samples, 96.6% were C*07:06 and 3.4% were C*07:01. Each allele was exclusively associated with a specific set of other alleles consisting of the conserved haplotypes A*01:01-C*07:01-B*08:01-DRB1*03:01-DQB1*02:01 (100%) and A*33:03-C*07:06-B*44:03-DRB1*07:01-DQB1*02:02 (95.6%), respectively. None carried C*07:18. With the continuous discovery of novel alleles, periodic updates with testing for newer alleles will be useful to support related research and clinical settings in each population.


Assuntos
Alelos , Etnicidade , Antígenos HLA-C/genética , Haplótipos/genética , Frequência do Gene , Técnicas de Genotipagem , Teste de Histocompatibilidade/tendências , Humanos , Coreia (Geográfico) , Reação em Cadeia da Polimerase , Polimorfismo Genético
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