Using Next-Generation Sequencing Technology to Confirm the HLA Rare Alleles Detected by PCR-SSOP / 中国实验血液学杂志

OBJECTIVE@#To confirm the HLA genotypes of the samples including 4 cases of magnetic bead probe HLA genotyping result pattern abnormality and 3 cases of ambiguous result detected by PCR sequence-specific oligonudeotide probe (SSOP) method.@*METHODS@#All samples derived from HLA high-resolution typing laboratory were detected by PCR-SSOP. A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality and 3 samples of ambiguous result were further confirmed by PCR sequence-based typing (SBT) technology and next-generation sequencing (NGS) technology.@*RESULTS@#A total of 4 samples of magnetic bead probe HLA genotyping result pattern abnormality were detected by PCR-SSOP method. The results of SBT and NGS showed that the HLA-A genotype of sample 1 did not match any known genotypes. NGS analysis revealed that the novel allele was different from the closest matching allele A*31:01:02:01at position 154 with G>A in exon 2, which resulting in one amino acid substitution at codon 28 from Valine to Methionine (p.Val28Met). The HLA-C genotype of sample 2 was C*03:119, 06:02, sample 3 was C*03:03, 07:137, and sample 4 was B*55:02, 55:12. A total of 3 samples with ambiguous result were initially detected by PCR-SSOP method. The re-examination results of SBT and NGS showed that the HLA-B genotype of sample 5 was B*15:58, 38:02, sample 6 was DRB1*04:05, 14:101, and sample 7 was DQB1*03:34, 05:02. Among them, alleles C*03:119, C*07:137 and DRB1*14:101 were not included in the Common and Well-documented Alleles (CWD) v2.4 of the Chinese Hematopoietic Stem Cell Donor Database.@*CONCLUSION@#The abnormal pattern of HLA genotyping results of magnetic probe by PCR-SSOP method suggests that it may be a rare allele or a novel allele, which needs to be verified by sequencing.

Childhood aplastic anaemia with paroxysmal nocturnal haemoglobinuria clones: A retrospective single-centre study in South Africa

Background: Paroxysmal nocturnal haemoglobinuria (PNH) clones in children are rare but commonly associated with aplastic anaemia (AA) and myelodysplasia.Objective: This study aimed to determine the prevalence of PNH clones in paediatric patients with idiopathic AA, identify differences in clinical and laboratory features and outcomes, and determine the impact of clone size on clinical presentation.Methods: Patients with confirmed idiopathic AA who were tested for PNH between September 2013 and January 2018 at the Inkosi Albert Luthuli Central Hospital, Durban, KwaZulu-Natal, South Africa, were included. PNH clones were detected in neutrophils and monocytes by flow cytometry using fluorescent aerolysin, CD24, CD66b and CD14. Results: Twenty-nine children with AA were identified and 11 were excluded. Ten patients (10/18, 55.6%) had PNH clones ranging from 0.11% to 24%. Compared to the PNH-negative group, these children were older (median: 10 years vs 4 years, p= 0.02) and had significantly lower total white cell counts (median 1.7 × 109/L vs 3.2 × 109/L; p= 0.04). There was no difference in median absolute neutrophil count or haemoglobin concentration. Four patients in each group received immunosuppressive therapy (IST). At six months, all four patients with PNH clones had responded, compared to one in the PNH-negative group. Conclusion: More than half of children with AA had a PNH clone. The size of the clone did not impact clinical severity; however, IST use may positively impact prognosis. We recommend early initiation of IST in patients with AA to avoid delays associated with human leukocyte antigen typing.

Optimización de unidades formadoras de colonias y detección del virus de papiloma humano en sangre de cordón umbilical / Colony-forming units optimization and human papillomavirus detection in umbilical cord blood

Resumen Introducción: Se requiere analizar diversos parámetros para el control de calidad adecuado de las unidades de sangre de cordón umbilical (USCU) cuando se utilizan con fines terapéuticos. Objetivo: Optimizar las unidades formadoras de colonias (UFC) de cultivos clonogénicos y detectar el genoma del virus del papiloma humano (VPH) en USCU. Métodos: Se incluyeron 141 muestras de sangre de cordón umbilical (SCU), de segmento y de UFC de cultivos clonogénicos de USCU. Se realizó extracción de ADN, cuantificación y amplificación por PCR del gen endógeno GAPDH. Se detectó el gen L1 del VPH con los oligonucleótidos MY09/MY11 y GP5/GP6+; los productos de PCR se migraron en electroforesis de agarosa. El ADN purificado de las UFC se analizó mediante electroforesis de agarosa y algunos ADN, con la técnica sequence specific priming. Resultados: La concentración de ADN extraído de UFC fue superior comparada con la de SCU (p = 0.0041) y la de segmento (p < 0.0001); así como la de SCU comparada con la de segmento (p < 0.0001). Todas las muestras fueron positivas para la amplificación de GAPDH y negativas para MY09/MY11 y GP5/GP6+. Conclusiones: Las USCU criopreservadas fueron VPH netativas; además, es factible obtener ADN en altas concentraciones y con alta pureza a partir de UFC de los cultivos clonogénicos.

Abstract Introduction: Analysis of several markers is required for adequate quality control in umbilical cord blood units (UCBU) when are used for therapeutic purposes. Objective: To optimize colony-forming units (CFU) from clonogenic cultures and to detect the human papillomavirus (HPV) genome in UCBU. Methods: One hundred and forty-one umbilical cord blood (UCB), segment or CFU samples from UCBU clonogenic cultures were included. DNA extraction, quantification and endogenous GAPDH gene PCR amplification were carried out. Subsequently, HPV L1 gene was detected using the MY09/MY11 and GP5/GP6+ oligonucleotides. PCR products were analyzed with electrophoresis in agarose gel. CFU-extracted purified DNA was analyzed by electrophoresis in agarose gel, as well as some DNAs, using the SSP technique. Results: CFU-extracted DNA concentration was higher in comparison with that of UCB (p = 0.0041) and that of the segment (p < 0.0001), as well as that of UCB in comparison with that of the segment (p < 0.0001). All samples were positive for GAPDH amplification and negative for MY09/MY11 and GP5/GP6+. Conclusions: Cryopreserved UCBUs were HPV-negative. Obtaining CFU DNA from clonogenic cultures with high concentrations and purity is feasible.

Neutropenia aloimune neonatal em gêmeas idênticas / Neonatal alloimmune neutropenia in identical twins

A neutropenia aloimune neonatal (NAN) é uma patologia causada pelo antagonismo imunológico, como a doença hemolítica do recém-nascido ou a trombocitopenia aloimune neonatal, mas relacionada aos neutrófilos, em vez de glóbulos vermelhos ou plaquetas. Descreveremos um caso clínico de duas gêmeas idênticas nascidas a termo, com Apgar de 8 e 9, sendo que após algumas horas do nascimento apresentaram febre. Um exame de sangue revelou neutropenia grave que resultou em sepse. O diagnóstico da NAN foi realizado clinicamente e por testes de histocompatibilidade. A prova cruzada por citometria de fluxo foi positiva, usando soro da mãe e suspensões celulares (granulócitos e linfócitos) das gêmeas e do pai. Este teste não fornece informações sobre para qual sistema genético os anticorpos foram positivos, se contra os antígenos específicos de neutrófilos humanos (HNA) ou contra os antígenos leucocitários humanos (HLA). Para o esclarecimento, realizamos o teste de aglutinação de granulócitos (GAT) com um painel de doadores fidelizados e com antígenos HNA1-5 conhecidos, utilizando o soro materno como reagente. Foi também realizada a pesquisa de anticorpos anti-HLA e anti-HNA no soro materno. Os genótipos HLA e HNA foram identificados, permitindo conhecer as especificidades dos anticorpos maternos contra os antígenos dos neutrófilos do marido e das filhas. O diagnóstico de NAN não é realizado na maioria dos hospitais de nosso país e do exterior, devido à dificuldade de execução dos testes de histocompatibilidade, no entanto a prova cruzada por citometria de fluxo pode facilmente ser implantada nos laboratórios clínicos, sendo que está descrita detalhadamente nesse caso clínico.

Neonatal alloimmune neutropenia (NAN) is a disease caused by immunological antagonism, such as hemolytic disease of the newborn or neonatal alloimmune thrombocytopenia, but related to neutrophils rather than to red blood cells or platelets. We will describe a clinical case of two identical twins born with Apgar 8 and 9 that started with fever few hours after delivery. A blood test revealed severe neutropenia, which was followed by sepsis. The diagnosis of NAN was done clinically and by histocompatibility testing. Flow cytometry crossmatch was positive, using mother serum and cell suspensions (granulocytes and lymphocytes) from the twin girls and from the father. This test did not provide information about the genetic system for which the antibodies are positive, if against human neutrophil antigens (HNA) or human leucocyte antigens (HLA). To clear this, the granulocyte agglutination test (GAT) was performed with a panel of control donors with known HNA1-5 antigens, using the maternal serum as a reagent. We did also a Luminex screening assay for detection of anti-HLA and anti-HNA antibodies in the mother serum. The HLA and HNA genotypes were identified, which allowed to define specificities in mother's antibodies against the neutrophil surface antigens from her husband and from the twins. The diagnosis of NAN diagnose is not done in most hospitals worldwide, mainly by the difficulty in executing the histocompatibility test. However, the crossmatch by flow cytometry could be easily done in clinical laboratories following the method described in this article.

Optimization of HLA-B*27 ALLELE Genotyping by PCR-SSP

OBJECTIVES: HLA-B27 is strongly associated with ankylosing spondylitis (AS) and its presence helps to confirm AS diagnosis. Due to the high HLA polymorphism and the differentiated contribution of alleles and molecules encoded by them, HLA-B*27 allele identification is relevant in the clinical follow-up, diagnosis, and treatment of this spondyloarthropathy. Inexpensive genotyping techniques with high specificity and sensitivity are of great interest in histocompatibility laboratories. This work aimed to optimize HLA-B*27 genotyping by Polymerase Chain Reaction Sequence-specific Primer (PCR-SSP), which is an accessible and inexpensive technique. METHODS: The PCR-SSP was standardized using 26 HLA-B*27 positive and 3 HLA-B*27 negative samples previously defined by Polymerase Chain Reaction Sequence-specific Oligonucleotide Probes (PCR-SSOP) (medium resolution, One Lambda®) and primers described by Duangchanchot et al. (2009). For validating the technique, 397 samples were genotyped using PCR-SSP as well as PCR-SSOP. RESULTS: The PCR-SSP technique was standardized for identifying the alleles HLA-B*27:02, HLA-B*27:CAFRW (05/13/16/17/28/37/38/39/42), HLA-B*27:CAFRZ (08/26/40), HLA-B*27:09 and HLA-B*27:12, which were found in 90 positive samples (22.67%). There was 100% agreement between the two techniques for heterozygous samples; however, two homozygous samples could not be detected by PCR-SSP. CONCLUSION: The HLA-B*27 genotyping using PCR-SSP, an easy-to-use, specific, and affordable technique, was optimized for heterozygous samples. This technique may contribute to AS diagnosis.

Everyone has a donor: contribution of the Chinese experience to global practice of haploidentical hematopoietic stem cell transplantation / 医学前沿

Human leukocyte antigen (HLA)-matched donors for hematopoietic stem cell transplantation (HSCT) have long been scarce in China. Haploidentical (haplo) donors are available for the vast majority of patients, but toxicity has limited this approach. Three new approaches for haplo-HSCT originated from Italy, China, and USA in 1990 and have been developed to world-renowned system up to now. The Chinese approach have been greatly improved by implementing new individualized conditioning regimens, donor selection based on non-HLA systems, risk-directed strategies for graft-versus-host disease and relapse, and infection management. Haplo-HSCT has exhibited similar efficacy to HLA-matched HSCT and has gradually become the predominant donor source and the first alternative donor choice for allo-HSCT in China. Registry-based analyses and multicenter studies adhering to international standards facilitated the transformation of the unique Chinese experience into an inspiration for the refinement of global practice. This review will focus on how the new era in which "everyone has a donor" will become a reality in China.

Annual Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2018) / 임상검사와정도관리

Here, we report the results of the first histocompatibility proficiency testing (PT) performed by the Korean Association of External Quality Assessment Service in 2018. The directly prepared PT specimens of whole blood, sera, and mononuclear cell suspensions were distributed to participants biannually. The number of participants was comparable to that in the previous external PT program, and the response rate was 88%–100%. The accuracy rates for human leukocyte antigen (HLA) A, B, C, DR, and DQ low and high resolution typing were 100%/100%, 100%/98%, 100%/99%, and 99%/98%, respectively; HLA-B27 typing, 99.1%; T cell and B cell crossmatching, 3.1% and 6.0%, respectively; and HLA antibody screening and identification, 100% and 100%, respectively. The results of HLA crossmatching were not reported from four participants due to poor cell viability. Further improvements of the specimen delivery process, grading criteria for crossmatching, and format of participant summary are warranted.

Size Estimation of HLA -Ⅰ class Typed Platelet Apheresis Donor Bank / 中国实验血液学杂志

OBJECTIVE@#To estimate the size of HLA -Ⅰ class typed platelet apheresis donor bank.@*METHODS@#A total of 16062 blood samples from Chinese Han voluntary unrelated marrow donors in Jiangsu were included in this study. Luminex-SSO was used to detect the HLA -Ⅰ class(A,B locus) antigens. The probability of finding at least one HLA matched unrelated donor was calculated based on the HLA -I class phenotype frequency.@*RESULTS@#The population genetic data of HLA -Ⅰ class in Jiangsu were obtained, the optinal bans size in HLA typed apheresis plateler donor registry databane hrad been estimated by evaluating the population genetic data of HLA-1 class same donor.@*CONCLUSION@#The establishment of HLA-1 class typed apheresis platelet donor bank with a total size of 1500 persons is acceptable, which can satisty the patients with phenotype freguency>0.002 to find at least 1 phenotype same donor in 95% probavility.

Frequência dos alelos do sistema antígeno leucocitário humano em doadores e pacientes pré-transplante de medula óssea / Human leukocyte antigen alleles frequency in donors and pre-transplant patients from bone marrow

Introdução: O estudo da frequência dos alelos detectados nos doadores e pacientes previamente selecionados para o transplante de medula óssea permite estimar as reais chances de um paciente em lista de espera encontrar um doador com antígeno leucocitário humano (Human leucocite antigen; HLA) idêntico não relacionado, além de facilitar e direcionar o planejamento do crescimento do Registro Nacional deDoadores de Medula Óssea. Objetivo: Descrever e analisar afrequência dos alelos do sistema HLA de classe I (HLA-A, -B e -C) e classe II (HLA-DRB1 e -DQB1) de doadores e pacientespré-transplante de medula óssea, do Hospital de Câncer deBarretos. Material e Métodos: Um total de 98 amostras dedoadores e 106 amostras de pacientes foi selecionado comtipificações em alta resolução, no período de outubro de 2014a outubro de 2015. As amostras foram tipificadas para os lociHLA-A, -B, -C, -DR e -DQ. Resultados: O predomínio daraça branca reflete a composição étnica do Brasil. As doençasde base mais comuns que levaram o paciente ao transplanteforam a leucemia aguda linfóide (34%) e mieloide (29,2%).Os grupos alélicos mais frequentes nos registros foramA*02, A*24, A*03, A*01, B*35, B*44, C*07, DQB1*03,DQB1*05, DQB1*06, DRB1*01 e DRB1*13. Conclusão: Osresultados encontrados reforçam a importância de conhecero perfil demográfico e imunogenético das regiões do Brasil,contribuindo desta forma na redução do tempo de espera porum doador histocompatível

Introduction: The study of allele frequencies detected in donors and patients previously selected for bone marrow transplantation allows us to estimate the real chances of a patient in the waiting list to find an Human leucocite antigen (HLA) identical unrelated donor. This also facilitates and drives the growth planning of the Brazilian Registry of planning Bone Marrow Transplantation (REDOME). Objective: Describe and analyze the frequency of HLA class I alleles (HLA-A*, -B* and ­C*) and class II alleles, genotypes, and haplotypes(HLA-DRB1* and -DQB1*) from donors and bone marrowpre-transplant patients. Material and Methods: A total of 98donor samples and 106 patient samples were selected withhigh resolution typing, from October 2014 to October 2015.Samples were typed for HLA-A, -B, -C, -DR and -DQ loci.Results: The predominance of the white race reflects theethnic composition of Brazil. The most common underlyingdiseases that led to transplantation patients were acutelymphoid leukemia (34%) and myeloid (29.2%). The mostfrequent allelic groups were A*02, A*24, A*03, A*01, B*35,B*44, C*07, DQB1*03, DQB1*05, DQB1*06, DRB1*01 andDRB1*13. Conclusion: The results reinforce the importanceof understanding the demographic and immunogenic profilefrom Brazilian Regions. This can contribute to the reduction ofwaiting time for a histocompatible donor.

Development of HLA-A, -B and -DR Typing Method Using Next-Generation Sequencing / 대한수혈학회지

BACKGROUND: Research on next-generation sequencing (NGS)-based HLA typing is active. To resolve the phase ambiguity and long turn-around-time of conventional high resolution HLA typing, this study developed a NGS-based high resolution HLA typing method that can handle large-scale samples within an efficient testing time. METHODS: For HLA NGS, the condition of nucleic acid extraction, library construction, PCR mechanism, and HLA typing with bioinformatics were developed. To confirm the accuracy of the NGS-based HLA typing method, the results of 192 samples HLA typed by SSOP and 28 samples typed by SBT compared to NGS-based HLA-A, -B and -DR typing. RESULTS: DNA library construction through two-step PCR, NGS sequencing with MiSeq (Illumina Inc., San Diego, USA), and the data analysis platform were established. NGS-based HLA typing results were compatible with known HLA types from 220 blood samples. CONCLUSION: The NSG-based HLA typing method could handle large volume samples with high-throughput. Therefore, it would be useful for HLA typing of bone marrow donation volunteers.

HLA DRB1*04:03 and Drug Reaction with Eosinophilia and Systemic Symptoms Induced by Oxcarbazepine: A Case Report / 대한소아신경학회지

Drug reaction with eosinophilia and systemic symptoms(DRESS), which occurs 2–8 weeks after taking a medication is a rare and potentially life-threatening drug-induced hypersensitivity reaction, which includes skin eruption, hematologic abnormalities, lymphadenopathy, and internal organ such as liver, lung, kidney involvement. Antiepileptic agents (e.g., carbamazepine, lamotrigine, phenytoin, and phenobarbital) and allopurinol are the most commonly reported causes. However, new antiepileptic agents, such as oxcarbazepine, rarely cause drug reaction with eosinophilia and systemic symptoms. A 11-year-old boy who was administered oxcarbazepine for 34 days developed widespread rashes, facial edema, fever, cough, nasal stuffiness, tonsillitis, and cervical lymphadenopathy. Laboratory test results showed leukocytosis, eosinophilia, thrombocytosis, elevated c-reactive protein, and elevated liver transaminase levels. As we suspected drug reaction with eosinophilia and systemic symptoms, we immediately withdrew oxcarbazepine and commenced corticosteroid therapy. The patient's skin lesions and abnormal laboratory results slowly improved. Before change the antiepileptic agents, we performed human leukocyte antigen (HLA) typing to assess the genetic risk factors of the drug reaction and the result was positive for HLA DRB1*04:03 known to cause severe acute drug hypersensitivity, such as Stevens-Johnson syndrome by oxcarbazepine in Koreans. We have presented the first report of drug reaction with eosinophilia and systemic symptoms associated with oxcarbazepine in a patient with HLA DRB1*04:03. Although DRESS by oxcarazepine is extremely rare and unpredictable, when suspected clinical symptoms occur, it is necessary to interrupt the causative drug rapidly and confirming the patient's HLA typing may help to select a safer alternative drug.

Results of Questionnaire Survey of Current Immune Monitoring Practice of Transplant Clinicians and Clinical Pathologists in Korea: Basis for Establishment of Harmonized Immune Monitoring Guidelines / 대한이식학회지

Detection of significant alloimmune response, which affects graft function and survival by effective immune monitoring, is critical for treatment decision making. However, there is no consensus regarding immune monitoring (IM) for kidney transplantation (flow KT) in Korea. The IM protocol may be affected by the level of immunological risk, the methods of desensitization and the availabilities of resources such as laboratory support and cost of tests. Questionnaire surveys designed to identify the current practices regarding immune monitoring of KT among transplant clinicians and clinical pathologists in Korea and eventually provide a basis for the establishment of harmonized immune monitoring guidelines in KT were administered as part of a Korean Society for Transplantation Sponsored Research Project. The survey results revealed significant variations in IM protocols and interpretation of tests affecting treatment decisions between institutes. Moreover, the results revealed a need to expand the histocompatibility tests into high resolution HLA typing in multiple loci and non-HLA antibody tests that facilitate the epitope analysis and eventually virtual crossmatching. The results of the questionnaire survey from clinical pathologists are addressing the urgent need for the standardization of interpretation and harmonization of results reporting in single antigen bead based HLA antibody identification. Finally, communication between clinicians and clinical pathologists to meet the clinical expectations regarding various immune monitoring tests is needed.

Uso de everolimo de novo em receptores de transplante renal com doador vivo HLA idêntico / De novo everolimus for recipients of kidney transplants from HLA identical donors

Resumo Introdução: Receptores de rim de doadores vivos HLA-idêntico apresentam menor risco para rejeição aguda e maior sobrevida do enxerto, quando comparado a outros tipos de transplante. Um regime imunossupressor sem inibidor de calcineurina (ICN) pode melhorar ainda mais esses resultados, através da redução de eventos cardiovasculares, metabólicos e tóxicos secundários a esse fármaco. Objetivo: Avaliar eficácia e segurança do novo tratamento imunossupressor com suspensão planejada do ICN. Métodos: Estudo prospectivo, aberto, braço único de tratamento em único centro para avaliar resultados do transplante renal HLA-idêntico em pacientes que recebem everolimo (EVR), tacrolimo (TAC) e corticoide, seguido da descontinuação do TAC 30 dias pós-transplante. Após análise interina de eficácia, a descontinuação do TAC foi postergada para o terceiro mês pós-transplante, através de emenda ao protocolo. Resultados: Trinta e nove pacientes foram incluídos. Apesar de as médias das concentrações de TAC e EVR terem respeitado os intervalos propostos, cinco pacientes tiveram rejeição aguda comprovada por biópsia e um paciente apresentou um episódio de glomerulite com depósitos de C4D. Esse resultado demandou o fim das inclusões. A proporção de pacientes com proteinúria > 0.5g/L não atingiu mais que 22% dos pacientes em nenhuma visita. Os eventos adversos mais frequentes foram relacionados ao uso de EVR: úlceras orais, dislipidemia e edema periférico. Conclusão: O regime proposto não foi eficaz para essa população, principalmente pela alta incidência de rejeição aguda. O perfil de segurança mostrou que a exposição prolongada a altas concentrações sanguíneas de EVR aumenta a incidência dos eventos adversos relacionados ao fármaco.

Abstract Introduction: Kidney transplant recipients from HLA-identical living donor have lower risk of acute rejection and greater graft survival compared to other types of kidney transplantation. Immunosuppressive regimens without calcineurin inhibitors (CNI) can further improve these results by reducing cardiovascular, metabolic and toxic events related to this drug class. Objective: This study aimed to evaluate efficacy and safety of a new immunosuppressive regimen with planned suspension of CNI. Methods: This was a prospective, single center and single treatment arm study to evaluate HLA-identical kidney transplant recipients receiving everolimus (EVR), tacrolimus (TAC) and corticosteroids, followed by TAC discontinuation 30 days after transplantation. TAC discontinuation was later postponed to the third month after an interim efficacy analysis. Results: Thirty-nine patients were included. Although mean TAC and EVR blood concentrations have remained within the proposed therapeutic ranges, five patients had biopsy-proven acute rejection and one patient had an episode of C4D-positive glomerulitis. This result led to the end of the inclusions. Interestingly, the proportion of patients with proteinuria greater than 0.5 g/L has not reached more than 22% of patients in any visit. Adverse events related to EVR use were the most incident in this population: oral ulcers, dyslipidemia and peripheral edema. Conclusion: The proposed scheme was not effective for this population, particularly due to a high incidence of acute rejection. Safety profile showed that prolonged exposure to a high concentration of blood EVR increases the incidence of adverse events related to this drug.

probability of finding a fully matched related donor: can it be helpful to determine the best alternative donor source?

Background: In Western society, only one-third of patients who need bone marrow transplantation [BMT] would have a fully matched sibling donor [MSD]. In Arab countries, there is scarce information about the likelihood of finding a fully MSD, although higher chance might be expected due to large family size

Objective: To report the probability of finding a fully matched sibling/related donor and probe the best strategy for alternative donor source

Design: A Retrospective Study

Setting: King Fahad Specialist Hospital-Dammam [KFSH-D], Saudi Arabia

Method: HLA-typing of 1,252 samples from 240 consecutive patients and their corresponding potential donors referred for HSCT were reviewed. HLA-low to medium resolution molecular typing by PCR -SSO for A, B, C, DR and DQ loci were performed on Luminex platform. The probability of finding a matched donor was determined by calculating the percentage of patients who are 10 out of 10 matched with corresponding donors

Result: The probability of finding MSD or relative in our populations was 59%. Ninety-five percent had fully matched siblings, 4% had fully matched parent/s, and 1% had fully matched relative. However, this rate was age dependent [28% in young children, 50% in older children and 70% in adults]

Conclusion: There is an overall high-rate of finding fully matched relative donors in Saudi compared to Western societies. Strategies to develop alternative donor sources should be prioritized taking into consideration this high rate, the current difficulty in establishing large registries and the promising outcome of haploidentical and cord blood transplantation

Enfermedad celíaca: revisión / Celiac disease: a review

La Enfermedad Celiaca (EC) tiene una prevalencia cercana al 1% de la población general y se considera que hay un número importante de pacientes asintomáticos no diagnosticados. Su presentación clínica es variable comprendiendo el clásico síndrome de malabsorción, formas menores y la EC silente. El diagnóstico serológico tiene una elevada sensibilidad y especificidad y siempre debe confirmarse con biopsia. El diagnóstico en pacientes en dieta libre de gluten incluye test de tipificación de HLA y prueba de dieta con gluten con estudio serológico e histológico posterior. El pilar del tratamiento es la dieta libre de gluten, que debe ser supervisada por un nutriólogo con experiencia. La monitorización de la terapia debe realizarse con serología. La EC mal controlada puede determinar complicaciones como linfoma y adenocarcinoma de intestino delgado. En el futuro es probable que nuevas terapias farmacológicas sean de utilidad en el manejo de la EC.

Celiac disease has a prevalence near to 1% of general population and there is an important amount of asymptomatic people not yet diagnosed. Clinical presentation includes the classical malabsorption syndrome, minor and silent celiac disease. Serologic diagnosis has an elevated sensitivity and specificity, and must be confirmed by biopsy. Diagnosis in those on gluten free diet includes HLA type and gluten challenge with posterior serologic and histologic evaluation. The core of the treatment is the gluten free diet that must be supervised by an expert nutritionist. Monitoring is with serology. Poor disease control can determine complications such as lymphoma and small bowel adenocarcinoma. In the future, it is likely that new pharmacologic therapies will be available for the management of celiac disease.

Frecuencia de genes HLA en pacientes con insuficiencia renal crónica procedentes del occidente y centro de Cuba / Frequency of HLA genes in patients with chronic kidney insufficiency, from western and central Cuba

Introducción: el trasplante es la terapia que permite la mayor sobrevida a los pacientes con insuficiencia renal crónica. Para prevenir el rechazo del órgano, en primer lugar es necesario un estudio de la compatibilidad de los antígenos leucocitarios humanos (HLA) del paciente y de los posibles donantes. En Cuba solo se había realizado la tipificación HLA por métodos serológicos, pero en la actualidad se emplean técnicas moleculares. Objetivo: caracterizar el polimorfismo de los alelos HLA A, B, DR y DQ por métodos moleculares en pacientes cubanos en espera de trasplante renal. Métodos: se estudiaron 410 pacientes con insuficiencia renal crónica de las regiones occidental y central del país a los que se les realizó tipificación molecular de los loci mencionados. Los resultados se expresaron según la nueva nomenclatura y fueron registrados en una base de datos confeccionada al efecto. Se compararon las frecuencias alélicas de la población blanca y no blanca y se determinó el porcentaje de frecuencia de los haplotipos para los alelos clase I y II. Resultados: los alelos A*11, A*30, A*74, B*42, B*51 y B*53 fueron más frecuentes en la población blanca mientras que los alelos B*58 y DRB1* 15 predominaron en los no blancos. Las frecuencias haplotípicas más encontradas en la clase I en la población blanca fueron A*02 B*51, A*02 B*44, A*02 B*35; y en la no blanca, A*01B*08, A*02B*51, A*02B*44. Para los alelos de la clase II, en la población blanca fueron DQB1*03, DRB1*04, DQB1*06, DRB1*13, DRB1*05, DRB1*01; y en los no blancos, DQB1*03, DRB1*04, DQB1*06, DRB1*13, DQB1*05, DRB1*01. Conclusiones: la caracterización de los pacientes con insuficiencia renal crónica con respecto a su tipificación HLA permitirá trazar estrategias futuras relacionadas con la donación y el trasplante en todo el país(AU)

Introduction: transplantation is the therapy allowing the highest possible survival in patients with chronic kidney insufficiency. To prevent rejection of the organ, first of all it is necessary to make a compatibility test of human leukocyte antigens (HLA) from the patient and the possible donors. In Cuba, only serological HLA typing had been made but at present, molecular techniques are being applied. Aim: characterization of polimorfirsm of alleles HLA A, B, DR y DQ by molecular techniques in Cuban patients awaiting renal transplantation. Methods: four hundred and ten patients with chronic kidney insufficiency from Western and Central Cuba were studied by molecular typing of the above mentioned loci. Results were expressed by the new nomenclature and were registered In a data base prepared for that purpose. Allele frequencies of white and no white population were compared and percentage of haplotype frequencies for alleles class I and II were determined. Results: alleles A*11, A*30, A*74, B*42, B*51and B*53 were more frequent in white population while B*58 y DRB1*, 15 were mostly found in no whites. Haplotypic frequencies most found in class I in white population were A*02 B*51, A*02 B*44, A*02 B*35; and in no whites, A*01B*08, A*02B*51, A*02B*44. For class II alleles, DQB1*03, DRB1*04, DQB1*06, DRB1*13, DRB1*05, DRB1*01 were the most found in white population; and in no whites, DQB1*03, DRB1*04, DQB1*06, DRB1*13, DQB1*05, DRB1*01. Conclusions: characterization of patients with chronic kidney insufficiency in respect to HLA typing will allow future strategies related to kidney donation and transplantation in the whole country(AU)

Sequence Analysis of A Novel HLA-B*13:68 Allele / 中国实验血液学杂志

<p><b>OBJECTIVE</b>The purpose of this research was to identify a novel HLA-B allele in Chinese population.</p><p><b>METHODS</b>The HLA typing of bone marrow donors was performed by PCR-SBT. The ambiguous novel HLA allele was confirmed with GSSP method.</p><p><b>RESULTS</b>The sequence of a sample was different from all alleles in the HLA-B databases. The sequence analysis showed that it differed from the closet matching allele HLA-B*13:01:01 at one nucleotide substitution, 137 T > C in Exon2, which resulted in an amino acid change from Phenylalanine (Phe) to Serine (Ser) at codon 22.</p><p><b>CONCLUSION</b>A novel allele was identified and named as HLA-B*13:68 by the WHO Nomenclature Committee.</p>

Interlaboratory Comparison of the Results of Lifecodes LSA Class I and Class II Single Antigen Kits for Human Leukocyte Antigen Antibody Detection

BACKGROUND: Although single antigen bead assays (SAB) are approved qualitative tests, the median fluorescence intensity (MFI) values obtained from SAB are frequently used in combination with quantitative significances for diagnostic purposes. To gauge the reproducibility of SAB results, we assessed the interlaboratory variability of MFI values using identical kits with reagents from the same lot and the manufacturer's protocol. METHODS: Six serum samples containing HLA-specific antibodies were analyzed at five laboratories by using Lifecodes LSA Class I and Class II SAB kits (Immucor, USA) from the same lot, according to the manufacturer's protocol. We analyzed the concordance of qualitative results according to distinct MFI cutoffs (1,000, 3,000, 5,000, and 10,000), and the correlation of quantitative MFI values obtained by the participating laboratories. The CV for MFI values were analyzed and grouped by mean MFI values from the five laboratories ( or =10,000). RESULTS: The categorical results obtained from the five laboratories exhibited concordance rates of 96.0% and 97.2% for detection of HLA class I and class II antibodies, respectively. The Pearson correlation coefficients for MFI values of class I and class II antibodies were between 0.947-0.991 and 0.992-0.997, respectively. The median CVs for the MFI values among five laboratories in the lower MFI range (<1,000) were significantly higher than those for the other MFI ranges (all P<0.01). CONCLUSIONS: Analysis of SAB performed in five laboratories using identical protocols and reagents from the same lot resulted in high levels of concordance and strong correlation of results.