Avaliação de antígeno leucocitário humano classe I e II em pacientes pediátricos com gastrite e úlcera duodenal ativas e Helicobacter pylori positivo / Evaluation of human leukocyte antigen class i and ii antigens in helicobacter pylori-positive pediatric patients with active gastritis and duodenal ulcer

ABSTRACT BACKGROUND: As being the first bacteria determined to be carcinogenic, Helicobacter pylori (H. pylori) is a pathogen localized in the stomach in more than half of the world population. Some earlier studies have found a relation between tissue histocompatibility antigens and gastric cancers depending on the regions. OBJECTIVE: The present study aimed to determine the distribution of human leukocyte antigen (HLA) class I and class II antigens in H. pylori-positive pediatric patients with active gastritis and duodenal ulcer, excluding cancer cases, in our center. METHODS: The study included 40 patients diagnosed with H. pylori-positive active gastritis and duodenal ulcer and 100 controls consisting of healthy donor candidates. The HLA class I and class II antigens were studied in the isolated DNA samples using the polymerase chain reaction sequence-specific oligonucleotide probes. RESULTS: The frequency of HLA-B*51 antigen was significantly higher in the patient group than in the control group (40% vs 17%; P=0.003). There was no difference between the two groups in terms of the frequencies of HLA-A, HLA-C, HLA-DR, and HLA-DQ antigens. CONCLUSION: It was determined that HLA-B*51 plays a critical role in H. pylori infection.

RESUMO CONTEXTO: Determinada como sendo a primeira bactéria cancerígena, o Helicobacter pylori (H. pylori) é um patógeno localizado no estômago em mais da metade da população mundial. Alguns estudos anteriores têm encontrado uma relação entre câncer gástrico e antígenos de histocompatibilidade de tecido dependendo das regiões. OBJETIVO: O presente estudo teve como objetivo determinar a distribuição em nosso centro do antígeno leucocitário humano (HLA) de classe I e antígenos classe II em pacientes pediátricos H. pylori-positivos com gastrite e úlcera duodenal ativas, excluindo casos de câncer. MÉTODOS: O estudo incluiu 40 pacientes H. pylori-positivos diagnosticados com gastrite e úlcera duodenal ativas e 100 controles consistindo de candidatos doadores saudáveis. Foram estudadas nas amostras de DNA isoladas o antígeno leucocitário humano classe I e antígenos classe II, utilizando-se as cadeias de sequência específica de polimerase do oligonucleotideo. RESULTADOS: A frequência do antígeno HLA - B * 51 foi significativamente maior no grupo de pacientes do que no grupo controle (40% vs 17%; P=0,003). Não houve diferença entre os dois grupos em termos das frequências dos antígenos HLA-A, HLA-DR, HLA-DQ e HLA-C. CONCLUSÃO: Determinou-se que o HLA - B * 51 desempenha um papel crítico na infecção pelo H. pylori.

The human leukocyte antigen G molecule (HLA-G) expression in patients with nasal polyposis / A expressão do antígeno humano leucocitário G (HLA-G) em pacientes com polipose nasossinusal

INTRODUCTION: Sinonasal polyposis (NP) is a chronic inflammatory pathology of the nasal/paranasal cavities which affects from 1%-4% of the population. Although polyps seem to be a manifestation of chronic inflammation in both allergic and non-allergic subjects, the pathogenesis of nasal polyposis remains unknown. HLA-G molecules are a kind of no classic class I antigen with anti-inflammatory and tolerogenic properties. Little attention has been paid to the role of HLA-G chronic inflammatory disorders. OBJECTIVE: The aim of this study is to investigate the expression of HLA-G in the NP. MATERIALS AND METHODS: Prospective study involving samples of patients presenting with nasal polyposis that were subjected to the immunohistochemistry technique. After a skin prick test, all patients were divided into atopic and nonatopic groups and classified as asthmatic or non-asthmatic. RESULTS: Immunohistochemical staining demonstrated a higher expression of the HLA-G molecule in samples from nonatopic than in those from atopic patients, and was significantly lower in the non-asthmatic patients. CONCLUSION: These results indicate that HLA-G may play an important role in the pathology of nasal polyposis. Considering the anti-inflammatory properties of HLA-G, this study suggests that it could reduce susceptibility to atopy and asthma. .

INTRODUÇÃO: Polipose nasossinusal (PNS) é uma patologia inflamatória crônica das cavidades nasais/paranasais que afeta 1%-4% da população. Embora os pólipos pareçam ser uma manifestação de inflamação crônica em ambos os indivíduos alérgicos e não alérgicos, a patogênese da polipose nasal permanece desconhecida. Moléculas HLA-G são antígenos não clássicos da classe I com propriedades anti-inflamatórias e tolerogênicas. Pouca atenção tem sido dada ao papel do HLA-G em doenças inflamatórias crônicas. OBJETIVO: Investigar a expressão de HLA-G na PNS. MATERIAIS E MÉTODOS: Estudo prospectivo de pacientes com polipose nasal que foram submetidas à técnica de imuno-histoquímica. Após realizarem teste cutâneo, os pacientes foram divididos em grupos atópicos e não atópicos e classificados como asmáticos ou não asmáticos. RESULTADO: A coloração imuno-histoquímica mostrou uma maior expressão da molécula HLA-G em pacientes não atópicos do que naqueles atópicos e foi significativamente inferior nos pacientes não asmáticos. CONCLUSÃO: Os resultados indicam que o HLA-G pode ter um papel importante na patologia da polipose nasal. Considerando as propriedades anti-inflamatórias do HLA-G, este estudo sugere que ele poderia reduzir a susceptibilidade a atopia e asma. .

A study on human leukocyte antigen class I molecules in paediatric bronchial asthma.

Childhood asthma, often associated with atopy, is more common in boys and may persist throughout life in 50% of cases. This case-control study was carried out to examine if any association of paediatric bronchial asthma with human leukocyte antigen (HLA) class I antigens. Thirty-six children with bronchial asthma diagnosed on basis of Global Initiative for Asthma (GINA) criteria and an equal number of healthy controls without history of bronchial asthma were studied. Low resolution HLA- ABC typing was performed by sequence specific primers (SSP) and the frequency of HLA–ABC antigens in the two groups was compared. Total serum immunoglobulin E (IgE) estimation was done as a marker of atopy by ELISA. The study included 24 boys and 12 girls aged 13 months to 11 yrs, of which 16 (44%) had positive family history. Serum IgE levels were elevated in 20 (55%) of the cases and 33% of controls with peak values of 4877 and 627 IU/ml, respectively. No statistically significant correlation was observed between childhood asthma and HLA class I antigens, however, a statistically significant correlation was observed between serum IgE levels and asthma, which was elevated in cases, as compared to normal population. Serum IgE levels did not show a linear trend, in that a direct correlation with the severity of disease was not observed.

Rational design of diagnostic and vaccination strategies for tuberculosis

The development of diagnostic tests which can readily differentiate between vaccinated and tuberculosis-infected individuals is crucial for the wider utilization of bacillus Calmette-Guérin (BCG) as vaccine in humans and animals. BCG_0092 is an antigen that elicits specific delayed type hypersensitivity reactions similar in size and morphological aspects to that elicited by purified protein derivative, in both animals and humans infected with the tubercle bacilli. We carried out bioinformatics analyses of the BCG_0092 and designed a diagnostic test by using the predicted MHC class I epitopes. In addition, we performed a knockout of this gene by homologous recombination in the BCG vaccine strain to allow differentiation of vaccinated from infected individuals. For that, the flanking sequences of the target gene (BCG_0092)were cloned into a suicide vector. Spontaneous double crossovers, which result in wild type revertants or knockouts were selected using SacB. BCG_0092 is present only in members of the Mycobacterium tuberculosis complex. Eight predicted MHC class I epitopes with potential for immunological diagnosis were defined, allowing the design of a specific diagnostic test. The strategy used to delete the (BCG_0092) gene from BCG was successful. The knockout genotype was confirmed by PCR and by Southern blot. The mutant BCG strain has the potential of inducing protection against tuberculosis without interfering with the diagnostic test based on the use of selected epitopes from BCG_0092.

Two Cases of Transfusion-related Acute Lung Injury Triggered by HLA and Anti-HLA Antibody Reaction

Transfusion-related acute lung injury (TRALI) is a serious adverse transfusion reaction that is presented as acute hypoxemia and non-cardiogenic pulmonary edema, which develops during or within 6 hr of transfusion. Major pathogenesis of TRALI is known to be related with anti-HLA class I, anti-HLA class II, or anti-HNA in donor's plasma. However, anti-HLA or anti-HNA in recipient against transfused donor's leukocyte antigens also cause TRALI in minor pathogenesis and which comprises about 10% of TRALI. Published reports of TRALI are relatively rare in Korea. In our cases, both patients presented with dyspnea and hypoxemia during transfusion of packed red blood cells and showed findings of bilateral pulmonary infiltrations at chest radiography. Findings of patients' anti-HLA antibodies and recipients' HLA concordance indicate that minor pathogenesis may be not as infrequent as we'd expected before. In addition, second case showed that anti-HLA class II antibodies could be responsible for immunopathogenic mechanisms, alone.

Comparative Evaluation of ELISA and Luminex Panel Reactive Antibody Assays for HLA Alloantibody Screening / 대한진단검사의학회지

BACKGROUND: For the detection of HLA antibodies, solid-phase tests using purified HLA antigens are increasingly used. In this study, we analyzed the panel reactive antibody (PRA) test results using ELISA and Luminex methods, and the results were compared with those of crossmatch test. METHODS: A total of 111 sera including 90 sera from kidney transplanted patients were tested. ELISA-PRA was performed using Lambda Antigen Tray Class I and II Mixed kits (One Lambda Inc., USA) and additional test was performed to identify HLA specificities. Luminex-PRA tests were performed using LABScreen Mixed kits (One Lambda Inc., USA) and LIFECODES LifeScreen Deluxe kits (Tepnel Co., USA). RESULTS: The positive rates of PRA were higher in Tepnel (P=0.006) and One Lambda Luminex (P<0.001) methods than ELISA, without significant difference between two Luminex methods (P=0.087). The overall concordance rate among the three PRA tests was 62.2% (69/111). The positive and negative predictive values of PRA tests for the flow cytometric crossmatch were 33.3-45.7% and 85.7-89.5%, respectively. Of the two Luminex methods, One Lambda showed higher positive rate than Tepnel for the detection of class I antibodies. The sensitivity of pretransplant PRA for the detection of posttransplant acute rejection episodes was higher in Luminex (P=0.007 for Tepnel, P=0.003 for One lambda) than ELISA method. CONCLUSIONS: Different methods used to detect HLA antibodies showed discrepant results. As the Luminex method was more sensitive than ELISA for the detection of HLA antibodies, it can be used as a routine test in the transplantation laboratory.

Evidencia del impacto de los anticuerpos anti-HLA y anti-MICA en la pérdida del injerto renal / Evidence on the role of HLA and MICA antibodies in renal graft loss

Antecedentes: Los anticuerpos anti-HLA y anti-MICA se han asociado cada vez con mayor frecuencia a menor supervivencia del injerto renal. El objetivo de este estudio es comunicar la frecuencia de pérdida del injerto dos años después de la detección de anticuerpos anti-HLA, anti-MICA, o ambos, en un grupo de receptores de trasplante renal (RTR). Métodos: Estudiamos a 196 RTR con injerto funcional. El suero de los pacientes fue analizado para la presencia de anticuerpos IgG anti-HLA clase I y clase II con Luminex utilizando LABScreen®Mixed y LABScreen® PRA. La presencia de anticuerpos anti-MICA en el mismo suero se analizó por Luminex. Resultados: De 196 RTR (edad promedio 36.7 años, 42% sexo femenino), 124 (63.3%) fueron negativos a todos los anticuerpos estudiados y 72 (36.7%) fueron positivos: 34 para anticuerpos anti-HLA solo, 29 para anticuerpos anti-MICA solo y nueve para anticuerpos anti-HLA+anti-MICA. A una mediana de seguimiento de 20.5 meses (1.2-25.2), ocho pacientes perdieron el injerto por daño crónico del mismo, confirmado por biopsia: 2/124 (1.6%) del grupo de anticuerpos negativos y 6/72 (8.3%) del grupo de anticuerpos positivos, con una supervivencia del injerto significativamente inferior para el grupo de anticuerpos positivos (p=0.046, log-rank test). Conclusiones: La presencia de anticuerpos circulantes estuvo asociados con riesgo incrementado para pérdida del injerto; la coexistencia de anticuerpos anti-HLA y anti-MICA produjo el riesgo más alto para pérdida del injerto en la población analizada.

BACKGROUND: HLA and MICA antibodies are increasingly associated with poorer graft survival. The aim of this study is to report the frequency of graft loss 2 years after the detection of HLA abs and MICA abs among a group of kidney transplant recipients. METHODS: We tested 196 patients with a functioning graft. Sera were screened for HLA and MICA IgG abs by Luminex, using the LABScreen Mixed, and LABScreen PRA. The sera were screened for MICA abs by Luminex. RESULTS: Of 196 kidney transplant recipients (mean age 36.7 years, 42% female), one hundred twenty four (63.3%) were negative to all tested abs, and 72 (36.7%) were positive for: HLA abs alone = 34, MICA abs alone = 29, and HLA+MICA abs = 9. At a median followup of 20.5 (1.2-25.2) months, 8 patients lost their grafts due to biopsy-confirmed chronic allograft injury: 2/124 (1.6%) ab-negative, and 6/72 (8.3%) ab-positive, with a significantly lower survival for the Ab-positive group (p = 0.046, log-rank test). CONCLUSIONS: The presence of circulating abs was associated with an increased risk of graft loss, and the coexistence of HLA and MICA abs increases the risk of graft loss.

Experience on Identification of Cross-Reactive Group Specificity Performed by Anti-human Globulin Panel Reactive Antibody Tests / 대한진단검사의학회지

BACKGROUND: Panel reactive antibody (PRA) is to screen and identify HLA antibody. Majority of antibody specificities in high-PRA are directed against cross reactive group (CREG). Thus, this study was to know the advantage of identifying CREG specificity and whether antibody specificities are changed according to CREG classification. METHODS: HLA class I antibodies were identified from 159 sera from 108 patients in Asan Medical Center, who had shown more than 5% PRA by anti-human globulin (AHG)-complement-dependent cytotoxicity (CDC). Tail analysis-based computer program was developed to identify specificities, applying both Rodey (R-ABC) and Takemoto (T-ABC) classification. The results were also compared with those obtained when without CREG application (ABC). RESULTS: Among 151 cases in which HLA specificities was identified, the frequency of CREG specificity was 22.5% in R-ABC and 27.2% in T-ABC. Eleven cases showed CREG specificities only in one classification. However, the individual antigen specificities in one hand were all included in the CREG identified in the other hand. CREG specificities in samples with PRA >50% (60%) were more frequently identified than those in samples with PRA < or =50% (9%) (in R-ABC, P<0.0001). Without applying CREG to interpretation, specificity was not identified in 9 cases. CONCLUSIONS: Application of CREG enhanced the rate of antibody identification. Antibody specificities of those cases where CREG specificities were different between Rodey and Takemoto classifications were almost the same when compared at the individual antigen level. Therefore, it was thought that it makes no difference to use any one of these two classifications in interpreting PRA.

HLA class I antibodies in thalassemic patients.

This study was undertaken to demonstrate the prevalence of HLA class I antibodies among 62 polytransfused patients. The diagnosis included beta-thalassemia major, beta-thalassemia/Hb E disease and severe Hb H disease. Their ages ranged from 1 year to 23 years with the mean age of 10.7 years. The number of packed red cell transfusions ranged from 3 to 235 with the mean of 60 episodes per patient. The standard microlymphocytotoxicity test was performed using 50 panels of lymphocytes which specifically identified the majority of HLA class I antibodies. 31/62 cases (50%) were positive for HLA class I antibodies. The detection of single or multiple antibodies depended upon the number of blood transfusions and the patients' ages. These antibodies were induced by the leukocytes present in the transfused packed red cells. Therefore, leukocyte-reduced packed red cells prepared by either additional inverted centrifrugation or leukocyte filter is suggested for the routine blood bank service.

Avaliaçäo da especifidade dos anticorpos linfocitotóxicos em lúpus eritematoso sistêmico: correlaçäo com atividade clínica de doença / Evaluation of lymphocytoxic antibodies specificity in systemic lupus erythematosus: correlation with the clinical activity of the disease

Pacientes portadores de lúpus eritematoso sistêmico (LES), caracterizados em relaçäo ao estadiamento clínico, em atividade e remisäo da doença, foram estudados quanto a presença de anticorpos linfocitotóxicos ciruclantes no soro, através da citoxicidade mediada por complemento (CMC). Soros de 35 pacientes (42 soros) foram testados contra painel de linfócitos periféricos de 31 indivíduos normais com tipagem para antígenos HLA classe I conhecidos (HLA A, B e C), e os experimentos executados em diferentes diluiçöes e temperaturas. As análises demonstraram que 66,66% dos soros apresentaram anticorpos linfocitotóxicos dirigidos contra células de pelo menos um dos doadores normais. A freqüência destes anticorpos mostrou significância estatística nos pacientes em atividade (80,95%) quando comparados aos em remissäo (52,38%). Doentes lúpicos que recebiam diferentes doses de corticosteróides foram separados em grupos, e concluímos que a CMC independe da quantidade de prednisona recebida pelos pacientes. Na maioria dos casos os anticorpos linfocitotóxicos näo estavam dirigidos contra os determinantes anigénicos de histocompatibilidade classe I, pois apenas 3 dos 42 soros reconheceram de forma constante células de doadores, especialmente os de antígenos HLA A1, A2, A3, A11, B5 e B35, permitindo inferir que outros marcadores da superfície linfocitária sejam os maiores pela CMC encontrada nos pacientes com LES. Neste estudo näo observamos variaçöes na identificaçäo dos anticorpos linfocitotóxicos quando executamos as reaçöes nas diferentes temperaturas (4- e 22-C)