Allele and Haplotype Frequencies of HLA-A, -B, -C, and -DRB1 Genes in 3,750 Cord Blood Units From a Kinh Vietnamese Population.

The frequencies and diversities of human leukocyte antigen (HLA) alleles and haplotypes are representative of ethnicities. Matching HLA alleles is essential for many clinical applications, including blood transfusion, stem cell transplantation, and tissue/organ transplantation. To date, the information about the frequencies and distributions of HLA alleles and haplotypes among the Kinh Vietnamese population is limited because of the small sample size. In this study, more than 3,750 cord blood units from individuals belonging to the Kinh Vietnamese population were genotyped using PCR sequence-specific oligonucleotide (PCR-SSO) for HLA testing. The results of the study demonstrated that the most frequently occurring HLA-A, -B, -C, and -DRB1 alleles were A*11:01 (25%), A*24:02 (12.3%), A*02:01 (11.2); A*03:03 (8.95%), A*02:03 (7.81%), A*29:01 (7.03%); B*15:02 (15.1%), B*46:01 (10.7%), B*58:01 (7.65%), B*38:02 (7.29%); C*08:01 (17.2), C*07:02 (16.2%), C*01:02 (15.2), C*03:02 (8.3%), C*15:05 (6.13); DRB1*12:02 (31.0%), DRB1*09:01 (10.47%), DRB1*15:02 (7.54%); DRB1*07:01 (6.68%), DRB1*10:01 (6.63%), respectively, with the highest allele diversity level observed in locus B (93 alleles). The most frequent haplotypes of two-locus combinations of HLA-A-B, HLA-A-C, HLA-A-DRB1, HLA-B-C, HLA-B-DRB1, and HLA-C-DRB1 haplotypes were A*11:01-B*15:02 (7.63%), A*11:01-C*08:01 (7.98%), A*11:01-DRB1*12:02 (10.56%), B*15:02-C*08:01 (14.0%), B*15:02-DRB1*12:02 (10.47%), and C*08:01-DRB1*12:02 (11.38%), respectively. In addition, the most frequent haplotypes of three- and four-locus sets of HLA-A-B-C, HLA-A-B-DRB1, HLA-A-C-DRB1, HLA-B-C-DRB1, and HLA-A-B-C-DRB1 were A*11:01-B*15:02-C*08:01 (7.57%), A*11:01-B*15:02-DRB1*12:02 (5.39%), A*11:01-C*08:01-DRB1*12:02 (5.54%), B*15:02-C*08:01-DRB1*12:02 (10.21%), and A*11:01-B*15:02-C*08:01-DRB1*12:02 (5.45%), respectively. This study provides critical information on the frequencies and distributions of HLA alleles and haplotypes in the Kinh Vietnamese population, accounting for more than 85% of Vietnamese citizens. It paves the way to establish an umbilical cord blood bank for cord blood transplantation programs in Vietnam.

Increased serum anti-CYP2E1 IgG autoantibody levels may be involved in the pathogenesis of occupational trichloroethylene hypersensitivity syndrome: a case-control study.

Occupational exposure to trichloroethylene (TCE) causes a systemic skin disorder with hepatitis known as TCE hypersensitivity syndrome (TCE-HS). Human Leukocyte Antigen (HLA)-B*13:01 is its susceptibility factor; however, the immunological pathogenesis of TCE-HS remains unknown. We herein examined the hypothesis that autoantibodies to CYP2E1 are primarily involved in TCE-HS. A case-control study of 80 TCE-HS patients, 186 TCE-tolerant controls (TCE-TC), and 71 TCE-nonexposed controls (TCE-nonEC) was conducted to measure their serum anti-CYP2E1 antibody (IgG) levels. The effects of TCE exposure indices, such as 8-h time-weighted-average (TWA) airborne concentrations, urinary metabolite concentrations, and TCE usage duration; sex; smoking and drinking habits; and alanine aminotransferase (ALT) levels on the antibody levels were also analyzed in the two control groups. There were significant differences in anti-CYP2E1 antibody levels among the three groups: TCE-TC > TCE-HS patients > TCE-nonEC. Antibody levels were not different between HLA-B*13:01 carriers and noncarriers in TCE-HS patients and TCE-TC. The serum CYP2E1 measurement suggested increased immunocomplex levels only in patients with TCE-HS. Multiple regression analysis for the two control groups showed that the antibody levels were significantly higher by the TCE exposure. Women had higher antibody levels than men; however, smoking, drinking, and ALT levels did not affect the anti-CYP2E1 antibody levels. Anti-CYP2E1 antibodies were elevated at concentrations lower than the TWA concentration of 2.5 ppm for TCE exposure. Since HLA-B*13:01 polymorphism was not involved in the autoantibody levels, the possible mechanism underlying the pathogenesis of TCE-HS is that TCE exposure induces anti-CYP2E1 autoantibody production, and HLA-B*13:01 is involved in the development of TCE-HS.

Down syndrome with neonatal alloimmune thrombocytopenia due to anti-HLA A31 and B61 antibodies.

Neonatal alloimmune thrombocytopenia (NAIT) arises from fetomaternal platelet incompatibility that results in transplacental passage of maternal antibodies mostly against fetal human platelet antigens (HPA), whereas NAIT due to anti-human leukocyte antigen (HLA) antibodies is extremely rare. Here, we report a case of Down syndrome (DS) with NAIT that was attributed to HLA antibodies. A boy with DS was delivered at 36 weeks' gestation. His platelet count declined to 13.0 × 109/L, suggestive of NAIT rather than other conditions, including transient abnormal myelopoiesis. Random platelet concentrates and intravenous immunoglobulin administration resolved the thrombocytopenia without clinical complications. Immunoserological investigations detected anti-HLA, but no anti-HPA antibodies in samples from the patient and the mother. HLA typing and cross-matching indicated that anti-HLA antibodies to paternal HLA A31 and B61, which had probably been induced during a prior pregnancy, led to NAIT in this case. Although it is a rare condition, healthcare providers should consider NAIT due to HLA antibodies and be vigilant for subsequent cases in DS.

Platelet transfusion refractoriness: how do I diagnose and manage?

Platelet refractoriness continues to be a problem for thrombocytopenic patients because the risk of a major spontaneous or life-threatening bleed significantly increases when platelet counts drop below 10 × 109/L. The majority of patients have nonimmune causes driving the refractoriness, such as bleeding, medications, or diffuse intravascular coagulation; however, this article is dedicated to the diagnosis and support of patients with immune-based platelet refractoriness. Antibodies to class I HLA molecules (A and B alleles) are responsible for most immune-based refractory cases, with antibodies to platelet antigens seen much less frequently. Patients may be supported with either crossmatch-compatible or HLA-matched/compatible platelet units. When trying to select HLA units it can be difficult to find a perfect "4 of 4" match for the patient's class IA and IB alleles. In these cases, it is better to use the antibody specificity prediction method, which identifies compatible units that lack antigens recognized by the patient's anti-HLA antibodies. For an algorithmic approach to the patient with platelet refractoriness, see Visual Abstract.

Familial HLA-B*52 Vasculitis: Maternal, Atypical Cogan's Syndrome with Takayasu Arteritis-mimicking Aortitis and Filial Takayasu Arteritis.

Cogan's syndrome (CS), a rare vasculitis characterized by non-syphilitic, interstitial keratitis and Ménière-like attacks, is classified into "typical" and "atypical" forms, while Takayasu arteritis (TAK) is a rare large-vessel vasculitis associated with human leukocyte antigen (HLA)-B*52. Very few cases meet both the CS and TAK classification criteria. We herein report a 53-year-old woman diagnosed with atypical CS and aortitis similar to TAK. Her 25-year-old daughter manifested TAK without symptoms of CS, and both are HLA-B*52 positive. Our case highlights the difficulties of distinguishing aortitis with atypical CS from aortitis with TAK.

Impact of Human Leucocyte Antigen epitope matched platelet transfusions in alloimmunised aplastic anaemia patients.

AIMS/OBJECTIVES: To explore the impact of Human Leucocyte Antigen (HLA)-A and B epitope-matched platelets on the outcome of platelet transfusions in alloimmunised patients with aplastic anaemia (AA). The relevance of HLA-C epitope mismatches was also investigated. BACKGROUND: Patients who become immunologically refractory (IR) to random platelet transfusions can experience an adequate rise in platelet count through the provision of HLA-compatible platelets using an antigen-matching algorithm. This approach has been shown to be effective in patients with a low calculated reaction frequency, but it is not always successful in highly sensitised patients. The use of HLA epitopes-selected platelets has been suggested as an alternative to the antigen matching approach. METHODS: The effect of HLA epitope matching (both Eplets and Triplets) on the outcome of platelet transfusion was analysed in 37 highly immunised AA patients previously transfused with HLA-A and B antigen-matched platelets. Epitope matching was determined using the HLAMatchmaker programme. The outcome of the transfusions was assessed by the platelet count increments (PCIs) obtained 1 and 24 hours post-transfusions. RESULTS: HLA-A and B epitope matching was equivalent to HLA antigen matching in raising platelet counts. There was no significant difference in PCI when HLA-C epitope mismatches were considered. In addition, transfusions with fewer than two antigen mismatches resulted in significantly higher PCIs compared to transfusions with more than two antigen mismatches. CONCLUSIONS: HLA epitope-matched platelet provision may represent a clinically effective transfusion strategy for patients IR to random platelet transfusions. Further prospective studies are required.

HLA-B5, 7, 8, 27, and 51 Antigens and Immune Thrombocytopenic Purpura: Is There an Association?

BACKGROUND: Immune thrombocytopenic purpura (ITP) is a bleeding disorder characterized by low platelet counts in peripheral blood, impairment of thrombopoiesis in bone marrow, and risk of mild to severe bleedings. ITP can be seen among both sexes in different ages. Although definitive pathogenesis of this disorder is still ambiguous, some of risk factors for ITP are recognized, including human leukocyte antigens (HLAs). OBJECTIVE: Our goal was to evaluate the possible association between HLA-B5, 7, 8, 27, and 51 antigens with ITP for the first time. We were hoping to achieve new hypothetical diagnostic/prognostic biomarkers to introduce a new subject for further studies on HLA class I antigens as possible risk factors for ITP. MATERIALS AND METHODS: A total of 37 patients with ITP were included in this study. After confirmation of ITP diagnosis, peripheral blood samples were collected from them. The expression of each of HLA antigens was evaluated by standard lymphocytotoxicity technique. RESULTS: Compared with other studied antigens, the expression of HLA-B5 and HLA-B51 was more prevalent among our patients. According to the results, 22% of patients were positive for HLA-B5 and HLA-B51. Furthermore, no significant association was found between HLAs expressions with complete blood count parameters. CONCLUSIONS: We conclude that there is an association between HLA-B5 and HLA-B51 with ITP and that they are not likely to be used as diagnostic or prognostic biomarkers. We suggest studying the association between HLA-B antigens and ITP in large-scale studies to determine whether or not there is a significant association.

Dose HLA-B5, 7, 8, 27, and 51 Antigens Associated to Behcet's disease? A Study in Southwestern Iran.

BACKGROUND: Behcet's disease is a potentially life threatening autoimmune disease with recurrent ulcers and unknown pathogenesis. Gender and human leukocyte antigen-B51 seem to have an effective role in the clinical features of the disease. OBJECTIVE: The aim of this study is to evaluate the frequency of HLA-B5, 7, 8, 27 and 51 in behçet's disease in southwestern Iranian patients who visited the rheumatology clinic and to find the association between these HLA types and the disease. METHODS: 63 patients with behcet's disease participated in this study and peripheral blood samples were collected from them. The expression of each HLA antigen was evaluated by standard lymphocytotoxicity technique. RESULTS: Compared to other studied antigens, the expression of HLA-B5 and HLA-B51 was more prevalent among our patients. According to the results, 25% and 21% of patients were positive for HLA-B5 and HLA-B51, respectively. CONCLUSIONS: HLA-B5 and HLA-B51 are dominant positive HLA antigens among behcet's disease patients in the southwest of Iran; however, we cannot conclude that these antigens are valuable diagnostic or prognostic biomarkers due to our study limitations. We suggest studying the association between HLA-B antigens and inflammation severity in patients to determine the possible prognostic value of HLA-B antigens in Iranian population in the southwest and this region needs more studies in HLA subject among BD patients because of the frequency of BD to evaluate the value of HLA typing in BD prognosis.

Absence of human leukocyte antigen-B*57:01 amongst patients on antiretroviral therapy in Nigeria: Implications for use of abacavir.

Background: The presence of human leukocyte antigen (HLA) B*57:01 allele predicts hypersensitivity reaction (HSR) to abacavir (ABC), a nucleoside reverse-transcriptase inhibitor used for human immunodeficiency virus (HIV) treatment. However, the prevalence of this allele amongst Nigerians with HIV is yet to be established. We aimed to determine the prevalence of HLA-B*57:01 allele amongst Nigerians with HIV infection. Methods: We conducted a multicentre cross-sectional epidemiologic survey. Between April 2016 and April 2017, patients were enrolled across five HIV treatment facilities in Nigeria. Participants' demographic information and their history of ABC exposure were obtained, and venous blood was obtained for HLA typing. Results: One thousand five hundred and four (1504) adults were enrolled, with a mean age of 44.6 ± 10.7 years, 1078 (71.7%) were female. 1463 (97.3%) were on antiretroviral therapy. ABC use was reported by 12 (0.8%) participants and none reported HSR. Of 1500 blood samples that were processed, 1458 (97.2%) were successfully typed. Of these, 132 (9.1%) were HLA-B*57 positive using non-specific low-resolution HLA-B*5701 primer mix. On further analysis, none of the 132 samples (0%) had the HLA-B*5701 allele. Conclusion: HLA-B*5701allele is rare amongst Nigerians.

A three-platelet mRNA set: MAX, MTURN and HLA-B as biomarker for lung cancer.

BACKGROUND: During the development of tumors, tumors "educate" platelets causing changes in their mRNAs expression profiles and phenotypes, thereby, tumor-educated platelet (TEP) mRNA profile has the potential to diagnose lung cancer. The current study aimed to examine whether TEPs might be a potential biomarker for lung cancer diagnostics. METHODS: Platelet precipitation was obtained by low-speed centrifugation and subjected to Trizol for total RNA extraction. Platelet MAX, MTURN, and HLA-B mRNA were selected by microarray, validated by qPCR, and analyzed combined with related clinical factors. RESULTS: Our results showed that a three-platelet mRNA set: MAX, MTURN, and HLA-B was significantly up-regulated in lung cancer patients as well as in early-stage lung cancer patients compared with those from healthy donors, the area under the curve (AUC) was 0.734, 0.787, respectively, among which platelet MTURN mRNA processed a dramatically high diagnostic efficiency in female patients with lung cancer, its AUC for female was 0.825. More importantly, the three-platelet mRNA set: MAX, MTURN, and HLA-B was associated with chemotherapeutic effect, low mRNA expression of this three-platelet set was correlated with "favorable" first chemotherapy response. CONCLUSIONS: A three-platelet mRNA set: MAX, MTURN and HLA-B enables blood-based lung cancer diagnosis and chemotherapy response prediction.

Human leukocyte antigens class I and II in patients with idiopathic granulomatous mastitis.

BACKGROUND: To determine the distribution of human leukocyte antigens (HLA) in patients with idiopathic granulomatous mastitis (IGM). METHODS: The study included 48 patients diagnosed with IGM and 50 controls consisting of healthy donor candidates. RESULTS: The frequencies of HLA-A*10, HLA-A*2403, HLA-B*18 and HLA-DR*17 antigens were significantly higher in the patient group than control group (p = 0.012, p = 0.012, p = 0.0001 and p = 0.005, respectively). However, the frequencies of HLA-A*29, HLA-B*14 and HLA-DR*1 were lower in the patient group than control group (p = 0.027, p = 0.013 and p = 0.015, respectively). When patients without/with relapse were compared, there was a significant difference in HLA-A*3 (p = 0.048) and HLA-A*32 (p = 0.011). Also, the patients with relapse and control group were compared in respects of HLA-A*10 (p = 0.0006), HLA-A*24 (p = 0.035), HLA-A*32 (p = 0.011), HLA-B*18 (p = 0.035), HLA-B*103 (p = 0.035) and HLA-DR*17 (p = 0.006). CONCLUSION: These findings may help to explain etiopathogenesis but still, further studies on this subject with more patients in different geographic regions are needed.

HLA Polymorphisms and Haplotype Diversity in Transylvania, Romania.

Transylvania is a historical region in the northwestern part of Romanian with a rather heterogeneous population. Our study is the first to determine human leukocyte antigen (HLA) profiles in a large population sample from this region and to compare them with other European population groups. HLA genes were examined in 2,794 individuals using the Single Specific Primer-Polymerase Chain Reaction (SSP-PCR) and Polymerase Chain Reaction Sequence-Specific Oligonucleotide (PCR-SSO) methods. All samples were tested for the HLA-A locus, 2,773 for HLA-B, 1,847 for HLA-C, and 2,719 for HLA-DRB1 loci. HLA gene frequency data from several European population groups (as presented in studies involving more than 1,000 individuals) served as reference in comparison with the local sample. The distribution of HLA genes in the studied population group was heterogeneous, as the Hardy-Weinberg equilibrium was statistically significant (P value < 0.01). The most common genes found in our sample group were A∗02 (0.27%), B∗35 (0.14%), C∗07 (0.25%), and DRB1∗11 (0.19%). The most common haplotype was A∗01~B∗08~C∗07~DRB1∗03 (1.26% in 1,770 individuals with complete data). This analysis confirmed the known heterogeneity of the Transylvanian population. The study indicates that the European population groups located in close vicinity (those from Serbia, Hungary, Wallachia, and Croatia) are genetically closest to the Transylvanian population.

HLA-B46 is associated with severe sacroiliitis in Japanese patients with psoriatic arthritis.

Objectives: The aim of the present study was to determine if the HLA phenotype is related to severe sacroiliitis in Japanese patients with psoriatic arthritis.Methods: This study was a single-center, retrospective, cross-sectional, observational study. We reviewed the clinical information and radiologic examinations of patients with psoriatic arthritis (PsA) who visited our hospital from January 2011 to December 2016. Radiographic changes in the sacroiliac joints were assessed by four independent investigators according to the recommendations of the Assessment of Spondyloarthritis International Society.Results: Of 113 PsA patients, 63 (55.8%) had sacroiliitis. The HLA phenotype was investigated in 39 patients. Ordered logistic regression analysis revealed that the presence of HLA-B46 was an independent risk factor for severe sacroiliitis in Japanese PsA patients (odds ratio 3.2; 95% confidence interval 1.16-9.81). Therefore, the clinical features were divided into two groups according to the presence of HLA-B46. Both the Nail Psoriasis Severity Index and grade of sacroiliitis were significantly higher in the HLA-B46-positive group (Mann-Whitney U test; p = .0003 and p = .028, respectively).Conclusion: HLA-B46 is considered a risk factor for severe sacroiliitis in Japanese patients with PsA.

Relationship of serum HLA-B alleles and TNF-α with rheumatic heart disease

Background/aim: Acute rheumatic fever and rheumatic heart disease are major causes of morbidity and mortality in developing countries. Genetic studies have determined that the immune response in rheumatic heart disease is genetically controlled and that there is a close relationship between the gene of concern and the class II human leukocyte antigen (HLA) gene. The aim of this study was to evaluate the relationship of serum HLA-B alleles and tumor necrosis factor alpha (TNF-α) with rheumatic heart disease. Materials and methods: A total of 50 consecutive patients with rheumatic heart disease and 50 controls were enrolled in the study. HLA alleles were analyzed using sequence-specific primer-polymerase chain reaction and nucleotide sequencing. Results: The HLA-B35 allele was significantly more common in patients with rheumatic heart disease than the control group (P = 0.043). The HLA-B44 allele was significantly more common in control patients than in patients with rheumatic heart disease (P = 0.014). There was a significant inverse correlation between high-sensitivity C-reactive protein and mitral valve area (P = 0.001). There was no correlation between TNF-α levels and mitral valve area (P = 0.066). Conclusion: Our findings confirmed the association between HLA-B alleles and rheumatic heart disease.

Case report: A transplant candidate with unexpected serum reactivity against the 45KE eplet on HLA-B alleles.

This case report describes the serum antibody specificity against the 45KE eplet which had not been yet shown to be antibody-verified. This antibody was produced by a 41-year-old European male with Berger's disease. His serum had HLA class I antibody reactivity as determined in IgG binding assays with single allele panels (OneLambda, ThermoFisher, Lot 8 and Lot 9). The HLAMatchmaker analysis revealed reproducible serum reactivity only with alleles carrying the 45KE eplet. The cause of this 45KE-specific immunization is unknown because this male patient had never been transfused nor received a previous transplant, Moreover, his mother's HLA type did not have any 45KE-carrying allele. This finding might be related to observations reported in the literature about the appearance of HLA-reactive antibodies following influenza vaccination but this possibility could not be investigated.

Carbamazepine-induced Stevens-Johnson syndrome/toxic epidermal necrolysis overlap in a Filipino with positive HLA-B75 serotype.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are two related mucocutaneous disorders with different severities. Although the incidence is low, SJS and TEN are life-threatening and predominantly drug-induced conditions. There is a strong relationship between the HLA-B*1502 allele and carbamazepine-induced SJS and TEN in different Southeast Asian populations. Here, we report a case of Filipino with SJS/TEN overlap probably induced by carbamazepine. The condition was treated with hydrocortisone followed by prednisone. The HLA-B*1502 allele was not found in this case. The patient tested positive for the HLA-B75 serotype, suggesting that carbamazepine-induced SJS/TEN may be serotype specific. Establishing the genotype before initiation of the drug may be advantageous for some patients and will aid physicians in determining the optimal drug therapy. Prevention of adverse drug reactions (ADR) may be done if pharmacists and other healthcare professionals work as a multidisciplinary ADR team to ensure that safe medication practices are realised.

An interdigitated electrode biosensor platform for rapid HLA-B*15:02 genotyping for prevention of drug hypersensitivity.

Prevention of life threatening hypersensitivity reactions to carbamazepine is possible through pre-treatment screening of the associated HLA-B*15:02 risk allele. However, clinical implementation of screening is hindered by the high cost and slow turnaround of conventional HLA typing methods. We have developed an interdigitated electrode (IDE) biosensor platform utilizing loop mediated isothermal amplification (LAMP) that can rapidly detect the HLA-B*15:02 allele. DNA amplification is followed by solid-phase hybridization of LAMP amplicons to a DNA probe immobilized on the IDE sensor surface, resulting in a change in sensor impedance. The testing platform does not require DNA extraction or post-amplification staining, achieving sample-to-answer in 1 h and 20 min. The platform was tested on 27 whole blood samples (14 HLA-B*15:02 positive and 13 negative) with sensitivity of 92.9% and specificity of 84.6% when applying a cutoff of impedance change. Based on these characters the LAMP-IDE platform has potential to be further developed into point-of-care use to help overcome barriers in HLA-B*15:02 screening.

Neonatal alloimmune thrombocytopaenia associated with maternal HLA antibodies.

Neonatal alloimmune thrombocytopaenia (NAIT) generally results from platelet opsonisation by maternal antibodies against fetal platelet antigens inherited from the infant's father. Newborn monochorionic twins presented with petechial haemorrhages at 10 hours of life, along with severe thrombocytopaenia. Despite the initial treatment with platelet transfusions and intravenous immunoglobulin, they both had persistent thrombocytopaenia during their first 45 days of life. Class I human leucocyte antigen (HLA) antibodies with broad specificity against several HLA-B antigens were detected in the maternal serum. Weak antibodies against HLA-B57 and HLA-B58 in sera from both twins supported NAIT as the most likely diagnosis. Platelet transfusion requirements of the twins lasted for 7 weeks. Transfusion of HLA-matched platelet concentrates was more efficacious to manage thrombocytopaenia compared with platelet concentrates from random donors. Platelet genotyping and determination of HLA antibody specificity are needed to select compatible platelet units to expedite safe recovery from thrombocytopaenia in NAIT.