Establishment and clinical application of the HLA genotype database of platelet-apheresis donors in Suzhou

The establishment of a platelet-apheresis donor database may provide a feasible solution to improve the efficacy of platelet transfusion in patients with immune platelet transfusion refractoriness (PTR). This study aimed to establish HLA genotype database in Suzhou, to provide HLA-I compatible platelets for PTR patients to ensure the safety and effectiveness of platelet transfusions. We used a polymerase chain reaction sequence-based typing (PCR-SBT) method to establish the database by performing high-resolution HLA-A, -B, and -C genotyping on 900 platelet-apheresis donors. HLA-I antibody was detected in patients using a Luminex device, and HLA-I gene matching was performed by an HLA-Matchmaker. We found that the highest frequency of the HLA-A allele was A*11:01 (17.06 %), followed by A*24:02 (14.67 %) and A*02:01 (13.61 %). The highest frequency of the HLA-B allele was B*46:01 (9.78 %), followed by B*40:01 (8.39 %) and B*13:02 (33 %). After the detection of platelet antibodies in 74 patients with immune PTR, we found 30 HLA-A antibodies and 48 HLA-B antibodies, and there were a variety of high frequency antibodies whose alleles were low in the donor database, such as HLA-A*68:02, and B*57:01. After avoiding donor-specific antibodies (DSA) matching, 102 of 209 platelet-compatible transfusions were effective, resulting in an effective rate of 48.8 %, which significantly improved the efficacy of platelet transfusion. The establishment of a platelet donor database is of great significance to improve the therapeutic effect of platelet transfusion in patients with hematologic disorder, and save blood resources, and it is also the premise and guarantee of precise platelet transfusion.

Autoimmune HLA Alleles and Neoepitope Presentation Predict Post-Allogenic Transplant Relapse

Introduction

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) can cure patients with high-risk myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). However, many patients relapse or develop debilitating graft-versus-host disease. Transplant restores T-cell reactivity against tumor cells, implicating patient human leukocyte antigen (HLA)-dependent antigen presentation via the major histocompatibility complex as a determinant of response. We sought to identify characteristics of the HLA genotype that influence response in allo-HSCT patients.

Methods

We collected HLA genotype and panel-based somatic mutation profiles for 55 patients with AML and MDS and available data treated at the University of California San Diego Moores Cancer Center between May 2012 and January 2019. We evaluated characteristics of the HLA genotype relative to relapse-free time and overall survival (OS) post-allo-HSCT using univariable and multivariable regression.

Results

In multivariable regression, the presence of an autoimmune allele was significantly associated with relapse-free time (hazard ratio [HR], 0.25; p = 0.01) and OS (HR, 0.16; p < 0.005). The better potential of the donor HLA type to present peptides harboring driver mutations trended toward better relapse-free survival (HR, 0.45; p = 0.07) and significantly correlated with longer OS (HR, 0.33; p = 0.01) though only a minority of cases had an HLA mismatch.

Conclusion

In this single institution retrospective study of patients receiving allo-HSCT for relapsed AML/MDS, characteristics of an individual's HLA genotype (presence of an autoimmune allele and potential of the donor HLA to better present peptides representing driver mutations) were significantly associated with better outcomes. These findings suggest that HLA type may guide the optimal application of allo-HSCT and merit evaluation in larger cohorts. ClinicalTrials.gov Identifier: NCT02478931.

HLA Class I Genotype Is Associated with Relapse Risk after Allogeneic Stem Cell Transplantation for NPM1-Mutated Acute Myeloid Leukemia

Mutation-bearing peptide ligands from mutated nucleophosmin-1 (NPM1) protein have been empirically found to be presented by HLA class I in acute myeloid leukemia (AML). We hypothesized that HLA genotype may impact allogeneic hematopoietic stem cell transplantation (allo-HCT) outcomes in NPM1-mutated AML owing to differences in antigen presentation. We evaluated the effect of the variable of predicted strong binding to mutated NPM1 peptides using HLA class I genotypes from matched donor-recipient pairs on transplant recipients' overall survival (OS) and disease-free survival (DFS) as part of the primary objectives and cumulative incidence of relapse and nonrelapse mortality (NRM) as part of secondary objectives. Baseline and outcome data reported to the Center for International Blood and Marrow Transplant Research from a study cohort of adult patients (n = 1020) with NPM1-mutated de novo AML in first (71%) or second (29%) complete remission undergoing 8/8 matched related (18%) or matched unrelated (82%) allo-HCT were analyzed retrospectively. Class I alleles from donor-recipient pairs were analyzed for predicted strong HLA binding to mutated NPM1 using netMHCpan 4.0. A total of 429 (42%) donor-recipient pairs were classified as having predicted strong-binding HLA alleles (SBHAs) to mutated NPM1. In multivariable analyses adjusting for clinical covariates, the presence of predicted SBHAs was associated with a lower risk of relapse (hazard ratio [HR], .72; 95% confidence interval [CI], .55 to .94; P = .015). OS (HR, .81; 95% CI, .67 to .98; P = .028) and DFS (HR, .84; 95% CI, .69 to 1.01; P = .070) showed a suggestion of better outcomes if predicted SBHAs were present but did not meet the prespecified P value of <.025. NRM did not differ (HR, 1.04; P = .740). These hypothesis-generating data support further exploration of HLA genotype-neoantigen interactions in the allo-HCT context.

Is HLA type a possible cancer risk modifier in Lynch syndrome?

Lynch syndrome (LS) is the most common inherited cancer syndrome. It is inherited via a monoallelic germline variant in one of the DNA mismatch repair (MMR) genes. LS carriers have a broad 30% to 80% risk of developing various malignancies, and more precise, individual risk estimations would be of high clinical value, allowing tailored cancer prevention and surveillance. Due to MMR deficiency, LS cancers are characterized by the accumulation of frameshift mutations leading to highly immunogenic frameshift peptides (FSPs). Thus, immune surveillance is proposed to inhibit the outgrowth of MMR-deficient cell clones. Recent studies have shown that immunoediting during the evolution of MMR-deficient cancers leads to a counter-selection of highly immunogenic antigens. The immunogenicity of FSPs is dependent on the antigen presentation. One crucial factor determining antigen presentation is the HLA genotype. Hence, a LS carrier's HLA genotype plays an important role in the presentation of FSP antigens to the immune system, and may influence the likelihood of progression from precancerous lesions to cancer. To address the challenge of clarifying this possibility including diverse populations with different HLA types, we have established the INDICATE initiative (Individual cancer risk by HLA type, http://indicate-lynch.org/), an international network aiming at a systematic evaluation of the HLA genotype as a possible cancer risk modifier in LS. Here we summarize the current knowledge on the role of HLA type in cancer risk and outline future research directions to delineate possible association in the scenario of LS with genetically defined risk population and highly immunogenic tumors.

Prediction of HLA genotypes from single-cell transcriptome data

The human leukocyte antigen (HLA) locus plays a central role in adaptive immune function and has significant clinical implications for tissue transplant compatibility and allelic disease associations. Studies using bulk-cell RNA sequencing have demonstrated that HLA transcription may be regulated in an allele-specific manner and single-cell RNA sequencing (scRNA-seq) has the potential to better characterize these expression patterns. However, quantification of allele-specific expression (ASE) for HLA loci requires sample-specific reference genotyping due to extensive polymorphism. While genotype prediction from bulk RNA sequencing is well described, the feasibility of predicting HLA genotypes directly from single-cell data is unknown. Here we evaluate and expand upon several computational HLA genotyping tools by comparing predictions from human single-cell data to gold-standard, molecular genotyping. The highest 2-field accuracy averaged across all loci was 76% by arcasHLA and increased to 86% using a composite model of multiple genotyping tools. We also developed a highly accurate model (AUC 0.93) for predicting HLA-DRB345 copy number in order to improve genotyping accuracy of the HLA-DRB locus. Genotyping accuracy improved with read depth and was reproducible at repeat sampling. Using a metanalytic approach, we also show that HLA genotypes from PHLAT and OptiType can generate ASE ratios that are highly correlated (R2 = 0.8 and 0.94, respectively) with those derived from gold-standard genotyping.

Finnish children carrying the high-risk HLA genotype have a 45-fold increased risk of type 1 diabetes compared to peers with neutral or protective genotypes

The association between HLA genotypes and type 1 diabetes is well known. We set out to examine incidence rates and ratios of type 1 diabetes depending on the risk afflicted by HLA genotype. Children with the high-risk genotype have a 45-fold disease risk compared to peers with neutral or protective genotypes.

Hypoglycemia Caused by Exogenous Insulin Antibody Syndrome: A Large Single-Center Case Series From China

CONTEXT

Exogenous insulin antibody syndrome (EIAS) can lead to unexpected and potentially life-threatening recurrent hypoglycemia.

OBJECTIVE

We aimed to better define autoimmune hypoglycemia caused by EIAS in patients with diabetes and shed light on the improvements in the identification and intervention for this rare but possibly life-threatening condition.

METHODS

We summarized the clinical characteristics of autoimmune hypoglycemia caused by EIAS in 23 patients with diabetes. Furthermore, we performed human leukocyte antigen (HLA) genotyping of 10 patients.

RESULTS

We identified a high frequency of autoimmune comorbidities (21.7%), food or drug allergy (48%), insulin allergy (30%), lipodystrophy at the insulin injection sites (22%), and antinuclear antibodies (25%) in the patients. Alternation between hyperglycemia and hypoglycemia was observed in more than 90% of the patients. Most patients showed a high insulin autoantibody titer (>90%) and inappropriately increased insulin concentration (insulin/C-peptide molar ratio >7, >85%). We detected similar frequencies of DRB1*0405-DQB1*0401 and DRB1*0901-DQB1*0303 compared with previously reported frequencies in type 1 diabetes, and a lower frequency of DRB1*0406 compared with insulin autoimmune syndrome. The spontaneous remission rate exceeded 70%.

CONCLUSION

Predisposing factors for autoimmune hypoglycemia caused by EIAS include a strong autoimmune background. Susceptible HLA genotypes for type 1 diabetes or insulin autoimmune syndrome might not explain susceptibility to this condition. Additionally, insulin autoantibodies and the insulin/C-peptide molar ratio are reliable screening options. The prognosis for this condition is favorable. Monitoring of insulin and insulin autoantibodies may contribute to treatment effectiveness.

LMP1-EBV Gene Deletion Mutations and HLA Genotypes of Nasopharyngeal Cancer Patients in Vietnam

Nasopharyngeal carcinoma (NPC) is the most common cancer among head and neck cancers in Vietnam. We aimed to identify the rate of a 30 bp deletion mutation of the LMP1-EBV gene in nasopharyngeal biopsy tissue samples, the HLA genotypes of NPC patients, and the relationship between these two targets. Patients with NPC at Can Tho Oncology Hospital from September 2014 to December 2018 were selected. A length of 30 bp of the del-LMP1-EBV gene was analyzed using a PCR technique, and the HLA genotypes in patients' blood samples were analyzed with PCR-SSO technology. HLA-B*15 gene carriers had the highest risk of 30 bp LMP1-EBV gene deletion mutation, which was found in 51 out of 70 patients (72.9%). Carriers of the HLA-B*15 allele had a 4.6-fold increased risk of a 30 bp del-LMP1-EBV gene compared with non-carriers of this allele. The initial identification of NPC was related to the 30 bp del-LMP1-EBV gene and high frequencies of the -A*02, -B*15, -DRB1*12, -DQB1*03, and -DQA1*01 HLA alleles. Our study results suggest an association of the 30 bp del-LMP1-EBV gene and the HLA-B*15 allele with NPC susceptibility.

THE MANAGEMENT OF REPETITIVE SUBACUTE THYROIDITIS IN A MALE PATIENT HAVING HLA-B35:01 AND B41:02 ALLELES

Context

Subacute thyroiditis (SAT) is an inflammatory disease of the thyroid gland and commonly affects females. Despite adequate treatment, the recurrence of SAT can be seen in some patients. Although there is insufficient data about the reasons for recurrences, HLA predisposition is one of the reasons thought to be responsible and is a current issue for clinicians.

Objective

This case report presented the management of 7 SAT attacks of a patient who had HLA-B35:01 and B41:02 alleles in the genotype analysis.

Case Report

A 37-year-old male patient who had consecutive 7 SAT attacks was presented in this report. Corticosteroid or non-steroidal anti-inflammatory drugs were initiated at each recurrence depending on the severity of clinical symptoms and laboratory findings. The genotype analysis showed the positivity for HLA-B35:01 and B41:02 alleles. The anti-thyroglobulin antibody was detected positive after the last attack. The patient was followed up as asymptomatic and euthyroid in the third month after the last attack.

Results

The management of some SAT cases may be challenging for clinicians. Although recurrence can be seen despite adequate treatment, repetitive seven attacks are extraordinary in SAT. HLA genotyping showed co-occurrence of HLA-B35:01 and B41:02 alleles in our patient. The co-occurrence of these alleles has been described firstly in this case. Explaining high recurrence rates of SAT with these HLA alleles is difficult, though the present case may shed light on further studies.

Association of Human Leucocyte Antigen Class II, with viral load and immune response to Epstein-Barr virus in adult and pediatric Systemic lupus erythematosus patients

OBJECTIVE

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, which is known to be associated with HLA-DRB1 and Epstein-Barr virus (EBV) infection. In the Indian subcontinent where there is high seroendemicity of EBV, we postulated that the association of this virus in adult SLE (aSLE) and pediatric SLE (pSLE) patients would be different and differentially associate with the HLA-DRB1 susceptibility and protective genes.

METHODS

A total of 109 aSLE, 52 pSLE, 215 adult healthy and 63 pediatric healthy controls were recruited. HLA-DRB1 genotyping by PCR-SSP, EBV load estimation by real-time PCR and antibody profiling (IgG & IgM) to EBV antigens by line blot assay were performed.

RESULTS

DRB1*15 was found predominant in pSLE patients and DRB1*03 in aSLE patients. DRB1*15/X heterozygous was predominant in overall SLE patients, although disease severity, like hypocomplementemia, higher autoantibody levels and more organ involvement was observed in *15/*15 homozygous state. EBV strongly associated with pSLE patients showing higher percent of EA-D IgG (p < 0.0001) and p22 IgG (p = 0.035) along with higher viral load (p = 0.001) as compared to healthy controls. In addition, the higher EBV DNA load significantly associated with anti-EA-D IgG (p = 0.013) and DRB1*15/*15 (p = 0.007) in pSLE patients as compared to aSLE patients.

CONCLUSIONS

This study therefore indicates that different HLA-DRB1 allotypes confer susceptibility to SLE in children and adults and disease may be triggered by increased EBV reactivation.

In Silico Model Estimates the Clinical Trial Outcome of Cancer Vaccines

Over 30 years after the first cancer vaccine clinical trial (CT), scientists still search the missing link between immunogenicity and clinical responses. A predictor able to estimate the outcome of cancer vaccine CTs would greatly benefit vaccine development. Published results of 94 CTs with 64 therapeutic vaccines were collected. We found that preselection of CT subjects based on a single matching HLA allele does not increase immune response rates (IRR) compared with non-preselected CTs (median 60% vs. 57%, p = 0.4490). A representative in silico model population (MP) comprising HLA-genotyped subjects was used to retrospectively calculate in silico IRRs of CTs based on the percentage of MP-subjects having epitope(s) predicted to bind ≥ 1–4 autologous HLA allele(s). We found that in vitro measured IRRs correlated with the frequency of predicted multiple autologous allele-binding epitopes (AUC 0.63–0.79). Subgroup analysis of multi-antigen targeting vaccine CTs revealed correlation between clinical response rates (CRRs) and predicted multi-epitope IRRs when HLA threshold was ≥ 3 (r = 0.7463, p = 0.0004) but not for single HLA allele-binding epitopes (r = 0.2865, p = 0.2491). Our results suggest that CRR depends on the induction of broad T-cell responses and both IRR and CRR can be predicted when epitopes binding to multiple autologous HLAs are considered.

Germline HLA-B evolutionary divergence influences the efficacy of immune checkpoint blockade therapy in gastrointestinal cancer

BACKGROUND

The human leukocyte antigen class I (HLA-I) genotype has been linked with differential immune responses to infectious disease and cancer. However, the clinical relevance of germline HLA-mediated immunity in gastrointestinal (GI) cancer remains elusive.

METHODS

This study retrospectively analyzed the genomic profiling data from 84 metastatic GI cancer patients treated with immune checkpoint blockade (ICB) recruited from Peking University Cancer Hospital (PUCH). A publicly available dataset from the Memorial Sloan Kettering (MSK) Cancer Center (MSK GI cohort) was employed as the validation cohort. For the PUCH cohort, we performed HLA genotyping by whole exome sequencing (WES) analysis on the peripheral blood samples from all patients. Tumor tissues from 76 patients were subjected to WES analysis and immune oncology-related RNA profiling. We studied the associations of two parameters of germline HLA as heterozygosity and evolutionary divergence (HED, a quantifiable measure of HLA-I evolution) with the clinical outcomes of patients in both cohorts.

RESULTS

Our data showed that neither HLA heterozygosity nor HED at the HLA-A/HLA-C locus correlated with the overall survival (OS) in the PUCH cohort. Interestingly, in both the PUCH and MSK GI cohorts, patients with high HLA-B HED showed a better OS compared with low HLA-B HED subgroup. Of note, a combinatorial biomarker of HLA-B HED and tumor mutational burden (TMB) may better stratify potential responders. Furthermore, patients with high HLA-B HED were characterized with a decreased prevalence of multiple driver gene mutations and an immune-inflamed phenotype.

CONCLUSIONS

Our results unveil how HLA-B evolutionary divergence influences the ICB response in patients with GI cancers, supporting its potential utility as a combinatorial biomarker together with TMB for patient stratification in the future.

A New Human Leukocyte Antigen Typing Algorithm Combined With Currently Available Genotyping Tools Based on Next-Generation Sequencing Data and Guidelines to Select the Most Likely Human Leukocyte Antigen Genotype

Background

High-precision human leukocyte antigen (HLA) genotyping is crucial for anti-cancer immunotherapy, but existing tools predicting HLA genotypes using next-generation sequencing (NGS) data are insufficiently accurate.

Materials and Methods

We compared availability, accuracy, correction score, and complementary ratio of eight HLA genotyping tools (OptiType, HLA-HD, PHLAT, seq2HLA, arcasHLA, HLAscan, HLA*LA, and Kourami) using 1,005 cases from the 1000 Genomes Project data. We created a new HLA-genotyping algorithm combining tools based on the precision and the accuracy of tools’ combinations. Then, we assessed the new algorithm’s performance in 39 in-house samples with normal whole-exome sequencing (WES) data and polymerase chain reaction–sequencing-based typing (PCR-SBT) results.

Results

Regardless of the type of tool, the calls presented by more than six tools concordantly showed high accuracy and precision. The accuracy of the group with at least six concordant calls was 100% (97/97) in HLA-A, 98.2% (112/114) in HLA-B, 97.3% (142/146) in HLA-C. The precision of the group with at least six concordant calls was over 98% in HLA-ABC. We additionally calculated the accuracy of the combination tools considering the complementary ratio of each tool and the accuracy of each tool, and the accuracy was over 98% in all groups with six or more concordant calls. We created a new algorithm that matches the above results. It was to select the HLA type if more than six out of eight tools presented a matched type. Otherwise, determine the HLA type experimentally through PCR-SBT. When we applied the new algorithm to 39 in-house cases, there were more than six matching calls in all HLA-A, B, and C, and the accuracy of these concordant calls was 100%.

Conclusions

HLA genotyping accuracy using NGS data could be increased by combining the current HLA genotyping tools. This new algorithm could also be useful for preliminary screening to decide whether to perform an additional PCR-based experimental method instead of using tools with NGS data.

Association between the HLA-B*1502 gene and mild maculopapular exanthema induced by antiepileptic drugs in Northwest China

BACKGROUND

The relationship between the HLA-B*1502 gene and maculopapular exanthema (MPE) induced by antiepileptic drugs (AEDs) has not yet been elucidated. In this study, we investigated the association between AED-induced MPE (AED-MPE) and the HLA-B*1502 gene in patients in Northwest China.

METHODS

We enrolled 165 subjects including nine patients with AED-MPE and 156 AED-tolerant patients as controls. HLA-B*1502 gene polymorphism was detected using digital fluorescence molecular hybridization (DFMH). The results of HLA genotyping were expressed as positive or negative for the HLA-B*1502 allele. An analysis of AED-MPE risk factors was performed using binary logistic regression, and differences in genotype frequencies between groups were assessed with the continuity correction chi-square test.

RESULTS

We found that the HLA-B*1502 gene was a risk factor for AED-MPE (P = 0.028). The incidence of MPE induced by the two types of AEDs was different, and the incidence of aromatic AEDs use was higher that of non-aromatic AEDs use (P = 0.025). The comparison of the gene frequencies of the HLA-B*1502 allele between the two groups taking aromatic AEDs was also statistically significant (P = 0.045). However, there were no significant differences in terms of age, gender, ethnicity, or region in patients with MPE induced by AEDs. In addition, no association between the HLA-B1502 allele and CBZ- or OXC-induced MPE was found.

CONCLUSIONS

In northwestern China, the HLA-B*1502 allele was associated with aromatic AED-MPE. Since MPE can develop into Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN), the HLA-B*1502 gene should be evaluated before administering AEDs.

Breast-Milk Microbiota Linked to Celiac Disease Development in Children: A Pilot Study From the PreventCD Cohort

Celiac disease (CeD) is an immune-mediated disorder triggered by exposure to dietary gluten proteins in genetically predisposed individuals. In addition to the host genome, the microbiome has recently been linked to CeD risk and pathogenesis. To progress in our understanding of the role of breast milk microbiota profiles in CeD, we have analyzed samples from a sub-set of mothers (n = 49) included in the PreventCD project, whose children did or did not develop CeD. The results of the microbiota data analysis indicated that neither the BMI, HLA-DQ genotype, the CeD condition nor the gluten-free diet of the mothers could explain the human milk microbiota profiles. Nevertheless, we found that origin country, the offspring’s birth date and, consequently, the milk sampling date influenced the abundance and prevalence of microbes in human milk, undergoing a transition from an anaerobic to a more aerobic microbiota, including potential pathogenic species. Furthermore, certain microbial species were more abundant in milk samples from mothers whose children went on to develop CeD compared to those that remained healthy. These included increases in facultative methylotrophs such as Methylobacterium komagatae and Methylocapsa palsarum as well as in species such as Bacteroides vulgatus, that consumes fucosylated-oligosaccharides present in human milk, and other breast-abscess associated species. Theoretically, these microbiota components could be vertically transmitted from mothers-to-infants during breastfeeding, thereby influencing CeD risk.

Sarcoidosis as an Autoimmune Disease

Despite the large number of performed studies, the etiology and pathogenesis of sarcoidosis still remain unknown. Most researchers allude to the possible autoimmune or immune-mediated genesis of the disease. This review attempts an integral analysis of currently available information suggesting an autoimmune genesis of sarcoidosis and is divided into four categories: the evaluation of clinical signs described both in patients with sarcoidosis and “classic” autoimmune diseases, the role of triggering factors in the development of sarcoidosis, the presence of immunogenic susceptibility in the development of the disease, and the analysis of cellular and humoral immune responses in sarcoidosis. Studying the etiology and pathogenesis of sarcoidosis will improve diagnostic procedures as well as the prognosis and patients' quality of life.

Human Leukocyte Antigen Genotype as a Marker of Multiple Sclerosis Prognosis

OBJECTIVE

In a previous pilot monocentric study, we investigated the relation between human leukocyte antigen (HLA) genotype and multiple sclerosis (MS) disease progression over 2 years. HLA-A*02 allele was correlated with better outcomes, whereas HLA-B*07 and HLA-B*44 were correlated with worse outcomes. The objective of this extension study was to further investigate the possible association of HLA genotype with disease status and progression in MS as measured by sensitive and complex clinical and imaging parameters.

METHODS

Hundred and forty-six MS patients underwent HLA typing. Over a 4-year period of follow-up, we performed three clinical and magnetic resonance imaging (MRI) assessments per patient, which respectively included Expanded Disability Status Scale, Multiple Sclerosis Severity Scale, Timed-25-Foot-Walk, 9-Hole Peg Test, Symbol Digit Modalities Test, Brief Visual Memory Test, California Verbal Learning Test-II, and whole-brain atrophy, fluid-attenuated inversion recovery (FLAIR) lesion volume change and number of new FLAIR lesions using icobrain. We then compared the clinical and MRI outcomes between predefined HLA patient groups.

RESULTS

Results of this larger study with a longer follow-up are in line with what we have previously shown. HLA-A*02 allele is associated with potentially better MS outcomes, whereas HLA-B*07, HLA-B*44, HLA-B*08, and HLA-DQB1*06 with a potential negative effect. Results for HLA-DRB1*15 are inconclusive.

CONCLUSION

In the era of MS treatment abundance, HLA genotype might serve as an early biomarker for MS outcomes to inform individualized treatment decisions.

HLA A*32 is associated to HIV acquisition while B*44 and B*53 are associated with protection against HIV acquisition in perinatally exposed infants

BACKGROUND

Human leukocyte antigen (HLA) molecules play a key role in the cellular immune system. They may be determinants of mother-to-child transmission which is the driving force in pediatric HIV infection. We intended to look at the impact of the distribution of these polymorphic HLA genes in the mother-to-child transmission (MTCT) of HIV in Cameroon.

METHODS

A total of 156 mother-baby pairs were enrolled in three hospitals of Yaounde, capital of Cameroon. After the extraction of the DNA from blood samples using the Qiagen Kit as per manufacturer' instructions, the polymorphism of the HLA class 1 ABC was determined using the PCR- sequence specific primers assay.

RESULTS

The distribution of HLA class 1 revealed that none of the allele studied was associated with transmitters or non-transmitters, so was not implicated in transmission. The regression analysis showed that HLA A*32 [OR 0.062 (CI; 0.0075 to 0.51)] is associated with HIV acquisition while HLA B*44 [OR 0.47 (CI; 0.21 to 1.14)] and HLA B*53 [OR; 0.14 (CI; 0.018 to 1.22)] were implicated in reducing the acquisition of HIV by infants. The homozygosity of locus C [OR 6.99 (CI; 1.81 to 26.88), p = 0.0027] was found as a risk factor for the acquisition, while the A*32-B*44 haplotype [OR 10.1 (CI 1.17 to 87.87), p = 0.03] was a risk factor for the transmission.

CONCLUSION

This study has found that HLA A*32, B*44 and B*53 have an impact in MTCT outcomes. The homozygosity of locus C and the A*32-B*44 haplotype were risk factors for acquisition and transmission respectively.

Association Between HLA Genotype and Cutaneous Adverse Reactions to Antiepileptic Drugs Among Epilepsy Patients in Northwest China

This study aimed to investigate the association between HLA genotypes and antiepileptic drug-induced cutaneous adverse reactions (AEDs-cADRs) among patients with epilepsy in Ningxia Hui Autonomous Region of Northwest China. Fifteen patients with AEDs-cADRs and 30 matched AEDs tolerant controls from anested case-control study were tested the HLA-A, HLA-B, and HLA-DRB1 genotype using the polymerase chain reaction sequence-based typing (PCR-SBT). Significant difference was not observed between AEDs-cADRs and AEDs tolerant groups in terms of HLA-A, HLA-B, and HLA-DRB1 genotype frequencies. Future studies using larger cohorts are needed to verify this observation.

Increased prevalence of pathogenic bacteria in the gut microbiota of infants at risk of developing celiac disease: The PROFICEL study

Celiac disease (CD) is an immune-mediated enteropathy involving genetic and environmental factors, whose interaction influences disease risk. The intestinal microbiota, including viruses and bacteria, could play a role in the pathological process leading to gluten intolerance. In this study, we investigated the prevalence of pathogens in the intestinal microbiota of infants at familial risk of developing CD. We included 127 full-term newborns with at least one first-degree relative with CD. Infants were classified according to milk-feeding practice (breastfeeding or formula feeding) and HLA-DQ genotype (low, intermediate or high genetic risk). The prevalence of pathogenic bacteria and viruses was assessed in the faeces of the infants at 7 days, 1 month and 4 months of age. The prevalence of Clostridium perfringens was higher in formula-fed infants than in breast-fed over the study period, and that of C. difficile at 4 months. Among breastfed infants, a higher prevalence of enterotoxigenic E. coli (ETEC) was found in infants with the highest genetic risk compared either to those with a low or intermediate risk. Among formula-fed infants, a higher prevalence of ETEC was also found in infants with a high genetic risk compared to those of intermediate risk. Our results show that specific factors, such as formula feeding and the HLA-DQ2 genotype, previously linked to a higher risk of developing CD, influence the presence of pathogenic bacteria differently in the intestinal microbiota in early life. Further studies are warranted to establish whether these associations are related to CD onset later in life.

HLA-A*31:01 and carbamazepine-induced DRESS syndrom in a sample of North African population

PURPOSE

Drug rash with eosinophilia and systemic symptoms (DRESS) is a serious adverse drug reaction. Carbamazepine is the most common causes of this syndrome. The HLA-A*31:01 allele has been shown to be strongly correlated with carbamazepine-induced DRESS syndrome in European, Japanese, Han Chinese and other asian population but not in African populations. So, our purpose is to study there is a correlation between HLA-A*31:01 and carbamazepine-induced DRESS syndrome in africain population?

METHODS

HLA class I (A and B) typing was performed on 7 subjects with carbamazepine-DRESS syndrome and 25 tolerants controls subjects. DNA typing HLA class I (A) alleles was checked by the polymerase chain reaction amplification Sequence Specific Oligonucleotide Probes (SSO) (reverse-SSO assay). High resolution HLA DNA Kit based on the Luminex technology (One Lambda^®) was used according to the manufacturer's protocol.

RESULTS

The HLA-A*31:01 allele, which has a prevalence of 1% in Tunisian population, was significantly associated with DRESS syndrome. It was detected in 57.14% of cases (4/7) and only 4% of controls subjects (1/25). Thus, the carrier frequency of HLA-A*31:01 allele in the cases group was also significantly higher than in the controls group (57, 14% vs 4% P = 0,004). Odds ratio is estimated 32 (OR = 32 [2.6; 389.2]) CONCLUSION: Similarly to other ethnicities, the presence of the HLA-A*31:01 allele was associated with carbamazepine-DRESS syndrome in a sample of North African population. Future study must be conducted on a larger sample in order to confirm these results.

Omitting duodenal biopsy in children with suspected celiac disease and extra-intestinal symptoms

BACKGROUND

The aim of our study is to evaluate if in children with highly positive serology and HLA-DQ2/DQ8 (triple test, TT) and only extra-intestinal symptoms, it is possible to omit performing an intestinal biopsy for celiac disease (CD) diagnosis, as suggested by the new European Society for Pediatric Gastroenterology, Hepatology and Nutrition ESPGHAN guidelines.

METHODS

In this retrospective study a total of 105 patients, suspected of having CD because of extra-intestinal symptoms and showing serum tissue transglutaminase antibody (anti-tTG) and anti-endomysial antibody (EMA) measurements and HLA genotyping, were considered for the final analysis (33 boys and 72 girls; age range 1.5-17.6 years).

RESULTS

Histological findings confirmed diagnosis of CD in 97 (92.4%) patients. Forty-one patients (39%) showed anti-tTG >10 times normal values, positive EMA and positive HLA-DQ2/DQ8 (positive TT). All of them had a diagnosis of CD, therefore there were no false positive cases. Sixty-four patients were negative for the TT. In eight cases, CD was ruled out and these were considered true negative cases. In the remaining 56 negative TT patients, intestinal biopsy confirmed CD diagnosis and they were considered false negatives. Based on these results, specificity for the TT was 100% and sensitivity was 42.3%.

CONCLUSIONS

On the basis of the present study, diagnosis of CD can be reliably performed without a duodenal biopsy in children with only extra-intestinal symptoms.

HLA genotype as a marker of multiple sclerosis prognosis: A pilot study

OBJECTIVE

The identification of a biomarker with prognostic value is an unmet need in multiple sclerosis (MS). The objective of this study was to investigate a possible association of HLA genotype with disease status and progression in MS, based on comprehensive and sensitive clinical and magnetic resonance imaging (MRI) parameters to measure disease effects.

METHOD

A total of 118 MS patients (79 females, 39 males) underwent HLA typing. Patient MS status was assessed at two time points in a 2-year interval, based on clinical scores (including EDSS, MSSS, T25FW, 9-HPT, SDMT, BVMT, CVLT-II) and MRI evaluations. Quantitative brain MRI values were obtained for whole brain atrophy, FLAIR lesion volume change and number of new lesions using MSmetrix. Predefined HLA patient groups were compared as of disease status and progression. Global assessment was achieved by an overall t-statistic and assessment per measurement by a Welch test and/or Mann Whitney U test. The effects of multiple covariates, including age, gender and disease duration as well as scan parameters, were also evaluated using a regression analysis.

RESULTS

The HLA-A*02 allele was associated with better outcomes in terms of MSSS, EDSS and new lesion count (Welch test p-value<0.05). The HLA-B*07 and HLA-B*44 alleles showed a global negative effect on disease status, although none of the measurements reached significance (p-value<0.05). Results for the HLA-DRB1*15, HLA-DQB1*06 and HLA-B*08 alleles were inconclusive. The influence of the confounding variables on the statistical analysis was limited.

Neuropeptide Y is a minor autoantigen in newly diagnosed type 1 diabetes patients

BACKGROUND

Autoantibodies (A) against Neuropeptide Y (NPY), was reported in 9% newly diagnosed type 1 diabetes (T1D) patients. A single nucleotide polymorphism (SNP) at rs16139 (T1128C) within the NPY-gene identified an amino acid substitution from leucine (L) to proline (P) (L7P) associated with both glucose tolerance and type 2 diabetes. We aimed to determine: (i) the influence of autoantibodies to leucine neuropeptide Y (NPY-LA) and autoantibodies to proline neuropeptide Y (NPY-PA) on the diagnostic sensitivity of type 1 diabetes (T1D), (ii) the association of NPYA with major islet autoantibodies, and (iii) the association of NPYA with HLA-DQ genotypes in newly diagnosed T1D patients.

METHODS

Serum from the HLA-DQ typed T1D patients (n = 673; median age 10 yr) from Skåne, Sweden, were analyzed for autoantibodies against NPY-L and NPY-P in a radioligand binding assay, and against glutamic acid decarboxylase 65 (GAD65), insulin, insulinoma associated protein-2 (IA-2), and zinc transporter 8 (ZnT8) in addition to islet cell antibodies (ICA). A total of 1006 subjects (median age 9 yr) were used as controls.

RESULTS

A total of 9.2% (n = 62) of the T1D patients were positive for NPY-LA (p < 0.001) and 7.6% (n = 51) for NPY-PA (p < 0.001) compared to 1.1% (n = 11) in controls. The NPY-LA and NPY-PA appeared together (κ = 0.63; p < 0.001) and the median levels correlated (R² = 0.603; p < 0.001). T1D patients diagnosed after 10 yr of age were at an increased risk for NPYA at diagnosis [odds ratio (OR = 2.46; 95% CI 1.46-4.16; p = 0.001)] adjusted for age at diagnosis, gender, autoantibody positivity, and HLA.

CONCLUSIONS

NPY is a minor autoantigen in children with newly diagnosed T1D. Therefore, NPY autoantibodies may be investigated in T1D autoimmunity.

Interaction between passive smoking and two HLA genes with regard to multiple sclerosis risk

Background: The recently described interaction between smoking, human leukocyte antigen (HLA) DRB1*15 and absence of HLA-A*02 with regard to multiple sclerosis (MS) risk shows that the risk conveyed by smoking differs depending on genetic background. We aimed to investigate whether a similar interaction exists between passive smoking and HLA genotype.

Methods: We used one case-control study with incident cases of MS (736 cases, 1195 controls) and one with prevalent cases (575 cases, 373 controls). Never-smokers with different genotypes and passive smoking status were compared with regard to occurrence of MS, by calculating odds ratios (ORs) with 95% confidence intervals (CIs). The potential interaction between different genotypes and passive smoking was evaluated by calculating the attributable proportion (AP) due to interaction.

Results: An interaction was observed between passive smoking and carriage of HLA-DRB1*15 (AP 0.3, 95% CI 0.02–0.5 in the incident study, and AP 0.4, 95% CI 0.1–0.7 in the prevalent study), as well as between passive smoking and absence of HLA-A*02. Compared with non-smokers without any of these two genetic risk factors, non-exposed subjects with the two risk genotypes displayed an OR of 4.5 (95% CI 3.3–6.1) whereas the same genotype for subjects exposed to passive smoking rendered an OR of 7.7 (95% CI 5.5–10.8).

Conclusions: The risk of developing MS associated with different HLA genotypes may be influenced by exposure to passive smoking. The finding supports our hypothesis that priming of the immune response in the lungs may subsequently lead to MS in people with a genetic susceptibility to the disease.

The risk of cutaneous adverse reactions among patients with the HLA-A* 31:01 allele who are given carbamazepine, oxcarbazepine or eslicarbazepine: a perspective review

Carbamazepine is a drug that is widely used for the treatment of epilepsy, trigeminal neuralgia and bipolar disorder. This drug is also known to cause cutaneous adverse drug reactions (cADRs) in up to 10% of patients. The recent progress in pharmacogenetics has revealed that human leukocyte antigen (HLA) genotypes are associated with a susceptibility to the cADRs caused by particular drugs. For carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis, very strong associations with HLA-B*15:02 have been found mainly in patients of Southeastern Asian origin. In some countries, prescreening HLA-B*15:02 allele has already been put to practical use as a biomarker to avoid the life-threatening adverse drug reactions. In this review, another risk factor for carbamazepine-induced cADRs is discussed, namely HLA-A*31:01. We compare the strength of the association between HLA-A*31:01 and carbamazepine-induced cADRs based on reports for various ethnic populations; discuss the difference between the HLA-A*31:01 and HLA-B*15:02 biomarkers and the usefulness of prescreening HLA-A*31:01 to detect patients at high risk for carbamazepine-induced cADRs; and refer to points that remain to be resolved.

Glucose tolerance and beta-cell function in islet autoantibody-positive children recruited to a secondary prevention study

AIMS

Children with type 1 diabetes (T1D) risk and islet autoantibodies are recruited to a secondary prevention study. The aims were to determine metabolic control in relation to human leukocyte antigen (HLA) genetic risk and islet autoantibodies in prepubertal children.

METHODS

In 47 healthy children with GADA and at least one additional islet autoantibody, intravenous glucose tolerance test (IvGTT) and oral glucose tolerance test (OGTT) were performed 8-65 d apart. Hemoglobin A1c, plasma glucose as well as serum insulin and C-peptide were determined at fasting and during IvGTT and OGTT.

RESULTS

All children aged median 5.1 (4.0-9.2) yr had autoantibodies to two to six of the beta-cell antigens GAD65, insulin, IA-2, and the three amino acid position 325 variants of the ZnT8 transporter. In total, 20/47 children showed impaired glucose metabolism. Decreased (≤ 30 μU/mL insulin) first-phase insulin response (FPIR) was found in 14/20 children while 11/20 had impaired glucose tolerance in the OGTT. Five children had both impaired glucose tolerance and FPIR ≤ 30 μU/mL insulin. Number and levels of autoantibodies were not associated with glucose metabolism, except for an increased frequency (p = 0.03) and level (p = 0.01) of ZnT8QA in children with impaired glucose metabolism. Among the children with impaired glucose metabolism, 13/20 had HLA-DQ2/8, compared to 9/27 of the children with normal glucose metabolism (p = 0.03).

CONCLUSION

Secondary prevention studies in children with islet autoantibodies are complicated by variability in baseline glucose metabolism. Evaluation of metabolic control with both IvGTT and OGTT is critical and should be taken into account before randomization. All currently available autoantibody tests should be analyzed, including ZnT8QA.