HLA Class II (DR, DQ, DP) Genes Were Separately Associated With the Progression From Seroconversion to Onset of Type 1 Diabetes Among Participants in Two Diabetes Prevention Trials (DPT-1 and TN07)

OBJECTIVE

To explore associations of HLA class II genes (HLAII) with the progression of islet autoimmunity from asymptomatic to symptomatic type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Next-generation targeted sequencing was used to genotype eight HLAII genes (DQA1, DQB1, DRB1, DRB3, DRB4, DRB5, DPA1, DPB1) in 1,216 participants from the Diabetes Prevention Trial-1 and Randomized Diabetes Prevention Trial with Oral Insulin sponsored by TrialNet. By the linkage disequilibrium, DQA1 and DQB1 are haplotyped to form DQ haplotypes; DP and DR haplotypes are similarly constructed. Together with available clinical covariables, we applied the Cox regression model to assess HLAII immunogenic associations with the disease progression.

RESULTS

First, the current investigation updated the previously reported genetic associations of DQA1*03:01-DQB1*03:02 (hazard ratio [HR] = 1.25, P = 3.50*10-3) and DQA1*03:03-DQB1*03:01 (HR = 0.56, P = 1.16*10-3), and also uncovered a risk association with DQA1*05:01-DQB1*02:01 (HR = 1.19, P = 0.041). Second, after adjusting for DQ, DPA1*02:01-DPB1*11:01 and DPA1*01:03-DPB1*03:01 were found to have opposite associations with progression (HR = 1.98 and 0.70, P = 0.021 and 6.16*10-3, respectively). Third, DRB1*03:01-DRB3*01:01 and DRB1*03:01-DRB3*02:02, sharing the DRB1*03:01, had opposite associations (HR = 0.73 and 1.44, P = 0.04 and 0.019, respectively), indicating a role of DRB3. Meanwhile, DRB1*12:01-DRB3*02:02 and DRB1*01:03 alone were found to associate with progression (HR = 2.6 and 2.32, P = 0.018 and 0.039, respectively). Fourth, through enumerating all heterodimers, it was found that both DQ and DP could exhibit associations with disease progression.

CONCLUSIONS

These results suggest that HLAII polymorphisms influence progression from islet autoimmunity to T1D among at-risk subjects with islet autoantibodies.

Genome-Wide Association Study Identifies IFIH1 and HLA-DQB1*05:02 Loci Associated With Anti-NMDAR Encephalitis

BACKGROUND AND OBJECTIVES

Anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis is a rare autoimmune neurologic disorder, the genetic etiology of which remains poorly understood. Our study aims to investigate the genetic basis of this disease in the Chinese Han population.

METHODS

We performed a genome-wide association study and fine-mapping study within the major histocompatibility complex (MHC) region of 413 Chinese patients with anti-NMDAR encephalitis recruited from 6 large tertiary hospitals and 7,127 healthy controls.

RESULTS

Our genome-wide association analysis identified a strong association at the IFIH1 locus on chromosome 2q24.2 (rs3747517, p = 1.06 × 10-8, OR = 1.55, 95% CI, 1.34-1.80), outside of the human leukocyte antigen (HLA) region. Furthermore, through a fine-mapping study of the MHC region, we discovered associations for 3 specific HLA class I and II alleles. Notably, HLA-DQB1*05:02 (p = 1.43 × 10-12; OR, 2.10; 95% CI 1.70-2.59) demonstrates the strongest association among classical HLA alleles, closely followed by HLA-A*11:01 (p = 4.36 × 10-7; OR, 1.52; 95% CI 1.29-1.79) and HLA-A*02:07 (p = 1.28 × 10-8; OR, 1.87; 95% CI 1.50-2.31). In addition, we uncovered 2 main HLA amino acid variation associated with anti-NMDAR encephalitis including HLA-DQβ1-126H (p = 1.43 × 10-12; OR, 2.10; 95% CI 1.70-2.59), exhibiting a predisposing effect, and HLA-B-97R (p = 3.40 × 10-8; OR, 0.63; 95% CI 0.53-0.74), conferring a protective effect. Computational docking analysis suggested a close relationship between the NR1 subunit of NMDAR and DQB1*05:02.

DISCUSSION

Our findings indicate that genetic variation in IFIH1, involved in the type I interferon signaling pathway and innate immunity, along with variations in the HLA class I and class II genes, has substantial implications for the susceptibility to anti-NMDAR encephalitis in the Chinese Han population.

Identification of Antibodies to DQβ:DRα Interisotypic Heterodimers in Human Sera

BACKGROUND

HLA class II antigens, DR, DQ, and DP, comprised an α and β chains, which typically combine, within the same isotype, to form the major histocompatibility complex:peptide complex. Interisotypic pairing is not commonly observed. Although reports of DQβ:DRα heterodimers exist, the pairing was reported to be unstable and, therefore, not studied to any extent.

METHODS

DQβ:DRα single antigens were produced through transfectant cell lines and used to identify and characterize positive reactive human sera by a multiplex bead-based assay.

RESULTS

Stable DQβ:DRα transfectants were constructed. Cell surface staining with class II-specific monoclonal antibodies revealed that some DQB1 alleles appear to be more efficient in expressing DQβ:DRα heterodimers. Interestingly, alleles within the same serological group varied in their efficiency of forming dimers on the cell surface. For example, DQβ0601:DRα had the highest transfection and cell membrane expression efficiency among 16 common DQB1 alleles tested. In contrast, DQβ0603:DRα-positive transfectants demonstrated minimal surface expression. Assembly of DQβ0601:DRα was not affected by the presence of a DQα chain. DQβ0601:DRα and DQβ0603:DRα single-antigen beads were used to screen human sera. Positive sera were identified that reacted to the unique epitopes of DQβ0601:DRα protein on the cell surface of the transfectants.

CONCLUSIONS

Our studies have demonstrated that unique DQβ:DRα heterodimers can be formed and are stably expressed on the cell surface. Such antigenic combinations, presented on single-antigen beads, demonstrated that patient sera can react with such heterodimers. Investigations on the potential clinical roles of antibodies against such interisotypic heterodimers are now possible.

Investigation of HLA susceptibility alleles and genotypes with hematological disease among Chinese Han population

Several genes involved in the pathogenesis have been identified, with the human leukocyte antigen (HLA) system playing an essential role. However, the relationship between HLA and a cluster of hematological diseases has received little attention in China. Blood samples (n = 123913) from 43568 patients and 80345 individuals without known pathology were genotyped for HLA class I and II using sequencing-based typing. We discovered that HLA-A*11:01, B*40:01, C*01:02, DQB1*03:01, and DRB1*09:01 were prevalent in China. Furthermore, three high-frequency alleles (DQB1*03:01, DQB1*06:02, and DRB1*15:01) were found to be hazardous in malignant hematologic diseases when compared to controls. In addition, for benign hematologic disorders, 7 high-frequency risk alleles (A*01:01, B*46:01, C*01:02, DQB1*03:03, DQB1*05:02, DRB1*09:01, and DRB1*14:54) and 8 high-frequency susceptible genotypes (A*11:01-A*11:01, B*46:01-B*58:01, B*46:01-B*46:01, C*01:02-C*03:04, DQB1*03:01-DQB1*05:02, DQB1*03:03-DQB1*06:01, DRB1*09:01-DRB1*15:01, and DRB1*14:54-DRB1*15:01) were observed. To summarize, our findings indicate the association between HLA alleles/genotypes and a variety of hematological disorders, which is critical for disease surveillance.

Characterization of the novel HLA-DQB1*02:01:01:21Q allele by sequencing-based typing

HLA-DQB1*02:01:01:21Q differs from HLA-DQB1*02:01:01:01 by one nucleotide substitution in the splice site in the beginning of intron 3.

Saliva direct PCR protocol for HLA-DQB1*02 genotyping

Celiac disease (CD) is an immune disorder, that is triggered by gluten ingestion in genetically predisposed individuals. The HLA-DQB1*02 allele is the main predisposing genetic factor and a candidate for first-line genotyping screening. We designed and validated a simple, DNA purification-free PCR protocol directly from crude saliva, enabling the detection of the DQB1*02 allele. This assay also distinguishes homozygous from heterozygous carriers. We propose this method for use in mass screening and/or epidemiological studies.

Family-based association of HLA-DRB1 and DQB1 alleles and haplotypes in a group of Iranian Type 1 diabetes children

This family-based study was conducted in a group of Iranians with Type 1 diabetes (T1D) to investigate the transmission from parents of risk and non-risk HLA alleles and haplotypes, and to estimate the genetic risk score for this disease within this population. A total of 240 T1D subjects including 111 parent-child trios (111 children with T1D, 133 siblings, and 222 parents) and 330 ethnically matched healthy individuals were recruited. High-resolution HLA typing for DRB1/DQB1 loci was performed for all study subjects (n = 925) using polymerase chain reaction-sequence-specific oligonucleotide probe method. The highest predisposing effect on developing T1D was conferred by the following haplotypes both in all subjects and in probands compared to controls: DRB1*04:05-DQB1*03:02 (Pc = 2.97e-06 and Pc = 6.04e-10, respectively), DRB1*04:02-DQB1*03:02 (Pc = 5.94e-17 and Pc = 3.86e-09, respectively), and DRB1*03:01-DQB1*02:01 (Pc = 8.26e-29 and Pc = 6.56e-16, respectively). Conversely, the major protective haplotypes included DRB1*13:01-DQB1*06:03 (Pc = 6.99e-08), DRB1*15:01-DQB1*06:02 (Pc = 2.97e-06) in the cases versus controls. Also, DRB1*03:01-DQB1*02:01/DRB1*04:02|05-DQB1*03:02 and DRB1*03:01-DQB1*02:01/DRB1*03:01-DQB1*02:01 diplotypes conferred the highest predisposing effect in the cases (Pc = 8.65e-17 and Pc = 6.26e-08, respectively) and in probands (Pc = 5.4e-15 and Pc = 0.001, respectively) compared to controls. Transmission disequilibrium test showed that the highest risk was conferred by DRB1*04:02-DQB1*03:02 (Pc = 3.26e-05) and DRB1*03:01-DQB1*02:01 (Pc = 1.78e-12) haplotypes and the highest protection by DRB1*14:01-DQB1*05:03 (Pc = 8.66e-05), DRB1*15:01-DQB1*06:02 (Pc = 0.002), and DRB1*11:01-DQB1*03:01 (Pc = 0.0003) haplotypes. Based on logistic regression analysis, carriage of risk haplotypes increased the risk of T1D development 24.5 times in the Iranian population (p = 5.61e-13). Also, receiver operating characteristic curve analysis revealed a high predictive power of those risk haplotypes in discrimination of susceptible from healthy individuals (area under curve: 0.88, p = 5.5e-32). Our study highlights the potential utility of genetic risk assessment based on HLA diplotypes for predicting T1D risk in individuals, particularly among family members of affected children in our population.

Next-generation sequencing identifies two novel HLA-DQB1 alleles, HLA-DQB1*03:519 and HLA-DQB1*06:01:35

We identified two novel HLA-DQB1 alleles by NGS, HLA-DQB1*03:519 and HLA-DQB1*06:01:35.

[The Polymorphism Analysis of HLA Class II Alleles Based on Next-Generation Sequencing and Prevention Strategy for Allele Dropout]

OBJECTIVE

To investigate the accuracy of next-generation sequencing technology (NGS) in detecting the polymorphisms of HLA-DRB1, DQB1, DQA1, DRB3, DRB4, DRB5, DPA1 and DPB1 alleles in randomly-selected unrelated healthy individuals from Shenzhen Han population, investigate the potential reason for HLA-DRB1 allele dropout in routine NGS, and establish an internal quality control system.

METHODS

NGS-based HLA class II genotyping was performed on 1 012 samples using the MiSeqDxTM platform. The suspected missed alleles indicated by the quality control software and HLA-DRB1 homozygotes were confirmed by PCR-SSOP or PCR-SBT methods.

RESULTS

A total of 139 alleles were detected, including HLA-DRB1(45), DRB3(7), DRB4(5), DRB5(7), DQA1(17), DQB1(21), DPA1(10) and DPB1(27). HLA-DRB1*09:01(17.09%),15:01(10.72%); DRB3*02:02(25.99%),03:01(10.18%); DRB4*01:03(36.46%); DRB5*01:01(15.42%); DQA1*01:02(20.01%),03:02(17.19%); DQB1*03:01(19.47%),03:03(17.98%), 05:02(11.66%), 06:01(10.67%); DPA1*02:02(54.45%), 01:03(31.18%) and DPB1*05:01(39.13%), 02:01(16.90%) alleles were the most common alleles in Shenzhen Han population (frequencies >10%). There was no statistical difference between the gene frequencies of HLA-DRB1 and DQB1 loci in our study. The HLA Common and Well-Documented Alleles in China (CWD2.4) (χ2=12.68, P >0.05). 94 cases of HLA-DRB1 homozygous samples detected by NGS were retested by PCR-SSOP or SBT method, and one case of allele dropout at HLA-DRB1 locus was found. SBT method confirmed that the allele of DRB1*04:03 was missed. The laboratory internal quality control system was established. Two cases of new alleles were detected and named by WHO Nomenclature Committee for Factors of the HLA System.

CONCLUSION

The HLA genotyping results based on NGS showed a significantly lower ambiguity rate. The HLA class II alleles exhibit genetic polymorphism in the Han population of unrelated healthy individuals in Shenzhen. The independent method based on NGS in clinical histocompatibility testing has limitations and requires internal quality control strategies to avoid allele-dropout events.

[Establishment and validation of prediction models for human leukocyte antigen haplotypes and human leukocyte antigen genotypes]

Objective: To establish prediction models for human leukocyte antigen (HLA) haplotypes and HLA genotypes, and verify the prediction accuracy. Methods: The prediction models were established based on the characteristic of HLA haplotype inheritance and linkage disequilibrium (LD), as well as the invention patents and software copyrights obtained. The models include algorithm and reference databases such as HLA A-C-B-DRB1-DQB1 high-resolution haplotypes database, B-C and DRB1-DQB1 LD database, G group alleles table, and NMDP Code alleles table. The prediction algorithm involves data processing, comparison with reference data, filtering results, probability calculation and ranking, confidence degree estimation, and output of prediction results. The accuracy of the predictions was verified by comparing them with the correct results, and the relationship between prediction accuracy and the probability distribution and confidence degree of the predicted results was analyzed. Results: The HLA haplotypes and genotypes prediction models were established. The prediction algorithm included the prediction of A-C-B-DRB1-DQB1 haplotypes according to HLA-A, B, DRB1, C, DQB1 genotypes, the prediction of C and DQB1 high-resolution results according to A, B and DRB1 high-resolution results, and the prediction of A, B, DRB1, C and DQB1 high resolution results according to the A, B and DRB1 intermediate or low resolution results. Validation results of "Predicting A-C-B-DRB1-DQB1 haplotypes basing on HLA-A, B, DRB1, C, DQB1 genotypes" model: for 787 data, the accuracy was 94.0% (740/787) with 740 correct predictions, 34 incorrect predictions, and 13 instances with no predicted results. For 847 data, the accuracy was 100% (847/847). The 2 411 and 2 594 haplotype combinations predicted from 787 and 847 data were grouped according to confidence degree, the accuracy was 100% (48/48, 114/114) for a confidence degree of 1, 96.2% (303/315) and 97.8% (409/418) for a confidence degree of 2 respectively. Validation results of "Predicting A, B, DRB1 and C, DQB1 high-resolution genotypes basing on HLA-A, B, DRB1 high, intermediate, or low resolution genotypes" model: when predicting C and DQB1 high resolution genotypes basing on A, B, and DRB1 high resolution genotypes, 89.3% (1 459/1 634) of the predictions were correct. The accuracy for the top 2 predicted probability (GPP) ranking was 79.2% (1 156/1 459), and for the top 10, it was 95.0% (1 386/1 459). Furthermore, when GPP≥90% and GPP 50%-90%, the prediction accuracy was 81.3% (209/257) and 72.8% (447/614) respectively. The accuracy of predicting C and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 high resolution genotypes from the China Marrow Donor Program was 87.0% (20/23). The accuracy of predicting A, B, DRB1, C, and DQB1 high resolution genotypes basing on the results of A, B, and DRB1 intermediate or low-resolution genotypes was 70.0% (7/10) and 52.5% (21/40) respectively. When predicting whether the patient is likely to have a HLA 10/10 matched donor, the accuracy of the top 2 GPP combinations with a proportion of ≥50% was 85.7% (6/7). Conclusions: When using A, B, DRB1, C, DQB1 genotypes to predict A-C-B-DRB1-DQB1 haplotype combinations, the results with a confidence degree of 1 and 2 are reliable. When predicting C and DQB1 genotypes according to A, B and DRB1 genotypes, the top 10 results ranked by GPP are reliable, and the top 2 results with GPP≥50% are more reliable.

HLA class II polymorphisms as prognostic biomarkers for right and left-sided colon cancer

BACKGROUND

Colon cancer (CC) is one of the most common malignancies worldwide. Characterization of new prognostic biomarkers for right-sided CC (RCC) and left-sided CC (LCC) may contribute to improving early detection. An association of human leukocyte antigens class II (HLA-II) with the predisposition to CC was suggested.

AIM OF THE STUDY

We evaluated the association of DRB1 and DQB1 with the risk of LCC and RCC.

PATIENTS AND METHODS

Our study comprised 93 CC patients and 100 healthy controls. Genotyping of HLA class II alleles were performed by the Polymerase Chain Reaction Sequence-Specific Primers (PCR-SSP).

RESULTS

DRB1*03 was positively associated with CC. In contrast, DRB1*11, DRB1*13, DQB1*03, and DQB1*05 were negatively linked to CC. Haplotype analysis revealed that DRB1*04-DQB1*04 and DRB1*09-DQB1*02 were positive, while DRB1*01-DQB1*05, DRB1*04-DQB1*03, DRB1*07-DQB1*02, DRB1*11-DQB1*03, DRB1*11-DQB1*05, and DRB1*13-DQB1*06 were negatively associated with CC. For sigmoid CC, DRB1*13, DRB1*11, and DQB1*05 were negative, while DRB1*04-DQB1*02, and DRB1*07-DQB1*03 were positively associated. DRB1*03 and DRB1*04-DQB1*04 were positive, while DRB1*11 and DQB1*03 were negatively linked to RCC. According to the LCC, DRB1*07, DRB1*11, DQB1*03, DQB1*05, and DRB1*07-DQB1*02 were negative. In contrast, DRB1*09-DQB1*02 was positively associated with LCC. Stratified analysis revealed that DRB1*11 is associated with higher risk of metastasis in CC and sigmoid CC, and tolerance to treatment in RCC. DQB1*03 was associated with lymph-node invasion in CC.

CONCLUSION

DRB1 and DQB1 polymorphisms could be used as future biomarkers for the early detection of subjects at a higher risk of developing RCC and LCC, metastasis in sigmoid CC, and tolerance to treatment in RCC.

Four new intronic variants of HLA-DQB1 detected by next-generation sequencing

Characterization of HLA-DQB1*02:02:01:18, -DQB1*02:02:01:19, -DQB1*03:02:01:20 and -DQB1*05:03:01:10 alleles in Spanish individuals.

Diversity of HLA-A, -B, -C, -DRB1, and -DQB1 alleles and haplotypes in Kazakhstani Tatar population and genetic relatedness to other populations

BACKGROUND

Kazakhstan is a transcontinental former Soviet Union republic whose present-day population comprises more than 100 ethnic groups. Insofar as Human Leukocyte Antigen (HLA) genotyping is useful for anthropological studies, data on the HLA profile of Kazakhstani Tatars are lacking.

OBJECTIVE

We extend our earlier findings on the unique HLA profile of distinct Kazakhstani populations by examining HLA class I and class II loci in Kazakhstani (Volga) Tatar minority population and its relatedness to those of bordering and worldwide communities.

METHODS

HLA class I and class II genotypes of the Kazakhstan Tatar minority were analyzed by PCR-SSP and were compared to neighboring populations using Neighbor-Joining (NJ) trees and standard genetic distances (SGD) analysis.

RESULTS

In total, 132 HLA alleles were identified in a sample of 103 Kazakhstani Tatars, of which HLA-A*02:01 (20.1 %), -B*07:02 (12.1 %), -C*07:02 (12.7 %), -DRB1*07:01 (18.1 %), and -DQB1*02:01 (19.6 %) were the most frequent. The most frequent two-locus haplotypes were B*07:02 ∼ C*07:02 (10.6 %) B*07:02 ∼ DRB1*15:01 (06.1 %), B*07:02 ∼ DQB1*06:02 (07.1 %), and DRB1*15:01 ∼ DQB1*06:02 (11.6 %).

CONCLUSIONS

Considering historical data, the close relatedness of Kazakhstani Tatars to European Russians (including Russian Tatars) suggests that Kazakhstani Tatars may be Russian Tatars, who originated from the Volga region, following their massive migrations to central Asia.

HLA sequencing identifies novel associations and suggests clinical relevance of DPB1*04:01 in ANCA-associated Granulomatosis with polyangiitis

Granulomatosis with polyangiitis (GPA) is a rare systemic autoimmune disease. Major contributions of HLA genes have been reported; however, HLA typing-based diagnosis or risk prediction in GPA has not been established. We have performed a sequencing-based HLA genotyping in a north Indian GPA cohort and controls to identify clinically relevant novel associations. PR3-ANCA-positive 40 GPA patients and 40 healthy controls from north India were recruited for the study. Targeted sequencing of HLA-A,-B,-C,-DRB1,-DQB1, and -DPB1 was performed. Allelic and haplotypic associations were tested. Molecular docking of susceptibility HLA alleles with reported super-antigen epitopes was performed. The association of substituted amino acids located at the antigen-binding domain of HLA was evaluated. Genetic association of five HLA-alleles was identified in GPA. The novel association was identified for C*15:02 (p = 0.04; OR = 0.27(0.09-0.88)). The strongest association was observed for DPB1*04:01 (p < 0.0001; OR = 6.2(3.08-11.71)), previously reported in European studies. 35 of 40 GPA subjects had at least one DPB1*04:01 allele, and its significant risk was previously not reported from the Indian population. Significantly associated haplotypes DRB1*03:01-DQB1*02:01-DPB1*04:01 (p = 0.02; OR = 3.46(1.11-12.75)) and DRB1*07:01-DQB1*02:02-DPB1*04:01 (p = 0.04; OR = 3.35(0.95-14.84)) were the most frequent in GPA patients. Ranging from 89 % to 100 % of GPA patients with organ involvement can be explained by at least one DPB1*04:01 allele. A strong interaction between the HLA and three epitopes of the reported super antigen TSST-1 of Staphylococcus aureus was confirmed. Our study highlighted the potential applicability of HLA typing for screening and diagnosis of GPA. A large multi-centric study and genotype-phenotype correlation analysis among GPA patients will enable the establishment of HLA-typing based GPA diagnosis.

Identification of the novel HLA-DQB1*03:512 allele by next-generation sequencing

HLA-DQB1*03:512 differs from DQB1*03:02:01 by one nucleotide substitution in codon 89 in exon 2.

Increased Frequency of the HLA-DRB1*04:04-DQA1*03-DQB1*03:02 Haplotype Among HLA-DQB1*06:02-Positive Children With Type 1 Diabetes

HLA-DR/DQ haplotypes largely define genetic susceptibility to type 1 diabetes (T1D). The DQB1*06:02-positive haplotype (DR15-DQ602) common in individuals of European ancestry is very rare among children with T1D. Among 4,490 children with T1D in the Finnish Pediatric Diabetes Register, 57 (1.3%) case patients with DQB1*06:02 were identified, in comparison with 26.1% of affected family-based association control participants. There were no differences between DQB1*06:02-positive and -negative children with T1D regarding sex, age, islet autoantibody distribution, or autoantibody levels, but significant differences were seen in the frequency of second class II HLA haplotypes. The most prevalent haplotype present with DQB1*06:02 was DRB1*04:04-DQA1*03-DQB1*03:02, which was found in 27 (47.4%) of 57 children, compared with only 797 (18.0%) of 4,433 among DQB1*06:02-negative case patients (P < 0.001 by χ2 test). The other common risk-associated haplotypes, DRB1*04:01-DQA1*03-DQB1*03:02 and (DR3)-DQA1*05-DQB1*02, were less prevalent in DQB1*06:02-positive versus DQB1*06:02-negative children (P < 0.001). HLA-B allele frequencies did not differ by DQB1*06:02 haplotype between children with T1D and control participants or by DRB1*04:04-DQA1*03-DQB1*03:02 haplotype between DQB1*06:02-positive and -negative children with T1D. The increased frequency of the DRB1*04:04 allele among DQB1*06:02-positive case patients may indicate a preferential ability of the DR404 molecule to present islet antigen epitopes despite competition by DQ602.

ARTICLE HIGHLIGHTS

Next generation sequencing identifies two novel HLA alleles, HLA-B*51:395 and HLA-DQB1*06:478

We identified two novel HLA alleles by NGS, HLA-B*51:395 and HLA-DQB1*06:478.

Total serum IgA levels and HLA-DQB1*02:01 allelic status

Immunoglobulin A Deficiency (IgAD) is the most common primary immunodeficiency and is significantly associated with Celiac Disease (CD), which recognizes a specific background of human leukocyte antigens (HLA) predisposition (including HLA-DQB1*02:01 allele). A number of studies investigated the role of HLA in IgAD etiopathogenesis: HLA-DQB1*02 alleles are included in the main haplotypes linked to this primary immunodeficiency. In this preliminary study, we investigated the potential impact of HLA-DQB1*02:01 allelic status on total serum IgA levels: 108 serum samples from the bone marrow donors' registry were analyzed for total IgA concentration with respect to the HLA-DQB1*02:01 status. Although total serum IgA levels between HLA-DQB1*02:01 carriers and HLA-DQB1*02:01 negative donors were not different, we observed a statistically significant difference (p=0.0118) in total serum IgA levels among donors with low IgA concentration (<80mg/dL) in the sub-analysis between HLA-DQB1*02:01 positive group (including both homozygous and heterozygous carriers) compared to HLA-DQB1*02:01 negative donors. Our results might suggest a role of HLA-DQB1*02:01 allelic variant in the determination of total serum IgA levels, at least in patients affected with IgA deficiency and/or otherwise predisposed to it; however, larger and more standardized studies are needed to confirm this speculation.

Characterization of the novel HLA-DQB1*03:516 allele by next-generation sequencing

HLA-DQB1*03:516 differs from DQB1*03:03:02:03 by one nucleotide substitution at position 197G>A in exon 2.

Discovery of three HLA-DQB1*03:01:01 variants: HLA-DQB1*03:01:01:54, -DQB1*03:01:01:56 and -DQB1*03:01:01:58

Three nucleotide substitutions in intronic regions give rise to the novel alleles: HLA-DQB1*03:01:01:54, -DQB1*03:01:01:56, -DQB1*03:01:01:58.

Investigating associations between HLA DQA1 ~ DQB1 haplotypes, H. pylori infection, metaplasia, and anti-CagA IgA seropositivity in a Turkish gastritis cohort

Helicobacter pylori was reported as an important cause of gastritis, and gastric ulcers and CagA oncoprotein-producing H. pylori subgroups were blamed to increase the severity of gastritis. Disparities were reported in that the presence of serum anti-CagA IgA was not parallel with CagA-positive H. pylori cohabitation. We hypothesized that the HLA-DQA1 ~ DQB1 haplotypes in human populations include protective haplotypes that more effectively present immunogenic CagA peptides and susceptible haplotypes with an impaired capacity to present CagA peptides. We recruited patients (n = 201) admitted for gastroendoscopy procedures and performed high-resolution HLA-DQA1 and DQB1 typing. Serum anti-CagA IgA levels were analyzed by ELISA (23.0% positive), and H. pylori was classified as positive or negative in gastric mucosal tissue slides (72.6% positive). The HLA DQA1*05:05 allele (29.1%) and HLA DQB1*03:01 allele (32.8%) were found at the highest frequency among gastritis patients of Turkish descent. In HLA DQA1*05:05 ~ DQB1*03:01 double homozygous (7.3%) and heterozygous (40.7%) haplotype carriers, the presence of anti-CagA IgA decreased dramatically, the presence of H. pylori increased, and the presence of metaplasia followed a decreasing trend. The DQ protein encoded by HLA DQA1*05:05-DQ*03:01 showed a low binding affinity to the CagA peptide when binding capacity was analyzed by the NetMHCIIPan 4.0 prediction method. In conclusion, HLA DQA1 ~ DQB1 polymorphisms are crucial as host defense mechanisms against CagA H. pylori since antigen binding capacity plays a crucial role in anti-CagA IgA production.

Three novel variants of HLA-DQB1*06 identified by next-generation sequencing

Characterization of HLA-DQB1*06:472, -DQB1*06:02:01:34 and -DQB1*06:04:01:06 alleles in Spanish individuals.

Three new HLA class II alleles detected in Bashkir individuals

The new HLA-DRB1*11:320, HLA-DRB1*15:218, HLA-DQB1*05:324 alleles characterized in bone marrow donors.

Association of HLA class I and II genes with cervical cancer susceptibility in a Han Chinese population

Cervical cancer (CC) is one of the leading causes of cancer-related death in females worldwide. Genome-wide association studies (GWASs) have identified CC-related susceptibility loci in HLA regions. To investigate the associations between HLA genes and cervical intraepithelial neoplasia (CIN) or cervical cancer (CC), six loci of HLA class I (HLA-A, -B, and -C) and II (HLA-DRB1, -DPB1, and -DQB1) were selected for genotyping, and the associations between these alleles or their haplotypes with CIN or CC risk or protection from disease were evaluated. In total, 2193 participants, including 909 healthy individuals in the control group, 769 patients with CC, and 515 patients with CIN2+ (CIN II and III), were enrolled in the current study. HLA genes were genotyped using the NGSgo Illumina MiSeq workflow, and the associations between these loci and CIN2+ or CC at the allele and haplotype levels were analyzed. The allele frequencies of HLA-A*33:03, B*58:01, C*03:02, DPB1*05:01, and DRB1*12:01 were lower in both the CC and CIN2+ groups than in the control group, whereas those of B*55:02, C*04:03, and DPB1*03:01 were higher in the CC group than in the control group. In the histologic CC type analysis, the differences in the frequencies of these alleles in squamous cell carcinoma (SCC) of the cervix and stage I CC showed a consistent trend. In the haplotype analysis, the frequency of A*33:03-C*03:02-B*58:01 was lower in the CC and CIN2+ groups than in the control group, and that of A*24:02-C*04:03-B*15:25 was higher in the CC group than in both the control and CIN2+ groups. These three different haplotype frequencies were also identified in the FIGO CC stage analysis. In addition, in human papilloma virus (HPV) genotype analyses, the frequencies of HLA-C*03:02 and DPB1*05:01 were significantly lower in the CC and CIN2+ groups than in the control group, and in SCC subgroup, the frequencies of HLA-DQB1*04:01 and DRB1*04:05 were higher in the HPV other genotype infection group than in the HPV16 infection group. In both HPV16 single infection and coinfection with other HPVs, the frequency of haplotype A*33:03-C*03:02-B*58:01 was lower in both CC and CIN2+ than in the control group, while the frequencies of A*11:01-C*14:02-B*51:01 and A*24:02-C*03:04-B*13:01 were higher in the CIN2+ than in CC and the control group. In the HPV16 and other HPV infection comparisons, the frequencies of DRB1*04:05-DQB1*04:01-DPB1*02:01 and DRB1*11:01-DQB1*03:01-DPB1*05:01 were lower in the HPV16 infection group than in the other HPV infection group. Our results suggest that the HLA class I and II genes may affect the risk of CIN and CC as well as the histologic CC types and FIGO stages of CC in the Han Chinese population. In addition, HLA genes were associated with HPV16 infection at both the allelic and haplotype levels.

Characterization of the novel HLA-DQB1 allele, DQB1*05:323 by next-generation sequencing

The novel HLA-DQB1*05:323 allele was characterized using next generation sequencing technology.

Genomic full-length sequence of the novel HLA-DQB1*04:01:01:04 allele

The sequence of HLA-DQB1*04:01:01:04 differs from HLA-DQB1*04:01:01:03 by four nucleotide deletion in intron 2.

Confirmation and extension of 18 HLA alleles identified in donors from the Russian bone marrow registry

Eighteen HLA allele sequences were confirmed and extended: 3 HLA-A, 6 HLA-B, 3 HLA-C, 2 HLA-DRB1, and 4 HLA-DQB1 alleles.

Discovery of the HLA-DQB1*06:465 allele, a variant of HLA-DQB1*06:04:01:01

HLA-DQB1*06:465 differs from HLA-DQB1*06:04:01:01 by a non-synonymous nucleotide substitution in codon 38.

The protective association of HLA-C*12:02 and HLA-DQB1*06:01 with severe acute hepatitis of unknown origin in the Japanese population

Global surveillance has been conducted to elucidate the pathogenesis of acute hepatitis of unknown origin (AHUO), However, the factors associated with the aggravation of this serious disease are unclear. Therefore, we conducted a HLA association study to identify HLA alleles or haplotypes predisposing or protective against Japanese AHUO. The HLA 5 locus (HLA-A, HLA-B, C, DRB1, and DQB1) 4-digit genotyping results of 72 AHUO patients who underwent liver transplantation at our institution between 2000 and 2021 were compared to those of 873 healthy Japanese controls. Protective associations of HLA-B*52:01 (p-corrected (pc) = 3.15 × 10-3 ), HLA-C*12:02 (pc = 1.66 ×10-3 ), HLA-DQB1*06:01 (pc = 1.42 × 10-2 ), and HLA-DRB1*15:02 (pc = 1.36 × 10-2 ) with severe AHUO in Japanese patients were observed. The amino acid residues of tryptophan at position 156, which are located in the antigen-binding grooves of the HLA-C protein, showed a protective association with AHUO, showing a significant difference from other amino acid variations (pc = 9.0 × 10-4 ). Furthermore, 5 amino acid residues of the HLA-DQB1 protein were also protectively associated with AHUO with a significant difference from other amino acid variations (pc = 1.42 × 10-2 to 2.89 × 10-2 ). These alleles have a protective association with the aggravation of AHUO in the Japanese population.

Next-generation sequencing identifies two novel HLA class II alleles: HLA-DRB1*12:107 and HLA-DQB1*06:476

We identified two novel HLA class II alleles by next-generation sequencing, HLA-DRB1*12:107 and HLA-DQB1*06:476.

Detection of the novel HLA-DQB1*06:474 allele in a Russian individual

One nucleotide substitution in codon 152 of HLA-DQB1*06:03:01:01 results in a novel allele, HLA-DQB1*06:474.

Description of two novel HLA alleles: HLA-DQB1*03:477 and HLA-DQB1*03:487

Compared to the HLA-DQB1*03:03:02:01, the HLA-DQB1*03:477 and HLA-DQB1*03:487 alleles each show one single nucleotide substitution.

Epigenome-wide methylation haplotype association analysis identified HLA-DRB1, HLA-DRB5 and HLA-DQB1 as risk factors for rheumatoid arthritis

The aim of this study was to compare nonrandom associations between physically adjacent single methylation polymorphism loci among rheumatoid arthritis (RA) and normal subjects for investigating RA-risk methylation haplotypes (meplotype). With 354 ACPA-positive RA patients and 335 normal controls selected from a case-control study based on Swedish population, we conducted the first RA epigenome-wide meplotype association study using our software EWAS2.0, mainly including (i) converted the β value to methylation genotype (menotype) data, (ii) identified methylation disequilibrium (MD) block, (iii) calculated frequent of each meplotypes in MD block and performed case-control association test and (iv) screened for RA-risk meplotypes by odd ratio (OR) and p-values. Ultimately, 545 meplotypes on 334 MD blocks were identified significantly associated with RA (p-value < .05). These meplotypes were mapped to 329 candidate genes related to RA. Subsequently, combined with gene optimization, eight RA-risk meplotypes were identified on three risk genes: HLA-DRB1, HLA-DRB5 and HLA-DQB1. Our results reported the relationship between DNA methylation pattern on HLA-DQB1 and the risk of RA for the first time, demonstrating the co-demethylation of 'cg22984282' and 'cg13423887' on HLA-DQB1 gene (meplotype UU, p-value = 2.90E - 6, OR = 1.68, 95% CI = [1.35, 2.10]) may increase the risk of RA. Our results demonstrates the potential of methylation haplotype analysis to identify RA-related genes from a new perspective and its applicability to the study of other disease.

A series of 7 cases of patients with narcolepsy with hypocretin deficiency without the HLA DQB1*06:02 allele

STUDY OBJECTIVES

We report data collected from 2 reference European sleep centers on a series of patients with narcolepsy with hypocretin-1 deficiency and absence of the human leukocyte antigens (HLA) DQB1*06:02 allele.

METHODS

Clinical data, HLA DQ markers, and cerebrospinal fluid assessments were collected retrospectively from Caucasian patients with a diagnosis of narcolepsy type 1 with cerebrospinal fluid hypocretin-1 deficiency (< 110 pg/ml) and absence of the HLA DQB1*06:02 allele, with follow-up with at least 1 visit within the last 4 years, consecutively admitted to 2 European sleep centers (Lugano, Switzerland and Montpellier, France).

RESULTS

Seven patients (3 of 29 patients in Lugano and 4 of 328 in Montpellier) were diagnosed with narcolepsy with hypocretin-1 deficiency and absence of HLA DQB1*06:02 (ie, 2% of patients with narcolepsy type 1). Regarding the HLA-DQB1 genotyping, 4 cases were positive for HLA DQB1*03:01, 1 for DQB1*03:02, and 3 for DQB1*02:01. Three patients had atypical cataplexy and 1 had no cataplexy. Only 2 patients had both a mean sleep latency of less than 8 minutes and more than 2 sleep onset rapid eye movement periods on the Multiple Sleep Latency Test, indicative of a less severe condition.

CONCLUSIONS

Although rare, this series of 7 cases confirms that hypocretin-deficient narcolepsy should not be excluded in the absence of HLA DQB1*06:02, especially if patients are carriers of other high-risk HLA-DQB1 alleles (DQB1*03:01, *03:02, *02:01). These data support the hypothesis that narcolepsy type 1 is a wider disease spectrum linked to the loss of hypocretin peptide.

CITATION

Miano S, Barateau L, De Pieri M, et al. A series of 7 cases of patients with narcolepsy with hypocretin deficiency without the HLA DQB1*06:02 allele. J Clin Sleep Med. 2023;19(12):2053-2057.

Human leukocyte antigen-DQ risk heterodimeric haplotypes of left ventricular dysfunction in cardiac sarcoidosis: an autoimmune view of its role

Cardiac sarcoidosis (CS) is the scarring of heart muscles by autoimmunity, leading to heart abnormalities and patients with sarcoidosis with cardiac involvements have poor prognoses. Due to the small number of patients, it is difficult to stratify all patients of CS by human leukocyte antigen (HLA) analysis. We focused on the structure of antigen-recognizing pockets in heterodimeric HLA-class II, in addition to DNA sequences, and extracted high-affinity combinations of antigenic epitopes from candidate autoantigen proteins and HLA. Four HLA heterodimer-haplotypes (DQA1*05:03/05:05/05:06/05:08-DQB1*03:01) were identified in 10 of 68 cases. Nine of the 10 patients had low left ventricular ejection fraction (< 50%). Fourteen amino-acid sequences constituting four HLA anchor pockets encoded by the HLA haplotypes were all common, suggesting DQA1*05:0X-DQB1*03:01 exhibit one group of heterodimeric haplotypes. The heterodimeric haplotypes recognized eight epitopes from different proteins. Assuming that autoimmune mechanisms might be activated by molecular mimicry, we searched for bacterial species having peptide sequences homologous to the eight epitopes. Within the peptide epitopes form the SLC25A4 and DSG2, high-homology sequences were found in Cutibacterium acnes and Mycobacterium tuberculosis, respectively. In this study, we detected the risk heterodimeric haplotypes of ventricular dysfunction in CS by searching for high-affinity HLA-class II and antigenic epitopes from candidate cardiac proteins.

Characterization of two novel alleles, HLA-C*03:638 and HLA-DQB1*03:02:38

Two novel HLA alleles were detected using next generation sequencing technology.

Four novel HLA alleles: HLA-DPA1*01:03:01:68, -DPA1*01:03:01:71, -DQA1*02:01:01:06, and -DQB1*06:03:01:19

Four novel HLA Class II alleles, HLA-DPA1*01:03:01:68, -DPA1*01:03:01:71, -DQA1*02:01:01:06, and -DQB1*06:03:01:19, characterized in Spanish individuals.

The new HLA-DQB1*05:304 allele identified in an Italian patient

DQB1*05:304 allele was identical to DQB1*05:02:01 except for a single nucleotide substitution.

Genomic sequence of the HLA-A*01:432, HLA-C*07:1068 and HLA-DQB1*02:213 alleles

The sequences of HLA-A*01:432, HLA-C*07:1068 and HLA-DQB1*02:213 alleles are reported.

HLA-A*02:06 allele may be susceptible to myelodysplastic syndrome in Zhejiang Han population, China

The association between HLA loci and haematological malignancy has been reported in certain populations. However, there are limited data for HLA loci at a high-resolution level with haematological malignancy in China. In this study, a total of 1115 patients with haematological malignancies (including 490 AML, 410 acute lymphoblastic leukaemia (ALL), 122 myelodysplastic syndrome [MDS] and 93 non-Hodgkin's lymphoma [NHL]) and 1836 healthy individuals as a control group in the Han population of Zhejiang Province, China, were genotyped for HLA-A, HLA-C, HLA-B, HLA-DRB1 and HLA-DQB1 loci at high resolution. The possible association between HLA alleles and haplotypes and haematologic malignancy was analysed. The allele frequencies (AFs) of HLA-A*02:05, HLA-A*02:06, HLA-A*32:01, HLA-B*35:03, HLA-B*54:01, HLA-B*55:07, HLA-DRB1*04:05, HLA-DRB1*15:01, HLA-DQB1*04:01 and HLA-DQB1*06:02 in the MDS patients were much higher than those in the control group (P < 0.05), while the AFs of HLA-C*07:02, HLA-DRB1*03:01, HLA-DRB1*14:54, HLA-DQB1*02:01 and HLA-DQB1*05:03 were obviously lower than those in the control group (p < .05). Interestingly, the differences in these HLA alleles in patients with MDS were not significant after applying Bonferroni correction (Pc > .05), except for HLA-A*02:06 (Pc < .01). There were 13, 6 and 10 HLA alleles with uncorrected significant differences (p < .05) among patients with AML, ALL and NHL, respectively, compared with those in the control group, but the differences in these HLA alleles were not significant after correction (Pc > .05). Compared to those of the control group, there were some haplotypes over 1.00% frequency in patients with AML, MDS and NHL patients with uncorrected significant differences (p < .05). However, none of them showed a significant difference after correction as well (Pc > .05). The study reveals that HLA-A*02:06 may lead to susceptibility to MDS, but none of the HLA alleles were associated with AML, ALL or NHL after correction. These data will help to further understand the role of HLA loci in the pathogenesis of haematological malignancy in China.

A unique association? A narcolepsy type 1 case comorbid with Primary Biliary Cholangitis

The aim of the study was to present a woman affected of a narcolepsy with cataplexy (narcolepsy type 1) comorbid with an asymptomatic Primary Biliary Cholangitis (PBC). The HLA haplotype was DRB1*15:01, DQA1*01:02, DQB1*06:02. The allele DQB1*06:02 has been considered until now protective for PBC and dual pathology has not been published. We think the important clinical message of the Case would be of continuing to monitor adults with narcolepsy type 1 for late complications that may be associated with other autoimmune conditions. Clinicians should be aware of the relationship between Narcolepsy and PBC. This highlights the need for screening and management in these individuals.

Role of HLA class I and II alleles in susceptibility to ankylosing spondylitis in Chinese Han

OBJECTIVE

The objective of the study was to clarify the associations of HLA class I and II alleles with ankylosing spondylitis (AS) among Chinese Han.

METHODS

We performed HLA genotyping and Sanger sequencing for 68 HLA-B*27(-), 62 HLA-B*27(+) AS patients, and 70 controls. Case-control analyses and separate analyses of HLA-B*27(-) patients were performed. One-way ANOVA and Kruskal-Wallis multiple comparisons test were used to analyze the effects of HLA-A\B\C\DRB1\DQB1 alleles on clinical characteristics of HLA-B*27(-) and HLA-B*27(+) patients.

RESULTS

In the HLA-B*27(+) group, positive associations were seen with A*11:02, B*27:04, B*27:05, C*02:02, C*12:02, and DRB1*04:01 and negative associations were seen with A*33:03, B*07:02, B*57:01, and C*07:02. The age at onset was greater in HLA-B*27(-) patients than in HLA-B*27(+) patients (30.03 ± 15.15 vs. 23.08 ± 7.79 years). In the HLA-B*27(-) group, those with A*01:01, B*13:01, B*13:02, C*01:02, C*04:01, DQB1*02:01, DQB1*06:01, and DRB1*03:01 had an earlier onset than those without these alleles, while patients carrying B*40:02, C*07:02, C*12:02, C*15:02, DQB1*05:02, and DQB1*05:03 had a delayed onset. In the HLA-B*27(-) group, A*32:01(+), C*08:01(+), and DRB1*04:05(-) women were likely to develop AS. In the HLA-B*27(+) group, DQB1*03:02(+) women may be more likely to develop AS. DRB1*12:02 and HLA-B*27 interacted with the distribution of AS-affected sites. In the HLA-B*27(+) group, DRB1*12:02(+) patients were likely to have peripheral joint involvement.

CONCLUSION

HLA class I and II alleles other than HLA-B*27 contribute to AS predisposition and characteristics among Chinese Han patients.

Association Between HLA Alleles and Autoantibodies in Dermatomyositis Defined by Sarcoplasmic Expression of Myxovirus Resistance Protein A

OBJECTIVE

The diagnosis in the studies analyzing HLA of dermatomyositis (DM) was based on a combined clinical category of polymyositis/DM. This retrospective study investigated the associations of HLA with 5 DM-specific autoantibodies in Japanese patients diagnosed by muscle pathology.

METHODS

We diagnosed Japanese patients with DM based on sarcoplasmic expression of myxovirus resistance protein A. These patients underwent investigation for 5 DM-specific autoantibodies and HLA genotyping.

RESULTS

Of 175 patients (83 males and 92 females; range 1-86 yrs; mean 46 yrs), 173 (98.9%) had 1 of the 5 autoantibodies. Seven alleles-A*02:07, B*46:01, DRB1*04:07, DRB1*07:01, DRB1*08:03, DQB1*06:01, and DPB1*02:02-were more frequently detected in the patients with DM than healthy controls, but these associations were not significant after multiple testing correction. Stratifying by DM-specific autoantibodies, we found the associations of 6 already known and 7 new alleles-B*48:01, B*52:01, C*12:02, DRB1*04:05, DRB1*15:02, DPB1*05:01, and DPB1*09:01-with subsets of DM. Moreover, significant associations of 5 alleles with antinucleosome remodeling deacetylase complex (Mi-2) remained after multiple testing correction. In particular, the DRB1*04:07 (odds ratio [OR 28.9]; corrected P = 2.7 × 10-6) and DQB1*06:01 (OR 4.0; corrected P = 1.6 × 10-4) alleles were significantly more prevalent in patients with anti-Mi-2 antibody than in controls.

CONCLUSION

This study demonstrates DM-specific autoantibodies defined immunogenetic subsets of DM.

Association between Human Leukocyte Antigen (HLA) DQB1*06 and HLA DQB1*03 and adverse outcomes in a group of critically ill patients with COVID-19 in Tunisia: a cross-sectional study

Introduction

Human Leukocyte Antigen (HLA) system is a highly polymorphic genetic system associated with the prognosis of several infectious diseases. The aim of this study is to investigate the association of HLA polymorphism with the outcome of coronavirus disease 2019 (COVID-19) in Tunisian critically ill patients.

Methods

this retrospective cross-sectional study included 42 consecutive patients hospitalized in intensive care unit (ICU) for COVID-19 in March 2021. Genotyping of HLA loci was performed by LABType™ sequence-specific oligonucleotide (SSO) typing kits (One lambda Inc, USA). Statistical analyses were performed using Statistical Package for Social Sciences (SPSS®) version 23.0. A p-value <0.05 was considered significant. Multivariable regression analysis was performed for the association between HLA polymorphism with adverse outcomes with adjustment for potential confounders such as age, sex, co-morbidities and blood type.

Results

patients included in our study had a mean age of 64.5 ± 11.5 (34-83) years and were mainly men (64.3%; (n=27)). The most common cardiovascular risk factors were obesity (61.9%; (n=26)) and hypertension (26.2%; (n=11)). Thirty-two patients died (76.2%). Eleven patients (26.2%) required intubation during hospitalization. We found that HLA DQB1*06 allele was significantly associated with protection against mortality aOR: 0.066, 95% CI 0.005-0.821; p = 0.035. HLA DQB1*03 allele was significantly associated with protection against intubation aOR: 0.151, 95% CI 0.023-0.976; p = 0.047.

Conclusion

it was found that there are 2 protective HLA alleles against COVID-19 severity and mortality in critically ill patients. This could allow focusing on people genetically predisposed to develop severe forms of COVID-19.

Full-length characterization of the HLA-DQB1*03:25:01 allele in two Amerindian individuals

Genomic full-length characterization of the HLA-DQB1*03:25:01 allele.

Narcolepsy is associated with an increased risk of HLA-related autoimmune diseases: Evidence from a nationwide healthcare system data in South Korea

STUDY OBJECTIVES

To determine the incidence rate of narcolepsy in South Korea and closely examine the relationship between narcolepsy, which is believed to be an autoimmune response, and other systemic autoimmune diseases.

METHODS

We examined data from the South Korean nationwide health insurance claims database from 2010 to 2019. Our study included patients with narcolepsy as well as age- and sex-matched controls without narcolepsy. We estimated the incidence of narcolepsy and the odds ratio of narcolepsy and associated autoimmune comorbidities in South Korea.

RESULTS

We identified 8710 patients with narcolepsy (59.8% men and 40.2% women). The incidence of narcolepsy was 0.05%. Patients with narcolepsy were at a significantly high risk of ankylosing spondylitis, rheumatoid arthritis, and Sjögren's syndrome, which diseases are known to be related to human leukocyte antigen (HLA) genes.

CONCLUSIONS

Narcolepsy is closely related to systemic autoimmune diseases, particularly those related to HLA genes.

Amino acid polymorphisms in human histocompatibility leukocyte antigen class II and proinsulin epitope have impacts on type 1 diabetes mellitus induced by immune-checkpoint inhibitors

Introduction

Immune-checkpoint inhibitors are effective in various advanced cancers. Type 1 diabetes mellitus induced by them (ICI-T1DM) is a serious complication requiring prompt insulin treatment, but the immunological mechanism behind it is unclear.

Methods

We examined amino acid polymorphisms in human histocompatibility leukocyte antigen (HLA) molecules and investigated proinsulin epitope binding affinities to HLA molecules.

Results and Discussion

Twelve patients with ICI-T1DM and 35 patients in a control group without ICI-T1DM were enrolled in the study. Allele and haplotype frequencies of HLA-DRB1*04:05, DQB1*04:01, and most importantly DPB1*05:01 were significantly increased in patients with ICI-T1DM. In addition, novel amino acid polymorphisms in HLA-DR (4 polymorphisms), in DQ (12 polymorphisms), and in DP molecules (9 polymorphisms) were identified. These amino acid polymorphisms might be associated with the development of ICI-T1DM. Moreover, novel human proinsulin epitope clusters in insulin A and B chains were discovered in silico and in vitro peptide binding assays to HLA-DP5. In conclusion, significant amino acid polymorphisms in HLA-class II molecules, and conformational alterations in the peptide-binding groove of the HLA-DP molecules were considered likely to influence the immunogenicity of proinsulin epitopes in ICI-T1DM. These amino acid polymorphisms and HLA-DP5 may be predictive genetic factors for ICI-T1DM.

Study on the Relationship between Unexplained Recurrent Abortion and HLA-DQ Gene Polymorphism

Objective

The study aimed to investigate the relationship between human leukocyte antigen (HLA-DQB1) gene variants and recurrent miscarriage.

Methods

HLA-DQ gene polymorphisms (PCR-SSP) were detected in 50 couples with recurrent miscarriage (URSA group) and 30 couples with normal births (control group) using sequence-specific primer-guided polymerase chain reaction.

Results

The frequency of the DQB1 ∗ 0303 allele in the URSA group (21.50%) was substantially higher than that of the control group (11.67%) (P=0.0260 0.05, RR = 1.754); however, the frequency of the DQB1 ∗ 0302 allele in the URSA group (4.00%) was substantially lower than that of the control pair (10.00%) (P=0.0318 0.05, RR = 0.400); the frequency of sharing one allele was 46.00% (23/50) in the URSA group and 0.00% (0/30) in the normal control group; the frequency of sharing two alleles was 40.00% (2/50) in the URSA group and 43.33% (13/30) in the normal control group, with no significant difference between the two groups.

Conclusion

For the Zhejiang population, HLA-DQB1 ∗ 0303 may be a susceptibility gene for recurrent miscarriage, while HLA-DQB1 ∗ 0302 may be protective against recurrent miscarriage, especially for women.