HLA-DRB1 Haplotypes Research Articles

Distributions of MICA and MICB Alleles Typed by Amplicon-Based Next-Generation Sequencing in South Koreans.

Major histocompatibility complex class I chain-related genes A and B (MICA and MICB) play a role as ligands in activating the NKG2D receptor expressed in natural killer cells, γδ T-cells and αβ CD8 T-cells and have been defined in human diseases and haematopoietic stem cell transplantation (HSCT). MICA and MICB alleles were genotyped at the three-field level by amplicon-based next-generation sequencing (NGS) using a MiSeqDx system and compared with the results from previous studies in healthy South Korean donors. Exons 2-5 of MICA and exons 2-4 of MICB were amplified using a multiplex polymerase chain reaction (PCR). Sequence reads of ≥ 51 depth counts were consistently obtained for each sample exon, and target exons were determined to match reference sequences contained in the IPD-IMGT/HLA database. MICA and MICB alleles were tested using exon combinations. The program was designed to recognise specific sequences and discriminate between the MICA*008:01:01/*027 alleles. A total of 22 alleles were found in MICA and MICB. We observed 1 HLA-C ~ HLA-B ~ MICA ~ MICB ~ HLA-DRB1 haplotype with significant linkage disequilibrium between alleles at all neighbouring HLA loci. These results are consistent with previous microarray results. Genotyping of MICA and MICB was possible using 11-loci HLA genes. We updated the distribution of MICA and MICB based on three-field allele and haplotype frequencies containing linkage disequilibrium in South Koreans using amplicon-based NGS. These data suggest that high-resolution MICA and MICB typing data obtained using NGS may aid in performing HSCT and disease association studies.

Association between human leukocyte antigen class II-DR-DQ and narcolepsy: a case control study.

Narcolepsy is a neurologic disorder characterized by irresistible sleep attacks. Although its etiology is unknown, it is strongly associated with genetic variances in the human leukocyte antigen (HLA) complex. We investigated the association of HLA class II-DR-DQ alleles in a sample of patients with narcolepsy-cataplexy (narcolepsy type 1; NT1) and patients with narcolepsy without cataplexy (narcolepsy type 2; NT2) with a control group. Additionally, we compared demographic, clinical, and laboratory characteristics of patients with narcolepsy with or without the DQB1*06:02 allele. This case control study included 21 patients with NT1 (56.8%), 16 patients with NT2 (43.2%), and 100 controls. Sequence-based typing identified HLA-DRB1 alleles, and HLA-DQB1 typing was done using PCR-Sequence-Specific Oligonucleotide. Allele and haplotype frequencies were calculated by direct counting. Nocturnal polysomnography and Multiple Sleep Latency Test were performed in all participants. In the NT1 group, only one allele had a significantly higher frequency than in the NT2 group: DQB1*06:02 (61.9% vs. 18.8%;). Compared to controls, DQB1*06:02 (61.9% vs. 18.0% in controls) and DRB1*15:01(47.6% vs. 8.0%), had higher frequencies in patients with NT1. Multiple analyses showed that patients with NT1 had an increased chance of being HLA-DQB1*06:02 positive. HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 haplotype is associated with NT1 in our Brazilian patients. PSG was identified in DQB1*06:02 positive subgroup REM sleep latency (REML) ≤ 15 minutes, and all patients had two or more sleep-onset REM periods (SOREMPs) at MSLT. This study showed a strong association between HLA DQB1*06:02 and the haplotype HLA-DRB1*15:01-DQA1*01:02-DQB1*06:02 in patients with NT1. Patients with DQB1*0602 allele showed shorter REMLs at PSG. These results reinforce the suggestion of DQB1 genotyping as relevant to narcolepsy screening.

E034 Drug-induced accelerated nodulosis in a patient with rheumatoid arthritis

Abstract Background/Aims Drug-induced accelerated nodulosis (DIAN) is characterized by the occurrence or progression of multiple subcutaneous nodules in a patient treated for rheumatoid arthritis (RA). It was first and most commonly reported with methotrexate in RA patients. Methods A 37-year-old normotensive, non-diabetic, seropositive rheumatoid arthritis female presented with complaints of nodules over the bilateral hands and feet from the last three months. The treatment history included methotrexate therapy (10 mg/week) for one year. Methotrexate-induced rheumatoid accelerated nodulosis (MIAN) was suspected. Methotrexate was stopped and hydroxychloroquine was added considering the low disease activity. The nodules decreased in number as well as size. On follow-up, she presented with increased multiple joint pain and swelling with ESR 60 mm/hour, CRP 13.6 mg/L, and leflunomide was added. After six months of leflunomide use, she again developed multiple bilateral nodules on the extensor and palmar surface of fingers and feet, ranging from 0.5 to 1 cm. The CRP was 9.2 mg/L, ESR 80 mm/hour, complete blood count showed mild anaemia with normal renal and liver function tests. The nodule biopsy showed palisading granuloma consisting of lymphocytes and histiocytes in mid and deep reticular dermis with large foci of fibrin deposition and collagen degeneration s/o rheumatoid nodule. Leflunomide was stopped. Results The leflunomide was switched to sulfasalazine along with colchicine, and hydroxychloroquine was continued. The patient is doing well on follow-up in terms of disease activity and nodule size. Palmeiro. A.G., et al. 2022 reviewed 39 studies from 1st Jan 1988 to 1st Jan 2022 and found 109 cases of accelerated nodulosis. 99 patients had RA, methotrexate was the culprit drug in 89, followed by etanercept in 7 and leflunomide was in just 3 patients. Although there are no exact treatment guidelines, tumour necrosis factor inhibitors were avoided due to increased nodulosis risk. Recently, Valor-Méndez. L., et al 2020 reported improved nodulosis with Janus Kinase inhibitors like baricitinib, which seems to be a future option. Histologically, rheumatoid nodules and accelerated nodulosis are indistinguishable. The exact pathogenesis is unknown but, polymorphic variants of methionine synthase reductase or haplotype HLA-DRB1*0401, and adenosine A1 receptor promotion in multinucleated giant cells are associated. Conclusion Drug-induced accelerated nodulosis (DIAN) and MIAN are not that rare but diagnosis is challenging. It causes significant morbidity and affects the quality of life because of the predominant involvement of hands and feet. It should be suspected especially when disease activity is low or rapidly progressive nodules with a change in immunotherapy. Partial to total improvement can be achieved by identifying and stopping the culprit drug. We need specific guidelines, more treatment options, and a specific national registry to report such adverse effects with biologics and non-biologic disease-modifying antirheumatic drugs. Disclosure H. Singh: None. R. Kaur: None. G. Mohan: None.

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.

Understanding the link between neurotropic viruses, BBB permeability, and MS pathogenesis.

Neurotropic viruses can infiltrate the CNS by crossing the blood-brain barrier (BBB) through various mechanisms including paracellular, transcellular, and "Trojan horse" mechanisms during leukocyte diapedesis. These viruses belong to several families, including retroviruses; human immunodeficiency virus type 1 (HIV-1), flaviviruses; Japanese encephalitis (JEV); and herpesviruses; herpes simplex virus type 1 (HSV-1), Epstein-Barr virus (EBV), and mouse adenovirus 1 (MAV-1). For entering the brain, viral proteins act upon the tight junctions (TJs) between the brain microvascular endothelial cells (BMECs). For instance, HIV-1 proteins, such as glycoprotein 120, Nef, Vpr, and Tat, disrupt the BBB and generate a neurotoxic effect. Recombinant-Tat triggers amendments in the BBB by decreasing expression of the TJ proteins such as claudin-1, claudin-5, and zona occludens-1 (ZO-1). Thus, the breaching of BBB has been reported in myriad of neurological diseases including multiple sclerosis (MS). Neurotropic viruses also exhibit molecular mimicry with several myelin sheath proteins, i.e., antibodies against EBV nuclear antigen 1 (EBNA1) aa411-426 cross-react with MBP and EBNA1 aa385-420 was found to be associated with MS risk haplotype HLA-DRB1*150. Notably, myelin protein epitopes (PLP139-151, MOG35-55, and MBP87-99) are being used to generate model systems for MS such as experimental autoimmune encephalomyelitis (EAE) to understand the disease mechanism and therapeutics. Viruses like Theiler's murine encephalomyelitis virus (TMEV) are also commonly used to generate EAE. Altogether, this review provide insights into the viruses' association with BBB leakiness and MS along with possible mechanistic details which could potentially use for therapeutics.

Generation of a bank of clinical-grade, HLA-homozygous iPSC lines with high coverage of the Spanish population

BackgroundInduced pluripotent stem cell (iPSC)-derived cell therapies are an interesting new area in the field of regenerative medicine. One of the approaches to decrease the costs of iPSC-derived therapies is the use of allogenic homozygous human leukocyte antigen (HLA)-matched donors to generate iPSC lines and to build a clinical-grade iPSC bank covering a high percentage of the Spanish population.MethodsThe Spanish Stem Cell Transplantation Registry was screened for cord blood units (CBUs) homozygous for the most common HLA-A, HLA-B and HLA-DRB1 haplotypes. Seven donors were selected with haplotypes covering 21.37% of the haplotypes of the Spanish population. CD34-positive hematopoietic progenitors were isolated from the mononuclear cell fraction of frozen cord blood units from each donor by density gradient centrifugation and further by immune magnetic labeling and separation using purification columns. Purified CD34 + cells were reprogrammed to iPSCs by transduction with the CTS CytoTune-iPS 2.1 Sendai Reprogramming Kit.ResultsThe iPSCs generated from the 7 donors were expanded, characterized, banked and registered. Master cell banks (MCBs) and working cell banks (WCBs) from the iPSCs of each donor were produced under GMP conditions in qualified clean rooms.ConclusionsHere, we present the first clinical-grade, iPSC haplobank in Spain made from CD34 + cells from seven cord blood units homozygous for the most common HLA-A, HLA-B and HLA-DRB1 haplotypes within the Spanish population. We describe their generation by transduction with Sendai viral vectors and their GMP-compliant expansion and banking. These haplolines will constitute starting materials for advanced therapy medicinal product development (ATMP).

Distributions of the HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 alleles and haplotype frequencies of 1763 stem cell donors in the Colombian Bone Marrow Registry typed by next-generation sequencing.

The HLA compatibility continues to be the main limitation when finding compatible donors, especially if an identical match is not found within the patient's family group. The creation of bone marrow registries allowed a therapeutic option by identifying 10/10 compatible unrelated donors (URD). However, the availability and frequency of haplotypes and HLA alleles are different among ethnic groups and geographical areas, increasing the difficulty of finding identical matches in international registries. In this study, the HLA-A, -B, -C, -DRB1, and -DQB1 loci of 1763 donors registered in the Colombian Bone Marrow Registry were typed by next-generation sequencing. A total of 52 HLA-A, 111 HLA-B, 41 HLA-C, 47 HLA-DRB1, and 20 HLA-DQB1 alleles were identified. The 3 most frequent alleles for each loci were A*24:02g (20,8%), A*02:01g (16,1%), A*01:01g (7.06%); B*35:43g (7.69%), B*40:02g (7.18%), B*44:03g (6.07%); C*04:01g (15.40%), C*01:02g (10.49%), C*07:02g (10.44%); DRB1*04:07g (11.03%), DRB1*07:01g (9.78%), DRB1*08:02g (6.72%); DQB1*03:02g (20.96%), DQB1*03:01g (17.78%) and DQB1*02:01g (16.05%). A total of 497 HLA-A-C-B-DRB1-DQB1 haplotypes were observed with a frequency greater than or equal to 0.05% (> 0.05%); the haplotypes with the highest frequency were A*24:02g~B*35:43g~C*01:02g~DQB1*03:02g~DRB1*04:07g (3.34%), A*29:02g~B*44:03g~C*16:01g~DQB1*02:01g~DRB1*07:01g (2.04%), and A*01:01g~B*08:01g~C*07:01g~DQB1*02:01g~DRB1*03:01g (1.83%). This data will allow the new Colombian Bone Marrow Donor Registry to assess the genetic heterogeneity of the Colombian population and serve as a tool of interest for future searches of unrelated donors in the country.

Immunogenetic Profiling of SLE and LN among Jordanian Patients.

Systemic Lupus Erythematosus (SLE) is a prolonged inflammatory autoimmune disease, which is characterized by a high titer of serological autoantibodies. Interactions between environmental and genetic factors play a crucial role in the pathogenesis of SLE. Human Leukocyte Antigen (HLA) genes, namely HLA-class II genes, are one of the main candidate genes that increase susceptibility to SLE. The aim of this study was to investigate, for the first time, the association of HLA-DRB1 and HLA-DQB1 genes among Jordanian patients diagnosed with SLE and Lupus Nephritis (LN) using the Polymerase Chain Reaction-Sequence-Specific Primer (PCR-SSP) technique. This study showed that SLE is positively associated with DRB1*0301, DRB1*1101, DRB1*1102 and HLA-DQB1*0601. Furthermore, HLA-DRB1*0301, DRB1*1101, HLA-DRB1*1501 and HLA-DQB1*0601 were found to be linked to SLE patients with LN. In addition, haplotypes HLA-DRB1*0301/DQB1*0201 and HLA-DRB1*1501/DQB1*0601 were found to be linked to SLE and LN. Our findings may serve as possible predictive markers for early screening for LN risk in SLE patients. In light of these results, the role of HLA gene polymorphisms may help in understanding the clinical course, prognosis of the disease and developing better treatment strategies for SLE patients. In addition, it may help in early diagnosis, prevention, intervention and management of the disease.

Study of HLA class II loci reveals DQB1*03:03:02 as a risk factor for asthma in a Pakistani population.

Asthma, a chronic inflammatory disorder of the lungs and airways, typically results from a combination of multiple environmental and genetic factors. Human leucocyte antigen (HLA) region on chromosome 6p21 encodes the most highly polymorphic loci in the human genome, encoding genes with central roles in the immune function where HLA loci are strongly associated with various immune-mediated diseases such as autoimmunity, allergies and infection. The alleles of HLA class II genes such as DRB1 and DQB1 are the key genetic markers in the development of asthma and have been extensively studied in different ethnicities of the world population. However, the genetic screening of HLA class II alleles and haplotypes in Pakistani asthmatics has not been studied so far. The aim of the present study was to screen the HLA class II DRB1 and DQB1 alleles in asthma cases and controls in a Pakistani population. Seven hundred and two healthy controls and asthma patients were genotyped for HLA class II by sequence-specific polymerase chain reaction assays. The HLA-DRB1 and HLA-DQB1 allele and haplotype frequencies were calculated, and their risk or protective association with asthma was determined. Two-locus haplotypes of DRB1 and DQB1 alleles were imputed using Arlequin version 3.1 software. The signals of association with asthma were stronger at the DQB1 locus as compared to DRB1. HLA DQB1*03:03:02 (odds ratio [OR]=2.42, 95% confidence interval [CI]=1.34-4.25) was significantly associated with an increased risk of asthma, as was the haplotype comprised allele DRB1*07:01-DQB1*03:03:02 (OR=2.40, 95% CI=1.25-4.62). In contrast, DQB1*06 (OR=0.39, 95% CI=0.22-0.70) and DQB1*06:02 (OR=0.27, 95% CI=0.10-0.71) emerged as protective alleles for asthma. Our data concludes that the HLA DQB1*03:03:02 allele was a risk allele for asthma, whereas two DQB1 alleles, DQB1*06 and DQB1*06:02, were associated with asthma protection. Our findings highlight a prominent role for HLA-DQB1 alleles in asthma pathogenesis in studied Pakistani cases. More studies, especially with a larger study cohort are needed to confirm the utility of HLA DQB1*03:03:02 as a predictive marker.

MO206: HLA Frequency in A Spanish Transplant Patients Cohort With ANCA-Associated Vasculitis

Abstract BACKGROUND AND AIMS ANCA-associated vasculitis (AAV) is an autoimmune disease that causes end-stage renal disease in ∼20%–25% of patients who develop kidney failure with progression to end-stage kidney disease with requirement of renal replacement therapy. Previous studies have found a genetic association between some major histocompatibility complex (MHC) loci, like the locus DPB1*0401, and AAV. We conducted a retrospective observational unicentric study with the objective to identify other possible loci related to AAV. METHOD As MHC determination is not usually done in patients with AAV, we looked for patients with AAV included in the kidney transplant list with a complete classic HLA allele determination registered (A, B, C, DR, and DQ). Only 14 patients with diagnosis of AAV included in the kidney transplant list from August 1993 to December 2020 in our hospital centre fulfilled this inclusion criterion. To the statistical analysis, we compared the observed proportion to the theoretical one using a normal test, since the groups in our sample included at least five subjects. We also use a continuity correction factor to approach to a binomial test. RESULTS The highest allele frequency in our cohort were the HLA B*51and the haplotype HLA DRB1*04-DQB1*03:02. We identified a B*51 frequency of 42.8% (6/14 patients) in our AAV register, while its population frequency in Spain is 15%, difference = 27.86% [Confidence interval (CI) 1.93%–53.78%] P = .01. We detected a DRB1*04 frequency of 57.1% (8/14 patients) in our cohort, while the population frequency of DRB1*04 and its associated loci DQB1*03:02 is 22%, difference = 35.14% (CI 9.22%–61.07%) P < .05. CONCLUSION HLA B*51 and the haplotype DRB1*04-DQB1*03:02 are alleles more frequent in patients with AAV than general population. This could translate a genetic predisposition of people with these alleles to develop AAV.

HLA-DRB1 haplotypes predict cardiovascular mortality in inflammatory polyarthritis independent of CRP and anti-CCP status

BackgroundHaplotypes defined by amino acids at HLA-DRB1 positions 11, 71 and 74 associated with susceptibility to rheumatoid arthritis (RA) are associated with radiological outcome, anti-TNF response and all cause-mortality in RA. RA is associated with cardiovascular (CV) morbidity and mortality, but the increased prevalence of risk factors of CV disease in RA only partially explains this association. The aim of this study was to investigate whether amino acids at positions 11, 71 and 74 of HLA-DRB1 are associated with cardiovascular (CV) mortality in inflammatory polyarthritis (IP).MethodsThe Norfolk Arthritis Register (NOAR) is an incidence register of IP: recruitment 1990–2007, final follow-up 2011. Two thousand five hundred fourteen patients had available genetic and mortality data. Amino acids at positions 11, 71 and 74 of HLA-DRB1 were determined. Univariate Cox proportional hazard models were applied to assess the association of genetic markers and both all-cause mortality and cardiovascular mortality.ResultsAmong 2514 participants, 643 (25.6%) died during the study, and 343 (53.3%) of these deaths were attributed to CV causes. One thousand six hundred fifty (65.6%) participants were female, 709 (32.3%) were anti-CCP-positive and the median age of participants was 54.HLA-DRB1 haplotypes associated with susceptibility to rheumatoid arthritis (RA) consistently show the same magnitude and direction of association for overall and CV mortality in IP. For example, the SEA-haplotype, associated with the lowest susceptibility to RA, and the best radiographic outcome, was found to be associated with decreased CV mortality (HR 0.67, 95% CI 0.47, 0.91, p=0.023). Mediation analysis revealed associations were independent of anti-CCP status.ConclusionsHLA-DRB1 haplotypes associated with susceptibility to RA also predispose to increased risk of CV mortality in IP, independent of known CV risk factors. Associations were independent of anti-CCP status, which suggests in the future, genetic factors will add to the prediction of risk of cardiovascular mortality beyond serological markers.

Helicobacter pylori infection and disease severity in multiple sclerosis patients: Is there a link with HLA alleles?

Backgrounds: Environmental factors such as bacterial infections, as well as genetic factors—in particular the human leukocyte antigen (HLA) alleles—have been implicated in the etiology of multiple sclerosis (MS). This study aims to explore the relationship between Helicobacter pylori infection, HLA alleles, and disease severity in Iranian MS patients. Methods: The study population comprised 125 MS patients and 153 ethnically matched healthy controls. Stool antigen test was used to detect H. pylori, and the expanded disability status scale (EDSS) scores were assessed in the patients. HLA-DRB1 and DQB1 alleles and haplotypes were determined in both the patients and the controls. The relationships between H pylori infection, HLA alleles, and EDSS were also analyzed. Results: HLA-DRB1*15 and DQB1*06 alleles families and the DRB1*15~DQB1*06 haplotype were significantly more frequent in MS patients, whereas HLA-DRB1*14 and DRB1*14~DQB1*05 haplotype were less frequent. Of the 125 MS patients, 38 were diagnosed with active H. pylori infection. We found lower frequencies of HLA-DRB1*15 (P = .08) and DRB1*16 (P = .05) alleles and a higher frequency of DQB1*02 (P = .06) in the H. pylori-positive patients. HLA-DRB1*07 was more prevalent in patients with EDSS≤3.0 (P = .06). More severe MS cases (EDSS>3.0) were linked to H pylori positivity (P = .02), disease chronicity (P = .001), receiving non-steroidal anti-inflammatory drugs (P = .02), and female gender (P = .05). Conclusion: These preliminary findings suggest a link between H. pylori infection and the severity of MS H. pylori-positive patients regardless of the type of HLA carriage.

Genetic susceptibility to multiple sclerosis in African Americans.

ObjectiveTo explore the nature of genetic-susceptibility to multiple sclerosis (MS) in African-Americans.BackgroundRecently, the number of genetic-associations with MS has exploded although the MS-associations of specific haplotypes within the major histocompatibility complex (MHC) have been known for decades. For example, the haplotypes HLA-DRB1*15:01~HLA-DQB1*06:02, and HLA-DRB1*03:01~ HLA-DQB1*02:01 have odds ratios (ORs) for an MS-association orders of magnitude stronger than many of these newly-discovered associations. Nevertheless, all these haplotypes are part of much larger conserved extended haplotypes (CEHs), which span both the Class I and Class II MHC regions. African-Americans are at greater risk of developing MS compared to a native Africans but at lesser risk compared to Europeans. It is the purpose of this manuscript to explore the relationship between MS-susceptibility and the CEH make-up of our African-American cohort.Design/methodsThe African-American (AA) cohort consisted of 1,305 patients with MS and 1,155 controls, who self-identified as being African-American. For comparison, we used the 18,492 controls and 11,144 MS-cases from the predominantly European Wellcome Trust Case Control Consortium (WTCCC) and the 28,557 phased native Africans from the multinational “Be the Match” registry. The WTCCC and the African-Americans were phased at each of five HLA loci (HLA-A, HLA-C, HLA-B, HLA-DRB1 and HLA-DQB1) and the at 11 SNPs (10 of which were in non-coding regions) surrounding the Class II region of the DRB1 gene using previously-published probabilistic phasing algorithms.ResultsOf the 32 most frequent CEHs, 18 (56%) occurred either more frequently or exclusively in Africans) whereas 9 (28%) occurred more frequently or exclusively in Europeans. The remaining 5 CEHs occurred in neither control group although, likely, these were African in origin. Eight of these CEHs carried the DRB1*15:03~DQB1*06:02~a36 haplotype and three carried the DRB1*15:01~DQB1*06:02~a1 haplotype. In African Americans, a single-copy of the European CEH (03:01_07:02_07:02_15:01_06:02_a1) was associated with considerable MS-risk (OR = 3.30; p = 0.0001)–similar to that observed in the WTCCC (OR = 3.25; p<10−168). By contrast, the MS-risk for the European CEH (02:01_07:02_07:02_15:01_06:02_a1) was less (OR = 1.49; ns)–again, similar to the WTCCC (OR = 2.2; p<10−38). Moreover, four African haplotypes were “protective” relative to a neutral reference, to three European CEHs, and also to the five other African CEHs.ConclusionsThe common CEHs in African Americans are divisible into those that are either African or European in origin, which are derived without modification from their source population. European CEHs, linked to MS-risk, in general, had similar impacts in African-Americans as they did in Europeans. By contrast, African CEHs had mixed MS-risks. For a few, the MS-risk exceeded that in a neutral-reference group whereas, for many others, these CEHs were “protective”–perhaps providing a partial rationale for the lower MS-risk in African-Americans compared to European-Americans.

Identification of a Tolerogenic Factor V Peptide and Its Potential Role in FVIII Tolerance Induction

Inhibitory Anti-Drug Antibody (ADA) responses interfere with FVIII replacement efficacy in 25-30% of Hemophilia A (HA), greatly increasing patient morbidity and treatment costs. As an extension of previous work on tolerance-inducing peptides in IgG (Tregitopes) we investigated whether there were peptides in other ubiquitous serum proteins that could have high homology to peptides found in Factor VIII. We hypothesized that tolerance to cross-conserved peptides in other prevalent proteins might explain why anti-FVIII antibodies fail to develop in some severely FVIII-deficient HA patients. Using advanced computational modeling tools, we discovered in Factor V a potent regulatory peptide (FV1) with an immunologic profile (HLA and TCR binding) that is homologous to a non-identical peptide in FVIII. We postulated that treatment with a FV1-peptide containing biologic may be able to invoke tolerance to Factor VIII in patients who have anti-FVIII antibodies (Figure 1).Our preliminary studies support this hypothesis. We developed an ex vivo assay using human PBMC (peripheral blood mononuclear cells) in which the recall response to tetanus toxoid, a well-known immunogenic protein for which there is a T memory response, was found to be robust and strongly inhibited by FV1 but not by other FV peptides. Other FV peptides with similar HLA-binding properties did not suppress tetanus toxoid response.FV1 peptide also strongly inhibits proliferation of central and effector memory CD4 T and effector CD8 T cells without affecting cell viability. FV1 peptide at 4 mM reduced proliferation of effector and central memory T cells by more than 80% over the levels seen with 0.5 mg/ml TT and no peptide on a wide set of donors with HLA-DRB1 haplotypes covering the nine major supertypes in the human population. A peptide homologue to FV1 found in Factor VIII shows similar inhibitory activity on activated CD4 T cells.Using this assay, we are determining the evolution of markers on regulatory T cells, Antigen Presenting Cells, and effector T cells as well as the cytokine secretion profile over time in order to identify specific parameters associated with cell populations and soluble factors mediating immune suppression in response to FV1. This is the first time that we have reported that FV1 peptide may play a role in the induction of tolerance to FVIII in HA patients; the important implications of this work for treatment of HA, ADA and reduction of immunogenicity discussed. [Display omitted] DisclosuresGuillen:Epivax, Inc.: Employment. Rosenberg:Food & Drug Administration: Employment. Lelias:EpiVax, Inc.: Employment. Hindocha:EpiVax, Inc.: Employment. Terry:EpiVax, Inc.: Employment. Martin:EpiVax, Inc.: Equity Ownership. De Groot:EpiVax, Inc.: Equity Ownership.

Influence of HLA Class II Alleles and DRB1-DQB1 Haplotypes on Rheumatoid Arthritis Susceptibility and Autoantibody Status in the Chinese Han Population

ABSTRACT Human leukocyte antigen (HLA) class II alleles are considered to play a key role in the progress of rheumatoid arthritis (RA). This study was carried out to investigate the presence of HLA class II alleles and their influence on disease risk and autoantibody status in Chinese Han patients with RA. Here, HLA-DRB1, DQB1 and DPB1 genotyping was performed in 125 RA patients and 120 healthy controls by using the next-generation sequencing (NGS). Strong positive associations were shown between high-resolution typed HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01, DPB1*02:01:02 and RA patients. Moreover, the haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01 and HLA-DRB1*10:01:01~ DQB1*05:01:01 were found to be more frequent in RA populations than in healthy controls. These possible susceptible HLA alleles (HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02) also showed higher frequencies in seropositive RA patients as compared to normal controls. The present study provided evidence that alleles HLA-DRB1*04:05:01, DRB1*10:01:01, DQB1*04:01:01 and DPB1*02:01:02 constituted RA risk alleles, and haplotypes HLA-DRB1*04:05:01~ DQB1*04:01:01, HLA-DRB1*10:01:01~ DQB1*05:01:01 also showed prevalence in Chinese Han patients with RA. Serological results preliminary demonstrated patients carrying RA-risk HLA alleles might elevate the serum level of anti-citrullinated protein antibodies and rheumatoid factor and affect RA progression.

Association between human leukocyte antigens (HLAs) and human neutrophil antigens (HNAs) and autoimmune neutropenia of infancy in Danish patients.

BackgroundAutoimmune neutropenia of infancy (AIN) is a frequent cause of neutropenia in children. The disease is caused by antibodies against epitopes on the immunoglobulin G (IgG) Fc receptor type 3b (FcγIIIb). We investigated the possible association of human neutrophil antigens (HNA), human leukocyte antigen (HLA)‐DR, and HLA‐DQ alleles with AIN and the association of these genotypes with the presence of autoantibodies.MethodsEighty AIN cases with a median age of 13.5 months were included. Controls were healthy unrelated Danish blood donors. Anti‐HNA‐1a autoantibodies were detected using a flow cytometric granulocyte immunofluorescence test (Flow‐GIFT) with phenotyped donor cells for detection of antibody specificity. Molecular determination of HNA genotypes was determined using real‐time polymerase chain reaction (q‐PCR). High‐resolution HLA‐DRB1 and HLA‐DQB1 were determined by next‐generation sequencing.ResultsAntibodies against HNA‐1a were detected in 51% (n = 41) of AIN patients, and anti‐HNA‐1b was detected in 3% (n = 2) of cases. In 46% of cases, the antibodies were anti‐FcγIIIb‐reactive. FCGR3B*01+,*02‐,*03‐ was more common (odds ratio, 6.70; P < .0001), and FCGR3B*01‐,*02+,*03‐ was less common (odds ratio, 0.30; P < .0001) among AIN cases. HNA‐1a antibodies were significantly more frequent among AIN cases with the FCGR3B*01+,*02‐,*03‐ genotype (odds ratio, 3.86; P < .007). The HLA‐DRB1*14 ‐ HLA‐DQB1*05:03 haplotype was significantly more common (odds ratio, 7.44; P < .0001) in AIN patients.ConclusionThe HLA haplotype HLA‐DRB1*14 ‐ DQB1*05:03 is associated with Danish AIN cases. Among Danish AIN patients, anti‐HNA‐1a is the most common autoantibody, and the antibody is more common in cases with the FCGR3B*01+,*02‐,*03‐ genotype.

Study on the polymorphisms of HLA-ABCDQB1DRB1 alleles and haplotypes in Hubei Han population of China.

The present study aimed to analyse the frequencies of human leukocyte antigen HLA-ABCDQB1 and HLA-DRB1 alleles and haplotypes in a subset of 3,732 Han population from Hubei of China. All samples were typed in the HLA-ABCDQB1 and HLA-DRB1 loci using the sequence-based typing method; subsequently, the HLA polymorphisms were analysed. A total of 47 HLA-A, 89 HLA-B, 43 HLA-C, 49 HLA-DRB1 and 24 HLA-DQB1 alleles were identified in the Hubei Han population. The top three most frequent alleles in the HLA-ABCDQB1 and HLA-DRB1 were A*11:01 (0.2617), A*24:02 (0.1590), A*02:07 (0.1281); B*46:01 (0.1502), B*40:01 (0.1409) and B*58:01 (0.0616); C*01:02 (0.2023), C*07:02 (0.1691) and C*03:04 (0.1175); and DQB1*03:01 (0.2000), DQB1*03:03 (0.1900), DQB1*06:01 (0.1187); DRB1*09:01 (0.1790), DRB1*15:01 (0.1062) and DRB1*12:02 (0.0841), respectively. Meanwhile, the three most frequent two-loci haplotypes were A*02:07-C*01:02 (0.0929), B*46:01-C*01:02 (0.1366) and DQB1*03:03-DRB1*09:01 (0.1766). The three most frequent three-loci haplotypes were A*02:07-B*46:01-C*01:02 (0.0883), B*46:01-DQB1*03:03-DRB1*09:01 (0.0808) and C*01:02-DQB1*03:03-DRB1*09:01 (0.0837). The three most frequent four-loci haplotypes were A*02:07-B*46:01-C*01:02-DQB1*03:03 (0.0494), B*46:01-DRB1*09:01-C*01:02-DQB1*03:03 (0.0729) and A*02:07-B*46:01-DQB1*03:03-DRB1*09:01 (0.0501). The most frequent five-loci haplotype was A*02:07-B*46:01-C*01:02-DQB1*03:03-DRB1*09:01 (0.0487). Heat maps and multiple correspondence analysis based on the frequencies of HLA specificity indicated that the Hubei Han population might be described into Southern Chinese populations. Our results lay a certain foundation for future population studies, disease association studies and donor recruitment strategies.

Cigarette smoking patterns preceding primary Sjögren’s syndrome

BackgroundCigarette smoking is a well-established risk factor for several autoimmune diseases, but its role in primary Sjögren’s syndrome (pSS) remains unclear. Here, we investigated the association between cigarette smoking and...

Distribution of HLA-A, HLA-B, HLA-C, and HLA-DRB1 alleles and haplotypes in Jingpo minority in Yunnan province of China

HLA-A, HLA-B, HLA-C, and HLA-DRB1 allele frequencies and estimated haplotype frequencies from 105 unrelated healthy Jingpo ethnic subjects who living in Dehong Dai-Jingpo Autonomous Prefectures, Yunnan Province, southwest China has been reported. HLA genes were genotyped by SSOP typing method using Luminex Multi-Analyte Profiling system. Jingpo ethnic nationality belongs to southern group of East Asians, but with its specific HLA alleles and haplotypes characteristic.

Is multiple sclerosis progression associated with the HLA-DR15 haplotype?

BackgroundThe prevalence of multiple sclerosis is associated with the major histocompatibility complex class II DR15 haplotype HLA-DRB1*15:01∼HLA-DRB5*01:01.ObjectiveTo assess whether multiple sclerosis progression is associated with the main susceptibility haplotype HLA-DRB1*15:01∼HLA-DRB5*01:01.MethodsPatients (n = 1230) and healthy controls (n = 2110) were genotyped for HLA-DRB1 and HLA-DRB5. The baseline Expanded Disability Status Scale (EDSS) score was determined and patients were followed for at least 3 years.ResultsAfter follow-up of the consecutive cohort 349 patients were classified as having clinical isolated syndrome and 881 patients as having multiple sclerosis. The susceptibility allele HLA-DRB1*15:01 was more frequent in clinical isolated syndrome (odds ratio 1.56) and multiple sclerosis (odds ratio 3.17) compared to controls. HLA- DRB1*15:01 was the only enriched HLA-DRB1 allele in multiple sclerosis patients. Comparison of clinical characteristics between HLA-DRB1*15:01∼HLA-DRB5*01:01 negative and positive patients with multiple sclerosis showed that baseline EDSS score, disease duration and frequency of the category secondary progressive multiple sclerosis with relapse were increased in the HLA-DRB1*15:01∼HLA-DRB5*01:01 positive group.ConclusionThe study confirmed HLA-DRB1*15:01 and HLA-DRB5*01:01 as the main susceptibility alleles and showed weak indirect evidence for a role in progression of the disease.