HLA-DRB1*15:01 is a co-receptor for Epstein-Barr virus, linking genetic and environmental risk factors for multiple sclerosis.

The strongest genetic and environmental risk factors for MS, an inflammatory CNS disease, are HLA-DRB1*15:01 and EBV. This work shows that HLA-DRB1*15:01 acts as a co-receptor for EBV infection of a B cell line, suggesting a mechanistic link between both risk factors for MS.

Absence of the tag polymorphism for the risk haplotype HLA-DR2 for multiple sclerosis in Wixárika subjects from Mexico.

The HLA-DRB1*15:01 allele has a demonstrated risk for the development of multiple sclerosis (MS) in most populations around the world. The single nucleotide polymorphism (SNP) rs3129934 is found in linkage disequilibrium with the risk haplotype formed by the HLA-DRB1*15:01 and HLA-DQB1*06:02 alleles, and it is considered a reliable marker of the presence of this haplotype. Native Americans have a null or low prevalence of MS. In this study, we sought to identify the frequency of rs3129934 in the Wixárika ethnic group as well as in Mestizo (mixed race) patients with MS and in controls from western Mexico. Through real-time polymerase chain reaction (PCR) using TaqMan probes, we analyzed the allele and genotype frequencies of rs3129934 in Mestizo individuals with and without MS and in 73 Wixárika subjects from the state of Jalisco, Mexico. The Wixárika subjects were homozygote for the C allele of rs3129934. The allele and genotype frequency in Mestizos with MS was similar to that of other MS populations with Caucasian ancestry. The absence of the T risk allele rs3129934 (associated with the haplotype HLA-DRB1*15:01, HLA-DQ1*06:02) in this sample of Wixárika subjects is consistent with the unreported MS in this Amerindian group, related to absence of such paramount genetic risk factor.

HLA-DRB1*04:05 allele is associated with intracortical lesions on three-dimensional double inversion recovery images in Japanese patients with multiple sclerosis.

BACKGROUND: Cortical lesions (CLs) frequently observed in Caucasian patients with multiple sclerosis (MS) contribute to disability. However, it remains unclear whether CLs are associated with clinical features and genetic risk factors, such as HLA-DRB1*15:01 and -DRB1*04:05 in Asian MS patients. OBJECTIVE: To elucidate the frequency of CLs and their association with HLA-DRB1 and DPB1 alleles in Japanese MS patients. METHODS: Three-dimensional double inversion recovery imaging and clinical information were retrospectively obtained from 92 Japanese MS patients. RESULTS: CLs of any type, intracortical lesions (ICLs), and leukocortical lesions (LCLs) were detected in 39.1%, 26.1%, and 28.3% of patients, respectively. MS patients with ICLs had a significantly higher frequency of secondary progression and greater Expanded Disability Status Scale (EDSS) scores than those without ICLs. Similar trends were observed with CLs and LCLs. The number of all three lesion types positively correlated with EDSS scores. The frequency and number of ICLs were significantly higher in HLA-DRB1*15:01 carriers than in HLA-DRB1*15:01 non-carriers, but significantly lower in HLA-DRB1*04:05 carriers than in HLA-DRB1*04:05 non-carriers. Multivariate logistic regression analysis revealed a negative association of HLA-DRB1*04:05 with ICLs. CONCLUSION: ICLs are associated with greater disease severity in Japanese MS patients and are partly suppressed by the HLA-DRB1*04:05 allele.

Genetic predictors of Stevens-Johnson syndrome and toxic epidermal necrolysis induced by aromatic antiepileptic drugs among the Chinese Han population.

BACKGROUND: Previous studies suggested that one or more HLA alleles participate in the pathogenesis of AED-induced SJS/TEN, but most of these studies focused only on the HLA-B alleles. PURPOSE: The aim of this study was to investigate the pathogenesis of AED-induced SJS/TEN across a broader spectrum of HLA alleles, including the HLA-A, -B and -DRB1 alleles, to further explore the association between each HLA allele and SJS/TEN induced by aromatic AEDs. METHODS: A total of 27 patients exhibiting AED-induced SJS/TEN (16 CBZ-SJS/TEN, seven LTG-SJS/TEN, two PHT-SJS/TEN, and two PB-SJS/TEN patients) and 64 patients who exhibited tolerance to AEDs were recruited. High-resolution HLA genotyping was performed to estimate the prevalence of the HLA-A, -B and -DRB1 alleles for each subject. RESULTS: Fifteen subjects in the SJS/TEN group (12 exhibiting CBZ-SJS/TEN, two exhibiting LTG-SJS, and one exhibiting PB-SJS) carried the HLA-B*15:02 allele, whereas only 4/64 subjects in the AED-tolerant group carried this allele; the carrier rate of HLA-B*15:02 was significantly different between the groups (P<0.001). Nine patients in the SJS/TEN group carried the HLA-DRB1*15:01 allele, while 12/64 subjects in the tolerant group carried this allele; considering that two patients in the SJS/TEN group (one exhibiting LTG-SJS and one exhibiting PB-SJS) were homozygous for this allele, the prevalence of HLA-DRB1*15:01 expression between the two groups was significantly different (P=0.041). Furthermore, the carrier rates of HLA-A*33:03, HLA-B*58:01, and HLA-DRB1*03:01 were lower in the SJS/TEN group compared with the AED-tolerant group. The carrier rates of these alleles between the two groups were significantly different (P=0.009, 0.016, and 0.009, respectively). CONCLUSIONS: The HLA-DRB1*15:01 allele may represent a risk factor for AED-induced SJS/TEN among Han Chinese. The HLA-A*33:03, HLA-B*58:01, and HLA-DRB1*03:01 alleles may be "protectors" against AED-induced SJS/TEN, especially CBZ-SJS/TEN.

Association between exposure to combustion-related air pollution and multiple sclerosis risk.

BACKGROUND: Smoking and occupational pulmonary irritants contribute to multiple sclerosis (MS) development. We aimed to study the association between ambient air pollution and MS risk and potential interaction with the human leukocyte antigen (HLA)-DRB1*15:01 allele. METHODS: Exposure to combustion-related air pollution was estimated as outdoor levels of nitrogen oxides (NOx) at the participants' residence locations, by spatially resolved dispersion modelling for the years 1990-18. Using two population-based case-control studies (6635 cases, 8880 controls), NOx levels were associated with MS risk by calculating odds ratios (OR) with 95% confidence intervals (CI) using logistic regression models. Interaction between high NOx levels and the HLA-DRB1*15:01 allele regarding MS risk was calculated by the attributable proportion due to interaction (AP). In addition, a register study was performed comprising all MS cases in Sweden who had received their diagnosis between 1993 and 2018 (n = 22 173), with 10 controls per case randomly selected from the National Population register. RESULTS: Residential air pollution was associated with MS risk. NOx levels (3-year average) exceeding the 90th percentile (24.6 µg/m3) were associated with an OR of 1.37 (95% CI 1.10-1.76) compared with levels below the 25th percentile (5.9 µg/m3), with a trend of increasing risk of MS with increasing levels of NOx (P <0.0001). A synergistic effect was observed between high NOx levels (exceeding the lower quartile among controls) and the HLA-DRB1*15:01 allele regarding MS risk (AP 0.26, 95% CI 0.13-0.29). CONCLUSIONS: Our findings indicate that moderate levels of combustion-related ambient air pollution may play a role in MS development.

Analysis of Cdx2 VDR gene polymorphism rs11568820 in association with multiple sclerosis in Slovaks.

Vitamin D deficiency is involved in the pathogenesis of multiple sclerosis (MS), a severe autoimmune demyelinating disease of the central nervous system. The gene polymorphism Cdx-2 (rs11568820, G/A) seriously influences the trancriptional activity of the vitamin D receptor (VDR) that binds the vitamin D responsive elements of target genes including HLA-DRB1*15. The aim of the present study in Slovaks was to analyse the association of Cdx-2 variants with the risk of MS and disability progression, and to assess the DRB1*15:01 allele as a possible confounding factor. In total, 493 MS patients and 417 healthy controls were involved in this study. The genotyping of Cdx-2 was performed using restriction analysis; DRB1*15:01 positivity was determined by a high-resolution melting analysis of its surrogate marker rs3135388 (G/A). Our results did not prove any allelic association between Cdx-2 and a risk of MS (minor allele A - 0.181 in patients vs. 0.161 in controls, OR = 1.15, .95 CI = 0.90-1.47, p = 0.289). The logistic regression analysis, adjusted for sex and age, showed no differences in Cdx-2 genotype counts when using an additive, dominant or recessive genetic model (p = 0.351, 0.150, 0.240 respectively). The Cdx-2 variants were also not associated with disease disability progression, evaluated using the Multiple Sclerosis Severity Score. The HLA-DRB1*15:01 allele was found to strongly increase the risk of MS in our study (0.300 in patients vs. 0.101 in controls, OR = 3.83, .95 CI = 2.94-4.99, p = 1.016 × 10-26, dominant genetic model OR = 4.62, .95 CI = 3.40-6.26, p = 9.1 × 10-23). In summary, we found the Cdx-2 as a single genetic marker not to be associated with MS development or progression in Slovaks, independently of HLA-DRB1*15:01 status.

HLA-DRB1*15:01:43 and HLA-DRB1*15:01:44 alleles were identified by next-generation sequencing.

Compared with HLA-DRB1*15:01:01:01, the alleles HLA-DRB1*15:01:43 and HLA-DRB1*15:01:44 each show one nucleotide substitution respectively.

The novel HLA-DRB1*15:01:42 allele was identified by next-generation sequencing.

HLA-DRB1*15:01:42 differs from HLA-DRB1*15:01:01:01 by one single nucleotide substitution at position 732 C>T.

Expression Analysis of Long Non-coding RNA Lnc-DC in HLA-DRB1*15:01-Negative Patients with Multiple Sclerosis: A Probable Cause for Gender Differences in Multiple Sclerosis Susceptibility?

Multiple sclerosis is a disease that affects male and female patients differently. Several studies have been performed to explain the gender differences in MS susceptibility, but the genetic causes underlying gender differences remain unknown. The association between multiple sclerosis and the HLA-DRB1*15:01 haplotype has been confirmed to be female-specific. We hypothesized other immunological components such as lnc-DC may be gender-specific among multiple sclerosis patients, especially when MS patients are negative for the HLA-DRB1*15:01 allele. Therefore, the current study, considering the results of previous studies, aimed to evaluate the expression level of the lnc-DC gene in HLA-DRB1*15:01-negative female patients with relapsing remitting MS (RRMS). A total of 50 MS female patients and 50 female healthy controls were enrolled in this observational case-control study. HLA-DRB1*15:01, as a critical risk factor for MS, was ruled out in all patients. The peripheral blood mononuclear cells were obtained from all patients and total RNA was isolated and cDNA synthesis was carried out. The gene expression of lnc-DC was evaluated by real-time quantitative PCR. Our results have shown that lnc-DC expression level was significantly higher in total MS female patients compared with female controls (P = 0.0044). In addition, the correlation between lnc-DC with disease duration, EDSS, and age at onset did not reach a statistical significance in our study (r = 0.0336, P = 0.817; r = 0.0914, P = 0.5278 and r = 0.0743, P = 0.6083, respectively). Our results give further evidence that lnc-DC may play a gender-dependent role in MS pathogenesis.

Risk HLA-DRB1 alleles differentially influence brain and lesion volumes in Japanese patients with multiple sclerosis.

BACKGROUND: The effects of distinct HLA alleles on the brain and lesion volumes remain to be established, particularly in non-Caucasian populations. Two distinct susceptibility alleles, DRB1*15:01 and DRB1*04:05, are prevalent in the Japanese population; we therefore aimed to clarify the effects of HLA-DRB1 alleles on brain and lesion volumes in multiple sclerosis (MS). METHODS: A total of 66 patients with MS (50 relapsing remitting, 16 progressive) underwent brain MRI volumetry measuring fluid-attenuated inversion recovery (FLAIR) and T1 lesion volumes, and normalized whole-brain (NWBV), white matter (NWMV), gray matter (NGMV), cortical gray matter (NCGMV), deep gray matter (NDGMV) and thalamus (NTV) volumes, and HLA-DRB1 genotyping. RESULTS: Carriers of HLA-DRB1*15:01(+)*04:05(-) and HLA-DRB1*15:01(-)*04:05(+) comprised 25.8% and 31.8% of patients, respectively. HLA-DRB1*15:01 carriers showed negative correlations between disease duration and NWBV (rs = -0.484, p = .036), NWMV (rs = -0.593, p = .008), and NTV (rs = -0.572, p = .011), and positive correlations between disease duration and FLAIR (rs = 0.539, p = .017) and T1 lesion volumes (rs = 0.545, p = .016). By contrast, no significant correlation of any MRI parameters with disease duration was found in HLA-DRB1*04:05 carriers. HLA-DRB1*15:01 carriers had a significantly faster reduction in NWBV and NWMV by disease duration and smaller NDGMV than DRB1*15:01 non-carriers, whereas HLA-DRB1*04:05 carriers had a significantly slower increase in FLAIR and T1 lesion volumes than HLA-DRB1*04:05 non-carriers. CONCLUSIONS: Our study suggests that distinct HLA-DRB1 alleles could differentially influence brain and lesion volumes over the disease course of MS.

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

BACKGROUND: The prevalence of multiple sclerosis is associated with the major histocompatibility complex class II DR15 haplotype HLA-DRB1*15:01∼HLA-DRB5*01:01. OBJECTIVE: To assess whether multiple sclerosis progression is associated with the main susceptibility haplotype HLA-DRB1*15:01∼HLA-DRB5*01:01. METHODS: Patients (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. RESULTS: After 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. CONCLUSION: The 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.

The novel HLA-DRB1*15:01:37 allele discovered in a Taiwanese individual.

One nucleotide substitution at residue 477 of HLA-DRB1*15:01:01:01 results in a new allele, HLA-DRB1*15:01:37.

Five new HLA alleles with synonymous mutations: A*01:01:65, A*01:01:66, B*44:03:35, DRB1*15:01:30 and DQB1*02:01:24.

Immunogenetic information is provided on five novel alleles with synonymous mutations.

The CIITA genetic polymorphism rs4774*C in combination with the HLA-DRB1*15:01 allele as a putative susceptibility factor to multiple sclerosis in Brazilian females / O polimorfismo rs4774*C no gene CIITA em conjunção com o alelo HLA-DRB1*15:01 é um possível fator de susceptibilidade a esclerose múltipla em mulheres brasileiras

The objective of this study was to investigate the association between the HLA alleles at the DQA1, DQB1 and DRB1 loci, the CIITA genetic polymorphisms -168A/G and +1614G/C, and susceptibility to multiple sclerosis (MS) in a sample from Rio de Janeiro State, Brazil. Furthermore, we wished to determine whether any of these associations might be more significant in women compared with men. DNA samples from 52 relapsing-remitting MS (RRMS) patients and 126 healthy controls matched for sex and age were analyzed. We identified a significant HLA-DRB1*15:01-MS association that was female-specific (Odds Ratio (OR) = 4.78; p = 0.001). Furthermore, we observed that the +1614G/C mutation in combination with the HLA-DRB1*15:01 allele increased susceptibility to MS in females (OR = 4.55; p = 0.01). Together, these findings highlight the polygenic nature of MS.

O objetivo deste estudo foi investigar a associação entre alelos HLA, loci DQA1, DQB1 e DRB1, polimorfismos -168A/G e +1614G/C no gene CIITA, e suscetibilidade à esclerose múltipla (EM) em uma amostra de Rio de Janeiro, Brasil. Além disso, buscou-se determinar se alguma dessas associações pode ser gênero-dependente. Foram analisadas amostras de DNA de 52 pacientes com EM reincidente-remitente (EMRR) e 126 controles saudáveis ​​pareados por sexo e idade. Foi identificada associação significativa HLA-DRB1*15:01-EMRR, que foi específica para o gênero feminino (Odds Ratio (OR) = 4,78, p = 0,001). Além disso, observou-se que o polimorfismo +1614 G/C, em combinação com o alelo HLA-DRB1*15:01 provoca o aumento da susceptibilidade à EM em pacientes do sexo feminino (OR = 4,55, p = 0,01). Juntos, estes resultados destacam a natureza poligênica da EM.