Human leukocyte antigen alleles, genotypes and haplotypes frequencies in renal transplant donors and recipients from West Central India

Association between human leukocyte antigen (HLA) and end-stage renal disease (ESRD): a meta-analysis

Objectives

We recently studied the association between various human leukocyte antigen (HLA) alleles and end-stage renal disease (ESRD). According to our analysis, HLA-B*50 and HLA-DQA1*3 alleles were positively associated with ESRD, while B*40, DRB1*12, DRB1*13, and DQA1*6 alleles were negatively associated with ESRD. However, a single case-control study does not have enough statistical power to evaluate the possible impact of genetic polymorphism on any disease. Hence, the main objective of this meta-analysis is to determine the association between these abovementioned HLA alleles and ESRD.

Design

MEDLINE/PubMed, EMBASE, Web of Science, and Cochrane databases were searched through December 2020 for case-control studies on the associations between HLA polymorphisms and ESRD. Independent reviewers screened the texts of potentially eligible studies and assessed the risk of bias. The meta-analysis was conducted based on the checklists and guidelines based on PRISMA.

Results

We identified 26 case-control studies comprising 1,312 ESRD and 3,842 healthy subjects. A non-significant positive association was observed between HLA-B*50 (OR = 1.02, 95% CI [0.90, 1.24]), HLA-B*40 (OR = 1.75, 95% CI [0.98, 3.2]), HLA-DQA1*3, (OR = 1.17, 95% CI [0.74, 1.84]), DRB1*12 (OR = 1.05, 95% CI [0.94, 1.18]) alleles and ESRD. In addition, a non-significant negative association was observed between HLA-DRB1*13 (OR = 0.90, CI [0.81, 1.01]), HLA-DQB1*6 (OR = 0.79, 95% CI [0.58, 1.07]) alleles and ESRD.

Conclusions

Our meta-analysis indicates no significant association between HLA-B*50, HLA-DQA1*3, B*40, DRB1*12, DRB1*13, and DQA1*6 alleles and ESRD. Further studies with larger sample sizes and adjustments for confounders are required to confirm these conclusions.

Association of HLA-B*51:01, HLA-B*55:01, CYP2C9*3, and Phenytoin-Induced Cutaneous Adverse Drug Reactions in the South Indian Tamil Population

Phenytoin (PHT) is one of the most commonly reported aromatic anti-epileptic drugs (AEDs) to cause cutaneous adverse reactions (CADRs), particularly severe cutaneous adverse reactions (SCARs). Although human leukocyte antigen (HLA)-B*15:02 is associated with PHT-induced Steven Johnson syndrome/toxic epidermal necrosis (SJS/TEN) in East Asians, the association is much weaker than it is reported for carbamazepine (CBZ). In this study, we investigated the association of pharmacogenetic variants of the HLA B gene and CYP2C9*3 with PHT-CADRs in South Indian epileptic patients. This prospective case-controlled study included 25 PHT-induced CADRs, 30 phenytoin-tolerant patients, and 463 (HLA-B) and 82 (CYP2C9*3) normal-controls from previous studies included for the case and normal-control comparison. Six SCARs cases and 19 mild-moderate reactions were observed among the 25 cases. Pooled data analysis was performed for the HLA B*51:01 and PHT-CADRs associations. The Fisher exact test and multivariate binary logistic regression analysis were used to identify the susceptible alleles associated with PHT-CADRs. Multivariate analysis showed that CYP2C9*3 was significantly associated with overall PHT-CADRs (OR = 12.00, 95% CI 2.759–84.87, p = 003). In subgroup analysis, CYP2C9*3 and HLA B*55:01 were found to be associated with PHT-SCARs (OR = 12.45, 95% CI 1.138–136.2, p = 0.003) and PHT-maculopapular exanthema (MPE) (OR = 4.041, 95% CI 1.125–15.67, p = 0.035), respectively. Pooled data analysis has confirmed the association between HLA B*51:01/PHT-SCARs (OR = 6.273, 95% CI 2.24–16.69, p = <0.001) and HLA B*51:01/PHT-overall CADRs (OR = 2.323, 95% CI 1.22–5.899, p = 0.037). In this study, neither the case nor the control groups had any patients with HLA B*15:02. The risk variables for PHT-SCARs, PHT-overall CADRs, and PHT-MPE were found to be HLA B*51:01, CYP2C9*3, and HLA B*55:01, respectively. These alleles were identified as the risk factors for the first time in the South Indian Tamil population for PHT-CADRs. Further investigation is warranted to establish the clinical relevance of these alleles in this population with larger sample size.

Association between the HLA genotype and the severity of COVID-19 infection among South Asians

Regional variations are found in the incidence and severity of the COVID-19 infection. Human leukocyte antigen (HLA) polymorphism is one of the genetic factors that might have an impact on the outcome of the disease. This study explored the association between the HLA genotype and the severity of COVID-19 among patients from South Asia. Blood samples from 95 Asians (Bangladeshis, Indians, and Pakistanis) with COVID-19 were collected. The patients were divided according to the severity of their infection: mild (N = 64), severe (N = 31), and fatal (N = 20). DNA was extracted from all samples, and HLA genotyping was performed for both class I (A, B, and C) and class II (DRB1, DQA1, and DQB1) using the PCR-rSSO (polymerase chain reaction-reverse sequence-specific oligonucleotide) molecular method. The frequency of HLA-B*51 was significantly higher among patients in the fatal group than among those in the mild infection group (15% vs. 4.7%, p = 0.027). Additionally, the frequency of HLA-B*35 was significantly higher in the mild infection group than in the fatal group (21.1% vs. 7.5%, p = 0.050 [a borderline p-value]). In terms of HLA class II, DRB1*13 was significantly observed in the fatal group than in the mild infection group (17.5% vs. 11.3%, p = 0.049). However, the p-value for all alleles became insignificant after a statistical correction for the p-values (p_c  = 0.216, p_c  = 0.4, and p_c  = 0.49, respectively). Compared with all published data, this study highlights that the association between the HLA system and the COVID-19 outcome might be ethnic-dependent. Genetic variation between populations must be examined on a wider scale to assess infection prognosis and vaccine effectiveness.

HLA associations in South Asian multiple sclerosis

Background:

Previous efforts to identify Human Leukocyte Antigen (HLA) gene associations with multiple sclerosis (MS) in the South Asian population have been underpowered.

Aim:

To identify the primary HLA class II alleles associated with MS in Indians.

Methods:

We typed HLA-DRB1, -DQA1 and -DQB1 in 419 patients and 451 unrelated controls by polymerase chain reaction using sequence specific oligonucleotide probes (PCR-SSOP).

Results:

At the gene level DRB1 showed significant evidence of association ( p=0.0000012), DQA1 showed only marginal evidence of association ( p=0.04) and there was no evidence for association at DQB1 ( p=0.26). At the DRB1 locus association is confirmed with the *15:01 ( p=0.00002) and the *03 ( p=0.00005) alleles.

Conclusion:

Our study confirms that the risk effects attributable to the HLA- DRB1*15:01and DRB1*03 alleles seen in Europeans are also seen in Indians. The absence of any evidence of association with DQB1 alleles reflects the lower linkage disequilibrium between DQB1 alleles and DRB1 risk alleles present in this population, and illustrates the potential value of fine mapping signals of association in different ethnic groups.

HLA-B∗ 1502 is associated with carbamazepine induced Stevens-Johnson syndrome in North Indian population

The evidence of association between HLA-B(∗)1502 and anticonvulsant induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) from the Indian population is scant. Patients with a history of SJS/TEN secondary to carbamazepine or phenytoin were enrolled. The control group comprised of patients who had received carbamazepine/phenytoin for ⩾ 6 months without any adverse cutaneous event. Low-resolution DNA typing for HLA-B and high resolution HLA-B(∗)15 typing was performed. Seventeen patients with history of SJS/TEN secondary to carbamazepine (9) or phenytoin (8) and 50 tolerant controls (carbamazepine-37; phenytoin-13) were enrolled. The mean age of patients and controls was 33.9 ± 11.6 and 28.1 ± 9.9 years, respectively. HLA-B(∗)1502 was observed in 2/9 (22.2%) carbamazepine-SJS/TEN patients and none of the 37 carbamazepine tolerant controls (p = 0.035). HLA-B(∗)1502 was not observed in any of the 8 phenytoin-SJS/TEN patients or the 13 phenytoin tolerant controls. Our data suggests that HLA-B(∗)1502 is a risk factor for carbamazepine induced SJS/TEN. Therefore, HLA-B(∗)1502 testing should be performed prior to initiating carbamazepine in North Indian population.