Low prevalence of human leukocyte antigen-B*5701 in HIV-1-infected Chinese subjects: a prospective epidemiological investigation

Prevalence of the HLA-B*5701 Allele and Abacavir Hypersensitivity in Saudi HIV Patients: A Multicenter Study

Introduction Human immunodeficiency virus (HIV) incidence and prevalence are increasing in Saudi Arabia, with a total prevalence of 12,000 in 2020. Treatment of HIV patients includes multiple regimens that may involve abacavir (ABC), which is a potent drug for treating HIV and can be used as a single or combined pill. Unfortunately, its use was limited by the known associated hypersensitivity reaction (HSR). A worldwide literature review over the past decades reported that the incidence of ABC-related HSR is 5-8%. Methods The study was a cross-sectional multicentric study involving five governmental hospitals in Saudi Arabia and included all HIV patients who were following in these centers. Results Out of 3082 patients, 1293 were tested for HLA-B*5701. The prevalence for ABC-HSR is 1.59%, with variability among the five hospitals, with the highest in King Fahad Hospital in Hafuf (KFH-H) at 4.00% and the lowest in Dammam Medical Complex (DMC) at 0.49%. In previous studies, HLA-B*5701 associated with ABC-HSR varied among different ethnic groups. Our study showed that two patients developed ABC-HSR clinically while they were both negative for HLA-B*5701. Conclusion The fact that patients with negative genetic testing are still at risk of developing ABC-HSR makes continuing screening for HLA-B*5701 status essential, as the consequences of missing such a life-threatening HSR could be detrimental.

Relationship of HLA-B alleles on susceptibility to and protection from HIV infection in Turkish population

OBJECTIVE

Many human leukocyte antigen (HLA)-B alleles are associated with an increased risk of Acquired Immune Deficiency Syndrome (AIDS) and Human Immunodeficiency Virus (HIV) progression; however, their distribution varies among different racial/ethnic groups. Abacavir used in the treatment of AIDS significantly increases the risk of hypersensitivity reactions in patients with HLA-B*57:01. The aim of this study was to determine the distribution of HIV-associated HLA-B subgroups (high and low resolution) and HLA-B*57:01 associated with Abacavir sensitivity in Turkiye.

METHODS

This retrospective case-control study consisted of 416 (F/M:111/305) HIV positive patients and 416 (F/M:111/305) healthy controls. HLA-B alleles were identified using Luminex based low-resolution method and further subgrouped by sequence-based high-resolution typing.

RESULTS

Our data showed that in patients with HIV-1 infection, HLA-B*15, *35, and *51 allele frequencies were higher, while the HLA-B*07, *14 and *55 allele frequencies were lower as compared to the controls. It was determined that HLA-B*15:01, *35:01, *35:08, and *51:01 alleles frequencies were higher in the patients with HIV-1 infection compared to the controls as HLA-B*07:02, *14:01, *44:01, and *55:01 allele frequencies were detected low. HLA-B*57:01 allele positivity, which is important in Abacavir hypersensitivity, was lower than controls, and this difference was not statistically significant.

CONCLUSION

Our results suggest that, HLA-B*07, *14, and *55 alleles and HLA-B*07:02, *14:01, *44:01, and *55:01 subgroups might have a protective effect, while HLA-B*15, *35, and *51 alleles and HLA-B*15:01, *35:01, *35:08, and *51:01 subgroups might play a role in susceptibility to HIV-1 infection.

The Prevalence of HLA-B*57 Serotype Associated with Hypersensitivity Reactions in the Treatment of HIV İnfection in the Turkish Population

OBJECTIVES

The aim of our study is to reveal the prevalence of HLA-B*57 in the Turkish population and to provide new perspectives to physicians starting abacavir therapy in HIV patients.

BACKGROUND

Abacavir, one of the drugs used to treat HIV infection, can cause hypersensitivity reactions in some patients. These hypersensitivity reactions have been shown to be associated with the HLA-B*57:01 allele. High-resolution HLA-B*57:01 scanning has a time and cost disadvantage compared with low-resolution HLA-B*57 scanning. Before starting abacavir treatment, we will discuss whether high-resolution scanning is more beneficial in individuals who are positive on HLAB* 57 screening. This is the study with the largest cohort to investigate the prevalence of HLA-B*57 in Turkey.

METHODS

The results of 25 thousand 318 people who applied to Bursa Uludağ University Faculty of Medicine, Department of Immunology for HLA-B* typing were scanned.

RESULTS

In our study, the HLA-B*57 serotype was detected in 827 (3.3%) individuals.

CONCLUSION

Considering these results, it can be assumed that the prevalence of HLA-B*57:01 in Turkey is lower than 3.3%. Instead of a high-resolution HLA-B*57:01 scan in all patients starting abacavir therapy, a high-resolution HLA-B*57:01 scan might be of greater benefit in patients who are positive on a low-resolution HLA-B*57 scan.

HLA pharmacogenetic markers of drug hypersensitivity from the perspective of the populations of the Greater Middle East

Specific HLA associations with drug hypersensitivity may vary between geographic regions and ethnic groups. There are little to no data related to HLA-drug hypersensitivity on populations who reside in the Greater Middle East (GME), a vast region spanning from Morocco in the west to Pakistan in the east. In this review, the authors intended to summarize the significant HLA alleles associated with hypersensitive drug reactions induced by different drugs, as have been found in different populations, and to summarize the prevalence of these alleles in the specific and diverse populations of the GME. For example, HLA-B*57:01 allele prevalence, associated with abacavir-induced hypersensitivity, ranges from 1% to 3%, and HLA-DPB1*03:01 prevalence, associated with aspirin-induced asthma, ranges from 10% to 14% in the GME population. Studying pharmacogenomic associations in the ethnic groups of the GME may allow the discovery of new associations, confirm ones found with a low evidence rate and enable cost-effectiveness analysis of allele screening before drug use.

Prevalence of human leukocyte antigen HLA-B*57:01 in individuals with HIV in West and Central Africa

BACKGROUND

The presence of the human leukocyte antigen HLA-B*57:01 is associated with the development of a hypersensitivity reaction to abacavir (ABC). Limited data exist on HLA-B*57:01 prevalence in individuals with HIV-1 in Africa. This study aimed to estimate HLA-B*57:01 prevalence in individuals with HIV-1 in West and Central Africa.

METHODS

A cross-sectional study was conducted in four countries in West and central Africa (Burkina-Faso, Côte d'Ivoire, Gabon, and Togo) from January 2016 to February 2020 to determine the status of HLA-B*57:01 in adults with HIV-1. The presence of HLA-B*57:01 was determined by using Single Specific Primer-Polymerase Chain Reaction (SSP-PCR) in blood samples. Prevalence rates were stratified based on country.

RESULTS

A total of 4016 (69.8% women) individuals with HIV were enrolled. Their median age was 45, and the interquartile range was 38-52. We included 500 (12.4%) patients in Burkina-Faso, 1453 (36.2%) in Côte d'Ivoire, 951 (23.7%) in Gabon, and 1112 (27.7%) in Togo. The overall HLA-B*57:01 prevalence was 0.1% [95% CI: 0.0-0.2%]. The prevalence of HLA-B*57:01 was similar according to the four countries. Only one case was reported in each country except Togo, with no cases.

CONCLUSIONS

HLA-B*57:01 prevalence is low in individuals with HIV in West and central Africa, and there is no difference among countries. This study does not confirm the utility of HLA-B*57:01 allele testing for abacavir use in this region.

Access to precision medicine in Thailand: a comparative study

Purpose

This study explored health insurance coverage of genetic testing and potential factors associated with precision medicine (PM) reimbursement in Thailand.

Design/methodology/approach

The study employed a targeted review method. Thirteen PMs were selected to represent four PM categories: targeted cancer therapy candidate, prediction of adverse drug reactions (ADRs), dose adjustment and cancer risk prediction. Content analysis was performed to compare access to PMs among three health insurance schemes in Thailand. The primary outcome of the study was evaluating PM test reimbursement status. Secondary outcomes included clinical practice guidelines, PMs statement in FDA-approved leaflet and economic evaluation.

Findings

Civil Servant Medical Benefits Scheme (CSMBS) provided more generous access to PM than Universal Coverage Scheme (UCS) and Social Security Scheme (SSS). Evidence of economic evaluations likely impacted the reimbursement decisions of SSS and UCS, while the information provided in FDA-approved leaflets seemed to impact the reimbursement decisions of CSMBS. Three health insurance schemes provided adequate access to PM tests for some cancer-targeted therapies, while gaps existed for access to PM tests for serious ADRs prevention, dose adjustment and cancer risk prediction.

Originality/value

This was the first study to explore the situation of access to PMs in Thailand. The evidence alerts public health insurance schemes to reconsider access to PMs. Development of health technology assessment guidelines for PM test reimbursement decisions should be prioritized.

Diagnostic Test Criteria for HLA Genotyping to Prevent Drug Hypersensitivity Reactions: A Systematic Review of Actionable HLA Recommendations in CPIC and DPWG Guidelines

Introduction

Certain HLA variants are associated with an increased risk of hypersensitivity reactions to specific drugs. Both the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG) have issued actionable HLA gene - drug interaction guidelines but diagnostic test criteria remain largely unknown. We present an overview of the diagnostic test criteria of the actionable HLA - drug pairs.

Methods

A systematic literature search was conducted in PubMed, Embase, Web of Science and Cochrane Library. Original case-control and cohort studies were selected and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and number needed to genotype (NNG) were calculated for the actionable HLA-drug pairs.

Results

In general, the HLA tests show high specificity and NPV for predicting hypersensitivity reactions. The sensitivity of HLA tests shows a wide range, from 0-33% for HLA-B*1502 testing to predict lamotrigine induced SJS/TEN up to 100% for HLA-B*5701 to predict immunologically confirmed abacavir hypersensitivity syndrome (ABC-HSR). PPV is low for all tests except for HLA-B*5701 and ABC-HSR which is approximately 50%. HLA-B*5701 to predict ABC-HSR shows the lowest NNG followed by HLA-B*5801 for allopurinol induced severe cutaneous adverse drug reactions and HLA-B*1502 for carbamazepine induced SJS/TEN.

Discussion

This is the first overview of diagnostic test criteria for actionable HLA-drug pairs. Studies researching HLA genes and hypersensitivity are scarce for some of the HLA-drug pairs in some populations and patient numbers in studies are small. Therefore, more research is necessary to calculate the diagnostic test criteria more accurately.

Abacavir Hypersensitivity Reaction Reporting Rates During a Decade of HLA-B*5701 Screening as a Risk-Mitigation Measure

INTRODUCTION

Human leukocyte antigen (HLA)-B*5701 screening identifies patients at increased risk for abacavir (ABC) hypersensitivity reaction (HSR). Screening was adopted in GlaxoSmithKline and ViiV Healthcare clinical trials in 2007 and human immunodeficiency virus treatment guidelines in 2008. Company meta-analyses of trials pre-HLA-B*5701 screening reported HSR rates of 4-8%. We analyzed the effectiveness of HLA-B*5701 screening on reducing HSR rates using clinical trial, Observational Pharmaco-Epidemiology Research & Analysis (OPERA) cohort, and spontaneous reporting data.

METHODS

A meta-analysis examined 12 trials in 3063 HLA-B*5701-negative patients receiving an ABC-containing regimen from April 9, 2007, to September 22, 2015. Potential cases were identified using prespecified Medical Dictionary for Regulatory Activities (MedDRA) preferred terms (drug hypersensitivity, hypersensitivity, anaphylactic reaction, anaphylaxis) and adjudicated against a Company ABC HSR case definition. Investigator-diagnosed cases were identified and rates were calculated. In the OPERA cohort, 9619 patients initiating their first ABC-containing regimen from January 1, 1999, to January 1, 2016, were identified. Patients were observed from regimen start until the earliest-following censoring event: ABC discontinuation, loss to follow-up, death, or study end (July 31, 2016). OPERA physicians evaluated events against OPERA definitions for definite/probable cases of ABC HSR; rates were calculated pre- and post-2008. The Company case definition was used to identify spontaneously reported cases for four marketed ABC-containing products; reporting rates were calculated using estimated exposure from sales data, through December 31, 2016.

RESULTS

Suspected ABC HSR rates were 1.3% or less in the meta-analysis. In the OPERA cohort, the rate was 0.4% among patients initiating ABC post-2008 versus 1.3% pre-2008 (p<0.0001). Spontaneous reporting rates were low post-2008 (54 to 22 cases per 100,000 patient-years exposure [PYE]) versus pre-2008 (618 to 55 cases per 100,000 PYE).

CONCLUSIONS

Clinically suspected ABC HSR rates were 1.3% or less in HLA-B*5701-negative patients. Recognizing their limitations, data from the OPERA cohort and spontaneous reporting indicate that HLA-B*5701 screening has reduced reporting rates of suspected HSR in clinical practice. Where screening for HLA-B*5701 is standard care, patients should be confirmed negative for this allele before starting ABC treatment.