HLA Risk Alleles in Aromatic Antiepileptic Drug-Induced Maculopapular Exanthema

Molecular docking to investigate HLA-associated idiosyncratic drug reactions

Idiosyncratic drug reactions (IDRs) pose severe threats to patient health. Unlike conventionally dose-dependent side effects, they are unpredictable and more frequently manifest as life-threatening conditions, such as severe cutaneous adverse reactions (SCARs) and drug-induced liver injury (DILI). Some HLA alleles, such as HLA-B*57:01, HLA-B*15:02, and HLA-B*58:01, are known risk factors for adverse reactions induced by multiple drugs. However, the structural basis underlying most HLA-associated adverse events remains poorly understood. This review summarizes the application of molecular docking to reveal the mechanisms of IDR-related HLA associations, covering studies using this technique to examine drug-HLA binding pockets and identify key binding residues. We provide a comprehensive overview of risk HLA alleles associated with IDRs, followed by a discussion of the utility and limitations of commonly used molecular docking tools in simulating complex molecular interactions within the HLA binding pocket. Through examples, including the binding of abacavir and flucloxacillin to HLA-B*57:01, carbamazepine to HLA-B*15:02, and allopurinol to HLA-B*58:01, we demonstrate how docking analyses can provide insights into the drug and HLA allele-specificity of adverse events. Furthermore, the use of molecular docking to screen drugs with unknown IDR liability is examined, targeting either multiple HLA variants or a single specific variant. Despite multiple challenges, molecular docking presents a promising toolkit for investigating drug-HLA interactions and understanding IDR mechanisms, with significant implications for preemptive HLA typing and safer drug development.

Lamotrigine associated extensive hyperpigmentation: A case report and literature review

RATIONALE

Lamotrigine (LTG)-associated extensive hyperpigmentation is rare and may persist for a long time or even become permanent. LTG-associated cutaneous adverse reaction (CAR) manifests initially as mild maculopapular exanthema (MPE). The first step in CAR therapy is to immediately discontinue the offending LTG for predicting evolution to mild or severe forms not always possible. Here, we present a rare case of LTG-associated extensive hyperpigmentation for delaying the withdrawal of LTG.

PATIENT CONCERNS

We describe the case of a female adolescent with a history of depression managed with LTG, who developed a mild MPE. Unfortunately, the patient did not discharge LTG after the occurrence of MPE until 20 days later. Then she developed a residual extensive hyperpigmentation in her trunk and extremities.

DIAGNOSES

After a series of physical examinations and retracing past medical history, she was diagnosed with LTG-associated extensive hyperpigmentation.

INTERVENTIONS

The patient refused any treatment.

OUTCOMES

Nine months later, there still existed residual hyperpigmentation in her trunk and extremities, and the range and color of hyperpigmentation have not changed significantly.

LESSONS

This case suggests that LTG may cause not only MPE but also extensive hyperpigmentation. When a patient displays a mild MPE following the initiation of LTG in the outpatient clinic, LTG-associated CAR should not be overlooked as a diagnosis, and early withdrawal of LTG should be considered at first.

Update on HLA-B*15:02 allele associated with adverse drug reactions

HLA alleles, part of the major histocompatibility complex, are strongly associated with adverse drug reactions (ADRs). This review focuses on HLA-B*15:02 and explores its association with ADRs in various ethnic populations and with different drugs, aiming to provide insights into the safe clinical use of drugs and minimize the occurrence of ADRs. Furthermore, the review explores the potential mechanisms by which HLA-B*15:02 may be associated with ADRs, aiming to gain new insights into drug modification and identification of haptens. In addition, it analyzes the frequency of the HLA-B*15:02, genotyping methods, cost-effectiveness and treatment measures for adverse reactions, thereby providing a theoretical basis for formulating clinical treatment plans.

Carbamazepine cutaneous adverse reactions and HLA gene variation in the Chinese population: a systematic review and meta-analysis

Aim: Examining the association between HLA-A/B alleles and different carbamazepine (CBZ)-induced cutaneous adverse reactions in the Chinese population. Methods: A systematic review and meta-analysis of case-control studies was conducted. A systematic search was conducted of PubMed, Embase, the Cochrane Library, National Knowledge Infrastructure, the Chinese Biomedical Literature database and Wanfang Digital Periodicals. Results: 23 studies with a total of 1174 patients were included. In the Han population, HLA-B*15:02 is significantly associated with the increased risk of CBZ-related Stevens-Johnson syndrome/toxic epidermal necrolysis, and this correlation was not related to geographic distribution. HLA-A*31:01, B*38:02 are associated with CBZ-related maculopapular eruption in South Han population. HLA-A*31:01 is associated with CBZ-DRESS in Taiwan Han population. Conclusion: HLA-B*15:02, A*31:01 and B*38:02 genes were found to be involved in the occurrence of CBZ cutaneous adverse reactions in Han Chinese.

A single-tube multiplex real-time PCR for HLA-B*38:02 genotype by detecting highly specific SNPs

Purpose: HLA-B*38:02 is closely related to carbimazole/methimazole-induced agranulocytosis. This study aimed to develop and validate a rapid and economical method for HLA-B*38:02 genotyping. Methods: A single-tube multiplex real-time PCR detection system comprising amplification refractory mutation system primers and TaqMan probes was established for HLA-B*38:02 genotyping. Sequence-based typing was applied to validate the accuracy of the assay. Results: The accuracy of the assay was 100% for HLA-B*38:02 genotyping. The detection limit of the new method was 0.05 ng DNA. The positive rate of HLA-B*38:02 in the Han (8%, n = 100), Bouyei (17.8%, n = 90) and Tibetan (12.7%, n = 110) populations was significantly higher than that in the Uighur population (1%, n = 100) (p < 0.05). Conclusion: The proposed method is rapid and reliable for HLA-B*38:02 screening in a clinical setting.

Associations of HLA genetic variants with carbamazepine-induced cutaneous adverse drug reactions: An updated meta-analysis

Aggregated risk of carbamazepine (CBZ)-induced cutaneous adverse drug reactions (cADRs) with different HLA variants are unclear and limited in terms of the power of studies. This study aimed to assess the aggregated risk of CBZ-induced cADRs associated with carrying the following HLA variants: HLA-B*15:02, HLA-B*15:11, HLA-B*15:21, HLA-B*38:02, HLA-B*40:01, HLA-B*46:01, HLA-B*58:01, HLA-A*24:02, and HLA-A*31:01. Literature was searched in different databases following PRISMA guidelines. The outcomes were measured as odds ratio (OR) using RevMan software by a random/fixed effects model, where p < 0.05 was set as statistical significance. In total, 46 case-control studies met the inclusion criteria and were included in this analysis consisting of 1817 cases and 6614 controls. It was found that case-patients who carried the HLA-B*15:02 allele were associated with a significantly increased risk of CBZ-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) compared to controls (OR 26.01; 95% CI 15.88-42.60; p < 0.00001). The aggregated risk of cADRs was slightly higher in Asian compared to Caucasian patients (Asians: OR 14.84; 95% CI 8.95-24.61; p < 0.00001; Caucasians: OR 11.65; 95% CI 1.68-80.70; p = 0.01). Further, HLA-B*15:11, HLA-B*15:21, or HLA-A*31:01 allele was also associated with significantly increased risk of CBZ-induced cADRs (HLA-B*15:11: OR 6.08; 95% CI 2.28-16.23; p = 0.0003; HLA-B*15:21: OR 5.37; 95% CI 2.02-14.28; p = 0.0008; HLA-A*31:01: OR 5.92; 95% CI 4.35-8.05; p < 0.00001). Other HLA variants were not found to have any significant associations with CBZ-induced cADRs. Strong associations between the HLA-B*15:02, HLA-B*15:11, HLA-B*15:21, or HLA-A*31:01 allele with CBZ-induced cADRs have been established in this analysis. Pharmacogenetic testing of particular HLA alleles before initiation of CBZ therapy may be beneficial to patients and may help to eradicate cADRs substantially.

The Association of Human Leukocyte Antigen and COVID-19 in Southern China

Human leukocyte antigen (HLA) polymorphism is hypothesized to be associated with diverse immune responses toward infectious diseases. Herein, by comparing against multiple subpopulation groups as control, we confirmed that HLA-B*15:27 and HLA-DRB1*04:06 were associated with coronavirus disease 2019 susceptibility in China. Both alleles were predicted to have weak binding affinities toward viral proteins.