Unraveling the genetic link: an umbrella review on HLA-B*15:02 and antiepileptic drug-induced Stevens-Johnson syndrome/toxic epidermal necrolysis

PURPOSE

This umbrella review was conducted to summarize the association between HLA*1502 allele with antiepileptic induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

METHODS

Pubmed, Scopus and EMBASE were searched for eligible reviews in May 2023. Two authors independently screened titles and abstracts and assessed full-text reviews for eligibility. The quality of meta-analyses and case-control studies was appraised with Assessing the Methodological Quality of Systematic Reviews 2 and Newcastle-Ottawa Scale, respectively. Narrative summaries of each antiepileptic drug were analyzed. Preestablished protocol was registered on the International Prospective Register of Systematic Reviews Registry(ID: CRD42023403957).

RESULTS

Included studies are systematic reviews, meta-analyses and case-control studies evaluating the association of HLA-B*1502 allele with the following antiepileptics. Seven meta-analyses for carbamazepine, three meta-analyses for lamotrigine (LTG), three case-control studies for oxcarbazepine, nine case-control studies for phenytoin and four case-control studies for phenobarbitone were included. The findings of this umbrella review suggest that there is a strong association between HLA-B-1502 with SJS/TEN for carbamazepine and oxcarbazepine and a milder association for lamotrigine and phenytoin.

CONCLUSION

In summary, although HLA-B*1502 is less likely to be associated with phenytoin or lamotrigine-induced SJS/TEN compared to carbamazepine-induced SJS/TEN, it is a significant risk factor that if carefully screened, could potentially reduce the development of SJS/TEN. In view of potential morbidity and mortality, HLA-B*1502 testing may be beneficial in patients who are initiating lamotrigine/phenytoin therapy. However, further studies are required to examine the association of other alleles with the development of SJS/TEN and to explore the possibility of genome-wide association studies before initiation of treatment.

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.

Impact on carbamazepine usage and cutaneous adverse reactions before and after the reimbursement of HLA-B*1502 genotyping in Taiwan, 2000-2017: A nationwide longitudinal study

OBJECTIVE

The HLA-B*1502 allele is strongly associated with carbamazepine (CBZ)-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in the Han Chinese population. This study investigated the impact of HLA-B*1502 screening on CBZ utilization and rates of severe cutaneous allergic reactions (SCARs) and SJS/TEN over time in Taiwan, where screening for HLA-B*1502 genotyping before prescribing CBZ was reimbursed in June 2010.

METHODS

Using the Taiwan National Health Insurance Research Database, we analyzed 13 277 457 episodes of seeking treatment for epilepsy or neuralgia between 2000 and 2017. Episodes were categorized into quarters based on treatment time. Propensity score-based stabilized weighting (PSSW) ensured well-balanced covariates. The difference in 3-month SCAR and SJS/TEN rates between phase 2 (2011-2017) and phase 1 (2000-2009) was examined using a one-sample Z-test. Pearson correlation coefficients assessed the association between screening rate, the number of CBZ users and nonusers, and SCAR and SJS/TEN rates after HLA-B*1502 genotyping.

RESULTS

CBZ prescriptions reduced from 7% (2000-2003) to 6% (2004-2010) and 4% (2011-2017). The screening rates of CBZ nonusers and CBZ users increased from 0%, .5% in 2011 to .8%, 16% in 2017, respectively. After PSSW, the mean 3-month SCAR incidence rates (per 10 000 episodes) significantly decreased from phase 1 to phase 2 for CBZ users (6.91 vs. 3.09, p < .0001) and nonusers (1.96 vs. 1.65, p < .0001). SJS/TEN incidence rates (per 10 000 episodes) significantly decreased from phase 1 to phase 2 for CBZ users (2.94 vs. 1.93, p < .0001) but not for nonusers (.71 vs. .74, p = .1492). In phase 2, SCAR incidence rates were significantly and negatively correlated with the screening rate for both CBZ users (r = -.38, p = .0342) and nonusers (r = -.80, p < .001). No significant correlation was found between SJS/TEN incidence rates and screening rates.

SIGNIFICANCE

Recognizing HLA-B*1502 allele and avoiding CBZ therapy in HLA-B*1502-positive patients is critical for preventing CBZ-induced severe adverse events.

Genotyping for HLA risk alleles versus patch tests to diagnose anti-seizure medication induced cutaneous adverse drug reactions

Aim: To provide a comparison of genotyping for HLA risk alleles versus patch testing to determine which of these two tests is a better diagnostic tool for cutaneous hypersensitivity reactions caused by anti-seizure medication. Methods: A literature study was performed in PubMed to assess the sensitivity and specificity of HLA genotyping and patch tests for identifying anti-seizure medication induced cutaneous hypersensitivity reactions. Results: This study shows that HLA-B*15:02 genotyping shows high sensitivity for carbamazepine-induced SJS/TEN, especially in Han Chinese and Southeast Asian patients (66.7-100.0%) whereas the sensitivity of patch tests (0.0-62,5%), HLA-A*31:01 (0-50%) and HLA-B*15:11 (18.2-42.9%) are lower. On the contrary, for carbamazepine and phenytoin induced DRESS, patch tests (respectively 70.0-88.9% and 14.3-70.0%) show higher sensitivity than HLA tests (0-66.7% and 0-12.7%). Also for lamotrigine-induced DRESS patch tests perform better than HLA-B*15:02 (33.3-40.0 versus 0%). For anti-seizure medication induced MPE and for oxcarbazepine-induced SCARs more studies are needed. Conclusion: Use of HLA-B genotyping may aid clinicians in the diagnosis of carbamazepine, phenytoin, lamotrigine and oxcarbazepine induced SJS/TEN, particularly in Han Chinese and Southeast Asian patients. On the other hand, patch tests seem to perform better in the diagnosis of carbamazepine and phenytoin induced DRESS.

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 between HLA-B*15:02 and phenytoin-induced severe cutaneous adverse reactions: a meta-analysis

Aim: Phenytoin (PHT) is a common anticonvulsant agent known for inducing severe cutaneous adverse reactions (SCARs). HLA-B*15:02 as a risk factor of PHT-induced SCARs was reported in numerous studies with inconsistent results. This meta-analysis aimed to establish pooling evidence of this association. Materials & methods: Pooled odds ratios (ORs) with 95% CIs were estimated using a random-effects model. Results: A total of 11 studies on 1389 patients, were included for the analyses. There was a significant association between HLA-B*15:02 and PHT-induced SCAR (pooled OR = 2.29, 95% CI: 1.25-4.19, p = 0.008). Furthermore, there was a significant association regarding Stevens-Johnson syndrome/toxic epidermal necrolysis (OR = 3.63, 95% CI: 2.15-6.13, p < 0.001) but no association regarding drug reaction with eosinophilia and systemic symptom. Conclusion: The results supported the recommendations of HLA-B*15:02 screening before treatment with PHT.

Clinical Aspects of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis With Severe Ocular Complications in India

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a spectrum of rare, severe immunological blistering skin reactions which are triggered by medication intake or infections. The acute phase is characterized by necrolysis of the skin and desquamation of mucosa, primarily oral and ocular, with significant mortality rates. The chronic phase is characterized by multi-organ sequelae with increased rates of morbidity and reduced quality of life for patients who have survived the acute phase. Since the primary goal in the acute phase is saving the life of the patient, ocular involvement is often missed and a significant proportion of patients present to an ophthalmologist with the chronic ocular sequelae. In India, chronic ocular sequelae and low vision are observed in two-thirds of patients who present in the chronic phase of SJS/TEN. In the chronic phase of ocular involvement, there are definite windows of opportunity which if targeted with specific interventions such as scleral lenses and mucous membrane grafts can help reduce the incidence of corneal blindness and improve the quality of life for patients with SJS/TEN. Over the last decade, several studies from India have advanced the understanding of the natural course of ocular involvement in SJS/TEN and the outcomes of timely interventions in the chronic phase of the disease. We present an overview of the epidemiology of ocular complications of SJS/TEN in India, the specific challenges faced in the management of ocular complications in the acute stage and recent advances in management of the chronic ocular complications of the disease.

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.

Genetic Markers for Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis in the Asian Indian Population: Implications on Prevention

This review attempts to collate all the studies performed in India or comprising a population originating from India and to find out if there is an association between the HLA (human leucocyte antigen) type of individual and development of Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) subsequent to medication use. The authors performed a PubMed search of all articles published in English from 2009 to 2019 for articles that studied HLA type in patients who developed SJS/TEN after intake of a specific drug in the Asian Indian population or in individuals of Asian Indian origin. The selection criteria were satisfied by a total of 11 studies that reported HLA associations with specific drugs, which induced SJS/TEN, mainly anti-epileptic drugs, and cold medicine/non-steroidal anti-inflammatory drugs. These studies involved a small number of patients, and hence, there is limited evidence to conclude if these associations can be extrapolated to a larger population of the same ethnicity. Similar multi-center studies need to be conducted with a larger sample size to confirm these associations. This would have implications in policy making and for understanding the potential of using genetic markers as a screening tool before prescribing a drug to a patient, which might make them susceptible to developing a potentially life-threatening disease such as SJS/TEN. This is possibly the only mode of primary prevention for this potentially fatal severe cutaneous adverse drug reaction.

HLA-B*1502 is associated with aromatic anticonvulsant drug-induced cutaneous adverse drug reactions among the Hakka population in China

Background

The purpose of this study was to analyze the correlation between aromatic antiepileptic drug-induced cutaneous adverse drug reactions and HLA-B*1502 genotype in patients from the Hakka population in Meizhou.

Methods

A total of 214 epileptic patients taking aromatic (n = 94) or non-aromatic anticonvulsants (n = 120) were included in the study from September 2016 to May 2018. Clinical data for the patients were analyzed retrospectively and HLA-B*1502 genotype testing was carried out.

Results

Thirty patients were HLA-B*1502(+) (14.02%). The proportion of HLA-B*1502(−) genotype and incidence of adverse drug reactions (ADRs) differed significantly between the two drug groups. In the aromatic anticonvulsant group, maculopapular eruption (MPE), Stevens–Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and hypersensitivity syndrome (HSS) occurred in 10 patients, including eight HLA-B*1502(+) and two HLA-B*1502(−) patients. MPE, HSS, SJS, and TEN occurred in 26 patients in the non-aromatic anticonvulsant group, including one HLA-B*1502(+) and 25 HLA-B*1502(−) patients. There was a significant correlation between the proportions of HLA-B*1502(+) genotype and induced cutaneous adverse drug reactions in the two groups.

Conclusions

HLA-B*1502 is associated with aromatic anticonvulsant drug-induced cutaneous adverse drug reactions among the Hakka population in Meizhou, China.

Genetic variants associated with T cell-mediated cutaneous adverse drug reactions: A PRISMA-compliant systematic review-An EAACI position paper

Drug hypersensitivity reactions (DHRs) are associated with high global morbidity and mortality. Cutaneous T cell-mediated reactions classically occur more than 6 hours after drug administration and include life-threatening conditions such as toxic epidermal necrolysis, Stevens-Johnson syndrome, and hypersensitivity syndrome. Over the last 20 years, significant advances have been made in our understanding of the pathogenesis of DHRs with the identification of human leukocyte antigens as predisposing factors. This has led to the development of pharmacogenetic screening tests, such as HLA-B*57:01 in abacavir therapy, which has successfully reduced the incidence of abacavir hypersensitivity reactions. We have completed a PRISMA-compliant systematic review to identify genetic associations that have been reported in DHRs. In total, 105 studies (5554 cases and 123 548 controls) have been included in the review reporting genetic associations with carbamazepine (n = 31), other aromatic antiepileptic drugs (n = 24), abacavir (n = 11), nevirapine (n = 14), trimethoprim-sulfamethoxazole (n = 11), dapsone (n = 4), allopurinol (n = 10), and other drugs (n = 5). The most commonly reported genetic variants associated with DHRs are located in human leukocyte antigen genes and genes involved in drug metabolism pathways. Increasing our understanding of genetic variants that contribute to DHRs will allow us to improve diagnosis, develop new treatments, and predict and prevent DHRs in the future.

Preparation of placental tissue transplants and their application in skin wound healing and chosen skin bullous diseases - Stevens-Johnson syndrome and toxic epidermal necrolysis treatment

Unique properties of amniotic membrane make it a promising source for tissue engineering and a clinically useful alternative for patients suffering from chronic wounds including, for example, ulcers, burns, ocular surface damages and wounds occurring in the course of bullous diseases like stevens-johnson syndrome and toxic epidermal necrolysis. Its use has many advantages over standard wound care, as it contains pluripotent cells, nutrients, anti-fibrotic and anti-inflammatory cytokines, growth factors and extracellular matrix (ECM) proteins. Placental tissues can be prepared as a medical component, an advanced therapy medicinal product or a tissue graft. In addition to basic preparation procedures such as washing, rinsing, cutting, drying and sterilisation, there are many optional steps such as perforation, crosslinking and decellularisation. Finally, transplants should be properly stored-in cryopreserved or dehydrated form. In recent years, many studies including basic science and clinical trials have proven the potential to expand the use of amniotic membrane and amnion-derived cells to the fields of orthopaedics, dentistry, surgery, urology, vascular tissue engineering and even oncology. In this review, we discuss the role of placental tissues in skin wound healing and in the treatment of various diseases, with particular emphasis on bullous diseases. We also describe some patented procedures for placental tissue grafts preparation.

Genetic markers of severe cutaneous adverse reactions

Adverse drug reactions can cause considerable discomfort. They can be life-threatening in severe cases, requiring or prolonging hospitalization, impeding proper treatment, and increasing treatment costs considerably. Although the incidence of severe cutaneous adverse reactions (SCARs) is low, they can be serious, have permanent sequelae, or lead to death. A recent pharmacogenomic study confirmed that genetic factors can predispose an individual to SCARs. Genetic markers enable not only elucidation of the pathogenesis of SCARs, but also screening of susceptible subjects. The human leukocyte antigen (HLA) genotypes associated with SCARs include HLA-B*57:01 for abacavir (Caucasians), HLA-B*58:01 for allopurinol (Asians), HLA-B*15:02 (Han Chinese) and HLA-A*31:01 (Europeans and Koreans) for carbamazepine, HLA-B*59:01 for methazolamide (Koreans and Japanese), and HLA-B*13:01 for dapsone (Asians). Therefore, prescreening genetic testing could prevent severe drug hypersensitivity reactions. Large-scale epidemiologic studies are required to demonstrate the usefulness and cost-effectiveness of screening tests because their efficacy is affected by the genetic differences among ethnicities.