Carbamazepine-induced toxic effects and HLA-B*1502 screening in Taiwan

Outcomes of pediatric patients with suspected allergies to COVID-19 vaccines

Background

Adverse effects following immunizations (AEFIs) can contribute to vaccine hesitancy.

Objective

We evaluated clinical outcomes of AEFIs subsequent to administration of the coronavirus disease 2019 (COVID-19) vaccine at 2 pediatric allergy centers.

Methods

Data on pediatric patients referred for COVID-19 AEFI concerns between March 2021 and October 2022 were reviewed. The collected data included patient demographics, clinical characteristics, outcomes of prior COVID-19 vaccination, recommendations after consultation, and outcomes of revaccination.

Results

The 163 patients were separated into 2 groups based on the absence (n = 89 [54.6%]) or presence (n = 74 [45.4%]) of prior COVID-19-related AEFIs. The most common reason for referral without a prior AEFI was another suspected drug allergy (n = 58 [35.6%]). All patients in this group were recommended for COVID-19 vaccination. Of the 163 patients, 82 (92.1%) proceeded with vaccination, with 77 of them (93.9%) tolerating vaccination. Most of those with a prior COVID-19-related AEFI had a delayed cutaneous reaction (n = 60 [37.0%]); 1 patient (0.6%) had suspected anaphylaxis. In this group, 6 (8.1%) were advised to postpone COVID-19 vaccination until their debilitating skin conditions had improved in response to further treatment, whereas 45 (77.6%) tolerated subsequent vaccination to the same or an alternate COVID-19 vaccine type. The most common AEFI on revaccination was urticaria (in 8 of 11 patients [72.7%]). AEFI on revaccination was significantly associated with a history of spontaneous urticaria or angioedema (relative risk = 3.6 [95% CI = 1.30-9.99]; P = .020) and urticaria following COVID-19 vaccination previously (relative risk = 4.12 [95% CI = 1.22-13.87]; P = .017).

Conclusions

Children with a history of urticaria or angioedema related or unrelated to prior COVID-19 vaccination were at higher risk of a COVID-19-related AEFI on revaccination, although most were able to complete the vaccination series under the management of our immunology/allergy service.

Vancomycin Drug Reaction with Eosinophilia and Systemic Symptoms: Meta-Analysis and Pharmacovigilance Study

Background: Drug reaction with eosinophilia and systemic symptoms is a severe cutaneous reaction with a high mortality rate. It is challenging to diagnose due to its similar presentation to infectious disease syndromes, variation with the culprit drug, and lack of awareness. Methods: We searched PubMed, and Embase, for RegiSCAR-scored observational studies, the FDA Adverse Events Reporting System (FAERS) for adverse event reports, and the Allele Frequency Net Database (AFND) for HLA allele frequency. In our meta-analysis, we employed a random effects model to subgroup patients by ethnicity to determine the proportion of DRESS cases compared with various associated medications. Additionally, we identified a correlation between the proportion of cases and the presence of the HLA*A-32:01allele, which is suspected to predispose individuals to DRESS. Results: Twenty-one studies on 1949 DRESS cases in vancomycin and 2558 antimicrobial DRESS reports in the FAERS database were analyzed. Meta-analysis showed a 27% incidence of vancomycin-DRESS, with Caucasians having the highest proportion at 36%. The median latency for symptom onset was 21 days, with no female predisposition. The proportional incidence of vancomycin-DRESS did not correlate with the HLA-A*32:01 allele. The adjusted ROR for vancomycin was 2.40 compared to other antimicrobials, and the risk increased by 77% with concurrent antimicrobials. Piperacillin/tazobactam had a similar DRESS reporting risk at 0.95 (95%CI: 0.88-1.02). Conclusions: Vancomycin significantly contributes to the incidence of DRESS and is more closely related to ethnicity than to allele frequency, indicating that the HLA-A*32:01 allele may not be directly involved. Furthermore, the use of other antimicrobials can influence the reaction, underscoring the need to minimize antimicrobial use for better coverage.

Drug-Induced Serious Cutaneous Reactions in Hospitalized Patients: A Cross-Sectional Study

Background: Serious adverse drug reactions (ADRs) can lead to hospital admission and can be fatal, but some of them are preventable. This study aimed to determine the types and frequencies of serious cutaneous ADRs and the methods employed to manage and prevent them, as well as to assess the factors related to their seriousness. Methods: A cross-sectional study was conducted retrospectively on inpatients and outpatients at a tertiary care hospital. All data were collected from the medical records database over a period of 3 years. Serious cutaneous ADRs were identified in the hospital database using the International Classification of Disease and Related Health Problems, 10th Revision (ICD-10). Results: A total of 2151 cases were retrieved using the ICD-10, and 436 patients were randomly selected for this study. Of these, 218 patients experienced ADRs (50.0%). The major clinical symptoms of the eight serious ADRs included anaphylaxis (38.5%) and urticaria (30.2%). The most commonly suspected drug group was antibiotics (45.0%). The main methods of ADR management were drug treatment (84.4%) and drug withdrawal (81.2%). The primary method of ADR prevention was patient drug allergy cards (52.3%). Factors affecting the severity of ADRs were having an underlying condition (p = 0.031) and the concomitant use of drugs (p = 0.044). Conclusions: Anaphylaxis was the most common serious ADR. Patients with underlying diseases and those taking concomitant drugs are more likely to present with serious ADRs. The prevention of serious ADRs should be promoted at all levels in hospitals to reduce harm and prevent their reoccurrence.

Overlapping of DRESS and Stevens-Johnson syndrome due to first-line antituberculosis drugs: a case report

The overlap of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) and Stevens-Johnson syndrome (SJS) caused by antituberculosis drugs represents an extremely rare event. This situation can manifest between 2 and 8 weeks after the first exposure to the medication. The overlap of these conditions can lead to atypical clinical manifestations, thus complicating the early diagnosis and the implementation of early treatment. This report describes the case of a patient who developed the DRESS/SJS overlap 35 days after starting antituberculosis treatment. The patient experienced severe skin and systemic involvement, a situation that required her admission and monitoring in the intensive care unit. From our experience with this case, we conclude the importance of an accurate and timely diagnosis using validated scoring systems such as RegiSCAR to confirm the clinical diagnosis of DRESS/SJS and ALDEN to assess the likelihood of drug causality. Timely intervention with corticosteroids plays a key role in moderating the exaggerated immune response, helping to alleviate dermatological symptoms and prevent long-term organ damage. In addition, the availability of safe therapeutic alternatives for tuberculosis treatment allows for more effective and safer management in these patients.

Class I HLA Alleles Are Associated With an Increased Risk of Osimertinib-Induced Hypersensitivity

BACKGROUND

Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), shows superior lung cancer treatment efficacy. However, osimertinib-induced severe hypersensitivity, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), is frequently observed in Asian populations and hinders cancer treatment.

OBJECTIVE

We investigated the genetic HLA predisposition and immune pathomechanism of osimertinib-induced hypersensitivity.

METHODS

We enrolled 17 patients with osimertinib-induced delayed hypersensitivity (seven with severe SJS/TEN and 10 with mild maculopapular exanthema), 98 osimertinib-tolerant subjects, and 2,123 general population controls. We performed HLA genotyping, drug-induced lymphocyte activation test, and surface plasmon resonance assay.

RESULTS

HLA-B∗51:02 was present in 83.3% of osimertinib-induced SJS/TEN patients but in only 3.3% of the general population controls (P = 2.8 × 10-7; corrected P = 6.9 × 10-6; odds ratio [OR] = 146), and 0% of osimertinib-tolerant controls (P = 6.5 × 10-8; corrected P = 1.6 × 10-6; OR = 707). The association of HLA-B∗51:01 and HLA-A∗24:02 with osimertinib-induced maculopapular exanthema patients, rather than with osimertinib-tolerant subjects (P = .002, OR = 15.7 for HLA-B∗51:01; and P = .003, OR = 9.5 for HLA-A∗24:02), was identified as a phenotype-specific association. Granulysin, the SJS/TEN-specific cytotoxic protein, was significantly higher in plasma of SJS/TEN patients (39.8 ± 4.5 ng/mL; P < .001) and in in vitro lymphocyte activation test (sensitivity = 83.3%; P < .01) compared with tolerant controls. Patients with osimertinib-induced hypersensitivity appeared to tolerate alternative EGFR-TKIs. Surface plasmon resonance results also confirmed that HLA-B∗51:02 protein has a higher binding affinity for osimertinib and lower or no affinity for other EGFR-TKIs.

CONCLUSIONS

HLA-B∗51:02 frequently occurs in Asian populations and is strongly associated with osimertinib-induced SJS/TEN. Our findings suggest HLA-B∗51:02 screening as a preemptive test to reduce osimertinib-induced severe hypersensitivity.

Exploring recent advances in drugs severe cutaneous adverse reactions immunopathology

Severe cutaneous adverse reactions to drugs (SCARs) are rare but life-threatening delayed allergies. While they primarily affect the skin, they can also affect internal organs. Accordingly, they present with diverse clinical symptoms that vary not only between SCARs subtypes but also among patients. Despite the availability of topical and systemic treatments, these only address the symptoms and not the cause. To develop more effective therapies, it is necessary to elucidate the complexity of the pathophysiology of SCARs in relation to their severity. In line with the new type IV hypersensitivity reactions nomenclature proposed by the European Academy of Allergy and Clinical Immunology (EAACI), this review highlights the current insights into the intricate immune mechanisms engaged, the interplay between the culprit drug and genetic predisposition in drug presentation mechanisms, but also how external factors, such as viruses, are implicated in SCARs. Their relevance to the development of targeted medicine is also discussed.

Characterizing the genetic architecture of drug response using gene-context interaction methods

Identifying factors that affect treatment response is a central objective of clinical research, yet the role of common genetic variation remains largely unknown. Here, we develop a framework to study the genetic architecture of response to commonly prescribed drugs in large biobanks. We quantify treatment response heritability for statins, metformin, warfarin, and methotrexate in the UK Biobank. We find that genetic variation modifies the primary effect of statins on LDL cholesterol (9% heritable) as well as their side effects on hemoglobin A1c and blood glucose (10% and 11% heritable, respectively). We identify dozens of genes that modify drug response, which we replicate in a retrospective pharmacogenomic study. Finally, we find that polygenic score (PGS) accuracy varies up to 2-fold depending on treatment status, showing that standard PGSs are likely to underperform in clinical contexts.

Toxic Epidermal Necrolysis Observed in a Patient With the HLA-B*1502 Treated With Levofloxacin

PURPOSE

To determine the relationship between HLA-B gene mutations and levofloxacin-induced toxic epidermal necrolysis (TEN).

METHODS

A 71-year-old Chinese woman developed TEN after oral administration of solifenacin (5 mg) and levofloxacin (0.5 g) for cystitis. HLA-B*5801 and HLA-B*1502 alleles were detected using real-time PCR.

FINDINGS

After supportive therapy (antiallergic treatments, plasma exchange, etc) and withdrawal of the culprit medication levofloxacin, the patient was discharged with re-epithelialization of the exfoliated skin. The patient was HLA-B*1502 allele positive and HLA-B*5801 allele negative.

IMPLICATIONS

This is the first report of levofloxacin-induced TEN suspected to be caused by mutations in the HLA-B*1502 allele.

Unraveling the genetic basis of epilepsy: Recent advances and implications for diagnosis and treatment

Epilepsy, affecting approximately 1% of the global population, manifests as recurring seizures and is heavily influenced by genetic factors. Recent advancements in genetic technologies have revolutionized our understanding of epilepsy's genetic landscape. Key studies, such as the discovery of mutations in ion channels (e.g., SCN1A and SCN2A), neurotransmitter receptors (e.g., GABRA1), and synaptic proteins (e.g., SYNGAP1, KCNQ2), have illuminated critical pathways underlying epilepsy susceptibility and pathogenesis. Genome-wide association studies (GWAS) have identified specific genetic variations linked to epilepsy risk, such as variants near SCN1A and PCDH7, enhancing diagnostic accuracy and enabling personalized treatment strategies. Moreover, epigenetic mechanisms, including DNA methylation (e.g., MBD5), histone modifications (e.g., HDACs), and non-coding RNAs (e.g., miR-134), play pivotal roles in altering gene expression and synaptic plasticity, contributing to epileptogenesis. These discoveries offer promising avenues for therapeutic interventions aimed at improving outcomes for epilepsy patients. Genetic testing has become essential in clinical practice, facilitating precise diagnosis and tailored management approaches based on individual genetic profiles. Furthermore, insights into epigenetic regulation suggest novel therapeutic targets for developing more effective epilepsy treatments. In summary, this review highlights significant progress in understanding the genetic and epigenetic foundations of epilepsy. By integrating findings from key studies and specifying genes involved in epigenetic modifications, we underscore the potential for advanced therapeutic strategies in this complex neurological disorder, emphasizing the importance of personalized medicine approaches in epilepsy management.

Update on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Diagnosis and Management

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are the most severe cutaneous adverse reactions that are typically drug-induced in adults. Both SJS and TEN have high morbidity and mortality rates. SJS/TEN imposes clinical challenges for physicians managing patients suffering from this condition, both because it is rare and because it is a rapidly progressing systemic disease with severe cutaneous, mucosal, and systemic manifestations. Although many cases of SJS/TEN have been reported in the literature, there is no consensus regarding diagnostic criteria or treatment. Significant progress has been made in understanding its genetic predisposition and pathogenesis. This review is intended to provide physicians with a comprehensive but practical SJS/TEN roadmap to guide diagnosis and management. We review data on pathogenesis, reported precipitating factors, presentation, diagnosis, and management SJS/TEN focusing on what is new over the last 5 years.

Reconsidering Semaglutide Use for Chronic Obesity in Patients of Asian Descent: A Critical Review

Semaglutide is a glucagon-like peptide 1 (GLP-1) receptor agonist. It is the first approved drug for chronic weight management in adults who are overweight or obese since 2014. Its increasing popularity has garnered significant media attention and led to a drug shortage, resulting in limited access for its intended use - patients with type 2 diabetes. Numerous studies have demonstrated its effectiveness in promoting weight loss. This review seeks to explain the use of semaglutide, a GLP-1 receptor agonist, to treat metabolic syndrome in the Asian American population. It raises concerns about the existing diagnostic and treatment approaches and stresses the necessity of integrating visceral fat and other ethnicity-specific risk predictors for the diagnosis of metabolic syndrome. The objective of this review is to examine the eligibility criteria for the prescription of semaglutide critically and determine whether Asians are being unfairly excluded and denied access to this medication due to ineffective prescription guidelines.

Stevens-Johnson syndrome and toxic epidermal necrolysis: Updates in pathophysiology and management

ABSTRACT

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening conditions characterized by extensive detachment of the epidermis and mucous membranes. These severe disorders carry a high mortality rate, and their pathogenesis remains largely unclear. Furthermore, optimal therapeutic strategies for SJS/TEN remain a subject of ongoing debate. Early diagnosis of SJS/TEN is challenging, and reliable biomarkers for diagnosis or severity prediction have not been firmly established. Certain drugs, such as carbamazepine and allopurinol, have shown a strong association with specific human leukocyte antigen (HLA) types. Recently, the potential benefits of HLA screening prior to administering these drugs to reduce the incidence of SJS/TEN have been explored. Epidermal cell death in SJS/TEN lesions is caused by extensive apoptosis, primarily through the Fas-Fas ligand (FasL) and perforin/granzyme pathways. Our findings suggest that necroptosis, a form of programmed necrosis, also contributes to epidermal cell death. Annexin A1, released from monocytes, interacts with the formyl peptide receptor 1 to induce necroptosis. Several biomarkers, such as CC chemokine ligand (CCL)-27, interleukin-15, galectin-7, receptor-interacting protein kinases 3 (RIP3), and lipocalin-2, have been identified for diagnostic and prognostic purposes in SJS/TEN. Supportive care is recommended for treating SJS/TEN, but the efficacy of various therapeutic options-including systemic corticosteroids, intravenous immunoglobulin, cyclosporine, and tumor necrosis factor-α antagonists-remains controversial. Recent studies have investigated the potential benefits of tumor necrosis factor-α antagonists. In this review, we discuss recent advances in the understanding and management of SJS/TEN.

Association of HLA alleles with cephalosporin allergy in the Taiwanese population

Cephalosporin antibiotics are widely used in clinical settings, but they can cause hypersensitivity reactions, which may be influenced by genetic factors such as the expression of Human leukocyte antigen (HLA) molecules. This study aimed to investigate whether specific HLA alleles were associated with an increased risk of adverse reactions to cephalosporins among individuals in the Taiwanese population. This retrospective case-control study analyzed data from the Taiwan Precision Medicine Initiative (TPMI) on 27,933 individuals who received cephalosporin exposure and had HLA allele genotyping information available. Using logistic regression analyses, we examined the associations between HLA genotypes, comorbidities, allergy risk, and severity. Among the study population, 278 individuals had cephalosporin allergy and 2780 were in the control group. Our results indicated that certain HLA alleles, including HLA-B*55:02 (OR = 1.76, 95% CI 1.18-2.61, p = 0.005), HLA-C*01:02 (OR = 1.36, 95% CI 1.05-1.77, p = 0.018), and HLA-DQB1*06:09 (OR = 2.58, 95% CI 1.62-4.12, p < 0.001), were significantly associated with an increased risk of cephalosporin allergy reactions. Additionally, the HLA-C*01:02 allele genotype was significantly associated with a higher risk of severe allergy (OR = 2.33, 95% CI 1.05-5.15, p = 0.04). This study identified significant associations between HLA alleles and an increased risk of cephalosporin allergy, which can aid in early detection and prediction of adverse drug reactions to cephalosporins. Furthermore, our study highlights the importance of HLA typing in drug safety and expanding our knowledge of drug hypersensitivity syndromes.

Understanding clozapine-related blood dyscrasias. Developments, genetics, ethnicity and disparity: it's a CIN

Clozapine remains the gold standard intervention for treatment-resistant schizophrenia; however, it remains underused, especially for some minority groups. A significant impediment is concern about propensity to neutropenia. The aim of this article is to provide an update on current knowledge relating to: the pattern and incidence of severe blood dyscrasias; the effectiveness of current monitoring regimes in reducing harm; the mechanisms of and the distinctions between clozapine-induced neutropenia and agranulocytosis; benign ethnic neutropenia; and changes to the monitoring thresholds in the USA and other international variations. These all have implications for the practical use of clozapine; specifically, how barriers to initiating, maintaining and restarting clozapine can be understood and in many cases overcome, especially for patients from minority groups, potentially with simpler approaches than the use of lithium or G-CSF.

Molecular identification of HLA-B75 serotype markers by qPCR: A more inclusive pharmacogenetic approach before carbamazepine prescription

Genetic screening for HLA-B*15:02 before prescribing carbamazepine is standard practice to prevent severe cutaneous adverse reactions in Asian populations. These reactions are associated not only with this allele but also with closely related HLA-B75 serotype markers-HLA-B*15:11 and HLA-B*15:21-which are prevalent in several Asian countries. However, a reliable method for identifying HLA-B75 serotype markers is still not available. We developed an in-house quantitative PCR (qPCR) for HLA-B75 screening and validated it using 303 anonymized DNA samples. Due to inadequate quality control, the qPCR results for 11 samples were excluded. We analyzed the sensitivity and specificity of the test using 93 HLA-typed samples. The concordance between the qPCR method and an established screening method was assessed using 199 HLA-screened samples tested for HLA-B*15:02 at Songklanagarind Hospital, Songkhla, Thailand. All discordant results were confirmed by Sanger sequencing. The qPCR method demonstrated a sensitivity of 100% (95% confidence interval = 83.16%-100.00%) and a specificity of 100% (95% confidence interval = 95.07%-100.00%). Concordance analysis revealed a 96.5% agreement between methods (192/199; 44 positive and 148 negative results). All discordant results were due to HLA-B75 markers not being HLA-B*15:02 (two samples with HLA-B*15:11 and five samples with HLA-B*15:21). In conclusion, this qPCR method could be useful for identifying HLA-B75 carriers at risk of carbamazepine-induced reactions in Asian populations where carriers of HLA-B*15:02, HLA-B*15:11, or HLA-B*15:21 are common.

Economic Evaluation of HLA-B*15:02 Genotyping for Asian Australian Patients With Epilepsy

Importance

The HLA-B*15:02 allele has been associated with an increased risk of carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in specific Asian populations (including Han Chinese, Malaysian, Thai, and Vietnamese individuals). While HLA-B*15:02 genotype testing in Asian populations is recommended by several international prescribing guidelines, it is not subsidized by the Medicare Benefits Schedule in Australia.

Objective

To evaluate the cost-effectiveness of HLA-B*15:02 genotyping in Asian Australian patients with epilepsy.

Design, Setting, and Participants

A model with components of decision analysis and Markov simulation was developed to simulate clinical trajectories of adult Asian Australian patients with newly diagnosed epilepsy being considered for carbamazepine treatment. Cost-effectiveness and cost-utility analyses over a lifetime time horizon were conducted from the perspective of the Australian health care sector. The study was conducted in May 2023 and data analysis was performed from August 2023 to November 2023.

Intervention

No HLA-B*15:02 genotyping and the empirical initiation of treatment with carbamazepine vs HLA-B*15:02 genotyping and the initiation of treatment with valproate in allele carriers.

Main Outcomes and Measures

Life-years (LYs), quality-adjusted life-years (QALYs), and costs in 2023 Australian dollars (A$); incremental cost-effectiveness ratios.

Results

HLA-B*15:02 screening was associated with an additional mean cost of A$114 (95% CI, -A$83 to A$374; US$76; 95% CI, -US$55 to US$248) and a reduction in 0.0152 LYs (95% CI, 0.0045 to 0.0287 LYs) but improvement by 0.00722 QALYs (95% CI, -0.0247 to -0.01210) compared with no screening, resulting in an incremental cost-effectiveness ratio of A$15 839 per QALY gained (US$10 523 per QALY). Therefore, universal genotyping for Asian Australian individuals was cost-effective compared with current standards of practice at the A$50 000 per QALY willingness-to-pay threshold. Sensitivity analyses demonstrated that the intervention remained cost-effective across a range of costs, utilities, transition probabilities, and willingness-to-pay thresholds. At the A$50 000 per QALY willingness-to-pay threshold, universal screening was the preferred strategy in 88.60% of simulations.

Conclusions and Relevance

The results of this economic evaluation suggest that HLA-B*15:02 screening represents a cost-effective choice for Asian Australian patients with epilepsy who are being considered for treatment with carbamazepine.

Individualized Pharmacotherapy Utilizing Genetic Biomarkers and Novel In Vitro Systems As Predictive Tools for Optimal Drug Development and Treatment

In the area of drug development and clinical pharmacotherapy, a profound understanding of the pharmacokinetics and potential adverse reactions associated with the drug under investigation is paramount. Essential to this endeavor is a comprehensive understanding about interindividual variations in absorption, distribution, metabolism, and excretion (ADME) genetics and the predictive capabilities of in vitro systems, shedding light on metabolite formation and the risk of adverse drug reactions (ADRs). Both the domains of pharmacogenomics and the advancement of in vitro systems are experiencing rapid expansion. Here we present an update on these burgeoning fields, providing an overview of their current status and illuminating potential future directions. SIGNIFICANCE STATEMENT: There is very rapid development in the area of pharmacogenomics and in vitro systems for predicting drug pharmacokinetics and risk for adverse drug reactions. We provide an update of the current status of pharmacogenomics and developed in vitro systems on these aspects aimed to achieve a better personalized pharmacotherapy.

A genetics-guided approach to the clinical management of schizophrenia

Schizophrenia is a highly heritable, severe mental illness characterized by hallucinations, delusions, social withdrawal, and cognitive dysfunction present in ∼1% of populations across cultures. There have been recent major advancements in our understanding of the genetic architecture of schizophrenia. Both rare, highly penetrant genetic variants as well as common, low-penetrant genetic variants can predispose individuals to schizophrenia and can impact the way people metabolize psychoactive medications used to treat schizophrenia. However, the impact of these findings on the clinical management of schizophrenia remains limited. This review highlights the few places where genetics currently informs schizophrenia management strategies, discusses major limitations, and reviews promising areas of genetics research that are most likely to impact future schizophrenia care. Specifically, I focuss on psychiatric genetic counseling, genetic testing strategies, pharmacogenetics, polygenic risk, and genetics-guided treatment. Lastly, I emphasize important ethical considerations in the clinical use of genetics for schizophrenia management, including the exacerbation of healthcare inequalities and unintended consequences of new genetic technologies.

Severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs), which include Stevens-Johnson syndrome and toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (also known as drug-induced hypersensitivity syndrome), acute generalized exanthematous pustulosis, and generalized bullous fixed drug eruption, are life-threatening conditions. The pathogenesis of SCARs involves T cell receptors recognizing drug antigens presented by human leukocyte antigens, triggering the activation of distinct T cell subsets. These cells interact with keratinocytes and various immune cells, orchestrating cutaneous lesions and systemic manifestations. Genetic predisposition, impaired drug metabolism, viral reactivation or infections, and heterologous immunity influence SCAR development and clinical presentation. Specific genetic associations with distinct SCAR phenotypes have been identified, leading to the implementation of genetic screening before prescription in various countries to prevent SCARs. Whilst systemic corticosteroids and conventional immunomodulators have been the primary therapeutic agents, evolving strategies, including biologics and small molecules targeting tumour necrosis factor, different cytokines, or Janus kinase signalling pathways, signify a shift towards a precision management paradigm that considers individual clinical presentations.

Clinical characteristics and genetic HLA marker for patients with oxaliplatin-induced adverse drug reactions

BACKGROUND

Oxaliplatin is commonly used to treat gastrointestinal malignancies. However, its applications are limited due to potential adverse drug reactions (ADRs), particularly severe anaphylactic shock. There is no method to predict or prevent ADRs caused by oxaliplatin. Therefore, we aimed to investigate the genetic HLA predisposition and immune mechanism of oxaliplatin-induced ADRs.

METHODS

A retrospective review was performed for 154 patients with ADRs induced by oxaliplatin during 2016-2021 recorded in our ADR notification system. HLA genotyping was conducted for 47 patients with oxaliplatin-induced ADRs, 1100 general population controls, and 34 oxaliplatin-tolerant controls in 2019-2023. The in vitro basophil activation test (BAT) was performed and oxaliplatin-specific IgE levels were determined.

RESULTS

The incidence of oxaliplatin-induced ADRs and anaphylactic shock in our cohort was 7.1% and 0.15%, respectively. Of the 154 patients, 67.5% suffered rash/eruption; 26.0% of the patients who could not undergo oxaliplatin rechallenge were considered to show oxaliplatin-induced immune-mediated hypersensitivity reactions (HRs). The genetic study found that the HLA-DRB∗12:01 allele was associated with oxaliplatin-induced HRs compared to the general population controls (sensitivity = 42.9%; odds ratio [OR] = 3.4; 95% CI = 1.4-8.2; P = 0.008) and tolerant controls (OR = 12; 95% CI = 2.3-63.7; P = 0.001). The in vitro BAT showed higher activation of CD63+ basophils in patients with oxaliplatin-induced HRs compared to the tolerant controls (P < 0.05). Only four patients (8.5%) with oxaliplatin-induced ADRs were positive for oxaliplatin-specific IgE.

CONCLUSIONS

This study found that 26.0% of patients with oxaliplatin-induced ADRs could not undergo oxaliplatin rechallenge. HLA-DRB∗12:01 is regarded as a genetic marker for oxaliplatin-induced hypersensitivity.

DRESS syndrome due to anti-TB drugs: A complex case with successful re-desensitization of group A drugs

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare, life-threatening adverse reaction caused by certain medications. Clinical findings usually include rash, fever, lymphadenopathy, and eosinophilia, and in some cases, they may affect major organs. This reaction caused by antituberculosis (TB) medication poses a public health risk due to treatment discontinuation, adherence, or success in cure. We present a 23-year-old female patient who developed DRESS syndrome as a result of group A anti-TB drugs (ATDs), an exceedingly rare occurrence. The patient's medication was successfully retrieved using a re-desensitization protocol.

Frequencies of HLA-B alleles in Indonesian Malay Ethnic

Background

The HLA-B alleles have been used as a marker to predict drug-induced adverse reactions and as a major contributor to hypersensitivity reactions. We examined the feasibility of HLA-B alleles as pharmacogenomic markers of drug-induced hypersensitivity in an Indonesian Malay Ethnic.

Methods

Fifty-eight Indonesian individuals of Malay ethnicity were enrolled in this study. HLA-B alleles were determined using reverse sequence-specific oligonucleotide probe coupled with xMAP technology.

Results

HLA-B*15:02 (15.52%), HLA-B*35:05 (9.48%), and HLA-B*07:05 (7.76%) were frequent alleles in the Indonesian Malay ethnic populations. We discovered at least eight pharmacogenomics markers of drug-induced hypersensitivity: HLA-B*15:02, HLA-B*15:21, HLA-B*13:01, HLA-B*35:05, HLA-B*38:02, HLA-B*51:01, HLA-B*57:01, and HLA-B*58:01. HLA-B*15:02 was in the same serotype group with HLA-B*15:21, which is a B-75 serotype associated with genetic predisposition for carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis. The Indonesian population, represented by Malay, Javanese, and Sundanese ethnicities, was similar to South East Asian, Han Chinese, and Taiwanese populations based on HLA-B*15:02 frequency as the most common allele found in Malay ethnics.

Conclusion

We provided valuable information on the frequency of drug hypersensitivity-associated HLA-B alleles in Indonesian Malay ethnic population, which can improve treatment safety.

Race, ethnicity, ancestry, and aspects that impact HLA data and matching for transplant

Race, ethnicity, and ancestry are terms that are often misinterpreted and/or used interchangeably. There is lack of consensus in the scientific literature on the definition of these terms and insufficient guidelines on the proper classification, collection, and application of this data in the scientific community. However, defining groups for human populations is crucial for multiple healthcare applications and clinical research. Some examples impacted by population classification include HLA matching for stem-cell or solid organ transplant, identifying disease associations and/or adverse drug reactions, defining social determinants of health, understanding diverse representation in research studies, and identifying potential biases. This article describes aspects of race, ethnicity and ancestry information that impact the stem-cell or solid organ transplantation field with particular focus on HLA data collected from donors and recipients by donor registries or transplant centers.

Development of an ARMS multiplex real-time PCR assay for the detection of HLA-B*13:01 genotype by detecting highly specific SNPs

OBJECTIVES

HLA-B*13:01 was strongly associated with Dapsone Hypersensitivity Syndrome (DHS). This study aimed to develop and validate a rapid and economical method for HLA-B*13:01 genotyping.

METHODS

Two tubes multiplex real-time PCR detection system comprising amplification refractory mutation system primers and TaqMan probes was established for HLA-B*13:01 genotyping. Sequence-based typing was applied to validate the accuracy of the assay.

RESULTS

The accuracy of the assay was 100% for HLA-B*13:01 genotyping. The detection limit of the new method was 0.025 ng DNA. The positive rate of HLA-B*13:01 in the Bouyei (20%, n = 50) populations was significantly higher than that in the Uighur population (4%, n = 100), Han (4.5%, n = 200), and Tibetan (1%, n = 100) ( P  < 0.05).

CONCLUSION

The proposed method is rapid and reliable for HLA-B*13:01 screening in a clinical setting.

Quality indicators for epilepsy management in China: The development of a tool to assess care and first three-year report

OBJECTIVES

Epilepsy care in China has expanded considerably in the last decade but still remains largely unknown; we developed an easy-to-use tool to assess its quality.

METHODS

We adapted the Epilepsy Update Quality Measurement, produced by the American Academy of Neurology (AAN) for use in China: The Quality Indicator for Epilepsy Treatment-China National Action (QUIET-CHINA). This tool incorporates a standardized case report form initially for logging quality indicators for people with epilepsy during in-patient stays. Nine quality indicators covered seizures, drugs, diagnostics, screening for co-morbid conditions, counseling for woman of child bearing age, and a composite indicator was further proposed by total number of interventions performed divided by the total number of people eligible in each indicator. The tool also has an electronic reporting and data feedback system. 96 epilepsy centers in 31 jurisdictions in mainland China have been piloted since 2017.

RESULTS

Data from 11,600 individuals with epilepsy in the first 3-year study period were analyzed. The median age was 31; 60% were male. The composite indicators were 74%. Seizure freedom rate was less than 25% in all epilepsy types and post-surgical seizure freedom rate was 21%. 90% had seizure type and frequency, antiepileptic drugs recorded, while only 70% with active epilepsy were on regular antiepileptic drugs treatment. Investigations for diagnosis and etiology were performed in around 90% but screening for co-morbid conditions and counseling for women of childbearing potential was 38% and 15% respectively. Severe side effect happened in 2% individuals during the treatment.

CONCLUSION

The preliminary results of the national action provided some baseline information. Except for an overall improvement, a significant treatment gap still exists, and psychiatric co-morbidities or issues affecting women are not seen as a priority. QUIET-CHINA will be expanded to more and other levels of hospitals, to help narrow the treatment gap and equalize the comprehensive epilepsy care on the national level.

Role of Perampanel in the Management of Pediatric Epilepsies in Asia: Expert Opinion

Management of pediatric epilepsies poses unique challenges around diagnosis, treatment options, comorbidities, and the potential for these factors to interact with processes in the developing brain. In pediatric patients, broad-spectrum antiseizure medications (ASMs) with minimal potential for adverse events (AEs) and limited impact on cognition and behavior are preferred. Perampanel is a first-in-class ASM with broad-spectrum efficacy, a tolerable safety profile, minimal negative impact on cognitive function, and other features that make it a viable treatment option in this patient population. However, evidence and experience of its use in pediatric patients are less extensive than in adult patients. Experts in pediatric epilepsy across the region convened at a series of meetings to discuss the use of perampanel in pediatric patients, including dose optimization, AE prevention and management, and considerations in particular groups. This article summarizes key evidence for perampanel in the pediatric population and consolidates the experts' recommendations for using the ASM in managing pediatric epilepsies.

Mining local exome and HLA data to characterize pharmacogenetic variants in Saudi Arabia

Pharmacogenomics (PGx) is a promising field of precision medicine where efficacy of drugs is maximized while side effects are minimized for individual patients. Knowledge of the frequency of PGx-relevant variants (pharmacovariants) in the local population is a pre-requisite to informed policy making. Unfortunately, such knowledge is largely lacking from the Middle East. Here, we describe the use of a large clinical exome database (n = 13,473) and HLA haplotypes (n = 64,737) from Saudi Arabia, one of the largest countries in the Middle East, along with previously published data from the local population to ascertain allele frequencies of known pharmacovariants. In addition, we queried another exome database (n = 816) of well-phenotyped research subjects from Saudi Arabia to discover novel candidate variants in known PGx genes (pharmacogenes). Although our results show that only 26% (63/242) of class 1A/1B PharmGKB variants were identified, we estimate that 99.57% of the local population have at least one such variant. This translates to a minimum estimated impact of 9% of medications dispensed by our medical center annually. We also highlight the contribution of rare variants where 71% of the pharmacogenes devoid of common pharmacovariants had at least one potentially deleterious rare variant. Thus, we show that approaches that go beyond the use of commercial PGx kits that have been optimized for other populations should be implemented to ensure universal and equitable access of all members of the local population to personalized prescription practices.

A blinded in vitro analysis of the intrinsic immunogenicity of hepatotoxic drugs: implications for preclinical risk assessment

In vitro preclinical drug-induced liver injury (DILI) risk assessment relies largely on the use of hepatocytes to measure drug-specific changes in cell function or viability. Unfortunately, this does not provide indications toward the immunogenicity of drugs and/or the likelihood of idiosyncratic reactions in the clinic. This is because the molecular initiating event in immune DILI is an interaction of the drug-derived antigen with MHC proteins and the T-cell receptor. This study utilized immune cells from drug-naïve donors, recently established immune cell coculture systems and blinded compounds with and without DILI liabilities to determine whether these new methods offer an improvement over established assessment methods for the prediction of immune-mediated DILI. Ten blinded test compounds (6 with known DILI liabilities; 4 with lower DILI liabilities) and 5 training compounds, with known T-cell-mediated immune reactions in patients, were investigated. Naïve T-cells were activated with 4/5 of the training compounds (nitroso sulfamethoxazole, vancomycin, Bandrowski's base, and carbamazepine) and clones derived from the priming assays were activated with drug in a dose-dependent manner. The test compounds with DILI liabilities did not stimulate T-cell proliferative responses during dendritic cell-T-cell coculture; however, CD4+ clones displaying reactivity were detected toward 2 compounds (ciprofloxacin and erythromycin) with known liabilities. Drug-responsive T-cells were not detected with the compounds with lower DILI liabilities. This study provides compelling evidence that assessment of intrinsic drug immunogenicity, although complex, can provide valuable information regarding immune liabilities of some compounds prior to clinical studies or when immune reactions are observed in patients.

Seventy-five years of service: an overview of the College of American Pathologists' proficiency testing program in histocompatibility and identity testing

The Histocompatibility and Identity Testing Committee offers an overview of the College of American Pathologists' (CAP) Proficiency Testing (PT) program, commemorating its significant 75th anniversary in 2024. The CAP PT program has undergone significant growth and evolution over the years, ultimately achieving Centers for Medicare and Medicaid Services approval. In 1979, CAP's partnership with the American Association for Clinical Histocompatibility Testing marked a pivotal moment, leading to the creation of the first proficiency testing survey in 1980. This laid the foundation for various PT programs managed by the CAP Histocompatibility and Identity Testing Committee, including HLA antibody testing, HLA molecular typing, engraftment monitoring, parentage/relationship testing, HLA disease associations and drug risk, and HLA-B27 typing. Each program's distinctive considerations, grading methodologies, and future prospects are detailed here, highlighting the continual evolution of histocompatibility and identity testing PT to support emerging technologies and evolving laboratory practices in the field.

Ocular Manifestations and Outcomes in Children With Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A Comparison With Adult Patients

PURPOSE

To compare the clinical features and visual outcomes in children and adults with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

DESIGN

Retrospective comparative case series.

METHODS

This retrospective study included 280 eyes of 140 patients (35 children and 105 adults) with SJS/TEN treated between 2010 and 2020. The primary outcome measures were the final best-corrected visual acuity (BCVA) and severity of dry eye. The secondary outcome measure was the medical and surgical therapies used.

RESULTS

Among 64 eyes of children recruited in the study, acute ocular involvement was found in 58 eyes (90.6%). The chronic score in pediatric patients was significantly higher than that in adult patients (P = .004). The use of antibiotics/nonsteroidal anti-inflammatory drugs (NSAIDs) and Mycoplasma infection were the more common etiologies in children. In all, 75% of eyes in children maintained a visual acuity of 20/40 or better at a mean follow-up time of 4.3 years. The severity of dryness was comparable between the child and adult groups. The proportion of eyes undergoing amniotic membrane and oral mucosa transplantation was significantly higher in children than in adults in the chronic stage, reflecting that children exhibit much more severe complications.

CONCLUSIONS

Although pediatric SJS/TEN patients have more severe ocular complications than adults, most children maintain long-term good vision. Early intervention and aggressive treatment help to preserve vision.

Impact of Pharmacogenomics in Clinical Practice

Polymorphisms of genes encoding drug metabolizing enzymes and transporters can significantly modify pharmacokinetics, and this can be associated with significant differences in drug efficacy, safety, and tolerability. Moreover, genetic variants of some components of the immune system can explain clinically relevant drug-related adverse events. However, the implementation of drug dose individualization based on pharmacogenomics remains scarce. In this narrative review, the impact of genetic variations on the disposition, safety, and tolerability of the most commonly prescribed drugs is reported. Moreover, reasons for poor implementation of pharmacogenomics in everyday clinical settings are discussed. The literature analysis showed that knowledge of how genetic variations can modify the effectiveness, safety, and tolerability of a drug can lead to the adjustment of usually recommended drug dosages, improve effectiveness, and reduce drug-related adverse events. Despite some efforts to introduce pharmacogenomics in clinical practice, presently very few centers routinely use genetic tests as a guide for drug prescription. The education of health care professionals seems critical to keep pace with the rapidly evolving field of pharmacogenomics. Moreover, multimodal algorithms that incorporate both clinical and genetic factors in drug prescribing could significantly help in this regard. Obviously, further studies which definitively establish which genetic variations play a role in conditioning drug effectiveness and safety are needed. Many problems must be solved, but the advantages for human health fully justify all the efforts.

HLA-targeted sequencing reveals the pathogenic role of HLA-B*15:02/HLA-B*13:01 in albendazole-induced liver failure: a case report and a review of the literature

Drug-induced liver injury (DILI) is one of the serious adverse drug reactions (ADRs), which belongs to immune-mediated adverse drug reactions (IM-ADRs). As an essential health drug, albendazole has rarely been reported to cause serious liver damage. A young man in his 30 s developed severe jaundice, abnormal transaminases, and poor blood coagulation mechanism after taking albendazole, and eventually developed into severe liver failure. The patient was found heterozygous of HLA-B*15:02 and HLA-B*13:01 through HLA-targeted sequencing, which may have a pathogenic role in the disease. This case report summarizes his presentation, treatment, and prognosis. A useful summary of the diagnosis and associated genetic variant information is provided.

Integrating real-world data in cost-effectiveness analysis of universal HLA-B*15:02 screening in Malaysia

AIMS

Despite the availability of newer antiseizure medications, carbamazepine (CBZ) remains the gold standard. However, patients of Asian ancestry are susceptible to CBZ-related severe cutaneous adverse reactions. Universal HLA-B*15:02 screening is a promising intervention to address this. With the increasing recognition of integrating real-world evidence in economic evaluations, the cost-effectiveness of universal HLA-B*15:02 screening was assessed using available real-world data in Malaysia.

METHODS

A hybrid model of a decision tree and Markov model was developed to evaluate 3 strategies for treating newly diagnosed epilepsy among adults: (i) CBZ initiation without HLA-B*15:02 screening (current practice); (ii) universal HLA-B*15:02 screening prior to CBZ initiation; and (iii) alternative prescribing without HLA-B*15:02 screening. The model was populated with real-world inputs derived from the Malaysian population. From a societal perspective, base-case analysis and sensitivity analyses estimated the costs and outcomes over a lifetime. Incremental cost-effectiveness ratios were calculated.

RESULTS

In the base-cases analysis, universal HLA-B*15:02 screening yielded the lowest total costs and the highest total quality-adjusted life years (QALYs) gained. Compared with current practice, universal screening was less costly by USD100 and more effective by QALYs increase of 0.1306, while alternative prescribing resulted in 0.1383 QALYs loss at additional costs of USD332. The highest seizure remission rate (56%) was estimated for universal HLA-B*15:02 screening vs. current practice (54%) and alternative prescribing (48%).

CONCLUSION

Our study suggests that universal HLA-B*15:02 screening is a cost-effective intervention in Malaysia. With the demonstrated value of real-world evidence in economic evaluations, more relevant standardization efforts should be emphasized to better inform decision-making.

Lifetime risk, life expectancy, loss-of-life expectancy and lifetime healthcare expenditure for Stevens-Johnson syndrome/toxic epidermal necrolysis in Taiwan: follow-up of a nationwide cohort from 2008 to 2019

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) not only cause acute, devastating mucocutaneous reactions but also have long-lasting implications on survivors' lives.

OBJECTIVES

To quantify the lifetime burden of SJS/TEN.

METHODS

The cumulative incidence rate (CIR), life expectancy (LE), loss-of-life expectancy (LoLE) and lifetime healthcare expenditure (HE) for SJS/TEN were estimated over the period from 2008 to 2019 using data from the National Health Insurance Research Database of Taiwan and life tables of vital statistics.

RESULTS

In this nationwide cohort of 6552 incident SJS/TEN cases, a trend towards a decrease in the CIR was observed between 2008 and 2019. Compared with the general population, patients with SJS/TEN experience a tremendous loss of 9.43 (1.06) [mean (SEM)] years of LE after diagnosis of SJS/TEN. Male patients with SJS/TEN had higher LoLE [10.74 (1.22) vs. 7.69 (1.43) years] and annual HE than females. Younger age at diagnosis of SJS/TEN was associated with longer LE but greater LoLE and higher lifetime HE. Patients with intensive care unit admission on diagnosis, malignancy, diabetes mellitus, end-stage renal disease and SJS/TEN-associated sequelae experienced substantially greater LoLE and HE per life year.

CONCLUSIONS

Patients with SJS/TEN suffer substantial loss-of-LE and HE, particularly young patients, compared with the general population. These data provide a reference estimate of the lifetime burden of SJS/TEN to help health authorities evaluate the cost-effectiveness of future preventive and treatment strategies to minimize the burden of SJS/TEN.

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.

Carbamazepine-Induced Severe Cutaneous Adverse Drug Reactions: A 21-Year Comparison Between Children and Adults in Malaysia

Severe cutaneous adverse drug reactions (SCARs) are a life-threatening condition. We aimed to identify all carbamazepine-induced SCARs voluntarily reported to the Malaysian pharmacovigilance database and to compare between children and adults. Adverse drug reaction reports for carbamazepine were extracted from 2000 to 2020, and divided into 2 groups, that is, children (aged 0-17 years) and adults (aged 18 years and above). Age, sex, race, and carbamazepine dose were analyzed using multiple logistic regression. Of 1102 carbamazepine adverse drug reaction reports, 416 reports were SCARs (99 children, 317 adults). Stevens-Johnson syndrome and toxic epidermal necrolysis were the main SCAR types for both age groups. Median time-to-onset for any type of SCAR was 13 days, regardless of age. In children, Malay individuals were 3.6 times more likely to report SCARs (95% confidence interval, 1.356-9.546; P = .010) compared to the Chinese population. In adults, carbamazepine-induced SCARs were reported as 3.6 times higher in those with a daily dose of 200 mg or less as compared to a daily dose of 400 mg or more. (95% confidence interval, 2.257-5.758; P < .001) Carbamazepine-induced SCARs reported in Malaysia were predominantly Stevens-Johnson syndrome or toxic epidermal necrolysis, with the majority in Malay individuals. Initiation therapy needs close monitoring between 2 weeks and 1 month.

How to assess pharmacogenomic tests for implementation in the NHS in England

AIMS

Pharmacogenomic testing has the potential to target medicines more effectively towards those who will benefit and avoid use in individuals at risk of harm. Health economies are actively considering how pharmacogenomic tests can be integrated into health care systems to improve use of medicines. However, one of the barriers to effective implementation is evaluation of the evidence including clinical usefulness, cost-effectiveness, and operational requirements. We sought to develop a framework that could aid the implementation of pharmacogenomic testing. We take the view from the National Health Service (NHS) in England.

METHODS

We used a literature review using EMBASE and Medline databases to identify prospective studies of pharmacogenomic testing, focusing on clinical outcomes and implementation of pharmacogenomics. Using this search, we identified key themes relating to the implementation of pharmacogenomic tests. We used a clinical advisory group with expertise in pharmacology, pharmacogenomics, formulary evaluation, and policy implementation to review data from our literature review and the interpretation of these data. With the clinical advisory group, we prioritized themes and developed a framework to evaluate proposals to implement pharmacogenomics tests.

RESULTS

Themes that emerged from review of the literature and subsequent discussion were distilled into a 10-point checklist that is proposed as a tool to aid evidence-based implementation of pharmacogenomic testing into routine clinical care within the NHS.

CONCLUSION

Our 10-point checklist outlines a standardized approach that could be used to evaluate proposals to implement pharmacogenomic tests. We propose a national approach, taking the view of the NHS in England. Using this approach could centralize commissioning of appropriate pharmacogenomic tests, reduce inequity and duplication using regional approaches, and provide a robust and evidence-based framework for adoption. Such an approach could also be applied to other health systems.

An association study of HLA with levofloxacin-induced severe cutaneous adverse drug reactions in Han Chinese

Levofloxacin-induced severe cutaneous adverse drug reactions (LEV-SCARs) remain unexplored. An association study of human leukocyte antigen (HLA) alleles with LEV-SCARs among 12 patients, 806 healthy subjects, and 100 levofloxacin-tolerant individuals was performed. The carrier frequencies of HLA-B∗13:01 (odds ratio [OR]: 4.50; 95% confidence interval [CI]: 1.15-17.65; p = 0.043), HLA-B∗13:02 (OR: 6.14; 95% CI: 1.73-21.76; p = 0.0072), and serotype B13 (OR: 17.73; 95% CI: 3.61-86.95; p = 4.85 × 10-5) in patients with LEV-SCARs were significantly higher than those of levofloxacin-tolerant individuals. Molecular docking analysis suggested that levofloxacin formed more stable binding models with HLA-B∗13:01 and HLA-B∗13:02 than with non-risk HLA-B∗46:01. Mass spectrometry revealed that nonapeptides bound to HLA-B∗13:02 shifted at several positions after exposure to levofloxacin. Prospective screening for serotype B13 (sensitivity: 83%, specificity: 78%) and alternative drug treatment for carriers may significantly decrease the incidence of LEV-SCARs.

Tools for Etiologic Diagnosis of Drug-Induced Allergic Conditions

Drug hypersensitivity reactions are a serious concern in clinical practice because they can be severe and result in lifelong sequelae. An accurate diagnosis and identification of the culprit drug is essential to prevent future reactions as well as for the identification of safe treatment alternatives. Nonetheless, the diagnosis can be challenging. In vivo and in vitro tests can be helpful, although none are conclusive; therefore, the tests are not usually performed in isolation but as part of a diagnostic algorithm. In addition, some in vitro tests are only available in research laboratories, and standardization has not been fully accomplished. Collaborating research is needed to improve drug hypersensitivity reaction diagnosis. In this review, we update the current available in vivo and in vitro tools with their pros and cons and propose an algorithm to integrate them into clinical practice.

The pharmacogenomics of carbamazepine-induced cutaneous adverse drug reaction in the South of Vietnam

Background: The relationship between HLA-B*15:02 and Severe Cutaneous Adverse Reactions was rigorously examined in Japanese, Han Chinese, Thais, and Caucasians. However, the number of studies about this topic in Vietnamese population is still limited and mostly focuses on the North of Vietnam. Objective: This study aims to clarify the genetic culprit of SCARs in Vietnamese population, particularly in the South of Vietnam, and to validate our result by a meta-analysis about this topic in Vietnamese. Method: A retrospective case-control study with 37 patients treated with carbamazepine monotherapy. Statistical calculation and meta-analysis were performed by R software. Result: HLA-B*15:02 increases the risk of SJS 12.5 times higher in CBZ-treated patients (p-value = 0.017). However, this allele has no impact on MCARs (Mild Cutaneous Adverse Reactions) of CBZ. The number needed to test and the number needed to genotype is two and nine patients respectively. Conclusion: This study recommends more investigations about the cost-effectiveness of this test to accelerate the protection of Southern Vietnamese from SCARs.

Ethnicity, Race and Skin Color: Challenges and Opportunities for Atopic Dermatitis Clinical Trials

The number of clinical trials conducted in patients with atopic dermatitis is increasing steadily. These trials are conducted in several countries across all continents and include patients of different ethnicity, race and skin color. This diversity is desired, but it also brings challenges, including the diagnosis and evaluation of disease severity in patients with different skin colors; the influence of ethnicity on the perception of quality of life and patient reported outcomes; the inclusion of ethnicities that are only present in one country or that live far from clinical research sites; and the reporting of drug safety information. There is a need to better train physicians on the evaluation of atopic dermatitis in patients with different skin colors and a need to improve the systematic reporting of ethnicity, race and skin color in clinical trial publications.

Black-Box Warnings of Antiseizure Medications: What is Inside the Box?

Antiseizure medications can cause serious adverse reactions and have deleterious drug interactions that often complicate the clinical management of patients. When the US Food and Drug Administration (FDA) wants to alert healthcare providers and patients about the risk of potentially serious or fatal drug reactions, the FDA requires the manufacturers of these medications to format these warnings within a "black-box" border, and prominently display this box on the first section of the package insert; such warnings are called "black-box warnings (BBWs)". The BBW is a way for the FDA to urge physicians to evaluate patients more rigorously and carefully weigh the risks and benefits, before prescribing medication that has the potential to cause serious adverse reactions, and to formulate a plan for close monitoring during therapy. The FDA BBW provides the extra layer of safety but many healthcare providers fail to comply with these warnings. Currently, there are 26 FDA-approved antiseizure medications in the US market, 38% of which have received BBWs, and most of the antiseizure medications with BBWs are older-generation drugs. Some antiseizure medications have multiple BBWs; for example, valproic acid has three BBWs including hepatotoxicity, fetal risk, and pancreatitis, carbamazepine has BBWs of serious skin and hematological reactions, and felbamate also has two BBWs including hepatic failure and aplastic anemia. The purpose of this review is to provide insight into each BBW received by antiseizure medications and discuss the FDA recommendations for evaluating the drug benefit/risk, and for monitoring parameters before the initiation of and during treatment.

Awareness of HLA-B* 15:02 screening in trigeminal neuralgia and the gene screening policy among dentists in Southern Thailand

OBJECTIVES

To determine the factors associated with public hospital dentists' awareness of HLA-B*15:02 screening in trigeminal neuralgia (TN) and the national gene screening policy in Thailand.

METHODS

Cross-sectional study. A validated questionnaire was distributed to public hospital dentists with at least 1 year of practice in Southern Thailand (n = 760) to assess their knowledge of TN, carbamazepine (CBZ) use, awareness of HLA-B*15:02 screening, and the gene screening policy.

RESULTS

A total of 385 dentists participated (50.7% response rate); 81.3% of respondents were aware of HLA-B*15:02 screening. However, 18.7% of dentists were not aware of the importance of gene testing. Furthermore, dentists who were aware of gene screening had significantly better knowledge of TN diagnosis and CBZ use than "unaware" dentists. Awareness of HLA-B*15:02 screening was also significantly associated with dental specialty. Moreover, 80.5% of respondents were not aware of the gene screening policy. The primary problems related to the policy were its inefficient publication, poor implementation, and lack of clinical practice guidelines (CPGs) to encourage dentists to follow the policy and prescribe gene tests.

CONCLUSION

While most hospital dentists were aware of the necessity of HLA-B*15:02 screening prior to prescribing CBZ in TN, the majority were unaware of the national gene screening policy. Dental specialty and knowledge were associated with awareness of HLA-B*15:02 screening.

Avoidance of cutaneous adverse drug reactions induced by antiepileptic drugs based on pharmacogenomics

Pharmacogenomics (PGx) is a research area aimed at identifying genetic factors that are associated with drug responses, including drug efficacy, adverse drug reactions, and the appropriate drug dosage on a case-to-case basis. To promote the clinical implementation of PGx testing, which is currently of limited use in clinical practice, recent research has focused on providing reliable evidence for its clinical utility. In neurology, psychiatry, and neurosurgery, several human leukocyte antigen (HLA) alleles have been reportedly associated with cutaneous adverse drug reactions (cADRs) induced by antiepileptic drugs, which significantly carry the risk of developing cADRs. Prior to using antiepileptic drugs such as carbamazepine and lamotrigine, which are prone to cause severe cADRs, preemptive HLA genetic testing and therapeutic interventions such as drug selection and dosage adjustment based on the results of the tests can reduce the incidence of cADRs in the population before the initiation of treatment.

A comparison of international treatment guidelines for Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are rare and life-threatening mucocutaneous diseases that occur almost exclusively as a result of adverse drug reactions, although there are rare cases attributed to infection, immunization, or malignancy.^1,2 Given the low incidence of these diseases as well as the high level of morbidity and mortality, randomized controlled clinical trials are difficult to perform, making it difficult to establish a "gold-standard" treatment. To date, there are only five published articles in the literature detailing evidence-based guidelines for the treatment of SJS and TEN, one of which is specifically tailored to pediatric and young adult patients.^3-7 These guidelines have significant overlap in regards to the importance of prompt discontinuation of the offending drug and the need for supportive care, but there are differences in regards to the ideal supportive care measures. Additionally, there is still no clear consensus agreement on the pharmacological treatment of SJS and TEN.^4-7 Herein, we aim to compare the international treatment guidelines for management of SJS and TEN as well as promote continued discussion and a multidisciplinary approach to establish consensus recommendations for these mucocutaneous emergencies.

A simple PCR-SSP method for detection of HLA-B*15:02, *15:13, and *15:21

Objectives

This study aims to develop a simple polymerase chain reaction (PCR) sequence-specific primer method, which will be used to genotype HLA-B*15:02, HLA-B*15:13, and HLA-B*15:21.

Methods

DNA was extracted from whole blood using a commercial DNA extraction kit. New specific primers were designed. The PCR was optimized for reproducibility and specificity. Parameters investigated included concentrations of MgCl2, primers concentration, and annealing temperature, to produce specific bands of interest. Known DNA samples were selected at random and tested using the PCR method.

Results

Simultaneously six duplex PCRs were successfully optimized using 1.0 mM MgCl2 and an annealing temperature of 62 °C. The method was also reproducible and specific. The results from the method showed 100% concordance with known DNA samples.

Conclusions

This study has successfully developed a simple and specific method to simultaneously genotype HLA-B*15:02, HLA-B*15:13, and HLA-B*15:21 using in-house developed PCR-SSP.

Using human genetics to improve safety assessment of therapeutics

Human genetics research has discovered thousands of proteins associated with complex and rare diseases. Genome-wide association studies (GWAS) and studies of Mendelian disease have resulted in an increased understanding of the role of gene function and regulation in human conditions. Although the application of human genetics has been explored primarily as a method to identify potential drug targets and support their relevance to disease in humans, there is increasing interest in using genetic data to identify potential safety liabilities of modulating a given target. Human genetic variants can be used as a model to anticipate the effect of lifelong modulation of therapeutic targets and identify the potential risk for on-target adverse events. This approach is particularly useful for non-clinical safety evaluation of novel therapeutics that lack pharmacologically relevant animal models and can contribute to the intrinsic safety profile of a drug target. This Review illustrates applications of human genetics to safety studies during drug discovery and development, including assessing the potential for on- and off-target associated adverse events, carcinogenicity risk assessment, and guiding translational safety study designs and monitoring strategies. A summary of available human genetic resources and recommended best practices is provided. The challenges and future perspectives of translating human genetic information to identify risks for potential drug effects in preclinical and clinical development are discussed.