Delayed hypersensitivity to antiepileptic drugs in children

Pharmacogenomics predictors of aromatic antiepileptic drugs-induced SCARs in the Iraqi patients

Introduction

Severe cutaneous adverse reactions (SCARs) are life-threatening and often linked to antiepileptic drugs (AEDs). Common types of SCARs include Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS). Immune-mediated mechanisms involving human leukocyte antigen (HLA) alleles have been implicated in the pathogenesis of this reaction. This study examines the association between specific HLA alleles (HLA-A, -B, and -DRB1) and AED-induced SCARs in the Iraqi population.

Methodology

A total of 50 patients diagnosed with SCARs and 90 tolerant controls were recruited from Dr. Saad Al-Wattari Hospital for Neurological Sciences and Baghdad Hospital - Medical City. HLA genotyping was performed using PCR-SSO method from peripheral blood samples. Statistical comparisons were made using the t-test or chi-square test, while univariate logistic regression with Bonferroni's correction (p < 0.05) were used to assess associations between HLA alleles and SCARs.

Results

Among the patients, SJS was the most prevalent type of SCARs observed. Analysis of HLA allele frequencies revealed significant associations between specific alleles. HLA-A∗02:01 was found to be significantly associated with a lower risk of AED-induced SJS (OR = 0.36; 95 % CI: 0.13-0.97), while HLA-A∗24:02 and HLA-B∗15:02 were associated with an increased risk of AED-induced SJS (OR = 3.60; 95 % CI: 1.21-10.72 and OR = 4.41; 95 % CI: 1.18-16.47, respectively). For AED-induced TEN, HLA-A∗01:02, HLA-B∗15:02, and HLA-B∗52:01 showed significant associations (OR = 6.92; 95 % CI: 1.39-34.37 and OR = 6.55; 95 % CI: 1.62-26.52, respectively), with HLA-DRB1∗03:01 being highly significant (OR = 5.09; 95 % CI: 1.72-15.00). Additionally, HLA-B∗40:02 was strongly associated with AED-induced DRESS (OR = 29.33; 95 % CI: 3.50-245.32).

Conclusion

This study identifies key HLA alleles associated with AED-induced SCARs in the Iraqi population. These findings could facilitate personalized medicine approaches, aiding in better prediction and prevention of SCARs in AED therapy.

Clinical observation and analysis of rash caused by lacosamide in children with epilepsy

PURPOSE

To draw clinical attention to rashes caused by lacosamide.

METHODS

This retrospective analysis included patients admitted to the Department of Pediatrics, Second Affiliated Hospital of Xi'an Jiaotong University between January 2021 and September 2023. We focused on patients who developed rashes after lacosamide treatment and analyzed all patients who exhibited rashes after lacosamide treatment to analyze the risk factors.

RESULTS

In total, 190 patients received lacosamide, of whom four developed allergies (2.1 %). Three patients had severe rashes, and two patients had high fever. All of these adverse events improved after the withdrawal of lacosamide. Of the 13 patients reported to date, including the four patients in this study, eight used various antiseizure medicines, including seven patients who used four or more antiseizure medicines. Four patients underwent testing for HLA-B*1502, and two patients were positive. Patients developed rashes within 1-10 days after treatment initiation, and the duration of the rash ranged 2-37 days.

CONCLUSIONS

Lacosamide-induced rash was detected in 2.1 % of patients in our cohort. Rashes are potentially serious, and prompt evaluation is required. Rashes are more likely to occur when multiple antiseizure medicines are used simultaneously, typically within 10 days of treatment initiation.

EAACI/ENDA position paper on drug provocation testing

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

Drug hypersensitivity, in vitro tools, biomarkers, and burden with COVID-19 vaccines

Hypersensitivity reactions to drugs are increasing worldwide. They display a large degree of variability in the immunological mechanisms involved, which impacts both disease severity and the optimal diagnostic procedure. Therefore, drug hypersensitivity diagnosis relies on both in vitro and in vivo assessments, although most of the methods are not well standardized. Moreover, several biomarkers can be used as valuable parameters for precision medicine that provide information on the endotypes, diagnosis, prognosis, and prediction of drug hypersensitivity development, as well on the identification of therapeutic targets and treatment efficacy monitoring. Furthermore, in the last 2 years, the SARS-CoV-2 (severe acute respiratory syndrome-coronavirus) pandemic has had an important impact on health system, leading us to update approaches on how to manage hypersensitivity reactions to drugs used for its treatment and on COVID-19 (Coronavirus disease) vaccines used for its prevention. This article reviews recent advances in these 3 areas regarding drug hypersensitivity: in vitro tools for drug hypersensitivity diagnosis, recently identified biomarkers that could guide clinical decision making and management of hypersensitivity reactions to drugs and vaccines used for COVID-19.

Antibiotic Allergy De-Labeling: A Pathway against Antibiotic Resistance

Antibiotics are one of the most frequently prescribed drugs. Unfortunately, they also are the most common cause for self-reported drug allergy, limiting the use of effective therapies. However, evidence shows that more than 90% of patients labeled as allergic to antibiotics are not allergic. Importantly, the label of antibiotic allergy, whether real or not, constitutes a major public health problem as it directly impacts antimicrobial stewardship: it has been associated with broad-spectrum antibiotic use, often resulting in the emergence of bacterial resistance. Therefore, an accurate diagnosis is crucial for de-labeling patients who claim to be allergic but are not really allergic. This review presents allergy methods for achieving successful antibiotic allergy de-labeling. Patient clinical history is often inaccurately reported, thus not being able to de-label most patients. In vitro testing offers a complementary approach but it shows limitations. Immunoassay for quantifying specific IgE is the most used one, although it gives low sensitivity and is limited to few betalactams. Basophil activation test is not validated and not available in all centers. Therefore, true de-labeling still relies on in vivo tests including drug provocation and/or skin tests, which are not risk-exempt and require specialized healthcare professionals for results interpretation and patient management. Moreover, differences on the pattern of antibiotic consumption cause differences in the diagnostic approach among different countries. A multidisciplinary approach is recommended to reduce the risks associated with the reported penicillin allergy label.

Exanthematous reactions to drugs in children

PURPOSE OF REVIEW

The true exanthematous reactions to drugs in children are rare and overdiagnosed. Drugs may cause exanthema either due to inducing an immune response or because of their interaction with viruses, if drugs are taken in the course of a viral infection. Also, viral infections are very often in children and they can provoke an exanthema which is difficult to differentiate from exanthematous reactions to drugs. Consequently, the majority of children are incorrectly labeled as 'allergic'.

RECENT FINDINGS

The correct diagnosis of exanthematous drug reactions in children is still an important and hot topic. Most information about the approach and management of drug hypersensitivity in children is applied from available guidelines and consensus statement for adults. Recently, a systematic clinical approach for timely differential diagnosis and management of rashes in children who present a cutaneous exanthema while receiving a drug, is proposed.

SUMMARY

It is important to consider the detailed clinical history of appearing and developing exanthematous drug reaction, as well as physical examination which includes the description and the distribution of exanthema and at the end making the appropriate diagnosis. Thus, it could reduce overdiagnosis and promote appropriate procedures, that will prevent the overlabeling of drug hypersensitivity in children.

Genetic Determinants in HLA and Cytochrome P450 Genes in the Risk of Aromatic Antiepileptic-Induced Severe Cutaneous Adverse Reactions

Adverse drug reaction (ADR) is a pressing health problem, and one of the main reasons for treatment failure with antiepileptic drugs. This has become apparent in the event of severe cutaneous adverse reactions (SCARs), which can be life-threatening. In this review, four hypotheses were identified to describe how the immune system is triggered in the development of SCARs, which predominantly involve the human leukocyte antigen (HLA) proteins. Several genetic variations in HLA genes have been shown to be strongly associated with the susceptibility to developing SCARs when prescribed carbamazepine or phenytoin. These genetic variations were also shown to be prevalent in certain populations. Apart from the HLA genes, other genes proposed to affect the risk of SCARs are genes encoding for CYP450 drug-metabolising enzymes, which are involved in the pharmacokinetics of offending drugs. Genetic variants in CYP2C9 and CYPC19 enzymes were also suggested to modulate the risk of SCARs in some populations. This review summarizes the literature on the manifestation and aetiology of antiepileptic-induced SCARs, updates on pharmacogenetic markers associated with this reaction and the implementation of pre-emptive testing as a preventive strategy for SCARs.