Updates on the immunopathology and genomics of severe cutaneous adverse drug reactions

Endotypes in Immune Mediated Drug Reactions: Present and Future of Relevant Biomarkers. An EAACI Task Force Report

Drug-induced immune reactions are an important burden for patients and health systems. They can be classified into immediate-drug hypersensitivity reactions (IDHRs) and delayed-DHRs (DDHRs) based on their phenotype. Drugs do not always behave as allergens and need to bind to proteins, forming adducts. Therefore, IDHRs can be classified as antigenic (IgE, and IgG mediated) and nonantigenic immune responses (complement activation-[CARPA], mas-related G-protein coupled receptor member X2 [MRGPRX2], cyclooxygenase [COX]-1 and cytokine release reactions [CRRs]). DDHRs are even more complex due to the different cell subsets and mechanisms involved, showing both antigenic and nonantigenic immune responses too. Since different endotypes result in similar phenotypes, the establishment of specific biomarkers is essential for an accurate diagnosis, with important relevance for the management of patients, as well as for risk stratification. The biomarkers of clinical utility are skin tests, specific IgE (sIgE), tryptase, and some HLA-DR genotyping. The diagnostic performance depends on the responsible drug. This review highlights that, unfortunately, most biomarkers have not gone beyond analytic or clinical validity. It is therefore important to set up multicentre translational studies to advance the validation process towards reaching a clinical utility phase.

Targeting the Galectin-7/TRPM2/Zn2+/DRP-1 Signaling Pathway: A Potential Therapeutic Intervention in the Pathogenesis of SJS/TEN

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) represent a spectrum of severe drug-induced cutaneous reactions. These conditions are characterized by widespread and confluent keratinocyte apoptosis, which differentiates them from erythema multiforme (EM). Mounting evidence has implicated the mitochondrial-dependent apoptosis pathway in the pathogenesis of SJS/TEN, but the potential roles and specific mechanisms of these pathways in SJS/TEN remain largely unexplored.

METHODS

Proteomic analyses were conducted to investigate differential protein expression in blister fluid (BF)-derived exosomes from suction surgery in healthy individuals (Con Exo) or patients with EM (EM Exo) or SJS/TEN (TEN Exo). Further analysis involved glutathione S-transferase (GST) pull-down assay, liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis, and validation of MS results through proximity ligation assay (PLA) and coimmunoprecipitation (co-IP). Phenotypic and mechanistic analyses were performed using immunohistochemistry (IHC) staining, enzyme-linked immunosorbent assay (ELISA), western blotting, reverse transcription-polymerase chain reaction (RT-PCR), co-IP, CCK-8 assay, adenosine triphosphate (ATP) level measurements, and flow cytometry.

RESULTS

Galectin-7 was markedly upregulated in BF-derived exosomes from SJS/TEN patients and showed a correlation with disease severity. Further analysis confirmed the interaction between galectin-7 and transient receptor potential (melastatin) 2 (TRPM2). BF-derived exosomes from SJS/TEN patients induced an imbalance in mitochondrial dynamics via galectin-7/TRPM2 upregulation. Activation of TRPM2 led to an elevation in mitochondrial Zn2+, which facilitated the recruitment of the fission factor dynamin-related protein-1 (DRP-1) to mitochondria to trigger mitochondrial fission in the keratinocyte. In addition, the recruitment of DRP-1-dependent mitochondrial fission via the voltage-dependent anion channel 1 (VDAC1)/hexokinase 2 (HK2)-mediated opening of the mitochondrial permeability transition pore (mPTP)-triggered cytochrome c release. These effects ultimately induce activation of the intrinsic mitochondrial apoptotic pathway and contribute to the pathogenesis of SJS/TEN.

CONCLUSIONS

Targeting the galectin-7/TRPM2/Zn2+/DRP-1 signaling pathway in keratinocytes presents a prospective therapeutic strategy for mitigating SJS/TEN in the future.

Single-cell immunopathology of recurrent acute generalized exanthematous pustulosis associated with vancomycin

Background

Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction to medication that presents within 72 hours of exposure with erythematous papules and plaques with overlying pustules. The immunopathogenesis and predisposing factors of AGEP are not well characterized.

Objective

To better understand the genetic risk factors and single-cell immunopathogenesis of AGEP, we longitudinally characterized a patient with recurrent AGEP after an initial episode triggered by vancomycin.

Methods

A clinical timeline over an 8-year period was paired with skin testing, histopathology, and immunogenetic and other testing at 3 time points. Skin biopsies performed on affected skin (positive vancomycin-delayed intradermal testing [IDT]) and unaffected control skin 8 years after the initial event were subjected to single-cell sequencing to measure gene and protein expression.

Results

The patient was HLA-A∗32:01 positive, which has been associated with vancomycin-induced drug reaction with eosinophilia and systemic symptoms. IDT remained positive over time, despite recurrent reactions without drug exposure. Clinical features and histopathology of IDT-positive skin were consistent with AGEP. Single-cell analysis of affected skin showed polyclonal TH17-like cells with gene expression signatures similar to T-cell response during prevalent infectious diseases.

Conclusions

This patient exhibited persistent vancomycin-positive IDT despite distinct nondrug episodes of ALEP/AGEP. This suggests that AGEP may be triggered by both antigen-specific and non-antigen-specific factors. AGEP-affected skin showed an inflammatory infiltrate with a TH17-like effector population, which may represent potentially actionable targets for therapeutic intervention. The presence of HLA-A∗32:01, a defined risk factor for vancomycin-induced drug reaction with eosinophilia and systemic symptoms, may indicate a shared predisposition, warranting further study.

Diagnosing and Managing Drug Reaction With Eosinophilia and Systemic Symptoms (DRESS) Amidst Remaining Uncertainty

Drug reaction with eosinophilia and systemic symptoms (DRESS), a severe cutaneous adverse reaction, represents a diagnostic and therapeutic challenge due to its varied, evolving clinical presentation, complex pathophysiology, and potential for severe systemic involvement. This article explores DRESS syndrome through 3 illustrative cases from diverse populations and with different background comorbidities. Cases highlight different challenges in DRESS care, including (1) the need for early diagnosis and severity scoring, (2) identification of offending drugs and risk stratification to consider a possible drug challenge, and (3) best practice management including long-term monitoring for emergent autoimmunity. Recent developments in our understanding of clinical spectrum of disease, genomic and nongenomic biomarkers, severity groupings, and pharmacological and longer-term management strategies are described. Critical gaps remain in several of these domains, particularly in vulnerable groups such as the immune-compromised. In the absence of robust evidence, we aim in this article to assist attending clinicians with current expert opinion in DRESS management. Finally, we highlight areas for further research needed to improve the clinical care and outcomes of DRESS.

Association of antibiotics with Stevens-Johnson syndrome and toxic epidermal necrolysis: A real-world pharmacovigilance study

BACKGROUND

Recent reports suggest antibiotics may cause severe allergic reactions, such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), exacerbating concerns about antibiotic safety.

OBJECTIVE

Given the limited real-world evidence, this study aims to analyse the FDA Adverse Event Reporting System to investigate the association between various antibiotics and SJS/TEN risk.

METHODS

Reports from infected patients (Q1 2014-Q4 2023) were extracted from the FDA Adverse Event Reporting System. Disproportionality analysis using information component identified risk signals of antibiotics associated with SJS/TEN. Subgroup analyses investigated the impact of age and gender on antibiotic-associated SJS/TEN. Also, a time of onset analysis was performed.

RESULTS

Among 78 593 infected patients, 1221 cases of SJS/TEN were identified from 30 369 antibiotic administrations. The median age of patients with SJS was 63 y, and with TEN was 60 y. Eleven positive signal drugs were detected through disproportionality analysis. Amoxicillin, piperacillin, ceftriaxone, cefuroxime, cefotaxime, azithromycin, sulfamethoxazole, trimethoprim, vancomycin, doxycycline, and gentamicin exhibited significant risk associations with SJS/TEN. Sulfamethoxazole had the highest risk. Patients with pneumonia, urinary tract infections, and sepsis had higher risks than those with respiratory tract infections. Male patients using specific antibiotics may have a higher risk than females, with no significant age difference.

CONCLUSIONS

Antibiotics including penicillins, cephalosporins, azithromycin, sulfamethoxazole, trimethoprim, vancomycin, doxycycline, and gentamicin are associated with an increased risk of SJS/TEN, with sulfamethoxazole presenting the highest risk. Patients with pneumonia, urinary tract infections, and sepsis are particularly vulnerable. These findings highlight the need for personalized antibiotic regimens based on infection site and patient gender.

Adalimumab combination with corticosteroid therapy for Stevens-Johnson syndrome/toxic epidermal necrolysis

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a severe acute mucocutaneous reactions associated with considerable mortality and poor prognosis. Corticosteroids and intravenous immunoglobulin (IVIG), as a traditional remedy, have been widely used in the treatment of SJS/TEN. Recent studies have reported the potential therapeutic benefits of tumor necrosis factor-alpha (TNF-α) antagonists on the disease. However, the optimal treatment remains unknown. This study is to compare the effectiveness and safety of TNF-α antagonist adalimumab conjunction with corticosteroid to traditional remedy on SJS/TEN. In this single-center, retrospective, observational study, we enrolled 53 SJS/TEN patients received either traditional remedy (Corticosteroids and IVIG) or a combination therapy (TNF-α antagonist conjunction with corticosteroid). The primary endpoint was duration of hospitalization and re-epithelization time, and the secondary endpoints including exposure time to high-dose steroids, and major adverse event incidence. 26 patients received traditional remedy and 27 patients received combination remedy. In comparison to traditional remedy, the combination remedy reduced the hospitalization duration (25 ± 4.7 vs. 22 ± 5.2 days; P = 0.032), re-epithelization time (19 ± 2.5 vs.17 ± 3.4 days; P = 0.019), and exposure time to high-dose steroids (18 ± 4 vs. 16 ± 2 days; P = 0.025). Obviously, TNF-α levels in the combination group showed a significant decreased on the discharge day comparing to the traditional group (3.9 ± 1.8 vs. 5.8 ± 2.2, p = 0.001). The major adverse event incidences were no significant statistically difference (P > 0.05) within 6 months of follow-up after hospital discharge, and no death happened between two groups. The combination remedy (adalimumab conjunction with corticosteroid) could be an optimal treatment to promote disease recovery without increasing adverse events and morality in SJS/TEN patients.

Flexible Nasendoscopy in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: A Ten-Year Otolaryngology Experience

Background and Objectives: The primary objective of this study was to identify factors predictive of laryngeal involvement in patients with Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). The secondary objective was to observe the effect of laryngeal involvement upon short-term patient prognosis, including intensive care unit (ICU) stay and intubation rates. We present the largest cohort of patients examined for upper aerodigestive manifestations of SJS/TEN. Materials and Methods: We performed a retrospective observational analytic study of patients at a state-wide Australian Burns referral center between January 2013 to December 2022. Inclusion criteria were adult patients who underwent flexible nasendoscopy (FNE) with biopsy-proven SJS/TEN. Data collected from medical records included patient factors, aerodigestive symptoms, bedside examination, FNE findings, TEN-specific severity-of-illness score (SCORTEN) on admission, and patient outcomes such as intubation and ICU admission. Results: Fifty-four patients with biopsy-proven SJS/TEN underwent FNE, with 17 (31.5%) identified to have laryngeal involvement. Laryngeal involvement was not significantly associated with intubation, ICU stay, or mortality (p > 0.05). The presence of either aerodigestive symptoms or oral cavity involvement was highly sensitive (94.1%, 95% CI 73.0-99.7%) for laryngeal involvement. Conclusions: We did not find laryngeal involvement in SJS/TEN to significantly impact short-term outcomes, including intubation or mortality. FNE is the gold standard of upper aerodigestive assessment. Simple clinical evaluation of the oral cavity and a history of aerodigestive symptoms also provided a sensitive predictor of the laryngeal complications of SJS/TEN.

Sensory neuroimmune signaling in the pathogenesis of Stevens-Johnson syndrome and toxic epidermal necrolysis

BACKGROUND

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening cutaneous reactions often triggered by medications. While the involvement of CD8+ T cells causing keratinocyte death is well recognized, the contribution of neural elements to the persistent skin inflammation has been largely overlooked.

OBJECTIVE

We investigated the potential neuroimmune regulation in SJS/TEN.

METHODS

Unbiased single-cell RNA sequencing and flow cytometry were performed using circulating CD8+ T cells from healthy controls and patients with SJS/TEN. ELISA and LEGENDplex assays were respectively used to detect neuropeptides and inflammatory mediators. Skin tissues were examined by immunofluorescence staining for neuropeptide-associated nerves and cytokine receptors. Calcium imaging, Smart-seq, and a 3-D skin model were used for cultured human CD8+ T cells.

RESULTS

Unbiased RNA sequencing revealed an upregulation of the receptor for neuropeptide calcitonin gene-related peptide (CGRP), known as RAMP1, in effector CD8+ T cells in SJS/TEN. Increased CGRP+ nerve fibers and CGRP levels, along with upregulated IL-15R and IL-18R on CD8+ T cells, were displayed in the affected skin of SJS/TEN. The CGRP-RAMP1 axis was necessary and sufficient to enhance receptors for IL-15 and IL-18 and cytotoxic activities in CD8+ T cells, ultimately resulting in keratinocyte apoptosis. Calcium influx was detected in CGRP-stimulated CD8+ T cells. HCN2, a hyperpolarization-activated cation channel, was required for this process and the subsequent cytotoxic effects.

CONCLUSIONS

Our study highlights the role of neural elements in regulating CD8+ T-cell-mediated inflammatory responses and provides new potential translational targets to improve the outcomes of severe cutaneous drug reactions.

Severe cutaneous drug toxicity following disitamab vedotin treatment for metastatic gastric cancer: a case report

Background

This study reports a case of severe cutaneous toxicity in a patient with metastatic gastric cancer induced by disitamab vedotin, emphasizing the need for careful monitoring and management in such treatments.

Case presentation

A 71-year-old female was admitted to hospital complaining of serious rashes following the first cycle of disitamab vedotin regimen for metastatic gastric cancer. The doctor diagnosedtoxic epidermal necrolysis (TEN) induced by the drug. The patient received high-dose methylprednisolone due to the side effects. This resulted in a gradual improvement of symptoms.

Conclusion

During the use of disitamab vedotin, patients need to be monitored for severe skin toxicity.

Immune checkpoint inhibitor-induced severe epidermal necrolysis mediated by macrophage-derived CXCL10 and abated by TNF blockade

Immune checkpoint inhibitors (ICI) represent new anticancer agents and have been used worldwide. However, ICI can potentially induce life-threatening severe cutaneous adverse reaction (SCAR), such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), hindering continuous ICI therapy. We examine 6 cohorts including 25 ICI-induced SJS/TEN patients and conduct single-cell RNA sequencing (scRNA-seq) analysis, which shows overexpression of macrophage-derived CXCL10 that recruits CXCR3+ cytotoxic T lymphocytes (CTL) in blister cells from ICI-SJS/TEN skin lesions. ScRNA expression profiles and ex vivo blocking studies further identify TNF signaling as a pathway responsible for macrophage-derived CXCL10 and CTL activation. Based on the trajectory analysis, ICI-activated T cells from whole blood are proposed to serve as the initial cells involved in inflammation, that lead to monocytes differentiating into macrophages and increasing their susceptibility to migrate to the lesion sites. Compared with systemic corticosteroids treatment, ICI-induced SJS/TEN patients treated with biologic TNF blockade showed a significantly rapid recovery and no recurrence of SCAR with continuous ICI therapy. Our findings identify that macrophage-eliciting CTL contribute to the pathogenesis of ICI-induced epidermal necrolysis and provide potential therapeutic targets for the management and prevention of SCAR induced by ICI therapy.

Fatal outcome related to drug reaction with eosinophilia and systemic symptoms: a disproportionality analysis of FAERS database and a systematic review of cases

Background

Drug rash with eosinophilia and systemic symptoms (DRESS) is a life-threatening severe cutaneous adverse reaction.

Objective

This study aims to study fatal DRESS cases using FAERS database and systematic review.

Methods

Data of the FDA Adverse Event Reporting System (FAERS) database were extracted and manipulated. Articles from Pubmed, Embase and CINAHL databases were screened.

Results

0.13% of the adverse events submitted to FAERS was identified as DRESS and the percentage of fatal cases was up to 6.62%. The top five drugs calculated to induce DRESS with the highest number of reported cases were allopurinol, lamotrigine, vancomycin, amoxicillin and carbamazepine. The top five drugs statistically related to fatal outcome with the highest number of reported cases were allopurinol, vancomycin, trimethoprim, sulfamethoxazole and lamotrigine. Skin manifestations remained the main reason for admission and the average time from dose to rash onset was 27.19 days. The most commonly cited culprit medication type were antibiotics (50.00%), anti-gout agents (15.38%) and anti-epileptic drug (11.54%).

Conclusions

We discussed fatal cases of DRESS through FAERS system and case reports, hoping to raise awareness when using relevant drugs.

Dissecting the pathogenic effects of smoking in blood DNA methylation on allergic diseases

Background

Allergic diseases, such as asthma and allergic rhinitis, present significant health challenges globally. Elucidating the genetic and epigenetic foundations is crucial for developing effective interventions.

Methods

We performed two-sample Mendelian Randomization (MR) analyses to investigate the associations between smoking behaviors and various allergic diseases, leveraging data from the FinnGen database. Additionally, we examined the relationships of DNA methylation (CpG sites) with allergic diseases, employing mQTLs as epigenetic proxies. Furthermore, we conducted reverse MR analyses on CpG sites that exhibited cross-allergic disease effects.

Results

In our genomic MR analysis, smoking behaviors such as smoking initiation and the number of cigarettes smoked per day were identified to be causally associated with an increased risk of asthma. Additionally, there was suggestive evidence linking smoking initiation to atopic contact dermatitis. Our epigenetic MR analysis found that methylation changes at 46 CpG sites, assessed via mQTLs, were significantly associated with asthma risk. Notably, cg17272563 (PRRT1), cg03689048 (BAT3), cg20069688 (STK19), and cg20513976 (LIME1) were identified with cross-allergic effects. Crucially, reverse MR analysis substantiated these associations.

Conclusions

Our study has highlighted the associations between smoking behaviors and allergic diseases in the genetic and epigenetic landscape, notably asthma. We identified several DNA methylation-related CpG sites, such as cg03689048 (BAT3), cg17272563 (PRRT1), and cg20069688 (STK19), which demonstrate cross-allergic potential and reverse causal relationships.

Non-IgE-mediated drug-induced hypersensitivity reactions in pediatrics

PURPOSE OF REVIEW

Despite their prevalence and potential severity, non-IgE-mediated drug-induced hypersensitivity reactions (DHRs) are under-researched and poorly defined, particularly in children. Presentations range from mild cutaneous reactions to severe systemic diseases, with pathophysiological mechanisms and reliable diagnostic markers not well established. The lack of validated tests often leads to permanent drug restrictions, reliance on second-line drugs, and increased costs. Focusing on recent advancements and areas needing further research, this review aims to enhance children's recognition, diagnosis, and management of non-IgE-mediated DHRs.

RECENT FINDINGS

Recent studies have enhanced the understanding of immediate and delayed non-IgE-mediated drug reactions. Key findings include the Mas-related G protein-coupled receptor X2 in mast cells and the identification of HLA alleles linked to severe cutaneous adverse reactions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Improved diagnostic techniques, including skin testing, show promise in identifying immediate and delayed non-IgE DHRs. Additionally, research highlights the impact of cofactors, drug metabolites, and co-infections on these DHRs and explores potential biomarkers for predicting reaction severity.

SUMMARY

Non-IgE-mediated DHRs are a significant cause of morbidity and treatment changes in pediatric patients. Recent research underscores their clinical presentations and mechanisms, paving the way for more precise diagnostic and therapeutic strategies to improve patient outcomes.

Assessment for Antibodies to Rifapentine and Isoniazid in Persons Developing Flu-Like Reactions During Treatment of Latent Tuberculosis Infection

BACKGROUND

Flu-like reactions can occur after exposure to rifampin, rifapentine, or isoniazid. Prior studies have reported the presence of antibodies to rifampin, but associations with underlying pathogenesis are unclear.

METHODS

We evaluated PREVENT TB study participants who received weekly isoniazid plus rifapentine for 3 months (3HP) or daily isoniazid for 9 months (9H) as treatment for Mycobacterium tuberculosis infection. Flu-like reaction was defined as a grade ≥2 of any of flu-like symptoms. Controls (3HP or 9H) did not report flu-like reactions. We developed a competitive enzyme-linked immunosorbent assays (ELISA) to detect antibodies against rifapentine, isoniazid, rifampin, and rifapentine metabolite.

RESULTS

Among 128 participants, 69 received 3HP (22 with flu-like reactions; 47 controls) and 59 received 9H (12 with flu-like reactions; 47 controls). In participants receiving 3HP, anti-rifapentine IgG was identified in 2 of 22 (9%) participants with flu-like reactions and 6 of 47 (13%) controls (P = .7), anti-isoniazid IgG in 2 of 22 (9%) participants with flu-like reactions and 4 of 47 (9%) controls (P = .9). Among participants receiving 9H, IgG and IgM anti-isoniazid antibodies were each present in 4 of 47 (9%) controls, but none among participants with flu-like reactions; anti-rifapentine IgG antibodies were not present in any participants with flu-like reactions or controls.

CONCLUSIONS

We detected anti-rifapentine, anti-isoniazid, and anti-rifapentine metabolite antibodies, but the proportions of participants with antibodies were low, and did not differ between participants with flu-like reactions and those without such reactions. This suggests that flu-like reactions associated with 3HP and 9H were not antibody mediated.

CLINICAL TRIALS REGISTRATION

NCT00023452.

Interleukin (IL)-1/IL-6-Inhibitor-Associated Drug Reaction With Eosinophilia and Systemic Symptoms (DReSS) in Systemic Inflammatory Illnesses

BACKGROUND

After introducing IL-1/IL-6 inhibitors, some patients with Still and Still-like disease developed unusual, often fatal, pulmonary disease. This complication was associated with scoring as DReSS (drug reaction with eosinophilia and systemic symptoms) implicating these inhibitors, although DReSS can be difficult to recognize in the setting of systemic inflammatory disease.

OBJECTIVE

To facilitate recognition of IL-1/IL-6 inhibitor-DReSS in systemic inflammatory illnesses (Still/Still-like) by looking at timing and reaction-associated features. We evaluated outcomes of stopping or not stopping IL-1/IL-6 inhibitors after DReSS reaction began.

METHODS

In an international study collaborating primarily with pediatric specialists, we characterized features of 89 drug-reaction cases versus 773 drug-exposed controls and compared outcomes of 52 cases stopping IL-1/IL-6 inhibitors with 37 cases not stopping these drugs.

RESULTS

Before the reaction began, drug-reaction cases and controls were clinically comparable, except for younger disease-onset age for reaction cases with preexisting cardiothoracic comorbidities. After the reaction began, increased rates of pulmonary complications and macrophage activation syndrome differentiated drug-reaction cases from drug-tolerant controls (P = 4.7 × 10-35 and P = 1.1 × 10-24, respectively). The initial DReSS feature was typically reported 2 to 8 weeks after initiating IL-1/IL-6 inhibition. In drug-reaction cases stopping versus not stopping IL-1/IL-6-inhibitor treatment, reaction-related features were indistinguishable, including pulmonary complication rates (75% [39 of 52] vs 76% [28 of 37]). Those stopping subsequently required fewer medications for treatment of systemic inflammation, had decreased rates of macrophage activation syndrome, and improved survival (P = .005, multivariate regression). Resolution of pulmonary complications occurred in 67% (26 of 39) of drug-reaction cases who stopped and in none who continued inhibitors.

CONCLUSIONS

In systemic inflammatory illnesses, recognition of IL-1/IL-6-inhibitor-associated reactions followed by avoidance of IL-1/IL-6 inhibitors significantly improved outcomes.

Untargeted metabolomics analysis reveals the potential mechanism of imatinib-induced skin rash in patients with gastrointestinal stromal tumor

Imatinib-induced skin rash poses a significant challenge for patients with gastrointestinal stromal tumor, often resulting in treatment interruption or discontinuation and subsequent treatment failure. However, the underlying mechanism of imatinib-induced skin rashes in gastrointestinal stromal tumor patients remains unclear. A total of 51 patients (27 with rash and 24 without rash) were enrolled in our study. Blood samples were collected concomitantly with the onset of clinical manifestations of rashes, and simultaneously collecting clinical relevant information. The imatinib concentration and untargeted metabolomics were performed by ultra-high-performance liquid chromatography-tandem mass spectrometry. There were no significant differences in age, gender, imatinib concentration and white blood cells count between the rash group and the control group. However, the rash group exhibited a higher eosinophil count (P<0.05) and lower lymphocyte count (P<0.05) compared to the control group. Untargeted metabolomics analysis found that 105 metabolites were significantly differentially abundant. The univariate analysis highlighted erucamide, linoleoylcarnitine, and valine betaine as potential predictive markers (AUC≥0.80). Further enriched pathway analysis revealed primary metabolic pathways, including sphingolipid signaling pathway, sphingolipid metabolism, cysteine and methionine metabolism, biosynthesis of unsaturated fatty acids, arginine and proline metabolism, and biosynthesis of amino acids. These findings suggest that the selected differential metabolites could serve as a foundation for the prediction and management of imatinib-induced skin rash in gastrointestinal stromal tumor patients.

[Delayed hypersensitivity reactions to drugs: Group Report of the Drug Allergy Committee of the Mexican College of Clinical Immunology and Allergy (CMICA).]

BACKGROUND

Adverse drug reactions are defined as unexpected reactions, either derived from the pharmacokinetics of the treatment (Type A) or as a host immune response (Type B), resulting in harmful or undesirable manifestations in the patient following the administration of pharmacological therapy. Type B reactions are less defined and are considered a result of hypersensitivity to pharmacological treatment, categorized as immediate (within 1 to 6 hours after exposure) and delayed or non-immediate (occurring 6 hours after exposure).

OBJECTIVE

A review to describe the immunological mechanisms of delayed hypersensitivity reactions to drugs.

METHODS

A search of major medical databases on delayed hypersensitivity reactions to drugs was conducted. The review was limited to articles published in the period between 2013 and 2023, taking into consideration articles written in English and Spanish.

RESULTS

The terms defining delayed hypersensitivity reactions to drugs, their classification, clinical manifestations, diagnosis, treatment algorithms, and prognosis.

CONCLUSIONS

Adverse drug reactions represent a challenge for the specialist physician, with a complex pathophysiology. A prompt diagnosis and treatment focused on the drug phenotype and its immunological expression are required to provide a multidisciplinary approach.

A systematic review of case-control studies of cytokines in blister fluid and skin tissue of patients with Stevens Johnson syndrome and toxic epidermal necrolysis

Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe cutaneous adverse reactions characterised by keratinocyte apoptosis, necroptosis and epidermal detachment. Several cytokines and cytotoxic proteins have been shown to be elevated in the blood and skin of SJS/TEN sufferers and biologics such as intravenous immune globulin and tumour necrosis factor (TNF)-alpha inhibitors have demonstrated good therapeutic potential. The exact pathogenic model of SJS/TEN however remains elusive. This systematic review aimed to evaluate the case-control studies of cytokines and cytotoxic proteins in the blister fluid and skin of adults with Stevens Johnson syndrome and/or toxic epidermal necrolysis. This review was registered with INPLASY and conducted in accordance with the PRISMA reporting guidelines. Potential bias was assessed using the NIH criteria. Eleven articles describing results from 96 cases and 170 controls were included. Fas, Fas ligand, Interleukin (IL)-8 and B-cell lymphoma (Bcl)-2 were elevated in SJS/TEN blister fluid and skin tissue, compared with healthy controls. IL-2, IL-6, TNF-alpha, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), interferon-gamma and matrix metalloproteinase-2 were elevated in SJS/TEN blister fluid compared with fluid sampled from lesional controls. Granulysin, IL-33, TGF-beta-1 and IL-13 were elevated in SJS/TEN skin tissue compared with lesional lichen planus tissue, as was IL-13, IFN-gamma, IL-2 and IL-5, when compared with erythema multiforme tissue. A wide array of cytokines and cytotoxic proteins are present at higher concentrations in the blister fluid and skin tissue of SJS/TEN patients compared with healthy and lesional controls. Our findings suggest that these proteins may be pathogenic, as well as possibly markers for diagnosis, disease severity and course. They may also prove to be useful therapeutic targets. More research is needed.

Delayed Skin Testing for Systemic Medications: Helpful or Not?

Cutaneous adverse drug reactions collectively are delayed drug reactions such as morbilliform drug eruption and severe cutaneous adverse reactions (SCARs). Morbilliform drug eruption may wane over time, be the result of drug viral interactions, and be amenable to slow reintroduction or rechallenge, whereas SCARs are HLA class I restricted, T-cell-mediated reactions that demonstrate durable immunity and warrant lifelong avoidance. SCARs such as drug reaction with eosinophilia and systemic symptoms, Stevens-Johnson syndrome and toxic epidermal necrolysis, acute generalized exanthematous pustulosis, and generalized bullous fixed drug eruption often occur in the setting of multiple drugs dosed together. Collectively, they lead to significant morbidity, mortality, and drug safety concerns that could severely limit future treatment options. Currently, no single or combination of diagnostic tests for SCARs such as ex vivo or in vitro testing, in vivo (skin) testing, or other adjunctive tests such as HLA typing have 100% negative predictive value. In this "Controversies in Allergy Review" article, we review the current literature on delayed skin testing (patch and delayed prick/intradermal test) and critically assess the evidence base of its utility across different drugs and clinical phenotypes of delayed hypersensitivity reactions.

Clues of HLAs, metabolic SNPs, and epigenetic factors in T cell-mediated drug hypersensitivity reactions

Drug hypersensitivities are common reactions due to immunologic responses. They are of utmost importance because they may generate severe and fatal outcomes. Some drugs may cause Adverse Drug Reactions (ADRs), such as drug hypersensitivity reactions (DHRs), which can occur due to the interaction of intact drugs or their metabolites with Human Leukocyte Antigens (HLAs) and T cell receptors (TCRs). This type develops over a period of 24-72 h after exposure and is classified as type IV of DHRs. Acute generalized exanthematic pustulosis (AGEP), Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS) are types of Severe Cutaneous Adverse Reactions (SCARs). In this review, we aim to discuss the types of ADRs, the mechanisms involved in their development, and the role of immunogenetic factors, such as HLAs in type IV DHRs, single-nucleotide polymorphisms (SNPs), and some epigenetic modifications, e.g., DNA/histone methylation in a variety of genes and their promoters which may predispose subjects to DHRs. In conclusion, development of promising novel in vitro or in vivo diagnostic and prognostic markers is essential for identifying susceptible subjects or providing treatment protocols to work up patients with drug allergies as personalized medicine.

Tissue-resident memory T cells in immunotherapy and immune-related adverse events by immune checkpoint inhibitor

Tissue-resident memory T cells (TRM) are a specialized subset of T cells that reside in tissues and provide long-term protective immunity against pathogens that enter the body through that specific tissue. TRM cells have specific phenotype and reside preferentially in barrier tissues. Recent studies have revealed that TRM cells are the main target of immune checkpoint inhibitor immunotherapy since their role in cancer immunosurveillance. Furthermore, TRM cells also play a crucial part in pathogenesis of immune-related adverse events (irAEs). Here, we provide a concise review of biological characteristics of TRM cells, and the major advances and recent findings regarding their involvement in immune checkpoint inhibitor immunotherapy and the corresponding irAEs.

Phenomic landscape and pharmacogenomic implications for HLA region in a Taiwan Han Chinese population

BACKGROUND

The human leukocyte antigen (HLA) genes, exhibiting significant genetic diversity, are associated with susceptibility to various clinical diseases and diverse in drug responses. High costs of HLA sequencing and the population-specific architecture of this genetic region necessitate the establishment of a population-specific HLA imputation reference panel. Moreover, there is a lack of understanding about the genetic and phenotypic landscape of HLA variations within the Taiwanese population.

METHODS

We created models for a Taiwanese-specific HLA imputation reference panel. These models were trained with the array genotype data and HLA sequencing data from 845 Taiwanese subjects. HLA imputation was applied for 59,448 Taiwanese subjects to characterize the HLA allele and haplotype frequencies. Additionally, a phenome-wide association study (PheWAS) was conducted to identify the phenotypes associated with HLA variations. The association of the biallelic HLA variants with the binary and quantitative traits were evaluated with additive logistic and linear regression models, respectively. Furthermore, an omnibus test with likelihood-ratio test was applied for each HLA amino acid position in the multiallelic HLA amino acid polymorphisms to compare the difference between a fitted model and a null model following a χ2 distribution of n-1 degree of freedom at a position with n residues. Finally, we estimated the prevalence of adverse drug reactions (ADR)-related HLA alleles in the Taiwanese population.

RESULTS

In this study, the reference panel models displayed remarkable accuracy, with averages of 99.3%, 98.9%, and 99.1% for 2-, 4-, 6-digit alleles of the eight classical HLA genes, respectively. For PheWAS, a total of 18,136 significant associations with HLA variants across 26 phenotypes are identified (p < 5×10-8), highlighting the pleiotropy feature of the HLA region. Among the independent signals, 15 are novel, including the association of HLA-B pos 138 variation with ankylosing spondylitis (AS), and rs9266290 and rs9266292 with allergy. Through an analysis spanning the entire HLA region, we identified clusters of phenotype correlations. Finally, the carriers of pharmacogenomic related HLA alleles, including HLA-C*01:02 (35.86%), HLA-B*58:01 (20.9%), and HLA-B*15:02 (8.38%), were characterized in the Taiwanese general population.

CONCLUSIONS

We successfully delivered the HLA imputation for 59,448 Taiwanese subjects and characterized the genetic and phenotypic landscapes of the HLA variations. In addition, we quantified the estimated prevalence of the ADR-related HLA alleles in the Taiwanese population. The developed HLA imputation reference panel could be used for estimation of population HLA allele frequencies, which can facilitate further studies in the role of HLA variants in a wider range of phenotypes in the population.

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.

Emerging Insights into Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Induced by Immune Checkpoint Inhibitor and Tumor-Targeted Therapy

Objective

Anticancer drugs have revolutionized tumor therapy, with cutaneous toxicities such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) being common immune-related adverse events. The debate over the efficacy of systemic corticosteroids in treating these conditions persists, while tumor necrosis factor (TNF)-alpha inhibitors show promise. This study aims to evaluate the effectiveness and safety of combination therapy involving the TNF-α inhibitor adalimumab for SJS/TEN induced by anticancer drugs.

Methods

A literature review of SJS/TEN cases induced by anticancer drugs from 1992 to 2023 was conducted, alongside an analysis of patients admitted to the First Affiliated Hospital of Fujian Medical University during the same period. Clinical characteristics, skin healing time, mortality, and adverse events were evaluated in two treatment groups: SJS/TEN patients treated with targeted anticancer therapies and immunotherapies.

Results

Among the 27 patients studied (18 with SJS or SJS-TEN overlapping and 9 with TEN), combination therapy with adalimumab significantly reduced mucocutaneous reepithelization time and healing duration compared to corticosteroid monotherapy. Patients receiving adalimumab combined with corticosteroids had lower actual mortality rates than those on corticosteroid monotherapy. The combination therapy also showed a trend towards reducing standardized mortality rates based on the Score of Toxic Epidermal Necrolysis (SCORTEN).

Conclusion

The findings suggest that adalimumab in combination with corticosteroids provides significant clinical benefits and is safer than corticosteroids alone for treating SJS/TEN induced by targeted anticancer therapies and immunotherapies. This study contributes valuable insights into potential treatment strategies for severe cutaneous adverse reactions to anticancer drugs, highlighting the importance of exploring alternative therapies such as TNF-α inhibitors in managing these conditions effectively.

Cutaneous adverse drug reactions

Cutaneous adverse drug reactions (ADRs) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Maculopapular exanthema and urticaria are the most common types of cutaneous ADR. Serious cutaneous ADRs, which may cause permanent sequelae or have fatal outcome, may represent 2% of all cutaneous ADR and must be quickly identified to guide their management. These serious reactions include bullous manifestations (epidermal necrolysis i.e. Stevens-Johnson syndrome and toxic epidermal necrolysis), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). Some risk factors for developing cutaneous ADRs have been identified, including immunosuppression, autoimmunity or genetic variants. All drugs can cause cutaneous ADRs, the most commonly implicated being antibiotics (especially aminopenicillins and sulfonamides), anticonvulsants, allopurinol, antineoplastic drugs, non-steroidal anti-inflammatory drugs and iodinated contrast media. Pathophysiology is related to immediate or delayed "idiosyncratic" immunologic mechanisms, i.e., usually not related to dose, and pharmacologic/toxic mechanisms, commonly dose-dependent and/or time-dependent. If an immuno-allergic mechanism is suspected, allergological explorations (including epicutaneous patch testing and/or intradermal test) are often possible to clarify drug causality, however these have a variable sensitivity according to the drug and to the ADR type. No in vivo or in vitro test can consistently confirm the drug causality. To determine the origin of a rash, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis (especially infectious etiologies) is required, completed with a literature search. Reporting to pharmacovigilance system is therefore essential both to analyze drug causality at individual level, and to contribute to knowledge of the drug at population level, especially for serious cutaneous ADRs or in cases involving newly marketed drugs.

Causes and Management of Cutaneous Adverse Drug Reactions: A Comprehensive Review

Cutaneous adverse drug reactions (CADRs) are one of the most broadly studied and rigorously researched conditions in recent dermatological advancements. Also termed as "toxidermia," they are heavily involved and are of utmost importance to be understood and studied in the modern healthcare industry. In simple terms, they are dermatological manifestations which result from systemic drug administration to patients. Since allopathy is influenced by the medicines and drugs provided to the patients, cutaneous skin eruptions are a common occurrence in recent times. It is a need of the hour to understand the causative factors for such skin eruptions and the correct management and handling of such disorders to provide better healthcare to patients. The withdrawal of the causative drug which induces the reaction plays a key role in treatment. The risk factors are to be thoroughly studied, and dosages must be in accordance with the patient's situation. They are some of the common public health problems. The age group which is affected is highly variable as people from all age groups can be affected. Those who are affected comprise approximately 10% of all hospitalized patients, and it is also observed in about 1-4% of people who are on multiple medications.

Changing patterns in the epidemiology of drug allergy

Drug allergy (DA) remains a complex and unaddressed problem worldwide that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. Underdiagnosis and overdiagnosis are common and due to the lack of standardized definitions and biomarkers. The true burden of DA is unknown, and recent efforts in data gathering through electronic medical records are starting to provide emerging patterns around the world. Ten percent of the general population engaged in health care claim to have a DA, and the most common label is penicillin allergy. Up to 20% of emergency room visits for anaphylaxis are due to DA and 15%-20% of hospitalized patients report DA. It is estimated that DA will increase based on the availability and use of new and targeted antibiotics, vaccines, chemotherapies, biologicals, and small molecules, which are aimed at improving patient's options and quality of life. Global and regional variations in the prevalence of diseases such as human immunodeficiency virus and mycobacterial diseases, and the drugs used to treat these infections have an impact on DA. The aim of this review is to provide an update on the global impact of DA by presenting emerging data on drug epidemiology in adult and pediatric populations.

Causal relationships of metabolites with allergic diseases: a trans-ethnic Mendelian randomization study

BACKGROUND

Allergic diseases exert a considerable impact on global health, thus necessitating investigations into their etiology and pathophysiology for devising effective prevention and treatment strategies. This study employs a Mendelian randomization (MR) analysis and meta-analysis to identify metabolite targets potentially associated with allergic diseases.

METHODS

A two-sample MR analysis was conducted to explore potential causal relationships between circulating and urinary metabolites and allergic diseases. Exposures were derived from a genome-wide association study (GWAS) of 486 circulating metabolites and a GWAS of 55 targeted urinary metabolites. Outcome data for allergic diseases, including atopic dermatitis (AD), allergic rhinitis (AR), and asthma, were obtained from the FinnGen biobank in Europe (cohort 1) and the Biobank Japan in Asia (cohort 2). MR results from both cohorts were combined using a meta-analysis.

RESULTS

MR analysis identified 50 circulating metabolites and 6 urinary metabolites in cohort 1 and 54 circulating metabolites and 2 urinary metabolites in cohort 2 as potentially causally related to allergic diseases. A meta-analysis of the MR results revealed stearoylcarnitine (OR 8.654; 95% CI 4.399-17.025; P = 4.06E-10) and 1-arachidonoylglycerophosphoinositol (OR 2.178; 95% CI 1.388-3.419; P = 7.15E-04) as the most reliable causal circulating metabolites for asthma and AR, respectively. Further, histidine (OR 0.734; 95% CI: 0.594-0.907; P = 0.004), tyrosine (OR 0.601; 95% CI: 0.380-0.952; P = 0.030), and alanine (OR 0.280; 95% CI: 0.125-0.628; P = 0.002) emerged as urinary metabolites with the greatest protective effects against asthma, AD, and AR, respectively.

CONCLUSIONS

Imbalances in numerous circulating and urinary metabolites may be implicated in the development and progression of allergic diseases. These findings have significant implications for the development of targeted strategies for the prevention and treatment of allergic diseases.

Drug Allergy in Women

Across all settings, women self-report more drug allergies than do men. Although there is epidemiologic evidence of increased drug allergy labeling in postpubertal females, the evidence base for female sex as a risk factor for true immune-mediated drug hypersensitivity reactions (DHRs), particularly in fatal drug-induced anaphylaxis, is low. A focus on the known immunologic mechanisms described in immediate and delayed DHR, layered on known hormonal and genetic sex differences that drive other immune-mediated diseases, could be the key to understanding biological sex variations in DHR. Particular conditions that highlight the impact of drug allergy in women include (1) pregnancy, in which a drug allergy label is associated with increased maternal and fetal complications; (2) multiple drug intolerance syndrome, associated with anxiety and depression; and (3) female-predominant autoimmune medical conditions in the context of mislabeling of the drug allergy or increased underlying risk. In this review, we describe the importance of drug allergy in the female population, mainly focusing on the epidemiology and risk, the mechanisms, and the associated conditions and psychosocial factors. By performing a detailed analysis of the current literature, we provide focused conclusions and identify existing knowledge gaps that should be prioritized for future research.

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.

Updates in SJS/TEN: collaboration, innovation, and community

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN) is a predominantly drug-induced disease, with a mortality rate of 15-20%, that engages the expertise of multiple disciplines: dermatology, allergy, immunology, clinical pharmacology, burn surgery, ophthalmology, urogynecology, and psychiatry. SJS/TEN has an incidence of 1-5/million persons per year in the United States, with even higher rates globally. One of the challenges of SJS/TEN has been developing the research infrastructure and coordination to answer questions capable of transforming clinical care and leading to improved patient outcomes. SJS/TEN 2021, the third research meeting of its kind, was held as a virtual meeting on August 28-29, 2021. The meeting brought together 428 international scientists, in addition to a community of 140 SJS/TEN survivors and family members. The goal of the meeting was to brainstorm strategies to support the continued growth of an international SJS/TEN research network, bridging science and the community. The community workshop section of the meeting focused on eight primary themes: mental health, eye care, SJS/TEN in children, non-drug induced SJS/TEN, long-term health complications, new advances in mechanisms and basic science, managing long-term scarring, considerations for skin of color, and COVID-19 vaccines. The meeting featured several important updates and identified areas of unmet research and clinical need that will be highlighted in this white paper.

Why drug exposure is frequently associated with T-cell mediated cutaneous hypersensitivity reactions

Cutaneous hypersensitivity reactions represent the most common manifestation of drug allergy seen in the clinic, with 25% of all adverse drug reactions appearing in the skin. The severity of cutaneous eruptions can vastly differ depending on the cellular mechanisms involved from a minor, self-resolving maculopapular rash to major, life-threatening pathologies such as the T-cell mediated bullous eruptions, i.e., Stevens Johnson syndrome/toxic epidermal necrolysis. It remains a significant question as to why these reactions are so frequently associated with the skin and what factors polarise these reactions towards more serious disease states. The barrier function which the skin performs means it is constantly subject to a barrage of danger signals, creating an environment that favors elicitation. Therefore, a critical question is what drives the expansion of cutaneous lymphocyte antigen positive, skin homing, T-cell sub-populations in draining lymph nodes. One answer could be the heterologous immunity hypothesis whereby tissue resident memory T-cells that express T-cell receptors (TCRs) for pathogen derived antigens cross-react with drug antigen. A significant amount of research has been conducted on skin immunity in the context of contact allergy and the role of tissue specific antigen presenting cells in presenting drug antigen to T-cells, but it is unclear how this relates to epitopes derived from circulation. Studies have shown that the skin is a metabolically active organ, capable of generating reactive drug metabolites. However, we know that drug antigens are displayed systemically so what factors permit tolerance in one part of the body, but reactivity in the skin. Most adverse drug reactions are mild, and skin eruptions tend to be visible to the patient, whereas minor organ injury such as transient transaminase elevation is often not apparent. Systemic hypersensitivity reactions tend to have early cutaneous manifestations, the progression of which is halted by early diagnosis and treatment. It is apparent that the preference for cutaneous involvement of drug hypersensitivity reactions is multi-faceted, therefore this review aims to abridge the findings from literature on the current state of the field and provide insight into the cellular and metabolic mechanisms which may contribute to severe cutaneous adverse reactions.

Association between HLA alleles and beta-lactam antibiotics-related severe cutaneous adverse reactions

Introduction: Beta-lactam antibiotics are one of the most common causes of antibiotics-related severe cutaneous adverse reactions (SCARs) including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reactions with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP). Recent evidence demonstrated that the human leukocyte antigen (HLA) polymorphisms play important roles in the development of drug-related SCARs. This study aimed to extensively characterize the associations between HLA genetic polymorphisms and several phenotypes of SCARs related to beta-lactam antibiotics. Methods: Thirty-one Thai patients with beta-lactam antibiotics-related SCARs were enrolled in the study. A total of 183 unrelated native Thai subjects without any evidence of drug allergy were recruited as the control group. Genotyping of HLA class I and class II alleles was performed. Results: Six HLA alleles including HLA-A*01:01, HLA-B*50:01, HLA-C*06:02, HLA-DRB1*15:01, HLA-DQA1*03:01, and HLA-DQB1*03:02, were significantly associated with beta-lactam antibiotics-related SCARs. The highest risk of SCARs was observed in patients with the HLA-B*50:01 allele (OR = 12.6, 95% CI = 1.1-142.9, p = 0.042), followed by the HLA-DQB1*03:02 allele (OR = 5.8, 95% CI = 1.5-22.0, p = 0.012) and the HLA-C*06:02 allele (OR = 5.7, 95% CI = 1.6-19.9, p = 0.011). According to the phenotypes of SCARs related to beta-lactam antibiotics, the higher risk of SJS/TEN was observed in patients with HLA-A*03:02, HLA-B*46:02 (OR = 17.5, 95% CI = 1.5-201.6, p = 0.033), HLA-A*02:06, HLA-B*57:01 (OR = 9.5, 95% CI = 1.3-71.5, p = 0.028), HLA-DQB1*03:02 (OR = 7.5, 95% CI = 1.8-30.9, p = 0.008), or HLA-C*06:02 (OR = 4.9, 95% CI = 1.1-21.4, p = 0.008). While eight HLA alleles including HLA-A*02:05, HLA-A*02:11, HLA-B*37:01, HLA-B*38:01, HLA-B*50:01, HLA-C*06:02, HLA-C*03:09, and HLA-DRB1*15:01 were associated with AGEP, the highest risk of AGEP was observed in patients with the HLA-B*50:01 allele (OR = 60.7, 95% CI = 4.8-765.00, p = 0.005). Among the four HLA alleles associated with DRESS including HLA-C*04:06, HLA-DRB1*04:05, HLA-DRB1*11:01, and HLA-DQB1*04:01, the HLA-C*04:06 allele had the highest risk of beta-lactam antibiotics-related DRESS (OR = 60.0, 95% CI = 3.0-1202.1, p = 0.043). However, these associations did not achieve statistical significance after Bonferroni's correction. Apart from the HLA risk alleles, the HLA-A*02:07 allele appeared to be a protective factor against beta-lactam antibiotic-related SCARs (OR = 0.1, 95% CI = 0.0-0.5, p = 3.7 × 10-4, Pc = 0.012). Conclusion: This study demonstrated the candidate HLA alleles that are significantly associated with several phenotypes of beta-lactam antibiotics-related SCARs. However, whether the HLA alleles observed in this study can be used as valid genetic markers for SCARs related to beta-lactam antibiotics needs to be further explored in other ethnicities and larger cohort studies.

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.

Renal Manifestations of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome: A Systematic Review of 71 Cases

Unlike other adverse drug reactions, visceral organ involvement is a prominent feature of drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and correlates with mortality. The aim of this study was to systematically review cases published in PubMed-indexed, peer-reviewed journals in which patients had renal injury during the episode of DRESS syndrome (DS). We found 71 cases, of which 67 were adults and 56% were males. Female sex was associated with higher mortality. Chronic kidney disease (CKD) was present in 14% of patients who developed acute kidney injury (AKI) during DS. In 21% of cases, the kidneys were the only visceral organ involved, while 54% of patients had both liver and kidney involvement. Eosinophilia was absent in 24% of patients. The most common classes of medication associated with renal injury in DS were antibiotics in 34%, xanthine oxidase inhibitors in 15%, and anticonvulsants in 11%. Among antibiotics, vancomycin was the most common culprit in 68% of patients. AKI was the most common renal manifestation reported in 96% of cases, while isolated proteinuria or hematuria was present in only 4% of cases. In cases with AKI, 88% had isolated increase in creatinine and decrease in glomerular filtration (GFR), 27% had AKI concomitantly with proteinuria, 18% had oliguria, and 13% had concomitant AKI with hematuria. Anuria was the rarest manifestation, occurring in only 4% of patients with DS. Temporary renal replacement therapy was needed in 30% of cases, and all but one patient fully recovered renal function. Mortality of DS in this cohort was 13%, which is higher than previously reported. Medication class, latency period, or pre-existing CKD were not found to be associated with higher mortality. More research, particularly prospective studies, is needed to better recognize the risks associated with renal injury in patients with DS. The development of disease-specific biomarkers would also be useful so DS with renal involvement can be easier distinguished from other eosinophilic diseases that might affect the kidney.

Advances in understanding of the pathogenesis and therapeutic implications of drug reaction with eosinophilia and systemic symptoms: an updated review

Drug reaction with eosinophilia and systemic symptoms or drug-induced hypersensitivity syndrome (DRESS/DIHS) is one type of severe cutaneous adverse reaction (SCAR). It is featured by fever, widespread skin lesions, protracted clinical course, internal organ involvement, and possibly long-term autoimmune sequelae. The presence of high-risk human leukocyte antigen (HLA) alleles, hypersensitivity reaction after culprit drug ingestion, and human herpesvirus reactivation may all contribute to its complex clinical manifestations. Some recent studies focusing on the roles of involved cytokines/chemokines and T cells co-signaling pathways in DRESS/DIHS were conducted. In addition, some predictors of disease severity and prognosis were also reported. In this review, we provided an update on the current understanding of the pathogenesis, potential biomarkers, and the relevant therapeutic rationales of DRESS/DIHS.