Clinical characteristics and HLA associations of azithromycin-induced liver injury.

BACKGROUND: Azithromycin (AZ) is a widely used antibiotic. The aim of this study was to characterise the clinical features, outcomes, and HLA association in patients with drug-induced liver injury (DILI) due to AZ. METHODS: The clinical characteristics of individuals with definite, highly likely, or probable AZ-DILI enrolled in the US Drug-Induced Liver Injury Network (DILIN) were reviewed. HLA typing was performed using an Illumina MiSeq platform. The allele frequency (AF) of AZ-DILI cases was compared to population controls, other DILI cases, and other antibiotic-associated DILI cases. RESULTS: Thirty cases (4 definite, 14 highly likely, 12 probable) of AZ-DILI were enrolled between 2004 and 2022 with a median age of 46 years, 83% white, and 60% female. Median duration of AZ treatment was 5 days. Latency was 18.5 days. 73% were jaundiced at presentation. The injury pattern was hepatocellular in 60%, cholestatic in 27%, and mixed in 3%. Ten cases (33%) were severe or fatal; 90% of these were hepatocellular. Two patients required liver transplantation. One patient with chronic liver disease died of hepatic failure. Chronic liver injury developed in 17%, of which 80% had hepatocellular injury at onset. HLA-DQA1*03:01 was significantly more common in AZ-DILI versus population controls and amoxicillin-clavulanate DILI cases (AF: 0.29 vs. 0.11, p = 0.001 and 0.002, respectively). CONCLUSION: Azithromycin therapy can lead to rapid onset of severe hepatic morbidity and mortality in adult and paediatric populations. Hepatocellular injury and younger age were associated with worse outcomes. HLA-DQA1*03:01 was significantly more common in AZ cases compared to controls.

Delayed skin testing for systemic medications: helpful or not?

Cutaneous adverse drug reactions (CADR) collectively are delayed drug reactions such as morbilliform drug eruption (MDE) and severe cutaneous adverse reactions (SCAR). Whereas MDE may wane over time, be the result of drug viral interactions and be amenable to slow reintroduction or rechallenge, SCAR are HLA class I restricted, T-cell mediated reactions that demonstrate durable immunity and warrant lifelong avoidance. SCAR such as drug reaction with eosinophilia and systemic symptoms (DRESS), Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN), acute generalized exanthematous pustulosis (AGEP) and generalized bullous fixed drug eruption (GBFDE) 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 SCAR 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.

Epistatic interaction between ERAP2 and HLA modulates HIV-1 adaptation and disease outcome in an Australian population.

A strong genetic predictor of outcome following untreated HIV-1 infection is the carriage of specific alleles of human leukocyte antigens (HLAs) that present viral epitopes to T cells. Residual variation in outcome measures may be attributed, in part, to viral adaptation to HLA-restricted T cell responses. Variants of the endoplasmic reticulum aminopeptidases (ERAPs) influence the repertoire of T cell epitopes presented by HLA alleles as they trim pathogen-derived peptide precursors to optimal lengths for antigen presentation, along with other functions unrelated to antigen presentation. We investigated whether ERAP variants influence HLA-associated HIV-1 adaptation with demonstrable effects on overall HIV-1 disease outcome. Utilizing host and viral data of 249 West Australian individuals with HIV-1 subtype B infection, we identified a novel association between two linked ERAP2 single nucleotide polymorphisms (SNPs; rs2248374 and rs2549782) with plasma HIV RNA concentration (viral load) (P adjusted = 0.0024 for both SNPs). Greater HLA-associated HIV-1 adaptation in the HIV-1 Gag gene correlated significantly with higher viral load, lower CD4+ T cell count and proportion; P = 0.0103, P = 0.0061, P = 0.0061, respectively). When considered together, there was a significant interaction between the two ERAP2 SNPs and HLA-associated HIV-1 adaptation on viral load (P = 0.0111). In a comprehensive multivariate model, addition of ERAP2 haplotypes and HLA associated adaptation as an interaction term to known HLA and CCR5 determinants and demographic factors, increased the explanatory variance of population viral load from 17.67% to 45.1% in this dataset. These effects were not replicated in publicly available datasets with comparably sized cohorts, suggesting that any true global epistasis may be dependent on specific HLA-ERAP allelic combinations. Our data raises the possibility that ERAP2 variants may shape peptide repertoires presented to HLA class I-restricted T cells to modulate the degree of viral adaptation within individuals, in turn contributing to disease variability at the population level. Analyses of other populations and experimental studies, ideally with locally derived ERAP genotyping and HLA-specific viral adaptations are needed to elucidate this further.

A systematic review and expert Delphi Consensus recommendation on the use of vaccines in patients receiving dupilumab: A position paper of the American College of Allergy, Asthma and Immunology.

BACKGROUND: Dupilumab is a monoclonal antibody that targets the interleukin (IL)-4 receptor alpha subunit, thus blocking the effects of IL-4 and IL-13, and has shown efficacy in treating various conditions including asthma, atopic dermatitis, eosinophilic esophagitis, and others. Because of its immune modulatory effects, clinical trials that studied dupilumab did not allow patients to receive live vaccines during the clinical trials because of an abundance of caution, and thus package inserts recommend that patients who are being treated with dupilumab should avoid live vaccines. Because dupilumab is now approved for use in patients from 6 months of age for the treatment of atopic dermatitis, this reported contraindication is now posing a clinical dilemma for patients and clinicians. OBJECTIVE: To perform a systematic review of literature on the safety and efficacy of vaccinations in patients who are receiving dupilumab and to provide expert guidance on the use of vaccines in patients who are receiving dupilumab. METHODS: A systematic review of the literature was performed, and an expert Delphi Panel was assembled. RESULTS: The available literature on patients who received vaccinations while using dupilumab overall suggests that live vaccines are safe and that the vaccine efficacy, in general, is not affected by dupilumab. The expert Delphi panel agreed that the use of vaccines in patients receiving dupilumab was likely safe and effective. CONCLUSION: Vaccines (including live vaccines) can be administered to patients receiving dupilumab in a shared decision-making capacity.

Perinuclear damage from nuclear envelope deterioration elicits stress responses that contribute to LMNA cardiomyopathy.

Mutations in the LMNA gene encoding lamins A/C cause an array of tissue-selective diseases, with the heart being the most commonly affected organ. Despite progress in understanding the perturbations emanating from LMNA mutations, an integrative understanding of the pathogenesis underlying cardiac dysfunction remains elusive. Using a novel conditional deletion model capable of translatome profiling, we observed that cardiomyocyte-specific Lmna deletion in adult mice led to rapid cardiomyopathy with pathological remodeling. Before cardiac dysfunction, Lmna-deleted cardiomyocytes displayed nuclear abnormalities, Golgi dilation/fragmentation, and CREB3-mediated stress activation. Translatome profiling identified MED25 activation, a transcriptional cofactor that regulates Golgi stress. Autophagy is disrupted in the hearts of these mice, which can be recapitulated by disrupting the Golgi. Systemic administration of modulators of autophagy or ER stress significantly delayed cardiac dysfunction and prolonged survival. These studies support a hypothesis wherein stress responses emanating from the perinuclear space contribute to the LMNA cardiomyopathy development.

Improving Clinical Practice Through Patient Registries in Allergy and Immunology.

Patient registries are a mechanism for collecting data on allergic and immunologic diseases that provide important information on epidemiology and outcomes that can ultimately improve patient care. Key criteria for establishing effective registries include the use of a clearly defined purpose, identifying the target population and ensuring consistent data collection. Registries in allergic diseases include those for diseases such as inborn errors of immunity (IEI), food allergy, asthma and anaphylaxis, pharmacological interventions in vulnerable populations, and adverse effects of pharmacologic interventions including hypersensitivity reactions to drugs and vaccines. Important insights gained from patient registries in our field include contributions in phenotype and outcomes in IEI, the risk for adverse reactions in food-allergic patients in multiple settings, the benefits and risk of biologic medications for asthma during pregnancy, vaccine safety, and the categorization and genetic determination of risk for severe cutaneous adverse reactions to medications. Impediments to the development of clinically meaningful patient registries include the lack of funding resources for registry establishment and the quality, quantity, and consistency of available data. Despite these drawbacks, high-quality and successful registries are invaluable in informing clinical practice and improving outcomes in patients with allergic and immunological diseases.

Patient-Reported Outcome Measures in Food and Drug Allergy.

A patient-reported outcome is directly reported by the patient without interpretation of the patient's response by anyone else. It refers to the patient's health (symptoms and feelings), quality of life, or functional status associated with health care or treatment. Patient-reported outcome measures (PROMs) are defined as the tools or instruments that are used to measure patient-reported outcomes. Health-related quality of life has been the most studied psychosocial PROM in food allergy, using validated questionnaires. In drug allergy, PROMs are useful in capturing patients' experiences of potential allergic reactions, including subjective symptoms such as headache, dizziness, or fatigue. Patient-reported outcome measures can also help differentiate true allergies from side effects or other nonallergic reactions and inform decisions about drug challenges and de-labeling strategies. Ensuring the chosen tool is validated for the specific allergy context is crucial for accurate data collection. Integrating patient-reported experiences alongside traditional methods can lead to more accurate assessments and personalized care.

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.

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 + rifapentine for 3 months (3HP) or daily isoniazid for 9 months (9H) as treatment for M. 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 2/22 (9%) participants with flu-like reactions and 6/47 (13%) controls (P = 0.7), anti-isoniazid IgG in 2/22 (9%) participants with flu-like reactions and 4/47 (9%) controls (P = 0.9), and anti-rifapentine metabolite IgG in 2/47 (4%) controls (P = 0.9). Among participants receiving 9H, IgG and IgM anti-isoniazid antibodies were each present in 4/47 (9%) controls, respectively, 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.