Distinct Epithelial-Innate Immune Cell Transcriptional Circuits Underlie Airway Hyperresponsiveness in Asthma.

Rationale: Indirect airway hyperresponsiveness (AHR) is a highly specific feature of asthma, but the underlying mechanisms responsible for driving indirect AHR remain incompletely understood. Objectives: To identify differences in gene expression in epithelial brushings obtained from individuals with asthma who were characterized for indirect AHR in the form of exercise-induced bronchoconstriction (EIB). Methods: RNA-sequencing analysis was performed on epithelial brushings obtained from individuals with asthma with EIB (n = 11) and without EIB (n = 9). Differentially expressed genes (DEGs) between the groups were correlated with measures of airway physiology, sputum inflammatory markers, and airway wall immunopathology. On the basis of these relationships, we examined the effects of primary airway epithelial cells (AECs) and specific epithelial cell-derived cytokines on both mast cells (MCs) and eosinophils (EOS). Measurements and Main Results: We identified 120 DEGs in individuals with and without EIB. Network analyses suggested critical roles for IL-33-, IL-18-, and IFN-γ-related signaling among these DEGs. IL1RL1 expression was positively correlated with the density of MCs in the epithelial compartment, and IL1RL1, IL18R1, and IFNG were positively correlated with the density of intraepithelial EOS. Subsequent ex vivo modeling demonstrated that AECs promote sustained type 2 (T2) inflammation in MCs and enhance IL-33-induced T2 gene expression. Furthermore, EOS increase the expression of IFNG and IL13 in response to both IL-18 and IL-33 as well as exposure to AECs. Conclusions: Circuits involving epithelial interactions with MCs and EOS are closely associated with indirect AHR. Ex vivo modeling indicates that epithelial-dependent regulation of these innate cells may be critical in indirect AHR and modulating T2 and non-T2 inflammation in asthma.

Proton pump inhibitors and the risk of acquiring a penicillin allergy label.

The negative consequences of having a penicillin allergy label are well established. Penicillin allergy de-labelling improves healthcare outcomes; however, less attention is paid to modifying risk factors leading to penicillin allergy development. In this propensity score-matched retrospective cohort study, we used a de-identified population-based database (TriNetX Research Network) and examined the 30-day risk of acquiring a penicillin allergy label in patients using proton pump inhibitors (PPIs). We demonstrated a higher risk of acquiring a penicillin allergy label among PPI users compared to controls.

Diagnosis of eosinophilic esophagitis in patients with dysphagia during the Coronavirus Disease 2019 (COVID-19) pandemic.

Background: The coronavirus disease 2019 (COVID-19) pandemic posed restrictions to many standard practices. Dysphagia is a common presentation of eosinophilic esophagitis (EoE) in adults, and biopsy via esophagogastroduodenoscopy (EGD) is required for diagnosis. We hypothesized that a diagnosis of EoE has declined during the pandemic. Objective: To investigate whether the COVID-19 pandemic influenced the likelihood of an EGD and an EoE diagnosis in patients with dysphagia. Methods: In this retrospective matched cohort study, we used the TriNetX US Collaborative Network to identify adult patients who presented with dysphagia to the emergency department (ED) during the year of and the year preceding the pandemic. Patients with a previous EoE diagnosis were excluded. The two cohorts were balanced for demographics, gastroesophageal reflux disease (GERD) diagnosis, obesity, H2 blockers and proton-pump inhibitors use, anemia, smoking, and alcohol use. The proportion of patients who received an EGD, and an EoE and a GERD diagnosis were contrasted up to 90 days from ED evaluation. Results: We identified 16,942 adult patients during the pandemic, and 16,942 adult patients the year preceding the pandemic who presented to the ED with a concern of dysphagia. During the 30-day follow-up period, no significant difference was observed in the proportion of patients who received an EGD during the pandemic versus the prepandemic period at 1, 7, and 30 days from ED evaluation. The proportion of patients who received an EoE diagnosis was not different, but slightly more patients received a GERD diagnosis during the pandemic versus prepandemic that was evident by day 30 (31.2% versus 30%; p ≤ 0.05). Conclusion: Our results revealed that the COVID-19 pandemic did not significantly impact diagnostic EGD and an EoE diagnosis.

Location of eosinophils in the airway wall is critical for specific features of airway hyperresponsiveness and T2 inflammation in asthma.

BACKGROUND: Eosinophils are implicated as effector cells in asthma, but the functional implications of the precise location of eosinophils in the airway wall is poorly understood. We aimed to quantify eosinophils in the different compartments of the airway wall and associate these findings with clinical features of asthma and markers of airway inflammation. METHODS: In this cross-sectional study, we utilised design-based stereology to accurately partition the numerical density of eosinophils in both the epithelial compartment and the subepithelial space (airway wall area below the basal lamina including the submucosa) in individuals with and without asthma and related these findings to airway hyperresponsiveness (AHR) and features of airway inflammation. RESULTS: Intraepithelial eosinophils were linked to the presence of asthma and endogenous AHR, the type that is most specific for asthma. In contrast, both intraepithelial and subepithelial eosinophils were associated with type 2 (T2) inflammation, with the strongest association between IL5 expression and intraepithelial eosinophils. Eosinophil infiltration of the airway wall was linked to a specific mast cell phenotype that has been described in asthma. We found that interleukin (IL)-33 and IL-5 additively increased cysteinyl leukotriene (CysLT) production by eosinophils and that the CysLT LTC4 along with IL-33 increased IL13 expression in mast cells and altered their protease profile. CONCLUSIONS: We conclude that intraepithelial eosinophils are associated with endogenous AHR and T2 inflammation and may interact with intraepithelial mast cells via CysLTs to regulate airway inflammation.

SMART - is it practical in the United States?

PURPOSE OF REVIEW: The 2020 focused updates to the asthma management guidelines by the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group advocate for inhaled corticosteroid (ICS)-formoterol combinations as single maintenance and reliever therapy (SMART) for patients with persistent asthma. We review the rationale, the evidence supporting SMART use in asthma, and barriers limiting its wide adoption in the United States. RECENT FINDINGS: A growing body of evidence supports the use of SMART over the conventional use of controller medicaments with an as-needed short-acting ß2 agonist for rescue therapy for the purpose of reducing the risk of asthma exacerbation and maintaining asthma control in adolescents and adults with persistent disease. Lack of US Food and Drug Administration approval, inconsistent insurance coverage, and limited options of ICS-formoterol combination available for use as SMART represent obstacles to wider integration of SMART in clinical practice. SUMMARY: SMART represents a paradigm shift in asthma management. By identifying and addressing the current and anticipated barriers to implementing SMART, its adoption by providers is likely to increase in the United States.

Use of omalizumab for management of idiopathic anaphylaxis: A systematic review and retrospective case series.

BACKGROUND: Patients with idiopathic anaphylaxis (IA) may fail to respond to a combination of high-dose H1 and H2 antihistamines and mast cell stabilizers. Treatment options for these patients are currently limited. OBJECTIVE: To describe the clinical experience of omalizumab use for the treatment of patients with IA with no evidence of underlying clonal mast cell disorders. METHODS: We performed a retrospective review at 2 separate institutions of medical records of patients with a diagnosis of IA without evidence of mast cell clonality who had received treatment with omalizumab. We searched PubMed for studies describing omalizumab use in similar patients. Information on symptoms and omalizumab therapy was compiled, and response pattern of anaphylaxis was determined. RESULTS: A total of 35 patients with IA and no evidence of mast cell clonality who received omalizumab were identified. The median age was 36 years at the start of omalizumab (range, 11-54 years; n = 29). The frequency of anaphylaxis episodes before omalizumab treatment varied from 2 total episodes to several episodes per month. The most often used initial omalizumab dose was 300 mg every 4 weeks (n = 16). Most patients ultimately achieved clinical response after starting omalizumab: complete response (63%, n = 22), partial response (28.5%, n = 10), with 3 nonresponders. CONCLUSION: Omalizumab may be an effective treatment option for patients with IA who do not have evidence of mast cell clonality and fail to respond to antihistamines and mast cell stabilizers.

A 71-year-old man with recurrent pulmonary mycobacterial avium complex infections and lymphopenia.

Mycobacterium avium complex (MAC) infections, generally viewed as opportunistic infections, often trigger an evaluation for an underlying immunodeficiency disorder. However, MAC infections can occur in patients who presumably are immunocompetent, particularly in those with an underlying structural lung disease. T-cell immunity plays a critical role in controlling MAC infection. We presented a case of lymphopenia, which complicated the clinical course of a pulmonary MAC infection in a patient who was negative for human immunodeficiency virus.

Hyper IgE syndromes: clinical and molecular characteristics.

Hyper IgE syndromes comprise a group of rare primary immunodeficiency disorders characterized by a triad of atopic dermatitis, recurrent skin and lung infections along with elevated IgE levels. Job syndrome or autosomal dominant hyper IgE syndrome because of heterozygous loss-of-function mutations with dominant negative effect in signal transducer and activator of transcription-3 is the prototype of these disorders. However, several other genetically characterized immunodeficiency disorders have been identified over the past decade and joined the umbrella of hyper IgE syndromes including autosomal recessive mutations in the DOCK8, ZNF431 and PGM3 genes and heterozygous mutations with dominant negative effect in the CARD11 gene. Moreover, a number of phenotypically distinct immunodeficiency disorders can mimic hyper IgE syndromes, adding to the diagnostic challenge. Herein, we will concisely review these disorders, their molecular bases, highlighting key distinguishing clinical and laboratory findings and therapeutic options.

Impact of Sulfonamide Allergy Label on Clinical Outcomes in Patients with Pneumocystis jirovecii Pneumonia.

INTRODUCTION: The presence of antibiotic allergy labels can have harmful impacts on clinical outcomes, particularly among immunosuppressed patients, in whom there have been associations with increased complications, readmission rates, and mortality. We explore the effects of a sulfonamide allergy label (SAL) on clinical outcomes in adult patients with Pneumocystis jirovecii pneumonia (PJP). METHODS: In this retrospective matched cohort study, we utilized TriNetX, a multicenter national database, to match 535 adult patients with PJP and SAL to an equal number of controls. We identified cases indexed between 01/01/2010 and 01/01/2023 utilizing ICD-10 codes for PJP and allergy status to sulfonamides and through detection of P. jirovecii antigen with immunofluorescence or PCR. Propensity score matching was performed in a 1:1 fashion for demographics and comorbidities, and our analysis included clinical outcomes that occurred within 30 days after the occurrence of the index event. RESULTS: While hospitalization risk tended to be lower among patients with SAL as compared to controls (RR: 0.90; 95% CI 0.81-1.01), there were no major differences in the risk of respiratory failure (RR: 0.94; 95% CI 0.84-1.05), prednisone use (RR: 1; 95% CI 0.91-1.10), intensive level of care requirement (RR: 0.85; 95% CI 0.69-1.06), intubation (RR: 0.85; 95% CI 0.61-1.19), or mortality (RR: 0.98; 95% CI 0.68-1.42). The presence of SAL did however impact antibiotic prescription patterns, with an underutilization of trimethoprim (RR: 0.50; 95% CI 0.43-0.59) and sulfamethoxazole (RR, 0.47; 95% CI 0.40-0.56) and overuse of alternative agents by patients with SAL as compared to controls. Yet, there was no difference in the occurrence of adverse outcomes such as hepatotoxicity (RR: 1.09; 95% CI 0.49-2.45) or acute kidney injury (RR: 0.94; 95% CI 0.78-1.14) between patients with SAL and controls. CONCLUSIONS: The presence of SAL alters antibiotic prescription patterns among adults with Pneumocystis infection but has no clinically significant impact on outcomes.

Artificial Intelligence-Generated Scientific Literature: A Critical Appraisal.

BACKGROUND: Review articles play a critical role in informing medical decisions and identifying avenues for future research. With the introduction of artificial intelligence (AI), there has been a growing interest in the potential of this technology to transform the synthesis of medical literature. Open AI's Generative Pre-trained Transformer (GPT-4) (Open AI Inc, San Francisco, CA) tool provides access to advanced AI that is able to quickly produce medical literature following only simple prompts. The accuracy of the generated articles requires review, especially in subspecialty fields like Allergy/Immunology. OBJECTIVE: To critically appraise AI-synthesized allergy-focused minireviews. METHODS: We tasked the GPT-4 Chatbot with generating 2 1,000-word reviews on the topics of hereditary angioedema and eosinophilic esophagitis. Authors critically appraised these articles using the Joanna Briggs Institute (JBI) tool for text and opinion and additionally evaluated domains of interest such as language, reference quality, and accuracy of the content. RESULTS: The language of the AI-generated minireviews was carefully articulated and logically focused on the topic of interest; however, reviewers of the AI-generated articles indicated that the AI-generated content lacked depth, did not appear to be the result of an analytical process, missed critical information, and contained inaccurate information. Despite being provided instruction to utilize scientific references, the AI chatbot relied mainly on freely available resources, and the AI chatbot fabricated references. CONCLUSIONS: The AI holds the potential to change the landscape of synthesizing medical literature; however, apparent inaccurate and fabricated information calls for rigorous evaluation and validation of AI tools in generating medical literature, especially on subjects associated with limited resources.

Comparative Impact of Asthma Biologics: A Nationwide US Claim-Based Analysis.

BACKGROUND: Biologic modifiers targeting type 2 (T2) airway inflammation are effective in reducing asthma exacerbation. However, real-world and comparative effectiveness studies remain limited. OBJECTIVE: To examine and compare the real-world impact of anti-T2 asthma biologics. METHODS: In this retrospective, new user cohort study, we used the MarketScan, a Commercial Claims and Encounters Database, to identify adult patients with asthma who began to receive an anti-T2 biologic agent (anti-IL-5s, dupilumab, or omalizumab). We examined the influence of the biologic class on asthma exacerbation by comparing the average number of asthma exacerbation 1 year before and after biologic initiation. We conducted multivariable regression analyses to compare the effectiveness of these asthma biologics on reducing the incidence of asthma exacerbations within 18 months of the initial administration of biologics while controlling for demographic variables, comorbidities, and asthma severity. RESULTS: We identified 5,538 asthma patients who were new to taking an anti-T2 biologic [mean age [±SD], 45.6 (12.78) years; 65.8% female). Asthma biologics reduced asthma exacerbation by 11% to 47%, particularly among patients with two or more asthma exacerbations in the year preceding biologic initiation (31% to 65% reduction). Biologics were especially effective in reducing asthma-related hospitalizations (44.6% to 60%). After adjusting for baseline demographics, asthma medication, and comorbidities, dupilumab was associated with a lower estimated mean number of asthma exacerbation per year and lower adjusted odds ratio for developing an asthma exacerbation relative to other biologics (50% to 80% less likely). CONCLUSIONS: Anti-T2 asthma biologics reduced asthma exacerbation in real-word settings. Evidence supports growing literature reporting that dupilumab might have a more favorable impact on asthma exacerbation relative to other asthma biologics.