Signatures of Mitochondrial Dysfunction and Impaired Fatty Acid Metabolism in Plasma of Patients with Post-Acute Sequelae of COVID-19 (PASC).

Exercise intolerance is a major manifestation of post-acute sequelae of severe acute respiratory syndrome coronavirus infection (PASC, or "long-COVID"). Exercise intolerance in PASC is associated with higher arterial blood lactate accumulation and lower fatty acid oxidation rates during graded exercise tests to volitional exertion, suggesting altered metabolism and mitochondrial dysfunction. It remains unclear whether the profound disturbances in metabolism that have been identified in plasma from patients suffering from acute coronavirus disease 2019 (COVID-19) are also present in PASC. To bridge this gap, individuals with a history of previous acute COVID-19 infection that did not require hospitalization were enrolled at National Jewish Health (Denver, CO, USA) and were grouped into those that developed PASC (n = 29) and those that fully recovered (n = 16). Plasma samples from the two groups were analyzed via mass spectrometry-based untargeted metabolomics and compared against plasma metabolic profiles of healthy control individuals (n = 30). Observational demographic and clinical data were retrospectively abstracted from the medical record. Compared to plasma of healthy controls or individuals who recovered from COVID-19, PASC plasma exhibited significantly higher free- and carnitine-conjugated mono-, poly-, and highly unsaturated fatty acids, accompanied by markedly lower levels of mono-, di- and tricarboxylates (pyruvate, lactate, citrate, succinate, and malate), polyamines (spermine) and taurine. Plasma from individuals who fully recovered from COVID-19 exhibited an intermediary metabolic phenotype, with milder disturbances in fatty acid metabolism and higher levels of spermine and taurine. Of note, depletion of tryptophan-a hallmark of disease severity in COVID-19-is not normalized in PASC patients, despite normalization of kynurenine levels-a tryptophan metabolite that predicts mortality in hospitalized COVID-19 patients. In conclusion, PASC plasma metabolites are indicative of altered fatty acid metabolism and dysfunctional mitochondria-dependent lipid catabolism. These metabolic profiles obtained at rest are consistent with previously reported mitochondrial dysfunction during exercise, and may pave the way for therapeutic intervention focused on restoring mitochondrial fat-burning capacity.

Characteristics and outcomes of ambulatory patients with suspected COVID-19 at a respiratory referral center.

RATIONALE: SARS-CoV-2 continues to cause a global pandemic and management of COVID-19 in outpatient settings remains challenging. OBJECTIVE: We sought to describe characteristics of patients with chronic respiratory disease (CRD) experiencing symptoms consistent with COVID-19, who were seen in a novel Acute Respiratory Clinic, prior to widely available testing, emergence of variants, COVID-19 vaccination, and post-vaccination (breakthrough) SARS-CoV-2 infections. METHODS: Retrospective electronic medical record data were analyzed from 907 adults with presumed COVID-19 seen between March 16, 2020 and January 7, 2021. Data included demographics, comorbidities, medications, vital signs, laboratory tests, pulmonary function tests, patient disposition, and co-infections. The overdispersed data (aod) R package was used to create a logit model using COVID-19 diagnosis by PCR as the dichotomous outcome variable. Univariate, conventional multivariate and elastic net machine learning were used to analyze data. RESULTS: Male gender, elevated baseline temperature, and respiratory rate predicted COVID-19 diagnosis. Eosinopenia, neutrophilia, and lymphocytosis were also associated with COVID-19 diagnosis. However, asthma and COPD diagnoses were not associated with SARS-CoV-2 PCR positive test. Male gender, low oxygen saturation, and lower forced expiratory volume in 1 s (FEV1) were associated with higher hospital referral. CONCLUSIONS: CRD patients with acute respiratory symptoms in the ambulatory setting were more likely to have COVID-19 if male, febrile and tachypneic. Patients with lower pre-morbid FEV1 and lower SPO2 are more likely to be referred to the hospital. A composite of vitals sigs and WBC differential help risk stratify CRD patients seeking care for presumed COVID-19.

Refractory neutrophilic asthma and ciliary genes.

BACKGROUND: Refractory asthma (RA) remains poorly controlled, resulting in high health care utilization despite guideline-based therapies. Patients with RA manifest higher neutrophilia as a result of increased airway inflammation and subclinical infection, the underlying mechanisms of which remain unclear. OBJECTIVE: We sought to characterize and clinically correlate gene expression differences between refractory and nonrefractory (NR) asthma to uncover molecular mechanisms driving group distinctions. METHODS: Microarray gene expression of paired airway epithelial brush and endobronchial biopsy samples was compared between 60 RA and 30 NR subjects. Subjects were hierarchically clustered to identify subgroups of RA, and biochemical and clinical traits (airway inflammatory molecules, respiratory pathogens, chest imaging) were compared between groups. Weighted gene correlation network analysis was used to identify coexpressed gene modules. Module expression scores were compared between groups using linear regression, controlling for age, sex, and body mass index. RESULTS: Differential gene expression analysis showed upregulation of proneutrophilic and downregulation of ciliary function genes/pathways in RA compared to NR. A subgroup of RA with downregulated ciliary gene expression had increased levels of subclinical infections, airway neutrophilia, and eosinophilia as well as higher chest imaging mucus burden compared to other RA, the dominant differences between RA and NR. Weighted gene correlation network analysis identified gene modules related to ciliary function, which were downregulated in RA and were associated with lower pulmonary function and higher airway wall thickness/inflammation, markers of poorer asthma control. CONCLUSIONS: Identification of a novel ciliary-deficient subgroup of RA suggests that diminished mucociliary clearance may underlie repeated asthma exacerbations despite adequate treatment, necessitating further exploration of function, mechanism, and therapeutics.

Sex and gender in asthma.

Asthma is a heterogenous disease, and its prevalence and severity are different in males versus females through various ages. As children, boys have an increased prevalence of asthma. As adults, women have an increased prevalence and severity of asthma. Sex hormones, genetic and epigenetic variations, social and environmental factors, and responses to asthma therapeutics are important factors in the sex differences observed in asthma incidence, prevalence and severity. For women, fluctuations in sex hormone levels during puberty, the menstrual cycle and pregnancy are associated with asthma pathogenesis. Further, sex differences in gene expression and epigenetic modifications and responses to environmental factors, including SARS-CoV-2 infections, are associated with differences in asthma incidence, prevalence and symptoms. We review the role of sex hormones, genetics and epigenetics, and their interactions with the environment in the clinical manifestations and therapeutic response of asthma.

Efficacy and safety of reslizumab in the treatment of eosinophilic granulomatosis with polyangiitis.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA), a rare vasculitis with substantial morbidity, is characterized by asthma, eosinophilia, sinusitis, pulmonary infiltrates, neuropathy, positivity for antineutrophil cytoplasmic antibody, and multiorgan vasculitis. Although treatment options previously included corticosteroids and immunosuppressants, anti-interleukin 5 therapies have gained interest in EGPA treatment. Mepolizumab was approved for and recently benralizumab was found to have safety and efficacy in EGPA. OBJECTIVE: To determine the safety and efficacy of reslizumab in EGPA. METHODS: In this open-label, pilot study, we evaluated the safety and efficacy of intravenous reslizumab (3 mg/kg) in EGPA in 10 subjects. Oral corticosteroid dose, adverse events, exacerbations, symptom control, disease activity, blood markers, and lung function were evaluated before, during, and after 7 monthly reslizumab treatments. RESULTS: Reslizumab was tolerated and resulted in a significant reduction in daily oral corticosteroid (P < .05). Of the 10 subjects, 3 experienced an EGPA exacerbation during the treatment. One had a severe adverse event, requiring removal from the study. CONCLUSION: Yielding similar results to other anti-interleukin 5 biologic medications, reslizumab is generally a safe and effective treatment for EGPA that warrants further study. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02947945.

Benralizumab as a Steroid-Sparing Treatment Option in Eosinophilic Granulomatosis with Polyangiitis.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA) is a vasculitis associated with significant morbidity and mortality that has historically been treated with systemic corticosteroids and immunosuppressants. The IL-5 antagonist mepolizumab was Food and Drug Administration approved in 2017 after demonstrating safety and efficacy in EGPA. We hypothesized that benralizumab, an IL-5 receptor antagonist approved for eosinophilic asthma, would demonstrate safety and efficacy in EGPA. OBJECTIVES: To determine the safety and efficacy of benralizumab in EGPA as measured by reduction in oral corticosteroid dose and EGPA exacerbations. METHODS: We conducted a prospective 40-week open-label pilot study of benralizumab 30 mg administered subcutaneously in 10 patients with EGPA. Adverse events, oral corticosteroid dosing, exacerbations, and lung function were evaluated before, during, and after benralizumab treatment. Paired tests and tests derived from longitudinal models were used to compare outcome variables between phases or visits. RESULTS: Benralizumab was well tolerated and resulted in reduction of median corticosteroid dose from 15 mg at the start to 2 mg at the end of treatment. Geometric mean corticosteroid dose was reduced from 11.6 mg during pretreatment to 6.3 mg during treatment phase. Five patients were able to achieve a dose of 0 mg. Mean annualized exacerbation rate was lowest during the treatment (1.5) compared with the pre- and posttreatment phases (4.6, P = .008 for treatment vs pre- and postphases combined). CONCLUSIONS: Benralizumab was well tolerated, facilitated oral corticosteroid reduction, and reduced exacerbations in EGPA. Larger controlled trials are warranted to further evaluate the role of benralizumab in EGPA.

Safety and efficacy of electronic cigarettes: a review.

Tobacco smoking remains the highest cause of preventable deaths worldwide. Electronic cigarettes have recently become popular as nicotine alternatives. With public use on the rise and recent tobacco industry interest, field experts and regulatory agencies voiced concerns about their safety and unregulated production. Electronic cigarettes are safer than conventional cigarettes and at least as safe as other approved nicotine replacement therapies. Further evidence is needed as their popularity increases amidst controversy over safety and efficacy.

Nebulized lidocaine blunts airway hyper-responsiveness in experimental feline asthma.

Nebulized lidocaine may be a corticosteroid-sparing drug in human asthmatics, reducing airway resistance and peripheral blood eosinophilia. We hypothesized that inhaled lidocaine would be safe in healthy and experimentally asthmatic cats, diminishing airflow limitation and eosinophilic airway inflammation in the latter population. Healthy (n = 5) and experimentally asthmatic (n = 9) research cats were administered 2 weeks of nebulized lidocaine (2 mg/kg q8h) or placebo (saline) followed by a 2-week washout and crossover to the alternate treatment. Cats were anesthetized to measure the response to inhaled methacholine (MCh) after each treatment. Placebo and doubling doses of methacholine (0.0625-32.0000 mg/ml) were delivered and results were expressed as the concentration of MCh increasing baseline airway resistance by 200% (EC200Raw). Bronchoalveolar lavage was performed after each treatment and eosinophil numbers quantified. Bronchoalveolar lavage fluid (BALF) % eosinophils and EC200Raw within groups after each treatment were compared using a paired t-test (P <0.05 significant). No adverse effects were noted. In healthy cats, lidocaine did not significantly alter BALF eosinophilia or the EC200Raw. There was no difference in %BALF eosinophils in asthmatic cats treated with lidocaine (36±10%) or placebo (33 ± 6%). However, lidocaine increased the EC200Raw compared with placebo 10 ± 2 versus 5 ± 1 mg/ml; P = 0.043). Chronic nebulized lidocaine was well-tolerated in all cats, and lidocaine did not induce airway inflammation or airway hyper-responsiveness in healthy cats. Lidocaine decreased airway response to MCh in asthmatic cats without reducing airway eosinophilia, making it unsuitable for monotherapy. However, lidocaine may serve as a novel adjunctive therapy in feline asthmatics with beneficial effects on airflow obstruction.

The potential use of tyrosine kinase inhibitors in severe asthma.

PURPOSE OF REVIEW: Severe asthma comprises heterogeneous phenotypes that share in common a poor response to traditional therapies. Recent and ongoing work with tyrosine kinase inhibitors suggests a potential beneficial role in treatment of severe asthma. RECENT FINDINGS: Various receptor and nonreceptor tyrosine kinase pathways contribute to aspects of airway inflammation, airway hyperresponsiveness, and remodeling of asthma. Selective and nonselective tyrosine kinase inhibitors may be useful to block pathways that are pathologically overactive or overexpressed in severe asthma. Recent in-vivo studies have demonstrated the utility of inhibitors against specific tyrosine kinases (epidermal growth factor receptor, c-kit/platelet derived growth factor receptor, vascular endothelial growth factor receptor, spleen tyrosine kinase, and janus kinase) in altering key aspects of severe asthma. SUMMARY: Asthma and even severe asthma does not consist of a single phenotype. Targeting key inflammatory and remodeling pathways engaged across subphenotypes with tyrosine kinase inhibitors appears to hold promise.

Endotracheal nebulization of N-acetylcysteine increases airway resistance in cats with experimental asthma.

N-acetylcysteine (NAC), a mucolytic and antioxidant, is speculated to cause bronchoconstriction in cats when delivered via aerosol. We hypothesized that in cats with experimental asthma, aerosol delivery of NAC (400mg cumulative dose) via an endotracheal tube would increase airflow limitation as measured by ventilator-acquired mechanics. After endotracheal drug delivery, airway resistance and inspiratory plateau pressure (Pplat) measurements were obtained in six mechanically ventilated asthmatic cats. Results demonstrated significantly increased airway resistance (P=0.0007) compared with aerosolized saline control; Pplats were not significantly different (P=0.059). All cats exhibited at least one adverse effect: excessive airway secretions (n=3), spontaneous cough (n=2), unilateral strabismus (n=1) and post-anesthetic death (n=1). No adverse reactions were noted with saline aerosol; cough was noted in one cat with methacholine challenge. In conclusion, airway resistance and adverse reactions were documented in all cats after NAC aerosol delivery. Further studies must be performed to evaluate if it is an effective mucolytic and/or antioxidant in cats and to determine if bronchodilator pre-treatment will negate NAC-induced bronchoconstriction.

Targeted combined aerosol chemotherapy in dogs and radiologic toxicity grading.

BACKGROUND: We investigated whether combination chemotherapy, targeted with the AeroProbe® Intracorporeal Nebulizing Catheter (INC), could be safely administered, and developed a radiologic grading scheme to monitor subclinical effects on the lungs. METHODS: In anesthetized and mechanically ventilated healthy dogs (n = 3), we introduced the INC via a flexible bronchoscope into the right caudal lung lobe and administered escalating dosages of gemcitabine (1, 2, 3, or 6 mg/kg) followed by cisplatin (10 mg/m(2)). Treatments were performed every 2 weeks for 4 treatments and dogs were monitored weekly with physical examination, biochemical tests, and thoracic radiographs. Dogs were sacrificed 2 weeks after the final treatment and tissues examined histologically. A radiologic grading scheme was developed to monitor subclinical pulmonary toxicity. RESULTS: No significant side effects occurred in any dog. All dogs developed focal pneumonitis radiographically, and chronic, severe pneumonia with fibrosis histologically limited to the treated portion of the lung. Radiologic scores increased over time following increasing doses of chemotherapy. CONCLUSIONS: Targeted aerosol delivery of gemcitabine and cisplatin by INC was clinically well tolerated. This minimally invasive method is promising for lung cancer treatment, especially given the lack of clinical toxicity. The proposed radiologic grading scheme provides a method to monitor subclinical local drug toxicity.

Increasing p53 protein sensitizes non-small cell lung cancer to paclitaxel and cisplatin in vitro.

AIM: To determine whether increasing p53 protein levels confers enhanced chemosensitivity in non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Three NSCLC cell lines, with different endogenous p53 expression, were transfected with wild-type p53 (wt-p53) or CD-1 (truncated wt-p53) genes. Cells were subsequently treated with cisplatin (CDDP) or paclitaxel (PAX). Cell viability was measured using Alamar Blue Assay. RESULTS: Cells transfected with CD-1 expressed 13-38% higher levels of p53 protein compared to cells transfected with the wt-p53 gene, despite their baseline endogenous levels. CD-1-transfected cells also had higher cell death when treated with CDDP (p<0.05) or PAX, exhibiting 30-60% higher death rates than cells transfected with the wt-p53 gene and 130-160% higher than untransfected cells. A significant positive correlation between p53 protein concentration and cytotoxic response was demonstrated (R(2) for CDDP=0.823; R(2) for PAX=0.909; p<0.001). CONCLUSION: Increasing intracellular p53 protein concentrations can augment the effect of CDDP and PAX in NSCLC, despite the baseline level of p53 protein expression.

How best to deliver aerosol medications to mechanically ventilated patients.

Pressurized metered-dose inhalers (pMDIs) and nebulizers are employed routinely for aerosol delivery to ventilator-supported patients, but the ventilator circuit and artificial airway previously were thought to be major barriers to effective delivery of aerosols to patients receiving mechanical ventilation. In the past two decades, several investigators have shown that careful attention to many factors, such as the position of the patient, the type of aerosol generator and its configuration in the ventilator circuit, aerosol particle size, artificial airway, conditions in the ventilator circuit, and ventilatory parameters, is necessary to optimize aerosol delivery during mechanical ventilation. The best techniques for aerosol delivery during noninvasive positive-pressure ventilation are not well established as yet, and the efficiency of aerosol delivery in this setting is lower than that during invasive mechanical ventilation. The most efficient methods of using the newer hydrofluoroalkane-pMDIs and vibrating mesh nebulizers in ventilator-supported patients also require further evaluation. When optimal techniques of administration are employed, the efficiency of aerosolized drug delivery in mechanically ventilated patients is comparable to that achieved in ambulatory patients.

Inhaled insulin: extending the horizons of inhalation therapy.

Targeted glycemic control in patients with type 1 and type 2 diabetes is grossly inadequate, despite data demonstrating reduced microvascular and macrovascular diabetic complications with intensive treatment. A significant proportion of individuals with poorly-controlled type 2 diabetes are resistant to initiating treatment with insulin. Several decades-long search for alternative forms of insulin delivery has finally resulted in the U.S. Food and Drug Administration's approval of the first inhaled insulin delivery system, Exubera. Inhaled insulin provides hope that minimizing barriers to initiating insulin therapy will improve the overall glycemic control in both type 1 and type 2 diabetic patients. Inhaled insulin is a powder formulation that has been approved for pre-meal administration in both type 1 and type 2 diabetic patients. The delivery system for Exubera employs compressed air for producing an aerosol, which is then inhaled by the patient. Insulin is transported across the alveolar-epithelial barrier into the blood and has onset of glucose-lowering activity within 10-20 min of inhalation. The duration of action of inhaled insulin is similar to that of subcutaneous regular insulin. Although there are some limitations to the use of inhaled insulin, the potential to improve adherence and thereby achieve target glycohemoglobin levels (< or = 6.5-7.0%) in poorly controlled diabetic patients outweigh its disadvantages.