Utility of eosinophil peroxidase as a biomarker of eosinophilic inflammation in asthma.

BACKGROUND: The relative utility of eosinophil peroxidase (EPX) and blood and sputum eosinophil counts as disease biomarkers in asthma is uncertain. OBJECTIVE: We sought to determine the utility of EPX as a biomarker of systemic and airway eosinophilic inflammation in asthma. METHODS: EPX protein was measured by immunoassay in serum and sputum in 110 healthy controls to establish a normal reference range and in repeated samples of serum and sputum collected during 3 years of observation in 480 participants in the Severe Asthma Research Program 3. RESULTS: Over 3 years, EPX levels in patients with asthma were higher than normal in 27% to 31% of serum samples and 36% to 53% of sputum samples. Eosinophils and EPX correlated better in blood than in sputum (rs values of 0.74 and 0.43, respectively), and high sputum EPX levels occurred in 27% of participants with blood eosinophil counts less than 150 cells/µL and 42% of participants with blood eosinophil counts between 150 and 299 cells/µL. Patients with persistently high sputum EPX values for 3 years were characterized by severe airflow obstruction, frequent exacerbations, and high mucus plug scores. In 59 patients with asthma who started mepolizumab during observation, serum EPX levels normalized in 96% but sputum EPX normalized in only 49%. Lung function remained abnormal even when sputum EPX normalized. CONCLUSIONS: Serum EPX is a valid protein biomarker of systemic eosinophilic inflammation in asthma, and sputum EPX levels are a more sensitive biomarker of airway eosinophilic inflammation than sputum eosinophil counts. Eosinophil measures in blood frequently miss airway eosinophilic inflammation, and mepolizumab frequently fails to normalize airway eosinophilic inflammation even though it invariably normalizes systemic eosinophilic inflammation.

A retrospective study of a novel 3-session rush venom immunotherapy protocol.

BACKGROUND: Venom immunotherapy (VIT) is an effective treatment for life-threatening stinging-insect hypersensitivity. Rush VIT protocols allow patients to reach maintenance dosing faster, thus conferring protection sooner. The published protocols vary in dosing regimens, monitoring parameters, and safety profiles. OBJECTIVE: To describe a novel 3-session outpatient rush VIT protocol with full therapeutic dosing achieved at the end of session 3. METHODS: We conducted a retrospective chart review of adult patients treated with rush VIT in an outpatient university allergy/immunology clinic. Demographic and clinical data, including the type of sting reaction, the number of venom allergens, and any systemic reactions (SRs) during VIT, were analyzed. RESULTS: Over a 14-year period, 55 patients (28 females and 27 males) with a median age of 47 years underwent our VIT protocol. A total of 46 patients (84%) tolerated the procedure without SR, and 53 (96%) attained full maintenance dosing. All reactions during rush were Brown anaphylaxis criteria grade 1 or 2. Although the most common venom allergy was yellow jacket, most patients had multiple venom allergies and received therapy with more than 1 venom. Furthermore, 10 patients were re-stung while on maintenance with only 1 patient having a mild SR. CONCLUSION: Our 3-session outpatient rush VIT protocol is effective and safe. Most patients had no SR and attained maintenance dosing. Compared with other 3-session rush protocols, our protocol requires non-invasive monitoring, and patients achieved monthly maintenance dosing immediately on completion.

An 82-year-old man with new skin lesions after COVID-19 vaccination.

Background: During the height of the SARS CoV-2 (severe acutre respiratory syndrome coronavirus disease 2019 [COVID 19]) pandemic, there have been numerous case reports of cutaneous reactions shortly after COVID-19 vaccine administration. Most reported cases are local injection-site reactions, whereas persistent or delayed cutaneous reactions have not been as common. Methods: We present the case of an 82-year-old man with persistent rash after the second COVID-19 vaccination. Results: A specific diagnosis was confirmed after the third skin biopsy. Conclusion: Patients are frequently referred to an allergist for various cutaneous reactions that occurred after vaccination, concerned about a possible drug allergy. This case emphasizes the importance of keeping a broad differential diagnosis when encountering a persistent skin rash not resolved by oral antihistamines or steroids.

Phenotyping of Severe Asthma in the Era of Broad-Acting Anti-Asthma Biologics.

Severe asthma is associated with significant morbidity and mortality despite the maximal use of inhaled corticosteroids and additional controller medications, and has a high economic burden. Biologic therapies are recommended for the management of severe, uncontrolled asthma to help to prevent exacerbations and to improve symptoms and health-related quality of life. The effective management of severe asthma requires consideration of clinical heterogeneity that is driven by varying clinical and inflammatory phenotypes, which are reflective of distinct underlying disease mechanisms. Phenotyping patients using a combination of clinical characteristics such as the age of onset or comorbidities and biomarker profiles, including blood eosinophil counts and levels of fractional exhaled nitric oxide and serum total immunoglobulin E, is important for the differential diagnosis of asthma. In addition, phenotyping is beneficial for risk assessment, selection of treatment, and monitoring of the treatment response in patients with asthma. This review describes the clinical and inflammatory phenotypes of asthma, provides an overview of biomarkers routinely used in clinical practice and those that have recently been explored for phenotyping, and aims to assess the value of phenotyping in severe asthma management in the current era of biologics.