Targeted Therapy for Severe Asthma: Identifying the Right Patients

Dose-Dependent Effect of Cotinine-Verified Tobacco Smoking on Serum Immunoglobulin E Levels in Korean Adult Males

BACKGROUND

Smoking is one of the risk factors to exacerbate allergic diseases, and it may affect serum immunoglobulin E (IgE) levels. However, few studies have relied on an objective biomarker to examine the effect of tobacco smoking on serum IgE levels.

METHOD

A nationwide cross-sectional study was conducted to examine the relationship between urinary cotinine (Ucot) concentrations and IgE levels in 973 males using data from the 2010 Korean National Health and Nutrition Examination Survey (KNHANES). Ucot was classified into four groups based on concentration (ng/mL) as follows: nonsmoker group (Ucot <50 ng/mL) and three tertile groups in smokers (T1 [Ucot: 50.00-921.28 ng/mL]; T2 [Ucot: 921.29-1869.36 ng/mL]; and T3 [Ucot ≥1869.37 ng/mL]). The dose-response relationships between Ucot concentrations and total serum IgE level were estimated using analysis of covariance (ANCOVA) and multiple linear regression analysis after adjusting for confounding variables.

RESULTS

We found a significant and positive dose-related effect of cigarette smoking as measured by Ucot concentrations on the total serum IgE level. The multivariate adjusted means of total serum IgE levels (SE) were 321.0 (36.3), 404.4 (102.7), 499.2 (79.2), and 534.7 (82.7) IU/mL, after adjusting for age, body mass index, alcohol ingestion, physical exercise, job, and household income. The regression coefficient β for total serum IgE was β = 68.6 with increasing level of Ucot group after adjusting for the same covariables (p = .009).

CONCLUSION

These findings suggest that the amount of smoking may have a dose-dependent effect on total serum IgE levels.

IMPLICATION

Smoking is one of the risk factors to exacerbate allergic diseases, and it may affect serum immunoglobulin E (IgE) levels, which is closely related to type 1 mediated allergic diseases. However, few studies have relied on an objective biomarker to examine the effect of tobacco smoking on serum IgE levels. We found that tobacco exposure, as measured by Ucot concentrations, increased the serum IgE levels in a dose-response manner in a representative sample of Korean adult males.

Six gene and TH2 signature expression in endobronchial biopsies of participants with asthma

BACKGROUND

Both the six gene signature (6GS: CPA3, DNASE1L3, CLC, IL1B, ALPL, and CXCR2) and T-helper 2 signature (TH2S: CLCA1, SERPINB2, and POSTN) are proposed as biomarkers in the identification of inflammatory phenotypes of asthma in induced sputum and epithelial brushings, respectively. The aim of this study was to explore patterns of gene expression of known signatures, 6GS and TH2S in endobronchial biopsies.

METHODS

This was an exploratory cross-sectional study of gene expression in endobronchial biopsies of 55 adults with asthma and 9 healthy controls (HC). The expression of the 6GS and TH2S was determined by quantitative polymerase chain reaction. Correlations with clinical and cellular characteristics were performed, and receiver operating characteristic was utilized to assess signatures' ability to predict asthma from HC and inflammatory phenotypes.

RESULTS

Gene expression of DNASE1L3 (P = .045) was upregulated in asthma compared with HC, and IL1B (P = .017) was upregulated in neutrophilic asthma compared with non-neutrophilic asthma. In asthma, the expression of CPA3 was negatively associated with ICS daily dose (r = -.339; P = .011), IL1B expression was positively associated with bronchial lavage fluid (BLF) total cell count (r = .340; P = .013) and both CLC and POSTN expression were associated with lymphocytes percentage in BLF (r = -.355, P = .009; r = -.300, P = .025, respectively). Both 6GS (area under curve [AUC] = 86.3%; P = .017) and TH2S (AUC = 72.7%; P = .037) could significantly predict asthma from HC. In addition, 6GS can identify neutrophilic (AUC = 93.2%; P = .005) and TH2S identifies eosinophilic (AUC = 62.7%; P = .033) asthma.

CONCLUSIONS AND CLINICAL RELEVANCE

There was increased expression of DNASE1L3 in asthma and IL1B in neutrophilic asthma. These results show similar upregulated patterns of expression in two genes of the 6GS in endobronchial biopsies, previously identified in sputum. The upregulation of DNASE1L3 and IL1B suggests that common mechanisms may be at play throughout the airway.

Pharmacokinetic/pharmacodynamic drug evaluation of benralizumab for the treatment of asthma

INTRODUCTION

In many severe asthmatics, eosinophils cause inflammation and airways hyperresponsiveness, resulting in frequent exacerbations, impaired lung function, and reduced quality of life. Interleukin-5 (IL-5) is a key cytokine for eosinophil growth, differentiation, recruitment, activation, and survival. Anti-IL-5-based therapies (mepolizumab and reslizumab are humanized monoclonal antibodies (hmAbs) that recognize free IL-5, benralizumab is a hmAb directed at the α subunit of the IL-5R) target the IL-5-signaling in eosinophilic asthma. Areas covered: The pharmacodynamic/pharmacokinetic profile of benralizumab and how it provided indications that permitted optimization of the design and timelines of the pivotal trials are described. Expert opinion: Benralizumab has the advantage over other anti-IL-5 therapies to target the IL-5Rα itself. Afucosylation enhances its interaction with its binding site and facilitates its pharmacological activity. Other benefits of benralizumab are fast (within 24 h) depletion of peripheral blood eosinophils, potent suppressive activity of bone marrow eosinophils and eosinophil precursors, tissue eosinophil apoptosis regardless of the presence of eosinophil survival factors and even at low IL-5R densities. The fact that benralizumab is dosed subcutaneously and is equally effective when given every eight weeks instead than every four weeks provides patients with convenience of self-administration and make it appealing for patients who dislike injections.