ABSTRACT
Asthma is a heterogeneous disease, in which asthmatic patients present with different clinical phenotypes, variable endotypes, and different response to asthma medicines. Thus, we are faced with an asthma paradox; asthma is diagnosed subjectively by clinical history and treated with biologically active drugs. To solve this paradox, we need objective airway biomarkers to tailor the proper medications to the proper patient. Biomarkers should have one or more of the following characteristics: 1] could differentiate poor symptoms perceivers from over-perceivers, 2] could predict disease activity and hence disease outcome, 3] could clarify asthma phenotype responders from non-responders, and finally 4] could characterize different clinical asthma phenotypes. Therefore, we have conducted a review of literature trying to apply those four parameters to different airway inflammatory biomarkers. We found that FeNO fulfilled the four proposed clinical parameters of airway inflammatory biomarkers whereas; serum periostin was the single best systemic biomarker of airway luminal and tissue eosinophilia in severe uncontrolled TH2 asthma phenotype. Thus, this may be considered a trial towards tailoring the proper medication to the proper patient. However, application of biomarkers in clinical practice requires easier and cheaper techniques together with standardized methods for sample collection and analysis
ABSTRACT
The incidence of asthma and obesity is increasing worldwide. Understanding the causal directions between asthma and obesity could have important therapeutic implications. However, the mechanism connecting the two is not well defined. This study was undertaken to compare pulmonary function tests [PFTs], C-reactive protein [CRP] and inflammatory cytokines in obesity and asthma in Egyptian adolescents and to investigate whether obese asthmatics have a specific inflammatory phenotype than lean asthmatics. Fifty asthmatic and 30 control subjects were enrolled in the study and divided into 2 sub-groups: obese and non-obese. Serum levels of CRP, leptin, tumor necrosis factor-alpha [TNF-alpha], interleukin-6 [IL-6], IL-5, body mass index [BMI] and PFTs were done for asthmatics and controls. Serum levels of IL-6, TNF-alpha and leptin in obese individuals whether asthmatic or not showed significant increase compared to lean ones [P < 0.01]. Body mass index [BMI] showed positive linear correlations with serum levels of IL-6, TNF-alpha, leptin and CRP. Serum IL-5 showed significantly higher levels in all asthmatics versus all controls [P < 0.01]. Also serum IL-5 showed non-significant difference between lean and obese asthmatics and it showed significant negative correlations with FEVl/FVC% and PEF. Serum levels oflL-6, TNF-alpha and leptin could be considered surrogate markers for obesity, whereas serum IL-5 is considered a marker of airway inflammation in bronchial asthma. Thus obesity and asthma have been shown to coexist together but systemic and airway inflammation appears to operate independent of each other