Exhaled Breath Condensate Pepsin and PH: Non-invasive Tests for Gastroesophageal Reflux in AECOPD

Abstract

Exacerbations of chronic obstructive pulmonary disease (COPD) are an important determinant of patient quality of life and can aggravate disease progression which is associated with increased morbidity and use of healthcare resources. Several clinical backgrounds are reportedly associated with exacerbation frequency, including age, low forced expiratory volume in (FEV1) and low body mass index (BMI) (Oostenbrink et al., 2004). Gastro-esophageal reflux disease (GERD) is a relatively common condition and is associated with a variety of respiratory disorders. GERD has been shown to worsen COPD control through oesophago-bronchial reflex, and to heighten bronchial reactivity and micro aspiration (Raghu et al., 2006). GERD has also been reported to be accompanied by neutrophilic airway inflammation. We therefore hypothesised that GERD could act as a confounding factor of exacerbations through similar mechanisms in COPD and/or by increasing airway inflammation. This is of particular importance and a descriptive questionnaire that covers symptoms associated with both acid reflux and gastric dysmotility is useful for recognizing these conditions. EBC is an exciting technology allowing an insight into bio-molecules of airway lining fluid, It is an important source of biomarkers both non-specific markers of oxidative stress and specific biomarkers indicating different aspects of pulmonary inflammation (De Laurentiis et al., 2008). As the ability to comprehensively measure many markers increase via high-throughput methods EBC will likely play a prominent role in disease diagnosis and characterization, At present it is primarily used in research but is emerging as a novel tool in diagnosing and managing inflammatory lung conditions and developing personalized pharmacological strategies (De Laurentiis et al., 2008). This study clearly demonstrates that EBC Pepsin and pH is a noninvasive technique no blood sample, chemicals or sophisticated laboratory equipments are needed and consequently no high cost per case. Moreover, diagnosis of GERD in AECOPD patients by EBC Pepsin and EBC pH levels is fast and easy. The current study was conducted on fifty cases EBC Pepsin and pH were done for all the patients, Patients with acute COPD exacerbation as compared to cough patients and healthy subjects had increased levels of pepsin in their EBC samples and lower pH level than the other two groups. The EBC pH in chronic cough patients with GERD was lower than in healthy controls but higher than patients AECOPD patients with GERD. COPD with GERD showed a lower pH in EBC than COPD without GERD on PPI treatment seemed to elevate this low pH to a level similar to other non-GERD COPD so we excluded in our study patients on PPI or Anti-Pepsin drugs (Ward et al., 2005).