Normative Data for pH of Exhaled Breath Condensate Alix O. Paget-Brown, Lina Ngamtrakulpanit, Alison Smith, Dorothy Bunyan, Stephanie Hom, Ashley Nguyen and John F. Hunt Chest 2006;129;426-430 DOI: 10.1378/chest.129.2.426

Division of Neonatology, Department of Pediatrics, University of Virginia, Charlottesville, VA 22908, USA.
Chest (Impact Factor: 7.48). 03/2006; 129(2):426-30. DOI: 10.1378/chest.129.2.426
Source: PubMed


Measurement of pH is one of the simplest and most technically validated biomarkers studied in exhaled breath condensate (EBC). The pH of EBC has been found to be lower than controls in many respiratory disorders. Published data from normal control subjects have been reasonably consistent, but the data sets are not large. This study was undertaken to establish normative EBC pH reference values.
Four hundred four healthy subjects of all ages were enrolled.
Each participant provided a single EBC sample using a disposable collector at modest temperature so that EBC was collected as a liquid.
Samples of EBC were bubbled with argon gas to standardize for carbon dioxide, and pH was recorded with a calibrated and validated glass microelectrode on stabilization. The median EBC pH was 8.0 with interquartile (25 to 75%) range of 7.8 to 8.1. There were no differences based on age, sex, or race. The distribution is skewed, with 6.4% of EBC samples having a pH range < 7.4.
An extensive normal data set now exists that reveals EBC pH is maintained in a modestly alkaline and tight range in subjects who consider themselves healthy.

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Available from: Dorothy Bunyan, Sep 30, 2015
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    • "Acidification occurs in several respiratory diseases (Borrill et al., 2008; Hunt, 2007; Horvarth et al., 2005). The level of EBC pH is unaffected by variables that include subject age, race, gender, collecting and storage temperature, acute airway obstruction, ammonia in the mouth, saliva pH, hyperand hypoventilation (Bloemen et al., 2007; Paget-Brown et al., 2006; Borrill et al., 2005; Wells et al., 2005; Vaughan et al., 2003). Acidification of EBC occurs in acidic materials generated from inflammatory cells (Hunt et al., 2002), and gastroesophageal reflux (Effros et al., 2005). "
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    ABSTRACT: Inhaled inorganic dusts, such as coal, can cause inflammation and fibrosis in the lungs, known as pneumoconiosis. Diagnosis of pneumoconiosis depends on morphological changes by radiological findings and functional change by pulmonary function test (PFT) . Unfortunately, current diagnostic findings are limited only to lung fibrosis, which is usually irreversibly progressive. Therefore, it is important that research on potential and prospective biomarkers for pneumoconiosis should be conducted prior to initiation of irreversible radiological or functional changes in the lungs. Analytical techniques using exhaled breath condensate (EBC) or exhaled gas are non-invasive methods for detection of various respiratory diseases. The objective of this study is to investigate the relationship between inflammatory biomarkers, such as EBC pH or fractional exhaled nitric oxide (FENO) , and pneumoconiosis among 120 retired coal miners (41 controls and 79 pneumoconiosis patients) . Levels of EBC pH and FENO did not show a statistically significant difference between the pneumoconiosis patient group and pneumoconiosis patients with small opacity classified by International Labor Organization (ILO) classification. The mean concentration of FENO in the low percentage FEV1 (< 80%) was lower than that in the high percentage (80% ≤) (p = 0.023) . The mean concentration of FENO in current smokers was lower than that in non smokers (never or past smokers) (p = 0.027) . Although there was no statistical significance, the levels of FENO in smokers tended to decrease, compared with non smokers, regardless of pneumoconiosis. In conclusion, there was no significant relationship between the level of EBC pH or FENO and radiological findings or PFT. The effects between exhaled biomarkers and pneumoconiosis progression, such as decreasing PFT and exacerbation of radiological findings, should be monitored.
    Toxicological Research 12/2010; 26(4):329-337. DOI:10.5487/TR.2010.26.4.329
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    • "The methods used in this study for pH measurement have been validated and were previously shown to be robust and reliable [9,13,24]. Normative data were characterized in 404 healthy subjects [26]. Our findings of EBC pH values measured immediately after collection or with deaeration corroborate our previous results and are in accordance to the published data referring to ECoScreen [6,15]. "
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    ABSTRACT: The collection of exhaled breath condensate (EBC) is a suitable and non-invasive method for evaluation of airway inflammation. Several studies indicate that the composition of the condensate and the recovery of biomarkers are affected by physical characteristics of the condensing device and collecting circumstances. Additionally, there is an apparent influence of the condensing temperature, and often the level of detection of the assay is a limiting factor. The ECoScreen2 device is a new, partly single-use disposable system designed for studying different lung compartments. EBC samples were collected from 16 healthy non-smokers by using the two commercially available devices ECoScreen2 and ECoScreen at a controlled temperature of -20 degrees C. EBC volume, pH, NOx, LTB4, PGE2, 8-isoprostane and cys-LTs were determined. EBC collected with ECoScreen2 was less acidic compared to ECoScreen. ECoScreen2 was superior concerning condensate volume and detection of biomarkers, as more samples were above the detection limit (LTB4 and PGE2) or showed higher concentrations (8-isoprostane). However, NOx was detected only in EBC sampled by ECoScreen. ECoScreen2 in combination with mediator specific enzyme immunoassays may be suitable for measurement of different biomarkers. Using this equipment, patterns of markers can be assessed that are likely to reflect the complex pathophysiological processes in inflammatory respiratory disease.
    BMC Pulmonary Medicine 11/2009; 9(1):48. DOI:10.1186/1471-2466-9-48 · 2.40 Impact Factor
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    • "Another possibility is that low pH values representing endogenous intermittent airway acidification events are normal rather than pathologic phenomena. Supporting this speculation are several recent studies that measured breath pH among healthy controls (Table 3) and found surprisingly low breath pH in a subset of subjects [25,29], including one large population-based study that found breath pH values as low as 4.4 in healthy children [30]. The possibility that intermittent low breath pH values reflect normal biologic processes calls into question the utility of breath pH measurement – especially one-time breath pH measurement – as a reliable biomarker of lung inflammation or respiratory health effects. "
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    ABSTRACT: Vigorous outdoors exercise during an episode of air pollution might cause airway inflammation. The purpose of this study was to examine the effects of vigorous outdoor exercise during peak smog season on breath pH, a biomarker of airway inflammation, in adolescent athletes. We measured breath pH both pre- and post-exercise on ten days during peak smog season in 16 high school athletes engaged in daily long-distance running in a downwind suburb of Atlanta. The association of post-exercise breath pH with ambient ozone and particulate matter concentrations was tested with linear regression. We collected 144 pre-exercise and 146 post-exercise breath samples from 16 runners (mean age 14.9 years, 56% male). Median pre-exercise breath pH was 7.58 (interquartile range: 6.90 to 7.86) and did not change significantly after exercise. We observed no significant association between ambient ozone or particulate matter and post-exercise breath pH. However both pre- and post-exercise breath pH were strikingly low in these athletes when compared to a control sample of 14 relatively sedentary healthy adults and to published values of breath pH in healthy subjects. Although we did not observe an acute effect of air pollution exposure during exercise on breath pH, breath pH was surprisingly low in this sample of otherwise healthy long-distance runners. We speculate that repetitive vigorous exercise may induce airway acidification.
    Environmental Health 02/2008; 7(1):10. DOI:10.1186/1476-069X-7-10 · 3.37 Impact Factor
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