Breath isoprene during acute respiratory exacerbation in cystic fibrosis

Abstract

Patients with cystic fibrosis (CF) experience a combination of chronic systemic oxidative stress, generation of free radicals in the lungs due to a hyperimmune response and a diminished ability to scavenge free radicals secondary to malabsorption and increased consumption. The authors asked the question, "Does breath isoprene content reflect systemic oxidative stress?"The study involved 12 CF patients and 12 matched healthy controls. The patients were sampled during acute respiratory exacerbation (increased respiratory symptoms, reduction in forced expiratory volume (FEV1) of >10%, and a decision to treat with intravenous antibiotics) and after two weeks of antibiotic treatment. Blood samples were examined for markers of oxidative stress. Breath samples were analysed for isoprene content.Malondialdehyde (MDA), erythrocyte membrane polyunsaturated fatty acids, protein sulphydryls and protein carbonyls all showed evidence of increased oxidative stress which was moderated by antibiotic treatment. Breath isoprene production rate was significantly lower in patients during exacerbation than in controls with a mean difference of -39 (95% confidence interval (CI) -11±57) pmol . min . kg -1 and increased to normal values following treatment (mean change 63 (95% CI 42±84) pmol . min . kg -1 ).In conclusion, breath isoprene cannot be considered a reliable marker of oxidative stress.

Real-time multi-marker measurement of organic compounds in human breath: towards fingerprinting breath

“…Average values for acetone and dimethyl sulfide were comparable to that observed in healthy adults (displayed in Table 1) whilst average methanol and isoprene values in the study subjects were generally lower than that observed in the group of healthy adults (consistent with a previous study on children's breath (Taucher et al, 1997)). Previous reports have linked dimethyl sulfide and isoprene to cystic fibrosis and respiratory exacerbation (Barker et al, 2006;Kamboures et al 2005;McGrath et al, 2000). However, the present results indicate no significant difference between dimethyl sulfide and isoprene in the cystic fibrosis ( (Wang et al, 2006;Enderby et al, 2009).…”

Early intervention and prevention of lung disease in cystic fibrosis: a European consensus

“…Therefore, the collection of exhaled breath condensates (EBC) has been suggested to detect and monitor the course of inflammatory markers in CF and other airways diseases [147]. Volatile compounds such as hydrogen peroxide (H 2 O 2 ) [148], nitric oxide [149], 8-isoprostane [150] and isoprene [151] have been measured in EBC from CF and other patients. However, whether these markers of inflammation can be used to monitor anti-inflammatory therapy in CF is still questionable.…”

Profiling allergic asthma volatile metabolic patterns using a headspace-solid phase microextraction/gas chromatography based methodology

“…Studies have been developed using HS-SPME in order to establish the volatile composition of human exhaled breath [8] or for a specific type of disease, for example diabetes [14], lung cancer [15] and cystic fibrosis [16] or for chemical substances exposure monitoring [17]. Studies concerning non invasive monitoring of allergic airway inflammation have been made using exhaled nitric oxide [18] or breath condensate [19].…”