Comparison of nitric oxide in exhaled air and pH of exhaled breath condensate in healthy children and children with asthma exacerbation

Basic pathogenic mechanism of asthma is an inflammatory process taking place in a mucous membrane of a bronchial tree. Parameters, used to evaluate this process so far, aren't objective enough and they are difficult to gain, especially in children. The possibility of an objective estimation of the inflammatory process in bronchial tree can influence more appropriate evaluation of a patient's condition and make treatment of asthma more adequate. There were many researches published in last few years, seeking for such tools, which in an easy, noninvasive and cheap way would reflect the intensification of inflammation in respiratory system. Nitric oxide (NO) concentration in exhaled air is considered as one of such indicators. Its concentration depends on iNOS activity - an enzyme activated by inflammatory factors. It is measured with methods using chemiluminescency. Rise in its concentration suggests rise in inflammatory process of bronchia. The other marker of inflammatory state taken into consideration in many researches is pH of exhaled breath condensate (EBC), which is a deriva-tive of fluid lining a surface of pulmonary alveoli. It is possible to measure concentration of many substances dissolved in it, but pH estimation is the easiest method of EBC evaluation. It was noticed that it falls in the run of diseases that go with inflammation in bronchial tree. Both mentioned methods are relatively cheap and easy to accomplish, even among pediatric population. The aim of this study was to evaluate NO and pH values in EBC in 17 children with asthma diagnosis and comparison of the results with values collected from a group of healthy children. Investigation was conducted at 26 children in the age from 8 to 17 year old. Between both groups of children it was gained statistically significant difference in values of NO concentration in exhaled air as well as pH of EBC. In the case of asthma exacerbation NO concentration was rising and pH value was falling, and both this parameters were correlating with each other. These results remain consistent with other researches using same parameters as indicators of bronchial and pulmonary inflammatory process intensification. They can become valuable and commonly used methods of evaluation of asthma.