[Exhaled nitric oxide (NO) in patients with respiratory tract diseases].

Nitric oxide (NO) is highly active molecule playing a key role in physiological as well as in pathological processes in the organism. Asthmatic patients show an increased expression of inducible nitric oxide synthase (iNOS) in airway epithelial cells and an increased level of NO in exhaled air. The aim of the study was to evaluate the exhaled NO in different groups of allergic patients and healthy volunteers. The study was conducted in the group of 94 patients and healthy subjects. NO was measured in exhaled air by means of chemiluminescence (model 280 nitric oxide analyzer. Sievers Instruments, Inc, USA. Healthy, nonsmoking subjects had exhaled NO levels of 10-20 ppB and smoking was one of the factors reduces exhaled NO. Exhaled NO was elevated in asthma patients. The patients with stable COPD have been shown to have exhaled NO on the same level that healthy smoking subjects. We observed, that the study patients with pollinosis who did not have asthma symptoms had increased levels of exhaled NO during pollen season. Measurement of exhaled NO is an easy, non-invasive procedure that can be used to monitor the level of airway inflammation.