Modification of exhaused breath condensate collection method in contact with plastic surface and measurement of H2O2 concentration in patients with lung cancer

Abstract

Lung cancer is one of the most common types of cancer in the world, in which the survival is approximately
equal to its mortality, which is largely due to the start of treatment at the stages indicating a later
tumor process. Therefore, an important area in modern oncology is the development of a screening model for the purpose of early non-invasive diagnosis of the disease. As a marker of lung cancer, the work examines
the exhaled breath condensate (EBC) from the exhaled air mixture, taking into account its sorption interaction with the plastic of Falcon type tubes. It has been shown that the key factor increasing the efficiency of collecting hydrogen peroxide is the cooling of the sample collection tube. Apparently, this contributed to a decrease in the sorption effect of H₂O₂ with the polypropylene surface of the plastic and, accordingly, led to a decrease in its decay rate to water. As a result of the work, the method for measuring the concentration of H₂O₂ in the EBC was modified using the Amplex^® Ultra Red reagent. The methods used earlier for such studies were not perfect enough and poorly reproducible. Using this method, it was found that in patients with lung cancer, the level of H₂O₂ in the EBC is 9 times higher than in healthy people. It is likely that overproduction of H₂O₂ can be caused both by a feature of tumor metabolism and by macrophages that migrate to the lungs during the development of malignant neoplasms. The data obtained indicate that the concentration of H₂O₂ in the E may be a potential marker for the early diagnosis of lung cancer.