Abstract
Asthma is a disease with multiple phenotypes and different degrees of severity. Severe inflammation appears when oxidative stress (OS) overwhelms the antioxidant defense. Knowing the role of OS in the increase of chromosome instability (CI) and, consequently, in cancer predisposition, it is important to carry out studies to establish limits for OS harmful effects. The aim of this study was to evaluate OS-related CI in asthma patients and the possible protective effect of antioxidants. For that purpose, spontaneous and OS-induced lymphocyte cultures from patients with mild and severe asthma, and from normal controls, were performed. Antioxidant-enriched cultures from severe patients were posteriorly performed. A hundred metaphases per culture were scored in order to estimate the frequency of CI. Our results showed that lymphocytes from severe patients had increased CI, both in spontaneous and OS-induced cultures. However, in lymphocytes from mild patients there were no differences compared to controls. This suggests that in patients subjected to extreme OS conditions, a genotoxic effect may occur at the cellular level. When lymphocytes from these patients were treated with antioxidants, a decrease in CI was observed. Understanding how CI correlates to asthma patients’ clinical situation may be pivotal to the design of future preventive measures.