title: DNA damage in peripheral blood of patients with chronic obstructive pulmonary disease (COPD).
abstract: Chronic obstructive pulmonary disease (COPD) is a condition characterized by chronic airway inflammation and remodeling, lung parenchymal inflammation, and destruction resulting in expiratory airflow obstruction, hyperinflation of the lung with loss of elastic recoil, and impairment of gas exchange. Skeletal muscles in individuals with COPD generate free radicals at rest, and production increases during contractile activity. Overproduction of free radicals may result in oxidant-antioxidant imbalance in favor of oxidants. This study evaluated the levels of genetic damage in peripheral blood of patients with COPD using the cytokinesis-blocked micronucleus (CBMN) and the comet assays. The study was conducted with 25 patients with COPD and 25 controls matched for age and sex. Results of both comet and CBMN assays showed an increase in the level of DNA damage. In the group of patients with COPD, the mean frequency of binucleate cells with micronuclei was 6.72+/-3.02, and in the control group, 4.20+/-2.08 (p=0.00233). Mean comet value was 26.84+/-19.61 in patients with COPD and 7.25+/-7.57 in the control group (p=0.00004). The increased frequency of micronuclei in patients with COPD was primarily assigned to clastogenic events and DNA amplification because the frequency of nucleoplasmic bridges and buds was also increased. Oxidative stress in lung cells is a constant source of free radicals that damage genetic material of both lung and circulating cells.
authors.affiliation: Health Science Institute, Feevale University, RS 239, 2755, CEP 93352-000, Novo Hamburgo, and Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, RS, Brazil. sharbelm@feevale.br
authors.forename: Sharbel Weidner
authors.initials: SW
authors.lastname: Maluf
authors.forename: Michelle
authors.initials: M
authors.lastname: Mergener
authors.forename: Luciane
authors.initials: L
authors.lastname: Dalcanale
authors.forename: Cassia C
authors.initials: CC
authors.lastname: Costa
authors.forename: Tiago
authors.initials: T
authors.lastname: Pollo
authors.forename: Michele
authors.initials: M
authors.lastname: Kayser
authors.forename: Luciano Basso
authors.initials: LB
authors.lastname: da Silva
authors.forename: Daniel
authors.initials: D
authors.lastname: Pra
authors.forename: Paulo José Zimermann
authors.initials: PJ
authors.lastname: Teixeira
mesh_terms: D000368:Aged; D004249:DNA Damage; D005260:Female; D042822:Genomic Instability; D006801:Humans; D008297:Male; D015162:Micronucleus Tests; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood*