[Markers of oxidative damage in blood of children with cystic fibrosis].

In cystic fibrosis (CF), as a result of chronic pulmonary infections and digestive malabsorption, an imbalance between the production of reactive oxygen species and their inactivation by protective systems is observed. This may cause impairment of cell metabolism and oxidative injury. The aim of this study was to examine whether markers of oxidative damage to protein (protein carbonyls) and lipids (malondialdehyde) may be modified in cystic fibrosis patients with pancreatic insufficiency. We have found that mean concentration of plasma protein carbonyls was 0.835 nmol/mg protein (the range of 0.31-1.71 nmol/mg protein) in CF patients (n = 57) and was higher by 30% than that in controls (n = 20). Plasma concentration of malondialdehyde (MDA) was 2.98 mumol/l in the range of 1.23-4.77 mumol/l. Among fifty seven patients studied, in 30 children MDA level was elevated above the highest values observed in the healthy group (2.80 mumol/l). Total radical-trapping antioxidant parameters (TRAP) amounted to 629 mumol/l and 735 mumol/l in CF patients and control, respectively. The difference was statistically significant (p < 0.005). The obtained results indicated that in CF patients oxidative stress caused oxidative modification of proteins and peroxidation of lipids which was accompanied by lowering of antioxidant protection. These results indicate that certain CF patients (especially those with exocrine pancreatic insufficiency) are susceptible to oxidative damage, therefore it seems that an adequate and balanced diet is essential for achieving and maintaining normal antioxidant defenses.