Oxidative stress markers in neonatal respiratory distress syndrome: advanced oxidation protein products and 8-hydroxy-2-deoxyguanosine in relation to disease severity.

OBJECTIVE

We assessed oxidant-antioxidant status and evaluated the role of lipid peroxidation, oxidative DNA damage, and protein oxidation in the development and severity of neonatal respiratory distress syndrome (RDS).

METHODS

Forty preterm neonates with RDS were compared with another 40 preterm neonates without RDS enrolled as controls. Total antioxidant capacity (TAC), malondialdehyde (MDA), advanced oxidation protein products (AOPPs), 8-hydroxy-2-deoxyguanosine (8-OHdG), and trace elements (copper and zinc) were measured in cord blood (day 0) for all neonates and repeated on day 3 for the RDS group.

RESULTS

Day 0 serum levels of MDA, AOPPs, and 8-OHdG were significantly higher in neonates with RDS than controls with a further increase on day 3. Days 0 and 3 levels of TAC, copper, and zinc were significantly lower in the RDS group compared with controls. Elevated serum levels of 8-OHdG and AOPPs were associated with severe RDS, invasive mechanical ventilation, and high mortality rate. 8-OHdG and AOPPs were positively correlated with MDA, oxygenation index, duration of ventilation, and duration of hospitalization.

CONCLUSIONS

Increased lipid, protein, and DNA oxidation is accompanied by alterations in the antioxidant defense status, which may play a role in the pathogenesis and severity of RDS.