[Creatine kinase BB activity in the serum and bronchial aspirate of preterm newborns with respiratory distress syndrome].

OBJECTIVE

The aim of this study was to test the utility of serum creatine kinase (CK) isoenzyme determinations as a marker of tissue injury in preterm newborns with respiratory distress syndrome (RDS).

PATIENTS AND METHODS

Two groups of neonates were studied, 26 suffering from RDS who required mechanical ventilation and 20 healthy newborns with gestational ages, hours of life and birth weights similar to the first group. The activity of CK and its isoenzymes was determined in the bronchial aspirate and serum samples that were obtained before and 24 hours after exogenous surfactant therapy. The isoenzymes were separated by electrophoresis on agarose gel and their activity expressed as a percentage of the total CK. Total proteins were quantified in the bronchial aspirate and CK enzymatic activity expressed in U/mg of protein x 10-3.

RESULTS

The CK-BB isoenzyme was significantly increased (p < 0.001) in the serum of infants with RDS compared with the control group. In the bronchial aspirate, the isoenzymatic study showed that the CK-BB isoenzyme represented 98-100% of the total enzymatic CK activity.

CONCLUSIONS

The study shows significant differences in the CK isoenzyme patterns of neonates with RDS compared to controls. An increase in serum levels of the CK-BB isoenzyme could be an effective marker of tissue injury in lung disease in the newborn.