Serum levels of C-reactive protein in neonatal respiratory distress syndrome.

Serum levels of C-reactive protein (CRP) were measured within 96 hours of birth in 55 neonates with respiratory distress syndrome (RDS), 19 neonates with no significant medical illness other than an unstable cardiovascular state, and 13 neonates with a variety of pulmonary and extra-pulmonary problems either alone or in combination with RDS. The median serum CRP level in patients with RDS (2 micrograms/ml) was neither elevated nor different from CRP levels in infants with unstable cardiovascular systems (median CRP level, 2 micrograms/ml); however, neonates with other problems including pneumonia, aspiration, and extrapulmonary sepsis had significantly elevated serum CRP values (median 24 micrograms/ml). CRP levels are not elevated in neonatal RDS. Measurement of this acute phase reactant provides a rapid and reliable means of helping to distinguish infants with uncomplicated RDS from those with other serious pulmonary and extrapulmonary disease.