Study of plasma endothelin-1 concentrations in Taiwanese neonates with respiratory distress

Endothelin-1 (ET-1) is a novel and potent endothelium-derived vasoconstriction peptide present in human plasma. In this study, plasma ET-1 concentrations were determined and their physiological significance was evaluated in Taiwanese neonates with respiratory distress.

Sixty newborn infants consisting of 22 with respiratory distress syndrome (RDS), 13 with transient tachypnea of newborn (TTNB), 4 with meconium aspiration syndrome, 10 healthy preterm and 11 healthy full-term infants were included for plasma ET-1 determination. Plasma ET-1 levels were measured by enzyme immunoassay at the of age of 1 day. For those who were diagnosed with RDS, plasma ET-1 concentrations were scheduled for evaluation at the ages of 1, 2, 3, 7, 14, 28, and 35 days as long as oxygen was being used.

On the first day of life, there was no significant difference in plasma ET-1 concentrations between healthy preterm and term infants (3.92 +/- 0.88 vs. 3.56 +/- 1.98 pg/mL, p = 0.606). However, plasma ET-1 concentrations of infants with RDS were significantly higher than those with TTNB (6.46 +/- 0.58 vs. 3.77 +/- 1.29 pg/mL, p < 0.001). In RDS infants, plasma ET-1 concentrations showed no significant difference between those who developed bronchopulmonary dysplasia (BPD, N = 4) and those who recovered (non-BPD, n = 18) (7.84 +/- 1.85 vs. 5.81 +/- 2.76 pg/mL, p = 0.242).

Plasma ET-1 concentrations were similar in preterm and term infants. ET-1 concentrations were higher in infants with RDS than in infants with TTNB, which suggests that plasma ET-1 levels can be useful in the differential diagnosis. However, the plasma ET-1 concentrations can not be a predictor for BPD.