The serum thioredoxin-1 levels are not associated with bronchopulmonary dysplasia and retinopathy of prematurity.

Abstract

We hypothesized that the serum TRX-1 in extremely preterm infants (EPIs) after birth was associated with the development of severe bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP). This single-centered retrospective study enrolled EPIs treated at our institution. Serum TRX-1 concentrations of the residual samples taken on admission, day 10-20 of life, and 36-40 weeks of postmenstrual age (PMA) were measured with an enzyme-linked immunosorbent assay. The serum TRX-1 levels on admission were not different between the severe BPD (n = 46) and non-severe BPD groups (n = 67): [median (interquartile range) 147 (73.0-231) vs. 164 (80.5-248) ng/mL] (P = 0.57). These had no significant difference between the severe ROP (n = 47) and non-severe ROP groups (n = 66): [164 (71.3-237) vs. 150 (80.9-250) ng/mL] (P = 0.93). The TRX-1 levels at 10-20 days of life and 36-40 weeks of PMA also had no association with the development of severe BPD and ROP. The serum TRX-1 levels after birth are not predictive of severe BPD and ROP. Serum thioredoxin-1 levels in extremely preterm infants on the day of birth are lower than those in term or near-term infants hospitalized for transient tachypnea of the newborn. In extremely preterm infants, the serum thioredoxin-1 levels on the day of birth, at 10-20 days of life, and at postmenstrual age of 36-40 weeks were not associated with severe bronchopulmonary dysplasia and retinopathy of prematurity. The thioredoxin system is under development in extremely preterm infants; however, the serum thioredoxin-1 level is not predictive for severe bronchopulmonary dysplasia and retinopathy of prematurity.