Serum concentrations of cytokines in infants with retinopathy of prematurity.

Retinopathy of prematurity (ROP) is the leading cause of blindness in preterm infants. In this study, we investigated the cytokine levels in cord blood of normal preterm neonates and preterm infants developed ROP. Serum levels of 10 cytokines in umbilical cord blood were measured by multiplex protein arrays from 62 healthy preterm neonates and 30 preterm neonate cases who developed ROP at later stage. Results showed that serum levels of cytokines including interleukin 7 (IL-7), monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein 1 alpha (MIP-1α), and macrophage inflammatory protein 1 beta (MIP-1β) were significantly increased in cases who developed ROP than in healthy preterm neonates (3.5-fold, 3.2-fold, 3.4-fold, and 2.1-fold, respectively), whereas levels of these four cytokines did not reveal any significant differences between healthy preterm infants and normal infants. When comparing the expression of cytokines in ROP patients with different clinical parameters, ROP cases whose gestational age at delivery earlier than 29.0 weeks demonstrated increased levels of MCP-1 and MIP-1β than those later than 29.0 weeks (p < 0.05). Also, ROP cases with birth weight less than 1.28 kg revealed significantly higher level of MIP-1β than those who were heavier than 1.28 kg (p < 0.05). These data indicated that levels of IL-7, MCP-1, MIP-1α, and MIP-1β were associated with increased risk of ROP, in which MIP-1β may be further correlated with the severity of ROP.