P-selectin in preterm infants suffering necrotizing enterocolitis

Background: Platelet selectin (P-selectin), an adhesion molecule expressed by activated endothelial cells, mediates the early phases of leukocyte adherence to the endothelium. Expression of P-selectin has been shown to be crucial to neutrophil recruitment in many human inflammatory processes as well as in animal models of intestinal ischemia-reperfusion, intestinal transplantation, and sepsis, but its role in NEC is unknown. Objective: To study P-selectin, a possible cause of NEC, in the blood of preterm infants. Study design: Twenty-four consecutive preterms, clinically suspected or proven to have NEC, were enrolled in this pilot study. Their weight ranged from 1 to 2.3 Kg (mean ±SD: 1.7±0.5 Kg), age ranged from 2 to 21 days (mean ±SD: 12±3.5 days) and their gestational age (GA) ranged from 29 to 33 weeks (mean ±SD: 31±3 weeks). In addition, 12 age- and weight-matched apparently healthy preterm infants served as a control group. Written consents were obtained from the parents of infants included in the study. All neonates were subjected to perinatal history, clinical examination, routine investigations (CBC, plain X-ray and abdominal ultrasonography (US), arterial blood gases and serum bicarbonate, serum sodium, CRP and blood culture), and measurement of blood P-selectin by direct immunofluorescent staining. Results: Infants with NEC clinically presented with significant PROM, gastric residual, abdominal distensions, hypoperfusion, hematochezia and evidence of NEC in abdominal X-ray and/or US, compared to control infants. Significant abnormal laboratory investigations in NEC cases included high CRP, hyponatremia, bandemia, thrombocytopenia, metabolic acidosis, and blood culture-proven neonatal sepsis. Abnormal blood P-selectin ( 20 units) was detected in 21 (87.5%) infants with NEC, with a mean level of 51±12.4 units that was significantly higher than that of control infants, P 0.001. A strong significant negative correlation was observed between blood P-selectin and each of GA, body weight, platelet count, arterial blood pH and bicarbonate, while it was a significant positive correlation with each of CRP and band cell count. Conclusion: P-selectin may have a role in the pathogenesis of NEC in preterm infants and may be used as a diagnostic tool.