P-selectin in preterm infants suffering necrotizing enterocolitis

ABSTRACT

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. To study P-selectin, a possible cause of NEC, in the blood of preterm infants. 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. 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. P-selectin may have a role in the pathogenesis of NEC in preterm infants and may be used as a diagnostic tool