Early Persistent Blood Eosinophilia in Necrotizing Enterocolitis Is a Predictor of Late Complications.

BACKGROUND Eosinophils infiltrate intestinal tissue during necrotizing enterocolitis (NEC) and adult bowel diseases. We theorized that epithelial damage causes eosinophilic activation and recruitment at NEC onset. OBJECTIVE We studied the relationship between persistent blood eosinophilia and medical or surgical complications during NEC. METHODS NEC cases and controls at MU Children's Hospital (2008-2013) underwent review. A Likert scale measured NEC severity. We utilized an SPSS database for statistical analyses. RESULTS Of 50 NEC cases, infants in group 1 (n = 15) had eosinophilia <2 days after onset and those in group 2 (n = 25) had NEC but no persistent eosinophilia. Group 3 (n = 46) consisted of controls, i.e. infants without NEC matched for birth weight and gestational age and group 4 (n = 4) of preterm infants with infection and ≤5 days of eosinophilia. Hematologic assessment defined persistent eosinophilia as ≥5% eosinophils for ≥5 days after NEC onset. Absolute eosinophil counts were 2 times higher in group 1 than in group 2 (p = 0.002). The mean duration of eosinophilia was 8 days in group 1 versus 1 day in group 2 (p < 0.001). A Likert score of NEC severity was 3-fold higher in group 1 than in group 2 (p < 0.001). Compared to group 2, group 1 infants were 8 times more likely to have hepatic fibrosis or intestinal strictures. CONCLUSIONS Early persistent blood eosinophilia is not currently a predictor of complications after the onset of NEC. This biomarker identifies immature infants at a high risk for adverse outcomes during NEC convalescence.