The role of absolute monocyte counts in predicting severity of necrotizing enterocolitis

OBJECTIVE: Necrotizing enterocolitis (NEC) is an inflammatory bowel disease of preterm infants marked by an absolute monocyte count (AMC) drop in peripheral blood. Our objective was to determine whether the degree of AMC drop at illness onset correlates with eventual severity of disease. STUDY DESIGN: The percentage change in AMC was retrospectively calculated for each of 29 rule-out NEC and 76 NEC cases from baseline to illness onset, and then compared across stages. RESULTS: Median AMC changes of +0.5% (p = 0.56) were found in rule-out NEC, compared with −44.5% (p < 0.0001) in Stage 2 and −81.9% (p < 0.0001) in Stage 3. An AMC change cutoff of −75% distinguishes Stages 2 and 3. CONCLUSIONS: The severity of NEC correlated with the extent of AMC change in a dose-response fashion. Percent AMC change may be a useful marker for identifying NEC at onset and prognosticating disease severity.