Early Diagnosis of Intra-Abdominal Inflammation and Sepsis by Neutrophil CD64 Expression in Newborns

Background: Newborn infants with intra-abdominal inflammation/sepsis often present with nonspecific signs in the early stages of the disease, but can rapidly develop life-threatening complications. A reliable 'early' biomarker would be invaluable. Objective: To evaluate the effectiveness of neutrophil CD64 as an 'early' biomarker of intra-abdominal inflammation/sepsis. Methods: Blood was collected from newborns with suspected intra-abdominal pathology for neutrophil CD64 and C-reactive protein (CRP) determination at the onset of clinical presentation and 24 h later. They were classified into three groups: intra-abdominal inflammation/sepsis (group 1), extra-abdominal sepsis (group 2) and nonsepsis (group 3). Between-group comparisons were made by Kruskal-Wallis and chi(2) tests. Receiver-operating characteristic curves and diagnostic utilities for single and combination of tests were determined. Results: 310 infants were recruited (102, 34 and 174 in groups 1, 2 and 3, respectively). CD64 (conventional cutoff = 6,010 antibody-PE molecules bound/cell) had substantially better sensitivity (0.81 vs. 0.56) and negative predictive value (0.90 vs. 0.79) for diagnosing intra-abdominal sepsis than CRP, at presentation. Pairing CD64 with routine abdominal radiograph (AXR) substantially increased the sensitivity and negative predictive value for group 1 to 0.99 and 0.99, respectively. By adjusting the CD64 cutoff to 12,500 units, a substantial improvement in specificity could be achieved (0.62 to 0.80) without significantly compromising sensitivity (0.99 to 0.97). Conclusions: CD64 is a sensitive and 'early' biomarker for diagnosing intra-abdominal inflammation/sepsis. Intra-abdominal catastrophes, including necrotizing enterocolitis, intestinal necrosis, perforation and peritonitis can confidently be excluded using CD64 and AXR early in the course of the disease. Copyright (C) 2010 S. Karger AG, Basel