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 χ(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.
Lam
Hugh Simon
HS
Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, SAR, China.
Wong
Samuel Po Shing
SP
Cheung
Hon Ming
HM
Chu
Winnie Chiu Wing
WC
Wong
Raymond Pui On
RP
Chui
Kit Man
KM
Liu
Flora Yuen Big
FY
Li
Karen
K
Fok
Tai Fai
TF
Ng
Pak Cheung
PC
D015415:Biomarkers / Q000097:blood; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007249:Inflammation / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D009504:Neutrophils / Q000276:immunology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D017452:Receptors, IgG / Q000096:biosynthesis* / Q000097:blood; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
D015415:Biomarkers; D017452:Receptors, IgG