Evaluation of Two Methods for Determination of CD64 as a Diagnostic Marker of Infection in Critically Ill Adults

Abstract

Objectives. Diagnostic markers of infection have had little innovation over the last few decades. CD64, a marker expressed on the surface of neutrophils, may have utility for this purpose. Methods. This study was conducted in an adult intensive care unit (ICU) in São Paulo, Brazil, with 89 patients. We evaluated CD64 in patients with documented or clinically diagnosed infection (infection group) and controls (patients without any evidence of infection) by two different methodologies: method #1, an in house assay, and method #2, the commercial kit Leuko64 (Trillium Diagnostics). Results. CD64 displayed good discriminating power with a 91.2% sensitivity (95% CI 90.7–91.6%) for detecting infection. The commercial kit (Leuko64) demonstrated higher specificity (87.3%) compared with method #1 as well as better accuracy (88.8%). Conclusions. CD64 seems to be a promising marker of infection in the intensive care setting, with Leuko64 showing a slight advantage.

The role of nCD64 in the diagnosis of neonatal sepsis in preterm newborns

“…Study results are inconsistent, possibly due to different methods used to measure nCD64 (ref. [24][25][26][27] or, especially, due to low homogeneity of study samples. A great proportion of the published studies fail to properly consider different patient groups (preterm vs full-term newborns), disease pathophysiology (in case of EOS, the disease has different dynamics depending on whether infection develops prenatally or is due to postnatal microbial invasion; LOS) or time of sample collection, ignoring the dynamics of increase in markers of infection.…”

“…First, our method is different from those commonly used to measure nCD64 (ref. [24][25][26] ) as it is based on the proportion of CD64-positive neutrophils which is not an index most frequently compared with the standard. Second, the study sample was small and, moreover, the NS rate was relatively low.…”