LAUSR

BACKGROUND Although early identification of sepsis improves outcome, prompt and correct diagnostic remains often challenging. The expression of the high affinity immunoglobulin-Fc fragment receptor I CD64 on neutrophils is upregulated during acute inflammation. We here aimed at determining the usefulness of its rapid measurement in diagnosing sepsis. METHODS Seventy-two consecutive patients were enrolled upon admission to Intensive Care Unit within a 2-month period. Sequential determination of serum C-reactive protein (CRP) and procalcitonin (PCT) concentrations was obtained. The neutrophil CD64-index was measured using Accellix-CD64® device, an in vitro diagnosis system allowing for an automatic and standardized measure. RESULTS Serum concentrations of CRP and PCT as well as the neutrophil CD64-index were higher in septic patients compared to all others (p<0.05 for the three markers). Only CD64- index was an independent predictor of sepsis, though with modest sensitivity and specificity (78 and 70% respectively). Repeat determination of CD64-index at day 2 correctly classified 85% of patients. CONCLUSIONS This prospective study demonstrates the moderate performance of the neutrophil CD64 index, assessed through the Accellix-CD64® device, in diagnosing sepsis in the critically ill patient. However, repeat measurements improve its accuracy and may help to predict ICU-acquired infections.