Background: Neutrophil CD64 has been shown to be a promising biomarker for bacterial infection and sepsis identification. However, the prognostic value of CD64 in predicting the likelihood of survival for patients in intensive care unit (ICU) is unclear.
Methods: A total of 797 patients in the ICU of Xin-Hua Hospital, Shanghai, China were enrolled. We determined the Acute Physiology and Chronic Health Evaluation II (APACHE II) scores from these patients and collected blood samples to measure the levels of neutrophil CD64, thyroid hormone and C-reactive protein (CRP). We assessed the association between APACHE II scores or these biomarkers and mortality of patients in the ICU. Receiver operating characteristic (ROC) curves were generated and the Area Under the Curve (AUC) for each indicator was determined.
Results: The AUC for CD64 was 0.752 ± 0.026, which was higher than that of FT3 (0.696 ± 0.028) and CRP (0.672 ± 0.026). APACHE II scores had the highest AUC (0.872 ± 0.018). The level of neutrophil CD64 expression positively associated with CRP and APACHE II, and negatively correlated with FT3. Multiple regression analysis revealed that APACHE II scores (Standard β value = 0.183, P < 0.001), CD64 (Standard β value = 0.518, P < 0.001) or log (CRP) (Standard β value = 1.203, P < 0.001) independently predicted ICU mortality.
Conclusion: CD64 had the greatest power for predicting ICU mortality other than APACHE II scores. This result indicates that CD64 may be used as a biomarker to in combination with the use of APACHE II scores to improve the accuracy of predicting mortality outcome for patients in the ICU.
Keywords: ICU; Neutrophil CD64; mortality; predictor.