Abstract:

Objective To investigate the role of absolute value of neutrophil CD64（nCD64） determined by cell solid-phase chip method in the diagnosis of bacterial infectious diseases. Methods Totally，120 bacterial infection patients（bacterial infection group），60 viral infection patients（viral infection group） and 92 healthy subjects（healthy control group） were enrolled from Ruijin Hospital，Shanghai Jiao Tong University School of Medicine from January 2024 to September 2024. The absolute value of nCD64 was determined using cell solid-phase chip method. White blood cell（WBC）count，procalcitonin（PCT） and C-reactive protein（CRP） were determined as well. Receiver operating characteristic（ROC） curve was used to evaluate the efficacy of the 4 indicators in diagnosing bacterial infectious diseases. Results The levels of absolute value of nCD64，WBC count，PCT and CRP in bacterial infection group were higher than those in viral infection group and healthy control group（P<0.05）. WBC count in viral infection group was lower than that in healthy control group（P<0.05）. There was no statistical significance in the absolute value of nCD64，PCT and CRP between viral infection group and healthy control group（P>0.05）. The areas under curves（AUC） of the absolute value of nCD64，WBC count，PCT，CRP were 0.934，0.868，0.868 and 0.856 for the differential diagnosis of bacterial infection and non-bacterial infection，respectively. The optimal cut-off value，sensitivity and specificity of the absolute value of nCD64 for diagnosing bacterial infectious diseases were >892 μL^-1，88.3% and 92.8%，respectively. The diagnostic efficacy of the absolute value of nCD64 for bacterial infectious diseases was better than WBC count，PCT and CRP（P<0.05）. Conclusions The absolute value of nCD64 can be used as one of the auxiliary diagnostic indicators for bacterial infection. Using cell solid-phase chip method to determine the absolute value of nCD64 in peripheral blood is easy to operate and cost-effective，which can be promoted and applied in primary hospitals.

Key words: Neutrophil CD64, Cell solid-phase chip method, White blood cell count, Procalcitonin, C-reactive protein, Bacterial infection