Clinical Value the Neutrophil CD64 Index in Predicting the Severity of Hemorrhagic Fever With Renal Syndrome

OBJECTIVE: The hemorrhagic fever with renal syndrome (HFRS) is an acute viral infectious disease characterized by multi-system damage involving complex mechanisms. Effective identification of critically ill patients is essential for the prognosis of HFRS. The aim of this study was to investigate the utility of the neutrophil CD64 index (nCD64 index) in predicting the severity of HFRS. METHODS: This study included 64 HFRS patients from the Center for Infectious Diseases of the Second Affiliated Hospital of Air Force Medical University between October 2023 and March 2024. The expression of CD64 on neutrophils was assessed using flow cytometry, and the nCD64 index was calculated. White blood cell (WBC), Procalcitonin (PCT), C-reactive protein (CRP), Il-6, and creatinine levels were measured for each patient, and Sequential Organ Failure Assessment (SOFA) scores were determined. RESULTS: The expression of nCD64 was generally elevated in HFRS patients and demonstrated a positive correlation with WBC, neutrophil, lymphocyte, monocyte, and PCT, as well as a negative correlation with platelet. The receiver operating characteristic (ROC) curve of nCD64 index for predicting high SOFA score patients outperformed those of CRP, creatinine and WBC, and was equivalent to that of IL-6 and PCT. CONCLUSION: The nCD64 index has the potential to serve as an effective biomarker for monitoring disease progression and assessing treatment efficacy in HFRS.