Effect of Neutrophil CD64 Index in Elderly Patient with Community-acquired Pneumonia

Abstract Background: Elderly patient with community-acquired pneumonia is the leading infectious cause of death. During the clinical diagnosis and treatment, some elderly patients do not have typical clinical symptoms .Therefore establishment of safe and effective diagnosis, prognostic assessment systems is important for clinicians. Objective: To evaluate the diagnostic and prognostic value of the neutrophil CD64(nCD64) in elderly patients with community-acquired pneumonia. Methods: One hundred and twenty-eight elderly patients(≥65year) diagnosed with community-acquired pneumonia from December 2018 to December 2020. All patients were further subdivided into two groups: Non severe community-acquired pneumonia(N-SCAP) group and severe community-acquired pneumonia (SCAP)group. nCD64 index, procalcitonin (PCT) level, C-reactive protein (CRP) level, White blood cell (WBC) counts and Neutrophil (NEUT) absolute counts were obtained and CURB-65 scores were calculated for each patient. Results: The nCD64, CRP ,PCT, WBC,NEUT levels,CURB-65 score were higher in severe community-acquired pneumonia group patients. The nCD64, CRP, PCT levels ,CURB-65 score were higher in non-survivors. The receiver operating characteristic (ROC) curve of nCD64 was higher than those of CRP, PCT, WBC, NEUT levels for diagnosing infection. The AUC of nCD64 for predicting 28-day mortality in community-acquired pneumonia was significantly higher than those of CRP ,PCT, WBC and NEUT. The AUC of nCD64 combined with CURB-65 score was significantly higher than that of CRP, PCT, WBC and NEUT parameter combined with CURB-65 score for predicting 28-day mortality. Conclusions: The neutrophil CD64 index is a valuable biomarker for diagnosis of infection and prognostic evaluation in elderly patients (≥65 year) with community-acquired pneumonia.