Flow Cytometric Determination of Neutrophil CD64 (nCD64) in Children with Community Acquired Pneumonia

Background The expression of CD64 in neutrophils (nCD64) has shown utility in the diagnosis of sepsis. The aim of this study was to evaluate the diagnostic value of neutrophil CD64 in pneumonia as an early marker for infection and correlate its level with the outcome of pneumonia. Materials and Methods Forty children diagnosed as pneumonia and admitted at pediatric department, Minia University Children’s Hospital, Egypt, were included in the study and another forty apparently healthy children served as controls. Both patients and controls were subjected to complete blood counts (CBC), quantitative C-reactive protein (CRP), arterial blood gases (ABG), and determination of CD64 expression on neutrophils by flow cytometry. Results The absolute count of nCD64 in patients with community acquired pneumonia was (1140±109.7) (RFU), significantly higher than in controls (327.3± 25.7) (RFU) (p=0.001). Significant positive correlations were found between CD64 and CRP (p=0.001, r=0.76) and total leucocytic count of patients (p=0.01, r=0.76). Significant negative correlations were present between CD64 and platelet count (p=0.008, r= - 0.7), age (p=0.001, r= - 0.9) and weight (p=0.01, r= - 0.8), respectively. Conclusion Determination of peripheral blood neutrophil CD64 is sensitive and specific for early diagnosis of pneumonia and high level is associated with clinical deterioration and poor outcomes.