Neutrophil CD64 As A Diagnostic Marker Of Bacterial Infection In Acute Exacerbation Of Chronic Obstructive Pulmonary Disease

Purpose The aim of this study was to determine the diagnostic accuracy of neutrophil CD64 as a diagnostic biomarker of bacterial infection in acute exacerbation of chronic obstructive pulmonary disease in comparison with white blood cell count(WBC),neutrophil percentage(Neu%),C-reactive protein(CRP)and procalcitonin(PCT).Methods A total of 64 patients with acute exacerbation of COPD and stable COPD were collected from The Second Affiliated Hospital of Soochow University from March 2016 to December 2016.According to the clinical symptoms,they were divided into two groups: AECOPD group(48 cases)and stable COPD group(16 cases).Twenty healthy controls were selected concurrently from medical examination center.The AECOPD group was further divided into two groups on the characteristics of sputum and bacterial culture of the samples: bacterial infection(28 cases)and non-bacterial infection(20 cases).According to the efficacy of antibiotic treatment,the AECOPD with bacterial infection were subdivided into effective group(22 cases)and ineffective group(6 cases).CD64 index,WBC,Neu%,CRP and PCT were analyzed by flow cytometry,blood analysis and electrochemiluminescence among patients with stable COPD or AECOPD as well as healthy controls.Results All CD64 index and the other inflammatory biomarkers were statistically significantly higher in patients with AECOPD caused by bacterial infection compared with patients with non-bacterial infection,stable COPD and healthy controls,and the differences were statistically significant(P?0.001).A week after effective antibiotic treatment,there was a statistical significant reduction of CD64 index in AECOPD caused by bacterial infection compared with the healthy control groups(P?0.001).The area under the ROC curve of CD64 was 0.949,which was the greatest compared with the other biomarkers of bacterial infection.If the cutoff value of CD64 was set to 0.399%,a sensitivity of 89.66% and specificity of 90.48% were achieved,which was higher than the other inflammation biomarkers.Conclusion Neutrophil CD64 can serve as a potential biomarker in diagnostis and therapy evaluation of bacterial infection in acute exacerbation of chronic obstructive pulmonary disease.