TY - JOUR T1 - Neutrophil CD 64 expression as a diagnostic marker of pneumonia in patients with acute COPD exacerbation JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P576 AU - Elena Titova AU - Marthe Wedø Aune AU - Kristin Fonn AU - Anne Hildur Henriksen AU - Arne Åsberg Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P576.abstract N2 - Background: Early detection of pneumonia in patients with acute exacerbation of COPD (AECOPD) is clinically important. The increased expression of CD64 (Fc gamma receptor 1) in neutrophils has been shown to be an early diagnostic biomarker of bacterial infections.Aim: To study the diagnostic accuracy of CD64 as a biomarker of pneumonia in patients with AECOPD.Methods: This was a prospective, observational study in patients admitted with AECOPD. Neutrophil CD64, C-reactive protein (CRP) and the leukocyte count were measured in blood samples obtained at admission. Pneumonia was defined as a new infiltrate on chest X-ray. CD64 was measured using a Celldyn Sapphire analyzer with reagents from Trillium Diagnostics. The diagnostic accuracies of CD64, CRP and the leukocyte count were compared using receiver operating characteristic (ROC) curve analysis. The best combination of test was derived using logistic regression.Results: Of the 112 included patients (58% females), mean age was 70 years, and a pulmonary infiltrate was found in 39 patients (35%). The data set was complete in all, except for CD64, which was measured in 71 patients. The area under the ROC curve of CD64, CRP and leukocytes was 0.73 (0.60-0.86), 0.79 (0.69-0.88) and 0.64 (0.53-0.76), respectively. In logistic regression modeling using age, gender, CRP, leukocytes, CD64, temperature, and the presence of expectorate and cough to predict pneumonia, only CRP and gender was statistically significant. The area under the ROC curve of a model with CRP and gender was 0.84.Conclusion: Neutrophil CD64 expression gives no additional information as a marker of pneumonia in patients with AECOPD. ER -