PCT discriminates aerobic and anaerobic bacteremia from nonbacterial blood infections: A 10 years study in CKD patients.

Background: Bacteremia can sometimes be difficult to substantiate. Its early distinction from non-bacterial blood stream infections in Chronic Kidney Disease patients is often a challenge due to functional deterioration of various components of immune system. Serum Procalcitonin assay is one of the biomarkers of sepsis. Thus the aim of this study is to analyze the usefulness of Procalcitonin as both diagnostic and prognostic marker for aerobic and anaerobic bacteremia and to assess the correlation between serum Procalcitonin and time to positivity. Methods: The study is based on the analysis of our data over a period of 10 years. We retrospectively analyzed 1168 Chronic Kidney Disease patients with suspected blood stream infections who had concurrent Procalcitonin data and blood culture results. Results: Procalcitonin levels were significantly correlated with Time to Positivity and also with survival of patients in positive blood cultures. Survival analysis revealed that patient with high Procalcitonin had significant low survival rate than patients with low Procalcitonin. Area under the Receiver operative characteristic curve for aerobes, anaerobes, fungus and negative blood cultures was 0.920, 0.913, 0.110 and 0.016 respectively. The optimal cut-off value of serum Procalcitonin for predicting aerobic bacteremia was 1.3 and 1.29 for anaerobic blood stream infections. Conclusions: Procalcitonin is a reliable and promising biomarker to discriminate aerobic and anaerobic bacteremia from non-bacterial blood stream infections. Procalcitonin may also predict the severity and prognosis of Blood stream infections but renal function should be taken into account.