Role of Procalcitonin in Differential Diagnosis of Pneumonia and Pulmonary Congestion Associated With End-Stage Renal Failure.

OBJECTIVES: We aimed to determine the role of procalcitonin in distinguishing between infectious and noninfectious causes, specifically the cause of the infiltrative appearances detected on lung radiographs of patients with end-stage renal failure receiving hemodialysis.

MATERIALS AND METHODS: Sixty-six patients between 19 and 87 years of age were enrolled. Patients were divided into 3 groups, with each group consisting of 22 patients: group 1 comprised pneumonia patients without end-stage renal failure, group 2 comprised pulmonary congestion patients with end-stage renal failure, and group 3 were healthy participants. All demographic and clinical characteristics of patients and healthy participants were noted, anteroposterior lung radiographs were taken, and blood samples were obtained for complete blood count, C-reactive protein, and procalcitonin measurements. Patients in group 2 received control posteroanterior lung radiography.

RESULTS: Group 1 demonstrated a significantly lower mean procalcitonin value than group 2 (P = .001) but significantly higher mean C-reactive protein and leukocyte levels (P < .05). In terms of mean C-reactive protein and leukocyte levels, there was no difference between groups 2 and 3 (P > .05). The classification performed by recognizing 0.5 ng/mL as the cutoff point for procalcitonin resulted in no significant differences between groups 1 and 2 (P = .103). However, a significant difference (P = .014) was found between these groups when basing the classification as 1.5 ng/mL cutoff point in group 2 and 0.5 ng/mL cutoff point in group 1. Procalcitonin level was below 1.5 ng/mL in all group 2 patients.

CONCLUSIONS: Our findings support that procalcitonin has no superiority over C-reactive protein in diagnosis of community-acquired pneumonia. Moreover, at procalcitonin values below 1.5 ng/mL in patients with end-stage renal failure who have pulmonary congestion but without clinical signs of infection, infiltrative appearances on lung images may be attributed to hypervolemia, which would in turn prevent unnecessary antibiotic therapies. We believe that measurement of C-reactive protein is still preferable to procalcitonin in revealing the inflammatory response due to its cost-effectiveness and ease in performance and the high diagnostic performance in transplant candidates.