Procalcitonin and severity of community-acquired pneumonia

The purpose of this study was to clarify the relationship between procalcitonin and the severity and prognosis of community-acquired pneumonia. The subjects were 162 patients with community-acquired pneumonia (disease severity, mild, 39 patients; moderate, 81 patients; severe, 37 patients; and super severe, 5 patients) in whom we examined the serum procalcitonin concentration at the start of treatment; we determined the relationship of procalcitonin status with disease severity and prognosis. The results showed that procalcitonin was positive in 12.8% of the patients with mild disease, 27.1% of the patients with moderate disease, 59.5% of the patients with severe disease, and 80.0% of the patients with super severe disease. The mortality of procalcitonin-positive patients was 37.7%, whereas that of the procalcitonin-negative patients was 12.8%. Based on the above findings, it is concluded that the more severe the community-acquired pneumonia, the higher is the positivity rate for procalcitonin, and the prognosis in procalcitonin-positive patients is worse than that in procalcitonin-negative patients.