Serum procalcitonin levels in patients with primary pulmonary coccidioidomycosis.

Abstract

The serum procalcitonin assay has emerged as a promising biomarker to distinguish between bacterial and viral respiratory tract infections but has not been used to differentiate coccidioidomycosis from bacterial infection. A correlation between procalcitonin serum levels and coccidioidomycosis has never been reported. To determine any association between serum procalcitonin levels and primary pulmonary coccidioidomycosis. We identified and enrolled 20 immunocompetent patients with symptomatic primary pulmonary coccidioidomycosis of < 8 weeks' duration and performed a one-time procalcitonin assay, with a cutoff of < 0.25 μg/L indicating a nonbacterial infection. Nineteen of 20 patients (95%) had serum procalcitonin of < 0.25 μg/L. The median procalcitonin level was 0.05 μg/L (range, < 0.05-0.87 μg/L; interquartile range, 0.05-0.05 μg/L). Sixteen of 20 patients (80%) had undetectable procalcitonin of < 0.05 μg/L. The four patients with detectable procalcitonin had a median value of 0.2 μg/L (range, 0.09-0.87 μg/L). In this pilot study, procalcitonin was not elevated in immunocompetent patients with primary pulmonary coccidioidomycosis at a median of 32 days after symptom onset. Larger prospective studies are needed to confirm this finding.