Prospective study on procalcitonin and other systemic infection markers in patients with leukocytosis.

Objective: To better assess the diagnosis of an infection in patients presenting at an emergency department with peripheral blood leukocytosis (>10 x 10(9) cells/l) on laboratory testing.

Methods: We prospectively evaluated serum procalcitonin concentration (PCT), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Patients were divided into two groups according to their final diagnosis: patients with infection and those without infection.