Dosage de la procalcitonine pour le diagnostic d'une fièvre chez l'adulte non neutropénique

Abstract

The level of procalcitonin increases during bacterial, fungal, or parasitic infections, while it remains low in viral infection or inflammatory diseases. Could procalcitonin level be used to confirm or rule out a bacterial infection in pyretic patients? Methods. – We prospectively studied procalcitonin in pyretic patients. Serum procalcitonin level was determined on day-1. Patients were divided into 2 groups: in group I those diagnosed as having a bacterial, fungal, or parasitic infection; in group II those presenting with either a viral infection or an inflammatory disease. In group I the difference between patients with an elevated procalcitonin level (subgroup Ia) and those with a normal procalcitonin level (subgroup Ib) was analyzed according to: the delay between onset of fever and admission, bacteria, age and gender of patients, previous antimicrobial treatment, type of infection (generalized or localized). Results. – Eighty-six patients were enrolled. Procalcitonin was significantly higher in group I than in group II ( p < 0.001). The sensitivity of serum procalcitonin level was 70.7%, the specificity was 92.8%, the positive predictive value (PPV) reached 95.3% and the negative predictive value (NPV) 60.5%, with a cut-off value of 0.5 ng ml –1. There was no significant difference between subgroup Ia and Ib for the studied characteristics. Conclusion. – The PPV value could lead to diagnosing an infection in patients with fever. The sensitivity and NPV were too low to rule out a bacterial infection if procalcitonin is < 0.5 ng ml –1 in a pyretic patient. We are currently unable to explain the difference between group Ia and group Ib.