Serum procalcitonin levels in critically ill patients colonized with Candida spp: new clues for the early recognition of invasive candidiasis?

Invasive candidiasis (IC) outcomes in intensive care units (ICUs) could be improved by the early administration of antifungals. The Candida Score (CS) prediction rule has been proposed for the selection of patients who could develop IC. Procalcitonin (PCT) levels allow prompt identification of sepsis, but their behavior in the setting of IC is unclear. We hypothesize that PCT could be helpful in the early diagnosis of IC in patients with Candida sp. colonization. Prospective observational study. Thirty-six ICUs in Spain, Portugal and France. Every non-neutropenic critically ill patient hospitalized for more than 7 days without concurrent bacterial infection. The CS was calculated weekly. Serums were collected concomitantly. Two hundred twenty PCT levels were measured in 136 patients [neither colonized nor infected (NCNI): n = 73; multifocal colonization (MF): n = 43; MF + IC: n = 20]. Baseline PCT levels were significantly higher in the MF + IC group than in other groups (p = 0.001). In patients with MF, the highest CS value calculated during the patient's stay was the sole independent predictor of IC. The receiver-operating curve analysis showed that the diagnosis values of PCT and CS were comparable (AUROCC = 0.713, and 0.727, respectively). Moreover, PCT increased the positive predictive value of CS from 44.7 to 59.3%. After 7 days of hospitalization, PCT levels in patients with MF who go on to develop IC are higher than in others. Serum PCT could also improve the predictive value of CS. PCT together with CS could therefore be considered for the assessment of IC risk.