The role of procalcitonin in neonatal intensive ca

Authors: Maria Teresa Montagna Caterina Coretti Antonella Rella Giovanna Barbuti Fabio Manca Osvaldo Montagna Nicola Laforgia Giuseppina Caggiano

Publish Date: 2012/06/12

Volume: 58, Issue: 1, Pages: 27-31

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Abstract

Candidemia is a major infectious complication in neonatal patients The isolation of yeasts from blood is still the “gold standard” for its diagnosis but other laboratory markers ie circulating antigens have been studied with varying specificities and sensitivities The aim of this study was to evaluate the role of procalcitonin for the diagnosis of candidemia in neonatal patients at high risk To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity the determination of procalcitonin serum levels was estimated by two systems Overall 90 patients from a Neonatal Intensive Care Units were enrolled of whom six developed Candida bloodstream infection Four of six infants with candidemia had slight increase of procalcitonin values 05–1 ng/mL Only one baby showed very high levels but he had fungal and bacterial sepsis at the same time while no elevation was observed in the sixth patient No statistically significant difference was observed between two different methods at the time of monitoring p  0643 Both methods showed a sensitivity of 833  at diagnosis while the specificity was 738 and 631  by methods A and B respectively In the light of the low sensibility and specificity of this assay we can assume that the determination of procalcitonin would not seem to play a significant role in the diagnosis of fungal infection in neonatal patientsThe neonates admitted in Neonatal Intensive Care Unit NICU are highly prone to develop invasive fungal infections IFIs as result of the mostly unavoidable presence of several risk factors The isolation of yeast from blood remains the “gold standard” for the diagnosis of candidemia in these patients but it is hampered by small amount of blood that can be drawn from neonates Connell et al 2007 Rabalais et al 1996 Smith and Congdon 1985 by nonspecific clinical symptoms and by frequent unavailability of Candida isolates from blood systems their sensitivity for fungi may be as low as 50  Benjamin et al 2000 2003 In addition blood cultures take some days to grow these organismsTo date other laboratory markers Creactive protein Candida mannan 1→3betadglucan antigen specific antibodies or DNA fungal detection are currently considered as a useful support to achieve an early diagnosis of deep mycoses However some of these still require standardization and further evaluation and are not affordable for all laboratories because of various economic and technical reasons Di Stefano et al 2004 Oliveri et al 2008 Mularoni et al 2010Procalcitonin PCT is the precursor of the hormone calcitonin normally produced by Ccells of the thyroid gland in response to hormonal stimuli and virtually undetectable in healthy subjects 05 ng/mL In response to inflammatory stimuli the PCT can be also produced by liver Nijsten et al 2000 and peripheral blood mononuclear cells Oberhoffer et al 1999 increasing up to 1000 ng/mL in patients with systemic bacterial infections or septic shock Assicot et al 1993 Meisner et al 1999 Furthermore it might help to distinguish bacteremia from noninfectious inflammatory conditions resulting in an important impact on therapeutic decisions Meisner 2002 Simon et al 2004 van Rossum et al 2004 Schneider and Lam 2007 Becker et al 2008Regarding the role of PCT in IFIs the literature data are still few and controversial Charles et al 2009 Christofilopoulou et al 2002 Huber et al 1997 mostly late elevations of PCT have been observed in patients with disseminated aspergillosis Beaune et al 1998 and in some children with invasive candidiasis Dornbusch et al 2005 Recently Martini et al 2010 studying the role of PCT in surgical patients with candidemia observed that low PCT levels less than 20 ng/mL were more likely related to candidemia than bacteremiaThe aim of this study was to evaluate whether PCT may be an additional marker for Candidarelated sepsis in neonatal patients at high risk of candidemia To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity the determination of PCT serum levels was estimated by two systemsThe eligible patients were preterm infants gestational age 35 weeks weighing ≤1500 g at birth or fullterm infants all showing at least one of following clinical signs apnea caused by respiratory stress hypothermia and tachycardia Infants delivered by mothers receiving antibiotics either before or during delivery not requiring intensive care with mucocutaneous candidiasis or with proven bacterial sepsis were excluded from our study Each enrolled patient was subjected to serum PCT assay from the third day of life T3 and repeated on the fifth T5 seventh T7 ninth T9 and 11th day T11 Serum samples were kept refrigerated at −70 °C until they were processed At the same interval time T3 T5 T7 T9 and T11 blood cultures were carried out and an electronic report form was completed including clinical and microbiological data

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