[Decreased plasma fibronectin (pFN) level in preterm infants with infections].

Plasma fibronectic (pFN) is a high molecular weight multifunction glycoprotein, which augments neutrophil and macrofage phagocytosis and acts as a nonspecific opsonin for the reticuloendothelial system. In this study we have determined pFN concentrations in fifty eight preterm infants to discriminate infected from non infected ones. Concentrations of pFN decreased from baselin in babies with early or late onset infections. The changes in pFN concentrations were not found before sepsis, but on day 1. By day 5 pFN concentrations have increased and have been no longer different from controls. We have calculated sensitivity (73.68%), specificity (74.36%), positive (58.35%) and negative (85.29%) predictive values of pFN and of other markers of infections (C-reactive protein--CRP-, Immature/Mature neutrophil ratio--I/M n. ratio-). Adding these tests to pFN, provided equal specificity and positive predictive value, but increased sensitivity (94.73%) and negative predictive value (96.43%). Thus, low concentrations of pFN may be a valuable but not early marker for neonatal infections. The combination of pFN, CRP and I/M n. ratio increase the precision of diagnostic testing.