OBJECTIVETissue factor (TF) is an important factor in extrinsic coagulation. Tissue factor pathway inhibitor (TFPI) is a negative regulator of coagulation mediated by TF. Studies on TF and TFPI focus mainly on adult objects, seldom have been done on newborns, especially on sick newborns. The aim of this study was to observe the changes of TF and TFPI in plasma of newborns with infection jaundice and to research the effect of jaundice and infection on the balance of TF and TFPI in newborns.

METHODSThe content of TF and TFPI in plasma of 21 jaundiced newborns with infection and 8 jaundiced newborns without infection as control was determined quantitatively with the enzyme-linked immunosorbent assay (ELISA).

RESULTSThe content of TFPI and TF in plasma of jaundiced newborn with infection was significantly higher than that of controls [TFPI (21.0 +/- 4.3) vs. (16.2 +/- 1.9) microg/L, P < 0.01; TF (177 +/- 79) vs. (51 +/- 24) ng/L, P < 0.01]. The ratio of TFPI/TF was significantly lower in newborn with infection jaundice than the controls (137 +/- 61 vs. 319 +/- 67, P < 0.01). The 21 jaundiced newborns with infection were divided into the severe hyperbilirubinemia group (serum bilirubin > or = 205.2 micromol/L, n = 10) and the mild hyperbilirubinemia group (serum bilirubin < 205.2 micromol/L, n = 11). There was no significant difference of TFPI level between the severe hyperbilirubinemia group and mild hyperbilirubinemia group (P > 0.05). The TF content in the severe hyperbilirubinemia group was higher than that in the mild hyperbilirubinemia group (216 +/- 79 vs.141 +/- 63, P < 0.01), while the ration of TFPI/TF was lower in the severe hyperbilirubinemia group than in the mild hyperbilirubinemia group (100 +/- 30 vs. 171 +/- 74, P < 0.01).

CONCLUSIONInfection might induce imbalance between the coagulation inhibition and activation in newborns. Hyperbilirubinemia can aggravate the imbalance induced by the infection through increasing plasma TF level.