Decreased plasma fibronectin in neonatal sepsis.

Fibronectin is a large opsonic glycoprotein which promotes reticuloendothelial system clearance of bacteria, immune complexes, collagenous debris, and damaged platelets. The concentration of plasma fibronectin is decreased in the newborn infant; however, the role of fibronectin in the onset and course of neonatal sepsis is unknown. Serial plasma fibronectin levels were determined in 19 neonates with documented bacterial sepsis. Plasma fibronectin concentrations decreased significantly (P less than .001) in all study infants concurrent with the development of septicemia. Recovery of plasma fibronectin to normal levels occurred by day 5 in premature neonates and by days 7 to 10 in term neonates. Fibronectin deficiency and resultant reticuloendothelial system impairment may decrease the ability of newborn infants to resist or clear bacterial infections. An acute reduction in the concentration of plasma fibronectin may be a valuable marker for neonatal sepsis.