Plasma
fibronectin (FN) is one of the major blood
opsonins. The content of the
glycoprotein reduces in
sepsis which in turn may aggravate the course of the
infection. FN is detectable in the content of
cryoglobulins and
cryofibrinogen. The formation of the
heparin precipitate following plasma incubation in the cold in the presence of
heparin is determined by FN involvement.
Fibrinogen (FG) is another main component of the
heparin precipitate. To determine the functional activity of plasma FN in
sepsis and other pathological conditions, a study was made of the ability of FN and FG to go into the precipitate formed in blood plasma in the cold after its incubation with
heparin. Unlike normal subjects in whom over 80% of FN on the average and about 20% of FG went into the
heparin precipitate, in patients with hemoblastoses and
aplastic anemia complicated by
sepsis, less than 40% of FN on the average and about 7% of FG went into the precipitate. In some patients with
sepsis, the
heparin precipitate did not form. The reduction of FN ability to go into the
heparin precipitate correlated with the gravity of the patients' condition. In uncomplicated hemoblastoses,
cryoglobulinemia and
cryofibrinogenemia and in immunocomplex pathology, the consumption of FN and FG during
heparin precipitate formation did not significantly differ from the control. The data indicate that
sepsis patients with blood system pathology may develop not only quantitative FN deficiency in the blood but also disorder of the functional activity of the
opsonin.