Opsonic Fibronectin Deficiency and Sepsis

Abstract

To address the possibility that opsonic fibronectin deficiency might lower resistance to sepsis, Sprague-Dawley rats (200 g) were partially depleted (35%) of their opsonic fibronectin prior to i.p. inoculation with Staphylococcus aureus. Mortality to S. aureus peritonitis was significantly (P < 0.05) increased in animals with fibronectin deficiency. In control animals, nonsurvival was also associated with significantly (P < 0.05) lower initial fibronectin levels than survival. Peritonitis itself also resulted in an early (within 1 h) depletion of opsonic fibronectin followed by a marked hyperopsonemia within 12 h in both groups. Thus, opsonic fibronectin depletion decreases resistance to sepsis and the development of sepsis itself will initiate opsonic fibronectin deficiency. Host defense against infection may depend on early restoration and maintenance of normal opsonic fibronectin levels following trauma, burn and operation, as well as the ability of the host to mount an appropriate hyperopsonemic elevation of fibronectin levels in response to infection.