MANNAN-BINDING PROTEIN AND COMPLEMENT-DEPENDENT OPSONIZATION IN ALCOHOLIC CIRRHOSIS

Mannan-binding protein is synthesized by the liver and functions in fi rst-line host defence by opsonizing mannose-rich microorganisms due to activation of the classical complement pathway independent of Clq, an d by an intrinsic ability to opsonize and mediate phagocytosis. We hav e investigated whether the increased susceptibility to bacterial infec tions in patients with cirrhosis could be explained by low plasma conc entrations of mannan-binding protein and impaired complement-dependent opsonization. We examined 51 patients with compensated alcoholic cirr hosis, 34 who were decompensated and 16 healthy controls. Irrespective of group, we found a significant correlation (p < 0.05) between plasm a mannan-binding protein concentration and deposition of the complemen t opsonin C4 on mannan from baker's yeast. In contrast to what was exp ected, this kind of opsonization and plasma levels of mannan-binding p rotein were significantly increased:in the patients with decompensated cirrhosis (p = 0.01 and p = 0.007, respectively). A significant corre lation (O < 0.05) was found between mannan-binding protein and erythro cyte sedimentation rate, fibrinogen and haptoglobin in these patients. Though the correlations were weak (rho = 0.49, rho = 0.48 and rho = 0 .40, respectively), the elevated levels of mannan-binding protein in t he patients with decompensated cirrhosis may reflect an acute phase re action. It is concluded that plasma levels of mannan-binding protein a re increased in patients with decompensated cirrhosis and that complem ent-dependent opsonization of mannan does not seem to be compromized i n patients with alcoholic cirrhosis.