title: Activation of the alternative complement pathway in ascitic fluid during spontaneous bacterial peritonitis.
abstract: We studied complement and immunoglobulin profiles on the serum and ascitic fluid of a patient before and during gram-negative spontaneous bacterial peritonitis (SBP). During the infection, activation of the alternative complement pathway in ascitic fluid was manifested by a 35% reduction in functional activity and depression of both properdin and factor B concentrations to nondetectable levels. Activation of the complement cascade was also demonstrated by a 50% reduction in the C3 concentration and depression of total hemolytic complement. There was no evidence of complement activation of a functionally intact complement system in the ascitic fluid of cirrhotic patients. Complement consumption in ascitic fluid may predispose the cirrhotic to SBP.
mesh_terms: D001202:Ascitic Fluid / Q000276:immunology*; D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003170:Complement Pathway, Alternative; D003171:Complement Pathway, Classical; D003165:Complement System Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D007710:Klebsiella Infections / Q000276:immunology*; D007711:Klebsiella pneumoniae; D008875:Middle Aged; D010538:Peritonitis / Q000276:immunology*; D011414:Properdin / Q000032:analysis
chemical_list: D003176:Complement C3; D003181:Complement C4; D007136:Immunoglobulins; D011414:Properdin; D003165:Complement System Proteins