title: Complement activation in patients with amebic liver abscess.
abstract: Serum or plasma concentrations of components of the classical (C1q, C4) and alternative (C3, factor B) pathways, regulatory protein factor H, and one of the C3 products of degradation, C3d, were determined in 19 patients with amebic liver abscess (ALA). Patients were divided into two groups. Thirteen patients that recovered under medical treatment who had a significantly shorter clinical course on admission (P less than 0.05) (group 1) exhibited either normal (C1q; C4; factor B; C3d) or increased levels of these components (C3, P less than 0.001; factor B, P less than 0.01). On the other hand, 16 patients that recovered after medical treatment and abscess drainage (group 2) exhibited significantly diminished serum levels of C1q (P less than 0.05), C3 (P less than 0.001), factor B (P less than 0.01) and factor H (P less than 0.05), and normal levels of C4, and C3d as compared to the control group. The relationships among the complement components studied were suggestive of activation of the complement system through the classical pathway in patients within group 1 and through both pathways in group 2. Sera of 3 out of the 5 patients who initially exhibited low plasma levels of C3d showed an increase during convalescence. Plasma levels of C3d were demonstrated to show a direct correlation with serum albumin and SGOT in this group of patients. Possible implications of the complement system in the immunopathogenesis of ALA are discussed.
mesh_terms: D003166:Complement Activating Enzymes / Q000378:metabolism; D003167:Complement Activation; D003172:Complement C1 / Q000378:metabolism; D015922:Complement C1q; D003176:Complement C3 / Q000378:metabolism; D003180:Complement C3b Inactivator Proteins / Q000378:metabolism; D015933:Complement C3d; D003181:Complement C4 / Q000378:metabolism; D011415:Complement Factor B / Q000378:metabolism; D017242:Complement Factor H; D004748:Entamoeba histolytica; D006801:Humans; D008101:Liver Abscess, Amebic / Q000276:immunology*
chemical_list: C493495:CFH protein, human; D003172:Complement C1; D003176:Complement C3; D003180:Complement C3b Inactivator Proteins; D003181:Complement C4; D015922:Complement C1q; D015933:Complement C3d; D017242:Complement Factor H; D003166:Complement Activating Enzymes; D011415:Complement Factor B