[Clinical significance of the estimations of complement and immune complexes].
Immune complexes (IC) interacting with complement (C) induce tissue injuries and the estimations of their sequential serum levels is clinically significant. In C, among the various parameters, total hemolytic activity (CH 50) is clinically the most useful especially in the diagnosis and treatment of SLE. Elevation of serum CH 50 levels is nonspecifically observed in patients with inflammations and malignancies, although its mechanism remain obscure. Decreased CH 50 levels were observed in various diseases including liver diseases, collagen diseases, kidney diseases, congenital C component deficiencies and so on. Among them, chronic liver disease is the most frequently encountered disease. Liver function should be checked first in cases with low CH 50. In IC, patho-etiological significance has been established and various methods for the estimation have been employed. However, their sensitivities and specificities are various and positivities obtained by these methods vary with the diseases. Clinical significance of IC estimation has been recognized to be limited to a few diseases including SLE, in which some clinical signs parallel the IC level. However, recent developments in the methods employing murine monoclonal antibodies to C1q and C3d and IgG rheumatoid factor are expected to help re-evaluation the significance of serum IC estimation in various diseases. Heat-pretreatment of sera at 56 degrees C or below produced the reactivity of IgG with rheumatoid factors. Therefore, serum samples should be estimated without heat-inactivation.
Yoshida
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Watanabe
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D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex / Q000032:analysis*; D015941:Complement Hemolytic Activity Assay; D003165:Complement System Proteins / Q000032:analysis*; D006801:Humans; D008099:Liver / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000276:immunology
D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D003165:Complement System Proteins