Antibody to G-actin in different categories of alcoholic liver disease: quantification by an ELISA and significance for alcoholic cirrhosis.
Autoantibodies to smooth muscle (ASMA), and to actin which is a major determinant of such reactivity, were measured in the serum of 94 patients with three defined categories of alcoholic liver disease, fatty liver, alcoholic hepatitis, and alcoholic cirrhosis, and in controls matched individually by age and sex with the patients. Autoantibody to monomeric G-actin was detected by an ELISA and autoantibody to polymeric F-actin by immunofluorescence staining of fibroblast stress fibers in cultured cells. Values for the ELISA were expressed as a percentage of the value for a strongly reactive standard serum. The mean value for antibody to G-actin in 40 patients with alcoholic cirrhosis (70 +/- 33%) was significantly greater than that for the matched controls (28 +/- 18%), but the mean value for the 30 patients with alcoholic hepatitis (46 +/- 16%) and the 24 with fatty liver (42 +/- 24%) did not differ significantly from the controls. High levels of reactivity with G-actin correlated significantly with HLA B7. ASMA was demonstrable to low titer in 11 of the 94 sera, and positive ASMA reactions by immunofluorescence correlated with high binding values to G-actin in the ELISA. Antibody to F-actin was found in only one serum and no controls. Thus in different liver diseases the reactivity of antibodies to monomeric G-actin and polymeric F-actin may differ, presumably because of specificity for different determinants of the actin molecule. Reactivity to G-actin may distinguish a group of alcoholic subjects in whom a predisposition to autoimmune reactivity is one of the determinants of progression of liver damage to cirrhosis.
D000199:Actins / Q000276:immunology*; D000941:Antigens / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006680:HLA Antigens / Q000235:genetics; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006801:Humans; D008104:Liver Cirrhosis, Alcoholic / Q000276:immunology*; D008108:Liver Diseases, Alcoholic / Q000276:immunology*; D009130:Muscle, Smooth / Q000276:immunology
D000199:Actins; D000941:Antigens; D001323:Autoantibodies; D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens