title: Different patterns of C3 and C4 activation in the varied types of juvenile arthritis.
abstract: Quantitative assays for C3 and C4 activation were carried out simultaneously on blood from children with varied types of juvenile arthritis. Factor VIII-related antigen was also measured as an indicator of vascular damage. In active systemic juvenile arthritis, the C4d/C4 ratio was frequently elevated and was usually associated with elevated C3d/C3 ratios and elevated concentrations of factor VIII-related antigen. Children with chronic polyarticular arthritis, no matter which forms of onset they had had, also had increased levels of the C4d/C4 ratio, C3d/C3 ratio, and factor VIII-related antigen, but these were less consistent and were not associated with each other. In contrast, in pauciarticular arthritis there was a uniquely isolated increase in the C3d/C3 ratio. This work implies that there are different mechanisms responsible for complement activation in the different types and at different stages of juvenile arthritis.
mesh_terms: D000293:Adolescent; D000941:Antigens / Q000032:analysis; D001171:Arthritis, Juvenile / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood; D002648:Child; D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis*; D015933:Complement C3d; D003181:Complement C4 / Q000032:analysis*; D015935:Complement C4b; D005169:Factor VIII / Q000032:analysis / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D014841:von Willebrand Factor
chemical_list: D000941:Antigens; D001323:Autoantibodies; D003176:Complement C3; D003181:Complement C4; D010446:Peptide Fragments; D014841:von Willebrand Factor; D015933:Complement C3d; D015935:Complement C4b; C032261:complement C4d; D005169:Factor VIII