title: The effect of aging on complement activity (CH50) and complement protein levels.
abstract: Total complement activity (CH50), and the protein levels of C1q, C4, C3, C5, C9, factor B and C1 inactivator were measured in the 1,130 sera obtained from healthy subjects aged between 20 and 79 years old. Increase in the levels of CH50, C1q, C4, C3, C5 and C9 and decrease of factor B were found in the older age group. The level of C1 inactivator showed little variation with aging.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D003167:Complement Activation; D003176:Complement C3 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D003182:Complement C5 / Q000032:analysis; D003186:Complement C9 / Q000032:analysis; D003165:Complement System Proteins / Q000032:analysis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D003176:Complement C3; D003181:Complement C4; D003182:Complement C5; D003186:Complement C9; D003165:Complement System Proteins