Both antibody dependant and independant complement pathway converge on which complement component
ref Harrison 17/e p2039,9/e p88 Complement component C3 is the most impoant and abundant protein in the complement system. It is placed on microbes to destroy them. By measuring complement C3 levels, especially in how they compare with other pas of the complement system, your healthcare provider can diagnose and monitor treatment of ceain diseases. One of the diseases that commonly involves abnormal C3 is systemic lupus erythematosus, or lupus, an autoimmune disorder.
C3
C5
C1q
C8
General anatomy