because spa forms complexes with igg that can activate complement , and the physiologic response during treatment often involves hypocomplementemia and reactions that are similar to those induced by anaphylatoxins , we used sensitive and specific radioimmunoassays to test the ability of spa reagents to generate c3a , c4a , and c5a from human serum .
C0002791
anaphylatoxins
C0009510
c3a