Lachmann P J, Voak D, Oldroyd R G, Downie D M, Bevan P C
Vox Sang. 1983;45(5):367-72. doi: 10.1111/j.1423-0410.1983.tb01928.x.
Using monoclonal antibodies to C3 it has been shown that the red blood cells of patients with cold haemagglutinin disease carry on their cells C3d,g (alpha-2D-globulin) rather than C3d. C3d,g seems to be the final product of in vivo C3 activation in fluid phase and on red cells. The cleavage of C3dg to C3d and C3g does not appear to occur in vivo either in the fluid phase or on red cell bound C3bi. In vitro C3-coated red cells prepared by antibody or low ionic strength techniques produce cells with C3d and C3bi as the predominant C3 fragment, whereas the Fruitstone technique in which coating occurs by the alternative pathway has principally C3b. The activity of C3 cleaving enzymes in whole serum is strongly influenced by the ionic conditions of the serum.
利用针对C3的单克隆抗体已表明，冷凝集素病患者的红细胞在其细胞上携带的是C3d,g（α-2D球蛋白）而非C3d。C3d,g似乎是液相和红细胞上体内C3激活的最终产物。C3dg裂解为C3d和C3g在体内液相或红细胞结合的C3bi中似乎均不会发生。通过抗体或低离子强度技术制备的体外C3包被红细胞产生的细胞以C3d和C3bi作为主要的C3片段，而通过替代途径进行包被的弗鲁伊施通技术产生的细胞主要含有C3b。全血清中C3裂解酶的活性受血清离子条件的强烈影响。
