Incubation of normal human serum with
hemodialysis membranes in vitro resulted in conversion of C3 which was detected by crossed immunoelectrophoresis. In addition, formation of C3d was also observed, as was detected by double-decker rocket immunoelectrophoresis. Furthermore, breakdown products of
complement (
iC3b, C4d & Bb) in plasma samples were measured by ELISA. The microassay plates were coated with
monoclonal antibodies which bind specifically to human
iC3b, C4d and Bb, respectively, while the plasma samples were drawn from five
polycystic kidney patients during initial
hemodialysis. As a result, the
iC3b and Bb levels in plasma were seen to increase during
hemodialysis but the C4d levels revealed no significant changes. It was also observed that the Bb levels in patients undergoing
hemodialysis were significantly higher than those in various renal and
collagen diseases.
Terminal complement complex (TCC) was not present in detectable amounts in normal human serum when measured by ELISA. However, incubation of normal human serum with
hemodialysis membranes in vitro resulted in detection of TCC. TCC was present in the same plasma samples drawned from the five
polycystic kidney patients during initial
hemodialysis. It is suggestive that activation of
complement by
hemodialysis membrane is predominantly mediated through the alternative pathway and products such as TCC and
anaphylatoxin are formed by this activation.