Circulating immune complexes after cadaver kidney transplantation.

351 sera from 27 human recipients of renal allografts and 21 healthy blood donors were assayed for circulating immune complexes by the Clq solid-phase radioimmune assay. Increased Clq-binding activity (Clq-BA) was detected in pretransplant sera from 5 patients with chronic pyelonephritis (PN) and 3 patients with chronic glomerulonephritis (GN). A significant decrease of Clq-BA immediately after transplantation could not be found. 6 weeks after transplantation only 2 patients of the PN group showed increased Clq-BA. Serial studies in 17 patients with rejection crises did not show any correlation between the level of serum Clq-BA and the occurrence of rejections. Furthermore, no correlation could be found between the occurrence of complement-dependent lymphocytotoxic antibodies measured by the 51Cr release technique and the level of serum Clq-BA. In contrast, our results show that the probability of graftectomy or graft failure is significantly higher, at least in the early phase after transplantation, when the serum Clq-BA is lowered for several weeks.