Effect of Renal Homotransplantation on the Metabolism of the Light Chains of Immunoglobulins

Abstract

The light (L) polypeptide chains of immunoglobulins are normally found in plasma in low concentrations ( < 20 [mu]g/ml). These proteins are almost entirely degraded by a catabolic process which is within the kidney or directly controlled by the kidney. The concentration of free L-chain proteins was measured in the serum and urine of 14 uremic patients who were undergoing hemodialysis in preparation for renal homotransplantation. Serum and urine concentrations were markedly increased in all patients and in some cases rose further during the anephric period following bilateral nephrectomy. After successful homotransplantation serum levels dropped rapidly and a diuresis of L-chain proteins was noted. Immediate failure of graft function was characterized by continued elevation of serum and urine concentrations of L-chains in a pattern similar to the pre-nephrectomy stage. In the period from 7 to 25 days post-transplantation 2 groups of patients were distinguished those with elevated serum and urine L-chain concentrations and those in whom serum and urine L-chain concentrations fell to or near normal. The 1st group had a higher incidence of subsequent irreversible renal homograft rejections when compared to the 2nd group. Homograft rejection was associated with a rise in the urine L-chain concentration. Successful treatment of a rejection episode was followed by the reverse series of events with urine L-chain concentration slowly returning to normal. Such measurements appear to provide an additional parameter of renal function and as such to serve as a prognostic and diagnostic guide in the course of renal homotransplantation.