Proteinuria After Human Renal Transplantation: I. Urinary Excretion of α₂-Microglobulin (Retinol-binding Protein), β₂-Microglobulin, Lysozyme and Albumin

Abstract

With the use of the protein/creatinine clearance ratio (C_P/C_cr), calculated from immunochemical determinations of α₂-microglobulin (retinol-binding protein), &microglobulin, lysozyme and albumin, proteinuria was studied during the early course of human renal transplantation. When substantial changes of creatinine clearance (C_cr) occurred, an inverse relationship was found between C_cr and C_p/C_cr for all four proteins. An exception was seen during the first days of six acute rejection crises, where opposite changes were observed in C_r/C_cr for albumin and the low molecular weight proteins. A slight but significant increase of albumin excretion related to C_cr was found during and after rejection crises, but for none of the proteins did the changes in C_r/C_cr precede other signs of acute rejection crisis.

The value of different methods expressing proteinuria after renal transplantation is discussed. It is concluded that more precise information is gained by calculating C_p/C_cr for specific proteins, as this parameter more truly reflects the mean protein excretion per nephron.