Urinary excretion of ten plasma proteins in patients with renal carcinoma

Urinary and serum proteins were studied preoperatively in 48 patients with renal carcinoma, using an automated immunoprecipitin reaction. The 24 h excretion and the renal clearance of albumin, transferrin, haptoglobin, IgG, IgA, and IgM and the 24 h excretion of the immunoglobulin lambda and kappa free light chains and beta2-microglobulin were significantly increased compared with a control group. The excretion of lysozyme was also increased, but not significantly. Increased protein excretion was the most common urinary finding in patients with renal carcinoma. The protein excretion was predominantly of the glomerular type, implying a glomerular injury. The serum concentrations of albumin and transferrin were significantly decreased and the serum concentration of haptoglobin significantly increased in patients with stage III and IV tumours compared with patients with stage I and II tumours. Abnormal serum concentrations of albumin, transferrin, and haptoglobin were indicative for advanced renal carcinoma.