Circulating immune complexes and immunosuppressive acidic protein in patients with renal cell carcinoma.

Sera from 23 patients with renal cell carcinoma were tested for circulating immune complexes by Clq binding assay and immunosuppressive acidic protein by single radial immunodiffusion. The mean values of circulating immune complexes and immunosuppressive acidic protein in the patients were significantly higher than those of normal controls, and over-all positive rates were 52 and 35 per cent, respectively. There was a significant correlation between immunosuppressive acidic protein levels and the extent of tumor invasion. Immunosuppressive acidic protein may be a more useful marker than circulating immune complexes. However, presently synthetic evaluations of patients with various nonspecific markers, including these 2 factors, will be necessary.