Staphylococcal protein A assay for detection of antibody directed at renal cancer cells.

Sera from 27 patients with renal cancer, 14 patients with transitional cell carcinoma of the bladder and 21 normal controls were tested against 2 renal cancer lines (CAKI-1 and CAKI-2) by the iodinated protein A assay. All sera tested against CAKI-2 were absorbed first with AB+ substance because CAKI-2 was found to have cell surface A antigen. Sera from 16 of 27 patients with renal cell carcinoma, 3 of 14 patients with transitional cell carcinoma of the bladder and 2 of 21 normal controls were reactive with CAKI-1. Sera from 11 of 27 patients with renal cell carcinoma, 2 of 14 patients with transitional cell carcinoma of the bladder and 3 of 21 normal controls were reactive with CAKI-2. There is a positive correlation between the number of counts obtained by the renal patients' sera tested against CAKI-1 and CAKI-2.