Maturation of monocytes in patients with renal cell carcinoma.

: Peripheral blood leukocytes were cultured from patients with renal cell carcinoma and compared with those from normal volunteers. The number of macrophage precursor cells recovered was 17.99 +/- 11.65 X 10(3) cells per ml of blood in patients with renal cell carcinoma, whereas the number recovered in normal individuals was 72.0 +/- 20.0 X 10(3) cells per ml of blood. The low macrophage yield in patients with renal cell carcinoma was not associated with serum factors, and there was no difference in the number of monocytes in the mononuclear cell preparations. Therefore, there seems to be an intrinsic defect in the macrophage maturation process in vitro in patients with renal cell carcinoma.