Serum levels of soluble interleukin-2 receptor in renal cell carcinoma.

OBJECTIVES

To evaluate increased serum soluble interleukin-2 receptor (sIL-2R) levels in patients with renal cell carcinoma (RCC).

METHODS

Serum sIL-2R levels were measured in 52 patients with RCC and 10 control subjects by an enzyme-linked immunosorbent assay (ELISA) technique. The correlation between serum sIL-2R levels and clinical stage, disease prognostic value, and inflammatory marker levels was analyzed.

RESULTS

Serum sIL-2R levels in patients with RCC were significantly higher than those in normal control subjects (857.2 +/- 660.0 versus 291.3 +/- 76.4 U/mL, P < 0.0001). High serum sIL-2R levels appeared to be related to advanced clinical stage (596.0 +/- 276.5 U/mL in Stage II, 776.1 +/- 398.8 U/mL in Stage III, and 1310.0 +/- 926.7 U/mL in Stage IV: Stage II vs. Stage III, P = 0.0078; Stage II vs. Stage IV, P < 0.0001). The overall cause-specific survival curves showed that patients with high sIL-2R levels (more than 1000 U/mL) had a significantly lower survival rate than those with low (less than 500 U/mL, P = 0.0003) or intermediate levels (500 to 1000 U/mL, P = 0.0007). C-reactive protein levels apparently increased in patients with high sIL-2R concentrations.

CONCLUSIONS

Measurement of serum sIL-2R concentrations in patients with RCC provides useful information for predicting the extent of disease and length of survival.