Serum levels of total and free prostate specific antigen in men on hemodialysis.

PURPOSE

The measurement of prostate specific antigen (PSA) is widely used in screening programs for early detection of prostate cancer. It has been recently shown that the ratio of free-to-total PSA in serum is lower in malignant than in nonmalignant prostatic disorders and, therefore, might be a parameter to improve screening specificity. We determine the influence of renal failure on serum levels of total and free PSA, and free-to-total PSA ratio.

MATERIALS AND METHODS

Serum concentrations of total and free PSA, and free-to-total PSA ratio were measured in 93 men undergoing hemodialysis. The control group consisted of 2,298 healthy blood donors.

RESULTS

Serum levels of total PSA were not significantly different between control and hemodialysis patients. Serum free PSA and free-to-total PSA ratio of hemodialysis patients were significantly higher than those of controls (p <0.01 to 0.001). However, these values did not change in uremic patients after hemodialysis. Although serum total and free PSA levels increased with each decade of age, they did not correlate with age in hemodialysis patients.

CONCLUSIONS

Serum free PSA as well as total PSA is not eliminated by hemodialysis, and elevated levels of free PSA and free-to-total PSA ratio in hemodialysis patients may be caused by a concomitant decrease in binding proteins. The reference ranges for total and free PSA, and free-to-total PSA ratio may not be necessarily beneficial in hemodialysis patients.