A radioimmune assay for human prostatic acid phosphatase-levels in prostatic disease.

Prostatic acid phosphatase from human seminal fluid was purified to homogeneity. The enzyme was characterized as to its purity, molecular weight and amino acid composition. Analytical isoelectric focusing of purified enzyme on polyacrylamide gels resolved the enzyme activity into eleven discrete bands, apparently due to various amounts of sialic acid associated with the glycoprotein. Antisera raised against the purified enzyme produced only one precipitan arc on immunoelectrophoresis. A double antibody radioimmune assay was developed and used to evaluate serum prostatic acid phosphatase in 226 patients without prostatic disease, in 186 patients with benign prostatic hyperplasia and in 93 patients with prostatic carcinoma. No statistical difference was noted in serum prostatic acid phosphatase between patients with benign prostatic hyperplasia and in those without prostatic disease Serum prostatic acid phosphatase was elevated in 94% of the patients with metastatic prostatic carcinoma. Significant elevations were also found in carcinoma patients without metastases.