Two-site monoclonal antibody-based immunoradiometric assay for measuring prostate secretory protein in serum.
We developed a double-determinant immunoradiometric assay for measuring serum prostate secretory protein (PSP), using monoclonal antibodies (MAb) against two different epitopes: MAb PSP-19 was the capture antibody and MAb PSP-6 was the tracer antibody. Assay sensitivity was 0.1 microgram/L. Analytical recovery of PSP was 93.5-104.6%, whereas the intra- and interassay mean CVs were 4.2% and 6.9%, respectively. In 92 normal men, ages greater than 50 years, the mean PSP concentration was 5.7 micrograms/L, with 10 (10.9%) men having concentrations greater than 10 micrograms/L. In contrast, 20 of 49 (40.8%) patients with benign prostate hyperplasia (BPH; mean PSP concentration 9.4 micrograms/L) and 46 of 100 (46%) patients with prostate cancer (mean PSP concentration 22.2 micrograms/L) had PSP concentrations greater than 10 micrograms/L. Mean serum PSP concentrations of the BPH (P less than 0.05) and prostate cancer (P less than 0.01) groups were significantly different from those of age-matched normal men. In a small group of patients, serial PSP concentrations correlated with the clinical course during therapy. Thus, PSP may be a useful marker for evaluating patients with prostate cancer.
Huang
C L
CL
Department of Microbiology and Immunology, Eastern Virginia Medical School, Norfolk 23507.
Liang
H M
HM
Brassil
D
D
Schellhammer
P F
PF
Rozzell
M
M
Newhall
K
K
Beckett
M L
ML
Wright
G L
GL
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins / Q000097:blood*; D005260:Female; D005615:Freezing; D006801:Humans; D015592:Immunoradiometric Assay / Q000592:standards / Q000706:statistics & numerical data; D008297:Male; D008593:Menopause; D008875:Middle Aged; D011247:Pregnancy; D011470:Prostatic Hyperplasia / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood; D029584:Prostatic Secretory Proteins; D011786:Quality Control; D012016:Reference Values
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D029584:Prostatic Secretory Proteins; C028321:estramustine-binding protein