Serum Prostate Specific Antigen Complexed toα1-Antichymotrypsin as an Indicator of Prostate Cancer

Abstract

Prostate specific antigen (PSA) in serum has recently been shown to occur in complex with alpha 1-antichymotrypsin and as an approximately 30 kDa. noncomplexed molecular form. We characterized PSA by 3 different assays in samples from 144 patients with benign prostatic hyperplasia (BPH) and 121 with carcinoma of the prostate. One of these noncompetitive assays measured total PSA by detecting PSA complexed to serine proteinase inhibitors and the noncomplexed molecular form, a second measured only PSA in complex with alpha 1-antichymotrypsin, whereas a third detected the noncomplexed form. PSA in complex with alpha 1-antichymotrypsin was the predominant form in all patient sera. Noncomplexed PSA constituted a minor fraction that was significantly smaller in patients with untreated prostate cancer than in those with BPH (p < 0.0001). The proportion of noncomplexed PSA does not correlate to the serum concentration of PSA or that of alpha 1-antichymotrypsin. In men with a serum PSA concentration of less than 10 micrograms./l. the combination of assays measuring total PSA immunoreactivity, the noncomplexed molecular form and PSA in complex with alpha 1-antichymotrypsin may facilitate discrimination between prostate cancer and BPH.

High grade intraepithelial neoplasia of prostate is associated with values of prostate specific antigen related parameters intermediate between prostate cancer and normal levels

“…In our study, patients with HGPIN had significantly higher R fPSA/tPSA than these with PCa (0.168 vs 0.133), but significantly lower than patients with BPH (0.185). These parameters and results of comparisons have been numerically similar to the respective value in other studies [9,10,20,21]. The volumes of prostate in patients with BPH and HG-PIN were similar (48.699 mL and 48.378 mL respectively).…”

“…HIPN occurs most frequently in the peripheral zone of the prostate and is usually located in close proximity to prostate cancer. deoxyribonucleic acid ploidy in HGPIN follows the [9,20]. Ratio fPSA/tPSA of ≤ 0.18 differentiates malignant from benign prostate pathology or latent from manifest cancer with a specificity of 91% and selectivity of 69% [22].…”

Time-resolved fluorescence imaging (TRFI) for direct immunofluorescence of PSA and alpha-1-antichymotrypsin in prostatic tissue sections

“…14 For detection of ACT, we employed an earlier described monoclonal IgG preparation (code 2G7) known to detect continuous epitopes accessible on both puri®ed ACT and ACT complexed to PSA. 20,24 Labeling of anti-PSA and anti-ACT Mabs with lanthanide chelates Fluorescent chelates of Eu (W1024) and Tb (W14016) and all reagents in the labeling procedure were generous gifts from Wallac OY (Turku, Finland). Labeling of the 2E9 and 2G7 Mabs with Eu and Tb, respectively, were performed according to the instructions of the DELFIA Eu-labeling kit with minor modi®cations.…”

Epitope mapping of human prostate specific antigen and glandular kallikrein expressed in insect cells

“…8 Af®rmation of the improved discrimination of cancer and BPH were con®rmed using the free PSA assay together with assays designed to measure total PSA and PSA-ACT. 9 Due to the extensive homology between PSA and hK2, the present immunoassays developed for PSA may crossreact with hK2. The hK2 mRNA levels have been reported to be 10±50% of that of PSA mRNA in prostatic tissue.…”