Prostate-specific antigen (PSA) test
Indications for prostate-specific antigen (PSA) test:
- Monitoring the course and effectiveness of prostate carcinoma therapy
- Monitoring the condition of patients with hypertrophy of the prostate in order to detect its malignant transformation
Prostate-specific antigen (PSA) test — is a physiological prostate excretory product, glycoprotein with a molecular weight of 33000 Da, relating to kallikrein, is a protease, that reduces the viscosity of semen.
The main forms in which prostate-specific antigen (PSA) is determined in the blood serum is a free, not forming complexes, the form of f-PSA (molecular weight of ≈33 kDa) and a complex of f-PSA with α1-antichymotrypsin (molecular weight of ≈100 kDa). Both forms constitute the main fraction of total prostate-specific antigen (t-PSA), which is most often determined in the serum.
A significant increase in the level of prostate-specific antigen (PSA) in serum can be detected in prostate carcinoma, as well as prostate hypertrophy and prostate inflammatory diseases. It is important to the dynamics of the level of prostate-specific antigen (PSA), not individual values.
The rise of PSA marker level is observed after a digital rectal examination, cystoscopy, colonoscopy, transurethral biopsy, laser therapy. The impact of these factors is especially expressed on the day after the procedure, and most significantly in patients with prostatic hypertrophy (benign prostatic hyperplasia). Therefore, blood sampling should be carried out a week after the procedure, or before them.