This protein promotes liquefaction of the ejaculate, penetrating the ducts of the prostate into the urethra. PSA penetrates into the blood in a very small amount (one milliliter of ejaculate contains almost a million micrograms, and blood serum in a normal state contains less than four nanograms.
All kinds of diseases have different effects on the growth of PSA in the blood.
The level increase occurs for the following reasons:
- insufficient blood supply to the prostate;
- infectious disease of the prostate;
- BPH;
- prostate cancer.
Every man over the age of forty should have a PSA (PSA) blood test at least once a year to avoid the risk of prostate growths.
In the event that the PSA values grow more than four nanograms, the patient will be offered an additional (more detailed) examination. In the normal state of the body, with age, there is a constant growth of the prostate (about 3 mm per year).
The average PSA level rises in proportion to the size of the prostate. With a significant increase in the indicator (above 10 ng / ml), a prostate biopsy is prescribed (in order to clarify the diagnosis).
PSA analysis (PSA)
PSA is found in the blood in a bound and free form.
The free form accounts for about 20% of the total value of the prostate-specific antigen.
If the ratio of free and total PSA is less than 0.15, then there is a serious suspicion of prostate cancer. If this figure is higher than 0.15, then the patient most likely has a prostate adenoma.
Today PSA analysis shows the norm at four nanograms per ml. However, this indicator misses every third malignant tumor. That is why the possibility of lowering the PSA threshold to 3 mg / ml is now being discussed.
It has been experimentally proven that there is a sharp increase (up to 30%) in the detection rate of cancer. In many European countries, a value of three nanograms has already been introduced, and this is very helpful in detecting prostate cancer.
Transcript of PSA analysis
A significant proportion of PSA is associated with alpha-1-antichymotrypsin.
In prostate cancer, tumor cells begin to produce increased antigen synthesis.
Differential diagnosis is made between prostate cancer and prostate adenoma.
PSA is determined by the immunochemiluminescent method (normal PSA = free PSA / total PSA).
If the blood test for total PSA shows from 2.5 to 4.0 ng / ml, then the normal value of free PSA will be above 10%. If the total PSA shows from 4.0 to 10.0 ng / ml, then the blood test for free PSA will show above 25%.
The material required for the analysis is blood serum (one ml).
Preparing for PSA Analysis
You should prepare for the analysis, taking into account the following recommendations:
- at least a week should pass from the day of the last mechanical effect on the prostate;
- blood sampling is done on an empty stomach, in the morning.
The material is collected in a vacuum system with or without coagulant activator.
The material must be delivered to the laboratory within two hours (material temperature - 2-8 degrees).
The results of the PSA analysis show its percentage in the blood.
The price of a blood test for PSA in Moscow is about 340 rubles (separately for general PSA and free PSA).
