Rapid self-test for the detection of PSA (Prostate Specific Antigen) in blood
Intended Purpose
The PROSTA-Check® is a manual qualitative immunochromatographic screening test for the detection of increased prostate specific antigen (PSA) level in men in finger prick whole blood sample. It can be used at home by lay users for self-testing for the assessment of prostate physiological status.
General Points
In man, the prostate antigen (PSA) is secreted by the prostate. This gland, situated in the abdomen under the bladder, surrounds the initial part of the urethra and plays an important role in the semen. The prostate antigen level gives information about the prostate physiological condition. Thus, levels above the norm may show pathology of the prostate (benign hypertrophy, prostatitis, cancer, etc.). The PSA assay could be performed at least once a year in men over 50 years or having a family history of prostate problems.
In case of prostate problem, early screening allows considerably increasing recovery possibilities.
Principle of the Test
The PROSTA-Check® test contains a couple of antibodies that specifically detect PSA by producing a coloured test line under the T mark on the cassette. A control line capturing the remaining reagents appears as a coloured line under the C mark on the cassette showing that the test performed well.
Test Procedure
Prepare everything properly before starting the testing procedure. Place the content of the box on a clean, dry and flat surface (e.g. table). Then perform the test as follows:
- Wash your hands thoroughly. Use soap and warm water. Dry your hand with clean towel.
- Prepare the test device and capillary pipette: Take them out from the protective pouch (tear at the notch) and place them in the reach of your hands (you will need them later). Discard the desiccant bag.
- Prepare the lancet. Hold the lancet without touching the trigger button. Unlock the cap twisting it off ¼ turn until you feel it separates from the lancet and then continue twisting it (2-3 rotations). Don’t pull just twist and discard the cap when finished. ①②
- Clean the end of the middle or ring finger with cotton damped with alcohol. Massage the chosen finger towards the tip for 10 to 15 seconds to enhance the blood flow.
- Prick the finger: put the lancet firmly against the side of the previously cleaned finger, and press the release trigger button.③ The lancet will automatically retract into the body of the device. Gently massage the finger to create a nice round blood droplet.④
- Collect the blood with the capillary pipette: Gently touch the blood droplet with the open end of the capillary pipette. It must be filled until the line indicated on the capillary pipette. Do not press the bulb, it fills by itself. Make another blood droplet if the line is not reached. As far as possible, avoid air bubbles. ⑤
- Put the blood collected with the pipette into the sample well of the device, by pressing on the pipette bulb. ⑥
- Wait 30-40 sec for the blood being totally absorbed into the sample well.
- Add the diluent: Unscrew the blue cap of the diluent dropper vial (leave the white cap tightly screwed) and add the diluent as follows: Hold the diluent dropper vial vertically and slowly add exactly 4 drops in the sample well of the device with an interval of 2-3 seconds between each drop. ⑦
- Read the result after 10 minutes. Do not interpret after 15 minutes.
Results Interpretation
The intensity and the colour of the lines do not have any importance for the interpre-tation of the test results.
Analyze
Result
Summary
Positive result
Negative result
Invalid result
Note: Never take any decision of medical relevance without first consulting the appro-priate healthcare professionall.
Performance Characteristics
The PROSTA-Check® test is accurate and has been used for more than 30 years by professionals (hospitals, laboratories) in the field. Evaluation reports show an overall agreement of 97% [91.06-99.61**] with referenced methods. Although this test is reliable, false positive or false negative results could be obtained.
**CI 95%: 95% Confidence Interval
Questions and Answers
How does PROSTA-Check® work?
Prostate specific antigen is a protein secreted in semen by the prostate. A part of this protein is found in blood. The blood PSA level allows an estimation of the prostate physiological condition. A value higher than the norm indicates prostate hypertrophy. This hypertrophy may be benign, may be due to prostatitis or may be cancerous in case of adenocarcinoma. Prostate pathology screening is for men aged 50 years and over .
The PROSTA-Check® test allows one to determine a high blood level, above 4 ng/mL (determined against W.H.O.* reference), of prostate specific antigen likely to show benign or malignant prostate hypertrophy.
*World Health Organization
When should this test be performed?
The PROSTA-Check® test can be performed at any time of the day.
However, in the following cases, it is recommended to wait the indicated time before using the test, to avoid false positive results:
waiting time
– Cycling/Ergometry 24 hours
– Ejaculation 24 hours
– Prostate massage 2-3 days
– Transrectal ultrasounds 2-3 days
– Cystoscopy 1 week
– Prostate transurethral resection / biopsy 4-6 weeks
Can the result be incorrect?
The results are accurate as long as the instructions are carefully respected.
Nevertheless, the result can be incorrect if the PROSTA-Check® test gets wet before performing the test or if the quantity of blood in the sample well is not correct. The plastic pipette provided in the box makes sure the collected blood volume is correct.
How to interpret the test if the colour and the intensity of the lines are different?
The colour and intensity of the lines have no importance for result interpretation. The lines should only be homogeneous and complete.
The test should be considered as positive regardless of the colour intensity of the test line (T), even weak.
What is the line that appears under the mark C (Control) for?
When this line appears, it only means that the test has been performed well.
If I read the result after 15 minutes, will the result be reliable?
No. The test should be read 10 minutes after adding the diluent. The results are reliable up to 15 minutes.
What do I have to do if the result is positive?
If the result is positive, it means that the PSA level present in your blood is higher than the norm (4 ng/mL) and that you should consult a doctor to show him the test results. Then, the doctor will decide what you have to do.
What do I have to do if the result is negative?
If the result is negative, it means that the PSA level in your blood is below 4 ng/mL. For people aged 50 years and over or having relatives suffering from prostate cancer, it is recommended to perform a test regularly (once a year).
Can drugs can interfere on PSA levels?
Some drugs (finasteride, dutasteride) can lower PSA levels.