Rapid self-test for assessing the physiological state of the liver in blood
Intended Purpose
The LIVER-Screen® is a manual qualitative immunochromatographic screening test for the immunological detection of increased transaminase (both ALT and AST) levels in finger prick whole blood sample. It can be used at home by lay users for self-testing for the assessment of liver physiological status. The test consists on a plastic housing containing one stick having two distinct zones for transaminases detection (red colour when positive) and one control zone (blue colour).
General Points
The Liver is an essential organ of the body having a critical role for health. It helps break down food, clean blood, produce proteins and store energy.
In case of liver problems, a number of symptoms may appear including dark urine or light-coloured stool, no desire to eat, yellowish eyes or skin (jaundice), swelling in your belly, weakness or feeling very tired. There might be many reasons for a problem occurrence in liver such as hepatitis, side effects of certain medications, cirrhosis due to heavy drinking, overweight especially in case of diabetes or high blood pressure.
Many tests could be performed on the liver but the most commonly used tests are transaminases (ALT and AST) enzymes assessment. These enzymes are released in the blood by the liver in response to damage or disease.
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
Three lines may appear in the reading window:
- one red line over the sign 1 corresponding to the ALT enzyme.
- one red line over the sign 2 corresponding to the AST enzyme.
- one blue line over the sign C corresponding to the control line.
The intensity and colour of the lines are not important in interpreting the test results.
Analyze
Result
Summary
Positive result
Negative result
Invalid result
Questions and Answers
How does the LIVER-Screen® test work?
In case of liver injury, transaminases (ALAT and/or ASAT) from liver cells enter the bloodstream. The LIVER-Screen® rapid test detects these transaminases using specific immunological reagents when the level of activity of the two enzymes is greater than 80 IU/L according to the international reference method *I.F.C.C. The LIVER-Screen® rapid test uses a pair of antibodies specific for transaminases (ALAT and/or ASAT) which produce one or two coloured lines, below the T mark on the cassette, in the event of an abnormal concentration of transaminases. A control line capturing excess reagent appears below the C mark on the cassette.
* International Federation of Clinical Chemistry.
When should the test be performed?
In the event of liver dysfunction, a number of symptoms may appear, such as dark urine, discoloured stools, loss of appetite, yellowish discolouration of the whites of the eyes or the skin, swelling of the abdomen, a feeling of weakness or extreme tiredness. In these cases, a LIVER-Screen® test is recommended. The test can be carried out at any time of the day.
Can I get incorrect results?
The results are accurate as long as the instructions are carefully respected.
Nevertheless, the result can be incorrect if LIVER-Screen® test gets wet before test performing or if the quantity of blood dispensed in the sample well is not correct. The plastic pipette provided in the box allows making sure the collected blood volume is correct.
How to interpret the test?
LIVER-Screen® test should be considered as positive when, in addition to a blue line, one or two visible red lines (either weakly or strongly coloured), corresponding to each transaminase (ALT and AST), appear. Hepatic problems may indeed lead to an increased concentration of one transaminase only.
What is the purpose of the blue line that appears below the C (Control) marker?
The appearance of the blue line simply means that the test has worked correctly.
I read the result after 15 minutes. Will I get a reliable result?
No: The test should be read 10 minutes after adding the diluent. The results are reliable up to 15 minutes.
What should I do if the result is positive?
If the result is positive, it means that the level of ALAT and/or ASAT transaminases in the blood is higher than normal (80 IU/L) and that you absolutely must consult your GP and show him/her the results of this test. Your doctor will then decide what further tests to carry out. Although determining ALT and ASAT levels is useful in diagnosing liver disease, it can be carried out in parallel with measuring the activity levels of other liver enzymes (alkaline phosphatase, lactate dehydrogenase, gamma-glutamyl transferase, etc.) and the concentration levels of other blood parameters such as urea, creatinine or bilirubin. Increased transaminase activity may be linked to other conditions or abnormalities (e.g. intensive sport, excess weight, etc.). Only a doctor can make a diagnosis after confirming these results with a clinical investigation and the results of additional tests.
What should I do if the result is negative?
If the result is negative, this means that the level of ALAT and/or ASAT transaminases is normal and below 80 IU/L. However, if symptoms persist, you should consult your GP.
How reliable is the LIVER-Screen® test?
Studies carried out on the LIVER-Screen® test show a correlation of 95.83% [89.19 – 99.04] ** with the reference method in clinical chemistry. Despite the reliability of this test, false positive or false negative results are possible.
**95% CI: 95% Confidence Interval