Rapid self-test for the detection of anti-tissue transglutaminase IgA antibodies associated with gluten intolerance (celiac disease) in blood
Intended Purpose
The GLUTEN’ALARM® is a manual qualitative immunochromatographic screening test for the detection of anti-tissue transglutaminase IgA antibodies in finger prick whole blood sample. It can be used at home by lay users for self-testing for the detection of potential Gluten intolerance and, therefore, Celiac disease.
General Points
Celiac disease is a long-term autoimmune disorder affecting the small intestine that can occur in genetically predisposed people. It is caused by intolerance to the ingestion of gluten which are various proteins found in wheat, barley and rye. It is estimated to affect 1% people worldwide. Typical symptoms include chronic diarrhea, abdominal pain, gas, weight loss but also anaemia, osteoporosis, extreme fatigue and even delayed growth in case children are affected.
Currently, the only treatment for Celiac disease, after being diagnosed, is a strict life long gluten-free diet. Currently, highly effective blood tests are the first line screening method to detect the Celiac disease. They are mainly based on the detection of anti tissue-transglutaminase (t-TG) IgA type antibodies.
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 15 minutes. Do not interpret after 20 minutes.
Results Interpretation
The intensity and the colour of the lines do not have any importance for the interpretation of the test results.
Analyze
Result
Summary
Positive result
Negative result
Invalid result
Questions and answers
How does GLUTEN’ALARM® work?
When gluten intolerance is present, there is a production of IgA type specific antibodies directed against t-TG. The GLUTEN’ALARM® test is detecting the anti-t-TG IgA antibodies in whole blood samples. A unique combination of anti-human IgA dye conjugate and t-TG membrane antigen allows the specific detection of these antibodies.
When present at a minimum concentration of 10 U/mL (determined against samples reference panels), a pink coloured line will appear under the T mark and will show evidences of gluten intolerance. Another pink line will always appear under the C mark indicating that the test performed well.
When should the test be performed?
GLUTEN’ALARM® test should be performed in case of gluten intolerance symptoms or in the case members of the family are already showing this problem. This disease is indeed occurring in genetically predisposed individuals. The test should be performed while being on regular diet (not gluten free diet) to make the result valid.
Can the result be incorrect?
The results are accurate as long as the instructions are carefully respected.
Nevertheless, the result can be incorrect if GLUTEN’ALARM® 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 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 20 minutes, will the result be reliable?
No. The test should be read 15 minutes after adding the diluent. The result is reliable up to 20 minutes.
What do I have to do if the result is positive?
If the result is positive, it means that anti-t-TG IgA type antibodies are present in blood and that you should consult a doctor to show the test results. Then, the doctor will decide whether additional investigation should be performed.
What do I have to do if the result is negative?
If the result is negative, it means that the test could not detect anti-t-TG IgA type antibodies in blood sample. In limited cases, IgA deficiency or other immunodeficient diseases may also lead to false negative results. Thus, it is recommended to consult a doctor if symptoms persist.
What is the accuracy of GLUTEN’ALARM®?
The GLUTEN’ALARM® test is accurate. Evaluation reports show an overall agreement of 96,7% [91,4 – 99,2**] with reference method. Although this test is reliable, false positive or false negative results could be obtained.
** CI 95%: 95% Confidence Interval
Information on Celiac disease
- Fasano A (Apr 2005). « Clinical presentation of celiac disease in the pediatric population ». Gastroenterology (Review). 128 (4 Suppl 1): S68-73.
- « Symptoms & Causes of Celiac Disease | NIDDK”. National institute of Diabetes
and Digestive and Kidney Diseases. June 2016. Archives from the original on 24 April 2017.
Retrieved 24 April 2017.