Problems with the RAST test for Gluten/Wheat. Part 1: Testing the Test.
March 27th, 2010One out of 133 individuals are estimated to have Celiac Disease. Yet only 1% of the affected population have been diagnosed. Why is this? One of the reasons is possibly the test requested by physicians. The most common blood test requested for allergies is the RAST test or RadioAllergoSorbent Test. Blood samples are taken to see if the blood contains IgE (Immunoglobulin E) antibodies that attached to an allergen’s surface. While the test is very safe, it can give “false negatives”. One needs to have the allergen in the blood stream for it to react; and it needs to be recent! How recent is the question? To answer this question, I asked my youngest son to volunteer to be my “guinea pig”. He just started going to a new physician who was not familiar with Celiac Disease. He made an appointment for his blood test for Monday. The Friday before he started a hi-gluten diet. He ate meals that consisted of: pasta, pizza, soft bread, and drank hi-gluten beer. By Saturday night his stomach was rebelling and he had diarrhea. On Sunday his stomach really started to hurt. By Monday morning he was so tired he could hardly get out of bed. He went for his blood test, then returned to his gluten-free diet. The next week he went for his results. The physician proudly announced to him that his test result of 14 was negative (My result was .7 ). My son then sat his physician down and educated him about the results. Why did the test give a “false negative”? Combined with my son’s symptoms, was 14 really a negative result?
To be continued…..
