Researchers from the University of Tokyo and the National Center for Child Health and Development say they have discovered substances in urine that can be used to check for food allergies, offering promise for an easier method of testing young children than taking blood samples.
People with food allergies react to proteins in foods and drinks like milk, eggs or wheat, showing symptoms like rashes, stomach pains and diarrhea. Around 1 to 2 percent of Japanese are said to have such allergies, but among young children the rate is higher, at 5 to 10 percent.
The team focused on the lipid "PGD2," which is created in large quantities by the cells of the immune system when a food allergy occurs. The team found in animal tests that the worse food allergy symptoms were, the more broken down PGD2 substances were present in the urine.
They also found that in the urine of around 140 children seen at the National Center for Child Health and Development in 2014 and 2015, the worse their food allergy symptoms were, the more these broken down substances were in the urine. The researchers say these substances appear unrelated to other allergic ailments like asthma and nasal inflammation.
Takahisa Murata, associate professor of pharmacology and immunology at the University of Tokyo, says, "We can't determine what food caused the allergy from the substances in the urine, but we may be able to take samples even from the urine of a baby diaper, and early detection (of food allergies) should be possible."
The researchers plan to work on creating a testing kit that can be used to check urine for the existence and severity of food allergies.