COLUMBUS, Ohio - The results of most commonly used blood tests for allergies can vary widely depending on which laboratory does the actual testing - and which laboratory procedure is used, a new study suggests.
This means that many people who are tested for allergies using these tests may be misdiagnosed, said Sheryl Szeinbach, a study co-author and a professor of pharmacy at Ohio State University.
Researchers obtained blood samples from 26 people with known allergies and then sent samples from each individual to six commercial laboratories. Each of the six laboratories used one of three common blood tests -- the RAST, AlaSTAT and the ImmunoCap - to test for allergies. The researchers compared the results of each test and found that only the labs using the Pharmacia ImmunoCap test had produced similar results, Szeinbach said.
Results from the two labs that used the ImmunoCap test agreed 98 percent of the time. However, results from the other two tests varied in agreement by as much as 50 percent, depending on the testing lab.
The research appears in the April issue of the journal Annals of Allergy, Asthma, & Immunology.
"The practical value of any lab test rests in its ability to give
accurate, consistent and therefore reliable results," Szeinbach
said. "With the exce
Contact: Sheryl Szeinbach
Ohio State University