ImmunoCAP Specific IgA measures antigen-specific IgA antibodies in human serum and plasma. Specific IgA antibodies are part of the body’s immune system. They are present in secretions such as saliva and mucosa, as well as in the blood. High levels in serum of specific IgA antibodies to food antigens may indicate increased exposure caused by damage to the intestinal mucosa. In coeliac disease, for example, the levels of specific IgA antibodies to gliadin are important for diagnosis.
Monitoring elevated levels of antigen-specific IgA antibodies in serum may help manage problems related to food, especially food-sensitive enteropathies in children. IgA antibodies may also be an indicator of tolerance development.
Expected test values
There are no recommended cut-off values for specific IgA antibodies in general, because they are markers for antigen exposure and not directly related to a disease. Results vary both within and between antigens. Geographical variations are also important, as are individual levels of exposure.
To determine whether levels are increased, the reference level of specific IgA antibodies to a particular antigen must be measured in a number of samples from normal healthy individuals and, if possible, compared with the levels in a group of patients.
As in all diagnostic testing, a definitive clinical diagnosis should not be based solely on the results of a single test method. A diagnosis should be made by the doctor after the evaluation of all clinical and laboratory findings.