Release of Mast Cell Tryptase into Saliva: A Tool to Diagnose Food Allergy by a Mucosal Challenge Test?

Background: Our aim was to examine whether measurement of the
saliva mast cell tryptase (MCT) concentrations before and after a
mucosal challenge test with the offending food would be helpful in
diagnosing food allergy. Methods: We performed a retrospective
analysis of 44 food challenge tests performed in 38 patients
between 2006 and 2009. Patients with a suspected history of food
allergy chewed the food until they developed symptoms or until the
amount of time known from the patients' history to usually be
required for the provocation of symptoms had passed. In 5 patients,
saliva samples for the measurement of MCT were collected at minutes
0, 1, 4, 8, 11, and 16 after the first onset of symptoms. The
remainder of the patients only had samples taken before chewing and
4 min after the end of the test period. Results: During repeated
measurements, MCT peaked about 4 min after the onset of symptoms (p
= 0.028). During 33 of the 44 tests (75.0%), we observed oral
symptoms during testing; after 25 of the 33 (75.8%) tests evoking
symptoms, the saliva MCT concentration increased. The MCT increase
was negative in all other tests where no oral symptoms could be
provoked. Conclusions: The measurement of saliva MCT 4 min after
the onset of symptoms may be helpful to diagnose food allergy.
Because of numerous confounding variables, however, a negative
saliva MCT increase does not exclude food allergy. Copyright (C)
2011 S. Karger AG, Basel