Mucosal brush biopsy testing of the inferior turbinate to detect local, antigen-specific immunoglobulin E

This study investigated the ability of mucosal brush biopsy testing (MBBT) from the inferior turbinate to detect local, antigen-specific immunoglobulin E (IgE) in patients with allergic rhinitis, and these results were then compared to skin prick testing (SPT).

A standard cytology brush was used to harvest epithelial cells from the inferior turbinates of 20 patients who tested positive to 2 or more airborne antigens out of a panel of 9 on SPT (N = 20). These cells were lysed and the resulting solution was tested for total and antigen-specific IgE using immunofluorescence.

Antigen-specific IgE for at least 1 antigen was detected in 15 (75%) patients on MBBT. A statistically significant association overall between the results of MBBT and SPT was present (p = 0.01), but no significant associations were seen when examining individual antigens. Patients with positive tests on MBBT had higher amounts of IgE and total protein in biopsy samples than patients without positive tests on MBBT. The mean wheal diameter in tests that were positive on MBBT were significantly larger than the mean wheal diameter in tests that were negative on MBBT (p < .0001). Eight tests were positive on MBBT that were negative on SPT in the same patients.

This study demonstrates for the first time that antigen-specific IgE can be detected using MBBT in the sinonasal cavity. MBBT is more likely to be positive in higher SPT grades and in biopsy samples with more protein present. MBBT is also able to detect local IgE that is not detected on SPT.