In previous papers, Carey and his colleagues have shown that IESCA has about the same molecular weight as -- but is distinct from -- a protein that serves as the basis for a currently available commercial AISNHL test. That test, based on a protein-separation test known as Western blot, is known to give accurate results only some of the time. The U-M team reported in previous paper in the Journal of Neuroscience that IESCA is identical to a protein called CTL2, or choline transport-like protein 2.
In the new study, the researchers tested blood from the 63 patients and 20 normal controls with two tests: a Western blot test and an immunofluorescence (IF) test based on KHRI-3. They correlated the results of those two tests with patients' response to steroid treatment, based on standard criteria and the results of hearing tests performed before and after treatment. They also considered patients' other autoimmune diseases, the length and pace of hearing loss progression before treatment, and age and gender.
Thirty of the patients were female, and 33 male; their average age was 47, reflecting the young age at which AISNHL typically begins. Twenty-six had lost hearing in both ears, the rest in the left or right ear. They had no known cause for hearing loss, and most had lost their hearing gradually over weeks, though eight had lost it over hours or days. Many also had dizziness, ringing or a sensation of fullness in their ears. In all, half regained some or all of their hearing after steroid treatment.
Seventy-five percent of the patients had "wine glass" staining with IF testing, and 68 percent had positive Western blot results for the same s
Source:University of Michigan Health System