P0 antibodies by Western blot

Category: Otology
Test Code: 350
Disease: Autoimmune Hearing Loss (SNHL)
Methodology: Western Blot
Reference Range: Qualitative
CPT Code: 84182.
Schedule / Turnaround Time: Assay performed once weekly. Report availability is within two weeks from the time of specimen receipt.
Specimen Requirements:

Specimen need not be refrigerated or frozen. Collect 2-3 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into white tube provided with Immco Diagnostics’ collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.

Sample Stability:

Sample is stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8˚C) up to five days and frozen (-20˚C or lower) up to one year.

Relevance:

Antibodies to P0 at the 30kD protein occur in 46% of patients with Meniere’s disease, 40% of patients with otosclerosis, 28% of patients with idiopathic progressive sensorineural hearing loss and in 18% of patients with sudden deafness. Sensorineural hearing loss (SNHL), commonly referred to as nerve deafness, may be caused by genetic factors, acquired factors (i.e. infections) or can be immune mediated. In the majority of cases, no cause of SNHL is apparent. Such cases are referred to as idiopathic SNHL. A subgroup of idiopathic SNHL cases is treatable with immunosuppressive therapy. The laboratory studies used to identify these cases should include serum antibody tests to 68kD (hsp-70) inner ear antigen and other auto antigens such as to P0, a 30 KD antigen. Approximately 60% of patients with progressive SNHL have antibodies to P0. A strong positive correlation between chronic progressive hearing loss and the presence of P0 antibodies has been observed.