Perilymph detection by beta 2-transferrin immunoblotting assay. Application to the diagnosis of perilymphatic fistulae.

beta 2-Transferrin, the asialotransferrin, is found in cerebrospinal fluid (CSF) and inner ear perilymph, but is absent from serum and other body fluids or secretions except the aqueous humor. The detection of this asialo-fraction of the transferrin in ear fluid microsamples with an immunoblotting technique is of great interest when a perilymphatic fistula (PLF) is suspected. beta 2-Transferrin was detected on microsamples collected by syringe or on micro-collagen sponges from 30 patients undergoing ear surgery. The problem is reviewed, the technique and sample preparation are explained and the results discussed. beta 2-Transferrin detection in the ear fluid allows the identification of perilymph, except in the CSF oto- or rhinorrheal context, and is proposed as a promising test to confirm perilymphatic fistula.