[Perilymph fistula: diagnosis by detection of perilymph in the middle ear by beta-2 transferrin immunofixation].

beta 2-transferrin is a specific protein found in the cerebrospinal fluid and in the perilymph. Detecting beta 2-transferrin in the middle ear is of great interest when a fistula of the perilymph is suspected. This protein can be detected on microsamples with an immunofixation technique. We searched for beta 2-transferrin in pure perilymph, cerebrospinal fluid and serum in 8 patients operated by translabyrinthine approach for acoustic tumor removal. Search for beta 2-transferrin was performed in liquid from the inner ear in 3 labyrinthectomies. Samples were taken on collagen sponges or with micro syringes. beta 2-transferrin was detected in the perilymph of patients operated for neurinoma and in 2 of the 3 labyrinthectomies. This protein was found in only one of the patients for which the diagnosis of perilymphatic fistula had been retained. Detection of beta 2-transferrin in the middle ear can be proposed as a specific diagnostic test for perilymphatic fistula when the clinical situation does not suggest a fistula involving cerebrospinal fluid.