Audiological evaluation in adult beta-thalassemia major patients under regular chelation treatment

With the improved life expectation of beta -thalassemia major patients, new clinical problems, such as hearing damage, must be evaluated. Fifty-seven patients (32 F, 25 M; age range 17-32 years) have been studied to define risk factors for development of sensorineural hearing loss. All patients with beta -thalassemia major received daily chelation therapy with subcutaneous injection of desferrioxamine (30-50 mgkg(-1)per day). We performed an otological visit and pure tone audiometry as well as impedance; patients were followed for 3 years. Four patients with a conductive hearing loss were excluded; 66.6% had a normal audiogram; 22.8% had a slight sensorineural deficit ( </=35 dB HL) with high frequency losses; only two patients (3.5%) had a moderate deficit (between 35 and 75 dB HL). In normal subjects ABR recording gave normal values. There was no association between age, ferritin level, therapeutic index (T.I.) and hearing loss. We conclude that no significant difference exists between beta -thalassemic patients and non-thalassemic subjects of the same age; desferrioxamine treatment seem to be non-ototoxic when employed at the present dosages, but the ototoxicity is probably related to individual susceptibility that is unforeseeable; in any case, the risk of ototoxicity seems to be much less than the benefits which derive from the use of this drug