Long-Term Effect of Enzyme Replacement Therapy with Fabry Disease

Objective. To determine the effects of enzyme replacement therapy (ERT) on the hearing acuity in patients with Fabry disease. Materials. The study sample comprised 34 ears of 17 affected patients who underwent pure-tone audiometry before and after ERT. Methods. The patients were studied in relation to factors such as changes in hearing, presence of accompanying symptoms, status of renal and cardiac function, age, and gender. Data of pure-tone audiometry obtained before ERT and at the final examination were compared. Results. At the end of the follow-up period, no significant worsening of hearing acuity was noted at the end of the follow-up period. SSNHL was detected in 10 ears of 6 patients. Steroid therapy successfully cured the disease in 9 of the 10 ears. Conclusions. No significant worsening of hearing acuity was noted from the beginning to the end of ERT. The rate of improvement in SSNHL of Fabry disease was excellent in the treated patients. Hearing loss is a factor that causes marked deterioration of the patients’ quality of life, and it is desirable that the hearing acuity of patients be periodically evaluated and prompt treatment of SSNHL be administered, if available. 1. Introduction Fabry disease is a genetic inborn error of metabolism in which the enzymatic activity of -galactosidase ( -Gal), a hydrolytic enzyme present in lysosomes, is decreased due to a gene mutation; this results in the accumulation of glycolipids, mainly in the vascular endothelium. This disorder was first reported in 1898 by 2 independent investigators, namely, Anderson from the UK and Fabry from Germany [1, 2]. The disease is acquired by X chromosome-linked inheritance, and male and female patients with Fabry disease are hemizygous and heterozygous, respectively. Further, male patients with Fabry disease can either present with the classic type of the disease or the late-onset subtype. The disease mainly involves the kidney, heart, and brain, and accordingly, affected patients often die in their 40？s or 50？s because of renal failure, heart failure, or cerebral infarction. In addition, angiokeratoma and hypohidrosis are present, with a variety of neurologic symptoms, including severe pain in the extremities, burning sensation, headache, dizziness, hearing loss, lack of motivation, and neurosis. According to the published literature, 54.5% [3] to 80% [4] of patients with Fabry disease experience hearing loss. In a previous study, we examined the relationship between hearing acuity and complications occurring in Fabry disease patients treated at our institution and found