Hearing improvement in patients with Fabry disease treated with agalsidase alfa

Prevalence of Fabry disease in men with tinnitus and sensorineural hearing loss

Fabry disease (FD) is a lysosomal storage disorder caused by pathogenic mutations in the alpha-galactosidase A (AGALA) encoding gene region. This rare disease affects several organs including the cochlea-vestibular system. Tinnitus and sensorineural hearing loss (SNHL) are reported among otoneurological symptoms. Early and correct diagnosis of FD is important with a view to available therapy. The aim of the study was to screen for alpha-galactosidase deficiency in men with tinnitus/SNHL. A prospective multicentric study including consecutive patients with SNHL confirmed by tone audiometry or tinnitus evaluated (10/2016-8/2019). The diagnosis of AGALA deficiency was done by dry blood spot method using a threshold of 1.2 µmol/l/h. Only men aged 18-60 were included. 181 patients were subject to evaluation. SNHL was reported in 126 (70%) patients, 50 (28%) patients had unilateral, 76 (42%) patients had bilateral SNHL. Tinnitus was found in 161 (89%) patients, unilateral in 96 (53%) and bilateral in 65 (36%) patients. Suspected FD was not detected in any patient; alpha-galactosidase The AGALA values ranged 1.5-8.8 µmol/l/h, an average of 3.4 µmol/l/h. None of the 181 patients participating in the study had AGALA levels below the threshold 1.2 µmol/l/h. The occurrence of tinnitus and sensorineural hearing loss in men appears to be an irrelevant clinical sign for FD systematic screening.

Otological aspects of Fabry disease in patients with normal hearing

We investigated the otological aspects of Fabry disease (FD) in patients with normal hearing. Forty-one patients (21 men, 20 women) with bilaterally normal hearing were recruited, and their otological symptoms and hearing evaluations, which included pure tone audiometry (PTA) and distortion product otoacoustic emission (DPOAE), were investigated. Ten of the 21 male (47.6%) and eight of the 20 female (40.0%) patients had otological symptoms, of which tinnitus was the most frequent. Cardiac dysfunction was more frequently observed in female patients. The average thresholds on PTA were below 25 dB at all frequencies, but DPOAE amplitudes were significantly lower in female patients at some frequencies. Otological symptoms were frequently observed in patients with FD, despite their normal hearing levels on PTA. DPOAE might provide useful information regarding cochlear disturbances related to the disease..

The effect of enzyme replacement therapy on clinical outcomes in male patients with Fabry disease: A systematic literature review by a European panel of experts

BACKGROUND

Enzyme replacement therapy (ERT) with recombinant human α-galactosidase has been available for the treatment of Fabry disease since 2001 in Europe and 2003 in the USA. Treatment outcomes with ERT are dependent on baseline patient characteristics, and published data are derived from heterogeneous study populations.

METHODS

We conducted a comprehensive systematic literature review of all original articles on ERT in the treatment of Fabry disease published up until January 2017. This article presents the findings in adult male patients.

RESULTS

Clinical evidence for the efficacy of ERT in adult male patients was available from 166 publications including 36 clinical trial publications. ERT significantly decreases globotriaosylceramide levels in plasma, urine, and in different kidney, heart, and skin cell types, slows the decline in estimated glomerular filtration rate, and reduces/stabilizes left ventricular mass and cardiac wall thickness. ERT also improves nervous system, gastrointestinal, pain, and quality of life outcomes.

CONCLUSIONS

ERT is a disease-specific treatment for patients with Fabry disease that may provide clinical benefits on several outcomes and organ systems. Better outcomes may be observed when treatment is started at an early age prior to the development of organ damage such as chronic kidney disease or cardiac fibrosis. Consolidated evidence suggests a dose effect. Data described in male patients, together with female and paediatric data, informs clinical practice and therapeutic goals for individualized treatment.

Characterization of vertigo and hearing loss in patients with Fabry disease

Background

Fabry Disease (FD) is an X-linked hereditary lysosomal storage disorder which leads to a multisystemic intralysosomal accumulation of globotriaosylceramid (Gb3). Besides prominent renal and cardiac organ involvement, patients commonly complain about vestibulocochlear symptoms like high-frequency hearing loss, tinnitus and vertigo. However, comprehensive data especially on vertigo remain scarce. The aim of this study was to examine the prevalence and characteristics of vertigo and hearing loss in patients with FD, depending on renal and cardiac parameters and get hints about the site and the pattern of the lesions.

Methods

Single-center study with 57 FD patients. Every patient underwent an oto-rhino-laryngological examination as well as videonystagmography and vestibular evoked myogenic potentials (VEMPs) and audiological measurements using pure tone audiometry and auditory brainstem response audiometry (ABR). Renal function was measured by eGFR, cardiac impairment was graduated by NYHA class.

Results

More than one out of three patients (35.1%) complained about hearing loss, 54.4% about vertigo and 28.1% about both symptom. In 74% a sensorineural hearing loss of at least 25 dB was found, ABR could exclude any retrocochlear lesion. Caloric testing showed abnormal values in 71.9%, VEMPs were pathological in 68%. A correlation between the side or the shape of hearing loss and pathological vestibular testing could not be revealed.

Conclusions

Hearing loss and vertigo show a high prevalence in FD. While hearing loss seems due to a cochlear lesion, peripheral vestibular as well as central nervous pathologies cause vertigo. Thus, both the site of lesion and the pathophysiological patterns seem to differ.

Electronic supplementary material

The online version of this article (10.1186/s13023-018-0882-7) contains supplementary material, which is available to authorized users.

Enzyme replacement therapy for Anderson-Fabry disease

BACKGROUND

Anderson-Fabry disease is an X-linked defect of glycosphingolipid metabolism. Progressive renal insufficiency is a major source of morbidity, additional complications result from cardio- and cerebro-vascular involvement. Survival is reduced among affected males and symptomatic female carriers.This is an update of a Cochrane review first published in 2010, and previously updated in 2013.

OBJECTIVES

To evaluate the effectiveness and safety of enzyme replacement therapy compared to other interventions, placebo or no interventions, for treating Anderson-Fabry disease.

SEARCH METHODS

We searched the Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register (date of the most recent search: 08 July 2016). We also searched 'Clinical Trials' on The Cochrane Library, MEDLINE, Embase and LILACS (date of the most recent search: 24 September 2015).

SELECTION CRITERIA

Randomized controlled trials of agalsidase alfa or beta in participants diagnosed with Anderson-Fabry disease.

DATA COLLECTION AND ANALYSIS

Two authors selected relevant trials, assessed methodological quality and extracted data.

MAIN RESULTS

Nine trials comparing either agalsidase alfa or beta in 351 participants fulfilled the selection criteria.Both trials comparing agalsidase alfa to placebo reported on globotriaosylceramide concentration in plasma and tissue; aggregate results were non-significant. One trial reported pain scores measured by the Brief Pain Inventory severity, there was a statistically significant improvement for participants receiving treatment at up to three months, mean difference -2.10 (95% confidence interval -3.79 to -0.41; at up to five months, mean difference -1.90 (95% confidence interval -3.65 to -0.15); and at up to six months, mean difference -2.00 (95% confidence interval -3.66 to -0.34). There was a significant difference in the Brief Pain Inventory pain-related quality of life at over five months and up to six months, mean difference -2.10 (95% confidence interval -3.92 to -0.28) but not at other time points. Death was not an outcome in either of the trials.One of the three trials comparing agalsidase beta to placebo reported on globotriaosylceramide concentration in plasma and tissue and showed significant improvement: kidney, mean difference -1.70 (95% confidence interval -2.09 to -1.31); heart, mean difference -0.90 (95% confidence interval -1.18 to -0.62); and composite results (renal, cardiac, and cerebrovascular complications and death), mean difference -4.80 (95% confidence interval -5.45 to -4.15). There was no significant difference between groups for death; no trials reported on pain.Only two trials compared agalsidase alfa to agalsidase beta. One of them showed no significant difference between the groups regarding adverse events, risk ratio 0.36 (95% confidence interval 0.08 to 1.59), or any serious adverse events; risk ratio 0.30; (95% confidence interval 0.03 to 2.57).Two trials compared different dosing schedules of agalsidase alfa. One of them involved three different doses (0.2 mg/kg every two weeks; 0.1 mg/kg weekly and; 0.2 mg/kg weekly), the other trial evaluated two further doses to the dosage schedules: 0.4 mg/kg every week and every other week. Both trials failed to show significant differences with various dosing schedules on globotriaosylceramide levels. No significant differences were found among the schedules for the primary efficacy outcome of self-assessed health state, or for pain scores.One trial comparing agalsidase alfa to agalsidase beta showed no significant difference for any adverse events such as dyspnoea and hypertension.The methodological quality of the included trials was generally unclear for the random sequence generation and allocation concealment.

AUTHORS' CONCLUSIONS

Trials comparing enzyme replacement therapy to placebo show significant improvement with enzyme replacement therapy in regard to microvascular endothelial deposits of globotriaosylceramide and in pain-related quality of life. There is, however, no evidence identifying if the alfa or beta form is superior or the optimal dose or frequency of enzyme replacement therapy. With regards to safety, adverse events (i.e., rigors, fever) were more significant in the agalsidase beta as compared to placebo. The long-term influence of enzyme replacement therapy on risk of morbidity and mortality related to Anderson-Fabry disease remains to be established. This review highlights the need for continued research into the use of enzyme replacement therapy for Anderson-Fabry disease.

Fabry disease presenting as apical left ventricular hypertrophy in a patient carrying the missense mutation R118C

Anderson-Fabry disease is an X-linked lysosomal storage disorder caused by abnormalities of the GLA gene, which encodes the enzyme α-galactosidase A. A deficiency of this enzyme leads to the lysosomal accumulation of glycosphingolipids, which may cause left ventricular hypertrophy that is typically concentric and symmetric. We present the case of a 60-year-old woman with symptoms of dyspnea, atypical chest pain and palpitations, in whom a transthoracic echocardiogram revealed an apical variant of hypertrophic cardiomyopathy. Analysis of specific sarcomeric genetic mutations was negative. The patient underwent a screening protocol for Anderson-Fabry disease, using a dried blood spot test, which was standard at our institution for patients with left ventricular hypertrophy. The enzymatic activity assay revealed reduced α-galactosidase A enzymatic activity. Molecular analysis identified a missense point mutation in the GLA gene (p.R118C). This case report shows that Anderson-Fabry disease may cause an apical form of left ventricular hypertrophy. The diagnosis was only achieved because of systematic screening, which highlights the importance of screening for Anderson-Fabry disease in patients with unexplained left ventricular hypertrophy, including those presenting with more unusual patterns, such as apical variants of left ventricular hypertrophy. This case also supports the idea that the missense mutation R118C is indeed a true pathogenic mutation of Anderson-Fabry disease.

Temporal intradiploic dilative vasculopathy: an additional pathogenic factor for the hearing loss in fabry disease?

Fabry disease (FD) is caused by progressive accumulation of neutral glycosphingolipids, including in ganglion neural and vascular endothelial cells, as a result of lysosomal α-galactosidase deficiency. High frequencies progressive sensorineural hearing loss (HL), sudden deafness, tinnitus and dizziness are otological symptoms frequently reported.A 45-year-old man with FD, on haemodialysis since age 25, complaining of progressive HL, was started on enzyme replacement therapy (ERT) because of cardiac complications. A bilateral sloping sensorineural HL was found at baseline audiological evaluation. Computed tomography of the ears showed enlargement of the intradiploic vascular channels, principally in the petrous bone. The magnetic resonance angiography showed elongation and ectasia of the middle cerebral arteries and the arteries of the Circle of Willis, particularly the internal carotid and the basilar arteries. Follow-up audiological evaluations documented progressive worsening of HL, mainly in the high frequencies range, despite high dose ERT and evidence of cardiac improvement.The intradiploic vascular abnormalities of the temporal bones reported herein have never been described in association with FD and may have contributed to the pathogenesis of progressive HL, by a 'stealing' effect upon the cochlear blood supply (like in cavernous haemangioma of the internal auditory meatus), in addition to the other mechanisms of ischaemic injury to the Organ of Corti described in FD. This clinical observation shows the value of comprehensive neuroimaging investigation of HL in FD and emphasizes the importance of early institution of specific therapy, before the occurrence of irreversible inner ear lesions and hearing damage.

Update on role of agalsidase alfa in management of Fabry disease

Fabry disease (FD) is an X-linked lysosomal storage disorder that affects both men and women. The manifestations of this heterogeneous disease are multisystemic and progressive. Prior to the development of enzyme replacement therapy, the management and treatment for Fabry disease was largely nonspecific and supportive. Because enzyme replacement therapy became commercially available in 2001, a variety of clinical benefits in Fabry patients have been consistently reported, including improved renal pathology and cardiac function, and reduced severity of neuropathic pain and improved pain-related quality of life. This update focuses on published data on the efficacy and tolerability of enzyme replacement therapy with agalsidase alfa, and gives a brief overview on some of the outstanding management issues in the treatment of this complex disease.

Enzyme replacement therapy for Fabry disease: some answers but more questions

Fabry disease (FD) is a multisystem, X-linked disorder of glycosphingolipid metabolism caused by enzyme deficiency of α-galactosidase A. Affected patients have symptoms including acroparesthesias, angiokeratomas, and hypohidrosis. More serious manifestations include debilitating pain and gastrointestinal symptoms, proteinuria and gradual deterioration of renal function leading to end-stage renal disease, hypertrophic cardiomyopathy, and stroke. Heterozygous females may have symptoms as severe as males with the classic phenotype. Before 2001, treatment of patients with FD was supportive. The successful development of enzyme replacement therapy (ERT) has been a great advancement in the treatment of patients with FD and can stabilize renal function and cardiac size, as well as improve pain and quality of life of patients with FD. In this review, we have provided a critical appraisal of the literature on the effects of ERT for FD. This analysis shows that data available on the treatment of FD are often derived from studies which are not controlled, rely on surrogate markers, and are of insufficient power to detect differences on hard clinical endpoints. Further studies of higher quality are needed to answer the questions that remain concerning the efficacy of ERT for FD.

The use of agalsidase alfa enzyme replacement therapy in the treatment of Fabry disease

BACKGROUND

Fabry disease is an X-linked lysosomal storage disease caused by deficiency of alpha-galactosidase A (alpha-Gal A), encoded by the GLA gene. The deficiency causes accumulation of neutral glycosphingolipids in various tissues, leading to neuronopathic pain, progressive renal dysfunction, cardiomyopathy and stroke. Enzyme replacement therapy (ERT) with agalsidase alfa (Replagal, Shire Human Genetic Therapies) is approved for use by 40 countries, but not the US.

OBJECTIVE

To evaluate agalsidase alfa in therapy of Fabry disease.

METHODS

An examination of relevant reports.

RESULTS/CONCLUSIONS

Clinical trials data, along with experience of the treatment collected through participation of treating physicians in a world-wide Fabry disease registry, have demonstrated that it improves pain and stabilizes renal function, as well as cardiomyopathy, in some patients. More data are needed to evaluate the role of treatment with this drug in the prevention of stroke and adverse cardiac events, and its overall effect on the lifespan and quality of life of affected individuals.

Vestibular and auditory deficits in Fabry disease and their response to enzyme replacement therapy

Progressive hearing (pHL) and vestibular (pVL) loss are frequent deficits in Fabry disease (FD). Recently, enzyme replacement therapy (ERT) with human alpha-galactosidase A has become available. Here, we investigate the association between pHL and pVL in FD and their ERT responses. Pure tone audiometry (PTA) and head impulse testing (HIT) were administered at baseline in 47 patients (25 male, 18-60 y; 22 female, 17-74 y), of whom 24 also received caloric irrigation (CI). Of the 47 patients, 38 (24 male) were tested both before and during ERT (follow- up < or = 60 months). ERT consisted of agalsidase alfa infusions. At baseline, pHL was present in 88% of males and 86% of females. Over all tested frequencies (range: 0.5-6 kHz), pHL was significantly (two-way ANOVA: p < 0.05) greater at higher age and in males,with largest deficits at high frequencies. When assessed with HIT, 80% of males and 77% of females had pVL. pVL was significantly greater at higher age and in males. Tested with CI, 21% of males and 0% of females had pVL. No associations among individual semicircular canal (SCC) deficits, as tested by HIT, and hearing was observed in individual ears. After > or = 18 months of ERT, pVL was significantly smaller than at baseline (ANOVA for HIT: p < 0.01). In contrast, pHL remained unchanged by ERT over 60 months (p > 0.05). We conclude that pHL and pVL prevalences are similar in FD. To detect pVL, HIT is more sensitive than CI. We speculate that pHL and pVL emerge from lesions within the vestibulocochlear labyrinth, because no specific patterns of vestibulo-cochlear deficits were observed, as expected if lesions were more proximal along the inferior or superior branch of the vestibulo-cochlear nerve or labyrinthine artery. Finally, ERT stabilizes auditory and even improves vestibular function.