Derralynn Hughes

Effects of enzyme replacement therapy on the cardiomyopathy of Anderson-Fabry disease: a randomised, double-blind, placebo-controlled clinical trial of agalsidase alfa

Background: Anderson–Fabry disease is an X-linked glycosphingolipid storage disorder caused by deficient activity of the lysosomal enzyme α-galactosidase A. This leads to a progressive accumulation of globotriaosylceramide (Gb3) in the lysosomes of cells throughout the body that ultimately results in premature death from renal, cardiac or cerebrovascular complications. Until recently, there was no effective therapy available for this disease. The present study was designed to assess the safety and efficacy of enzyme replacement therapy with agalsidase alfa on the cardiac manifestations of Anderson–Fabry disease. Method: The effects of therapy with agalsidase alfa on cardiac structure and function were assessed in a randomised, double-blind, placebo-controlled study of 15 adult male patients with Anderson–Fabry disease. The following parameters were measured at baseline and 6 months: left ventricular mass, QRS duration and levels of Gb3 in cardiac tissue, urine sediment and plasma. After 6 months of the randomised trial patients were enrolled in a 2-year open-label extension study. Results: Left ventricular mass, as measured by MRI, was significantly reduced following 6 months of treatment with agalsidase alfa compared with placebo (p = 0.041). A mean 20% reduction in myocardial Gb3 content as assessed by serial transvenous endomyocardial biopsies was demonstrated over the 6 months of enzyme replacement compared to a mean 10% increase in patients receiving placebo (p = 0.42) Conclusion: Enzyme replacement therapy with agalsidase alfa resulted in regression of the hypertrophic cardiomyopathy associated with Anderson–Fabry disease.

Natural history of Fabry disease in females in the Fabry Outcome Survey

Background: Fabry disease is a rare X linked lysosomal storage disorder resulting from deficiency of α-galactosidase A activity. Although the severity of clinical features in male patients is well described, only recently have studies reported the high prevalence of disabling clinical features in heterozygous females. Aims: This study sets out to examine the clinical features and natural history of Fabry disease in further detail in a large group of female patients. Methods: Data were obtained from 303 females enrolled in the Fabry Outcome Survey. Pain was assessed using the Brief Pain Inventory, and health related quality of life (HRQoL) was assessed using the European Quality of Life Questionnaire. A modified version of the Mainz Severity Score Index was also applied. Data on left ventricular mass (LVM) index, mean ventricular wall thickness, and glomerular filtration rate (GFR) were used to assess cardiac and renal involvement. Results: The most commonly reported clinical features in females were neurological (77%) and cardiac (59%). A history of renal involvement was recorded in 40% of cases. Neurological features were the earliest to develop (mean age: 16 years), whereas cardiac (mean age: 33.5 years) and renal (mean age: 37.3 years) features developed later. LVM index increased exponentially with age. In addition, age was negatively correlated with estimated GFR and HRQoL. Conclusions: Females with Fabry disease report important age related clinical features and clinical investigation demonstrates evidence of disease progression. This study highlights the importance of careful and longitudinal assessment of female heterozygote patients with Fabry disease.

Identification and Assessment of Anderson-Fabry Disease by Cardiovascular Magnetic Resonance Noncontrast Myocardial T1 Mapping

Background— Anderson-Fabry disease (AFD) is a rare but underdiagnosed intracellular lipid disorder that can cause left ventricular hypertrophy (LVH). Lipid is known to shorten the magnetic resonance imaging parameter T1. We hypothesized that noncontrast T1 mapping by cardiovascular magnetic resonance would provide a novel and useful measure in this disease with potential to detect early cardiac involvement and distinguish AFD LVH from other causes. Methods and Results— Two hundred twenty-seven subjects were studied: patients with AFD (n=44; 55% with LVH), healthy volunteers (n=67; 0% with LVH), patients with hypertension (n=41; 24% with LVH), patients with hypertrophic cardiomyopathy (n=34; 100% with LVH), those with severe aortic stenosis (n=21; 81% with LVH), and patients with definite amyloid light-chain (AL) cardiac amyloidosis (n=20; 100% with LVH). T1 mapping was performed using the shortened modified Look-Locker inversion sequence on a 1.5-T magnet before gadolinium administration with primary results derived from the basal and midseptum. Compared with health volunteers, septal T1 was lower in AFD and higher in other diseases (AFD versus healthy volunteers versus other patients, 882±47, 968±32, 1018±74 milliseconds; P<0.0001). In patients with LVH (n=105), T1 discriminated completely between AFD and other diseases with no overlap. In AFD, T1 correlated inversely with wall thickness (r=−0.51; P=0.0004) and was abnormal in 40% of subjects who did not have LVH. Segmentally, AFD showed pseudonormalization or elevation of T1 in the left ventricular inferolateral wall, correlating with the presence or absence of late gadolinium enhancement (1001±82 versus 891±38 milliseconds; P<0.0001). Conclusions— Noncontrast T1 mapping shows potential as a unique and powerful measurement in the imaging assessment of LVH and AFD.

Cardiovascular magnetic resonance measurement of myocardial extracellular volume in health and disease

Objective To measure and assess the significance of myocardial extracellular volume (ECV), determined non-invasively by equilibrium contrast cardiovascular magnetic resonance, as a clinical biomarker in health and a number of cardiac diseases of varying pathophysiology. Design Prospective study. Setting Tertiary referral cardiology centre in London, UK. Patients 192 patients were mainly recruited from specialist clinics. We studied patients with Anderson–Fabry disease (AFD, n=17), dilated cardiomyopathy (DCM, n=31), hypertrophic cardiomyopathy (HCM, n=31), severe aortic stenosis (AS, n=66), cardiac AL amyloidosis (n=27) and myocardial infarction (MI, n=20). The results were compared with those for 81 normal subjects. Results In normal subjects, ECV (mean (95% CI), measured in the septum) was slightly higher in women than men (0.273 (0.264 to 0.282 vs 0.233 (0.225 to 0.244), p<0.001), with no change with age. In disease, the ECV of AFD was the same as in normal subjects but higher in all other diseases (p<0.001). Mean ECV was the same in DCM, HCM and AS (0.280, 0.291, 0.276 respectively), but higher in cardiac AL amyloidosis and higher again in MI (0.466 and 0.585 respectively, each p<0.001). Where ECV was elevated, correlations were found with indexed left ventricular mass, end systolic volume, ejection fraction and left atrial area in apparent disease-specific patterns. Conclusions Myocardial ECV, assessed non-invasively in the septum with equilibrium contrast cardiovascular magnetic resonance, shows gender differences in normal individuals and disease-specific variability. Therefore, ECV shows early potential to be a useful biomarker in health and disease.

Increase in exhaled carbon monoxide during exacerbations of cystic fibrosis

BACKGROUND Non-invasive assessment of inflammation is likely to be useful in the management of cystic fibrosis (CF). Exhaled carbon monoxide (CO) concentrations are increased in patients with clinically stable CF. A study was undertaken to determine whether this marker of oxidative damage is further increased during exacerbations of the disease. METHODS Exhaled CO concentrations were measured in 12 healthy non-smoking control subjects (six men) of mean (SE) age 37 (2) years with forced expiratory volume in one second (FEV1) 95 (1)% predicted and in 44 patients with CF (20 men) of mean (SE) age 29 (1) years with FEV1 56 (3)% predicted using an on-line CO analyser. RESULTS Twenty nine patients were in a stable condition while 15 had clinically defined respiratory exacerbations (increased cough and production of sputum, change in the quality of the sputum, shortness of breath, sensation of chest congestion, and deterioration of FEV1) and represented the unstable group. Exhaled CO concentrations were 2.0 (0.15) ppm in the control group, were increased in the stable CF group to 2.7 (0.13) ppm (differences between means –0.67 (0.22), 95% confidence interval (CI) 0.22 to 1.12, p<0.01) and further increased in the unstable group to 4.8 (0.3) ppm (differences between means –2.15 (0.32), 95% CI 1.50 to 2.79, p<0.001). A significant correlation was found between the deterioration in FEV1 and exhaled CO concentrations. CONCLUSIONS This study shows that the measurement of exhaled CO is of potential value as an indicator of exacerbations in patients with CF and could be used as a simple method to monitor the course of the disease.

Fabry disease and the skin: data from FOS, the Fabry outcome survey

Background  Fabry disease (also known as Anderson–Fabry disease) is a rare, X‐linked lysosomal storage disorder that is characterized by accumulation of globotriaosylceramide throughout a range of tissues in the body.

Evolution of prodromal clinical markers of Parkinson disease in a GBA mutation-positive cohort.

IMPORTANCE Numerically, the most important genetic risk factor for the development of Parkinson disease (PD) is the presence of a glucocerebrosidase gene (GBA) mutation. OBJECTIVE To evaluate longitudinally and clinically a GBA mutation-positive cohort and the evolution of the prodromal features of PD. DESIGN, SETTING, AND PARTICIPANTS Participants in a study of the etiology and prodrome of PD were reevaluated in this clinic-based 2-year follow-up report. Patients with type 1 Gaucher disease (GD) and heterozygous GBA mutation carriers were recruited in 2010 from the Lysosomal Storage Disorder Unit at the Royal Free Hospital, London, England. Thirty patients who previously received a diagnosis of type 1 GD, 28 heterozygous GBA mutation carriers, and 26 genetically unrelated controls were included. Exclusion criteria included a diagnosis of PD or dementia for both the patients with GD and the GBA mutation carriers and any existing neurological disease for the controls. MAIN OUTCOMES AND MEASURES Assessment was performed for clinical markers using standardized scales for hyposmia, rapid eye movement sleep behavior disorder, depression, autonomic dysfunction, cognitive function, and parkinsonian motor signs (using the Unified Parkinsons Disease Rating Scale motor subscale [UPDRS part III]). RESULTS Over 2 years, depression scores were significantly worse for heterozygous carriers (mean baseline, 0.65; mean follow-up, 2.88; P = .01), rapid eye movement sleep behavior disorder scores were significantly worse for patients with GD (mean baseline, 0.93; mean follow-up, 2.93; P < .001) and heterozygotes (mean baseline, 0.10; mean follow-up, 2.30; P < .001), and UPDRS part III scores were significantly worse for patients with GD (mean baseline, 4.29; mean follow-up, 7.82; P < .001) and heterozygotes (mean baseline, 1.97; mean follow-up, 4.50; P < .001). For controls, there was a small but significant deterioration in the UPDRS part II (activities of daily living) score (mean baseline, 0.00; mean follow-up, 0.58; P = .006). At 2 years, olfactory and cognitive assessment scores were lower in patients with GD and heterozygotes compared with controls, but they did not differ significantly from baseline. When the results from the patients with GD and the heterozygotes were combined, a significant deterioration from baseline was observed, as reflected in the Rapid Eye Movement Sleep Behaviour Disorder Questionnaire (mean baseline, 0.51; mean follow-up, 2.63; P < .001), Beck Depression Inventory (mean baseline, 1.72; mean follow-up, 4.44; P = .002), and UPDRS part II (mean baseline, 0.88; mean follow-up, 2.01; P < .001) and part III scores (mean baseline, 3.09; mean follow-up, 6.10; P < .001) (all P < .01), and at 2 years, significant differences in University of Pennsylvania Smell Identification Test, Unified Multiple System Atrophy Rating Scale, Mini-Mental State Examination, Montreal Cognitive Assessment, and UPDRS part II and part III scores were observed between patients with GD/heterozygotes and controls (all P < .05). CONCLUSIONS AND RELEVANCE This study indicates that, as a group, GBA mutation-positive individuals show a deterioration in clinical markers consistent with the prodrome of PD. Within this group of individual, 10% appear to be evolving at a more rapid rate.

Glucocerebrosidase inhibition causes mitochondrial dysfunction and free radical damage

Highlights ► Glucocerebrosidase gene mutations are a risk factor for Parkinson’s disease. ► Glucocerebrosidase inhibition causes mitochondrial dysfunction & oxidative stress. ► These changes parallel important pathogenetic of Parkinson’s disease.

Prevalence of Anderson–Fabry disease in patients with hypertrophic cardiomyopathy: the European Anderson–Fabry Disease Survey

Objectives The prevalence of Anderson–Fabry disease (AFD) in patients presenting with unexplained left ventricular hypertrophy (LVH) is controversial. The aim of this study was to determine the prevalence of AFD in a large, consecutive cohort of patients with hypertrophic cardiomyopathy (HCM) using rapid mutation screening. Design, Setting and Patients A European multicentre cross-sectional study involving 13 referral centres. Inclusion criteria for the study were: men aged at least 35 years and women aged at least 40 years with unexplained LVH (maximum left ventricular wall thickness ≥1.5 cm). All patients were screened using a denaturing high-performance liquid chromatography protocol for rapid mutation screening of the α-galactosidase A (α-Gal A) gene and, if a sequence variant was found, direct sequencing was performed. 1386 patients (63.9% men, mean age 57.9±12.0 years) were enrolled in the study. Results Seven (0.5%) patients (age 57.4±9.0 years (45–72); three (43%) men) had pathogenic α-galactosidase A mutations. Polymorphisms were identified in 283 patients (20.4%). Maximal left ventricular wall thickness in patients carrying a disease-causing mutation was 18±2 mm (range 15–22); four patients had concentric LVH and the remainder had asymmetric septal hypertrophy. Conclusions The prevalence of AFD gene mutations in a large, consecutive cohort of European patients with unexplained LVH is 0.5%.

Belgian Fabry Study Prevalence of Fabry Disease in a Cohort of 1000 Young Patients With Cerebrovascular Disease

Background and Purpose— Data on the prevalence of Fabry disease in patients with central nervous system pathology are limited and controversial. In this study, we assessed the prevalence of Fabry disease in young patients presenting with cerebrovascular disease in Belgium. Methods— In this national, prospective, multicenter study, we screened for Fabry disease in 1000 patients presenting with ischemic stroke, transient ischemic attack, or intracranial hemorrhage; unexplained white matter lesions; or vertebrobasilar dolichoectasia. In male patients, we measured &agr;-galactosidase A (&agr;-GAL A) activity in dried blood spots. Female patients were screened for mutations by exonic DNA sequencing of the &agr;-GAL A gene. Results— &agr;-GAL A activity was deficient in 19 men (3.5%), although all had normal &agr;-GAL A gene sequences. Enzymatic deficiency was confirmed on repeat assessment in 2 male patients (0.4%). We identified missense mutations in 8 unrelated female patients (1.8%): Asp313Tyr (n=5), Ala143Thr (n=2), and Ser126Gly (n=1). The pathogenicity of the 2 former missense mutations is controversial. Ser126Gly is a novel mutation that can be linked to late-onset Fabry disease. Conclusion— &agr;-GAL A deficiency may play a role in up to 1% of young patients presenting with cerebrovascular disease. These findings suggest that atypical variants of Fabry disease with late-onset cerebrovascular disease exist, although the clinical relevance is unclear in all cases.