Major cardiovascular adverse events in Fabry disease patients receiving agalsidase alfa

Cardiovascular mortality (CVM) has become the major contributor to overall Fabry disease (FD) mortality in the enzyme replacement therapy (ERT) era. Our objectives were to describe causes and potential predictors of mortality in FD adult patients in Argentina, and to assess risk of major adverse cardiovascular events (MACE) in the ERT era. We retrospectively studied 93 consecutive patients treated with alphagalactosidase A (median follow up: 9.5 years from start of ERT). Mean age at ERT starting was 35 ± 16.3 years. Prevalence of cardiomyopathy and renal disease reached 47% and 41%, respectively. Eleven subjects (11.8%, 95% CI: 5-18%) died during follow up (1.24/100 patient-years). Mean overall survival was 71 years (95% CI: 66-75 years). Seven cases were considered as CVM; main causes were sudden death and stroke. Risk of MACE was 14% (95% CI: 6.9-21.1%; 1.47 events/100 patient-years from start of ERT). All but 2 subjects had at least one comorbid cardiovascular risk factor; however, 86% of patients remained free of MACE during follow-up. CVM remained low and our study was underpowered for detection of predictors of mortality, but it is worth noting that age at diagnosis and ERT starting, left ventricular mass index and renal disease trended to correlate with CVM. Prevalence of hypertension, diabetes and dyslipidemia were lower in FD patients when compared to population level data. As in the Argentinean general population, CVM was the leading cause of mortality among this cohort of consecutive FD patients treated with agalsidase alfa.

Neuro-Otological and Peripheral Nerve Involvement in Fabry Disease

Fabry disease (FD) is an X-linked lysosomal storage disease, with multisystemic glycosphingolipids deposits. Neuro-otological involvement leading to hearing loss and vestibular dysfunctions has been described, but there is limited information about the frequency, site of lesion, or the relationship with peripheral neuropathy. The aim was to evaluate the presence of auditory and vestibular symptoms, and assess neurophysiological involvement of the VIII cranial nerve, correlating these findings with clinical and neurophysiological features of peripheral neuropathy. We studied 36 patients with FD with a complete neurological and neuro-otological evaluation including nerve conduction studies, quantitative sensory testing (to evaluate small fiber by warm and cold threshold detection and cold and heat pain), vestibular evoked myogenic potentials, videonistagmography, audiometry and brainstem auditory evoked potentials. Neuro-otologic symptoms included hearing loss (22.2%), vertigo (27.8%) or both (25%). An involvement of either cochlear or vestibular function was identified in most patients (75%). In 70% of our patients the involvement of both cochlear and vestibular function could not be explained by a neural or vascular mechanism. Small fiber neuropathy was identified in 77.7%. There were no significant associations between neuro-otological and QST abnormalities. Neuro-otologic involvement is frequent and most likely under-recognized in patients with FD. It lacks a specific neural or vascular pattern, suggesting multi-systemic, end organ damage. Small fiber neuropathy is an earlier manifestation of FD, but there is no correlation between the development of neuropathy and neuro-otological abnormalities.

Velaglucerase alfa (VPRIV) enzyme replacement therapy in patients with Gaucher disease: Long-term data from phase III clinical trials

Type 1 Gaucher disease is an inherited lysosomal enzyme deficiency with variable age of symptom onset. Common presenting signs include thrombocytopenia, anemia, hepatosplenomegaly, bone abnormalities, and, additionally in children, growth failure. Fifty-seven patients aged 3–62 years at the baseline of two phase III trials for velaglucerase alfa treatment were enrolled in the single extension study. In the extension, they received every-other-week velaglucerase alfa intravenous infusions for 1.2–4.8 years at 60 U/kg, although 10 patients experienced dose reduction. No patient experienced a drug-related serious adverse event or withdrew due to an adverse event. One patient died following a convulsion that was reported as unrelated to the study drug. Only one patient tested positive for anti-velaglucerase alfa antibodies. Combining the experience of the initial phase III trials and the extension study, significant improvements were observed in the first 24 months from baseline in hematology variables, organ volumes, plasma biomarkers, and, in adults, the lumbar spine bone mineral density Z-score. Improvements were maintained over longer-term treatment. Velaglucerase alfa had a good long-term safety and tolerability profile, and patients continued to respond clinically, which is consistent with the results of the extension study to the phase I/II trial of velaglucerase alfa. EudraCT number 2008-001965-27; http://www.clinicaltrials.gov identifier NCT00635427. Am. J. Hematol. 90:584–591, 2015. © 2015 Wiley Periodicals, Inc.

Proinflammatory and proosteoclastogenic potential of peripheral blood mononuclear cells from Gaucher patients: Implication for bone pathology

Gaucher disease (GD) is caused by mutations in the GBA gene that confer a deficient level of activity of glucocerebrosidase (GCase). This deficiency leads to the accumulation of the glycolipid glucocerebroside in the lysosomes of cells of monocyte/macrophage system. Bone compromise in Gaucher disease patients is the most disabling aspect of the disease. However, pathophysiological aspects of skeletal alterations are still poorly understood. On the other hand it is well known that inflammation is a key player in GD pathology. In this work, we revealed increased levels of the proinflammatory CD14(+)CD16(+) monocyte subset and increased inflammatory cytokine production by monocytes and T cells in the circulation of GD patients. We showed increased levels of osteoclast precursors in PBMC from patients and a higher expression of RANKL in the surface of T cells. PBMC from patients presented higher osteoclast differentiation compared to healthy controls when cultured in the presence of M-CSF alone or in combination with RANKL. In vitro treatment with Velaglucerase reduced osteoclast levels to control levels. On the other hand THP-1 derived osteoclast precursors cultured in the presence of conditioned media from PBMC of GD patients presented higher differentiation to active osteoclasts. This induction involved TNF-α and RANKL.

Apical left ventricular hypertrophy and mid-ventricular obstruction in fabry disease

We report the case of a rare cardiac presentation of Fabry disease. Although concentric left ventricular hypertrophy is a major cardiac finding in Fabry disease, there is no case report of dynamic obstruction at mid-left ventricular level. We describe a 59-year-old-woman suffering from a severe form of Fabry disease, mimicking an apical hypertrophic cardiomyopathy with mid-ventricular obstruction. Differentiation of Fabry disease from hypertrophic cardiomyopathy is crucial given the therapeutic and prognostic differences. Fabry disease should always be suspected in an adult, independently of the pattern of left ventricular hypertrophy.

Two-dimensional speckle tracking echocardiography for early detection of myocardial damage in young patients with Fabry disease

Fabry disease (FD) is characterized by left ventricular hypertrophy (LVH). Conventional echocardiography is not sensitive enough to perform the preclinical diagnosis To assess whether longitudinal myocardial strain of the left ventricle (LV), using speckle tracking, is useful to detect early myocardial involvement in FD. Forty-four patients with FD who were diagnosed with genetic testing were prospectively included and were compared to a sex-matched control group. They were divided into three groups: 22 with LVH (Group I), 22 without LVH (Group II), and 22 healthy volunteers (Group III). LV longitudinal strain was measured from the apical views. An ANOVA test was used for multiple comparisons for variables with a normal distribution, and a Kruskal-Wallis test was used for variables with non-Gaussian distribution. Longitudinal LV strain was different in the three groups: it was ≥-15% in at least one segment in all Group I patients, in 50% of patients of Group II and in no patient of Group III. Seventy percent of the segments with abnormal strain in Group II were located in the basal regions (32/46). These findings show that the presence of at least one strain value ≥-15% demonstrates subclinical myocardial dysfunction in patients with preclinical FD. Longitudinal myocardial LV strain measured with speckle tracking is a useful tool to detect early myocardial involvement in young patients with FD. This information allows the detection and treatment of myocardial dysfunction at an early stage, which is of high clinical importance.

Velaglucerase alfa enzyme replacement therapy compared with imiglucerase in patients with Gaucher disease

Enzyme replacement therapy for Gaucher disease (GD) has been available since 1991. This study compared the efficacy and safety of velaglucerase alfa with imiglucerase, the previous standard of care. A 9-month, global, randomized, double-blind, non-inferiority study compared velaglucerase alfa with imiglucerase (60 U/kg every other week) in treatment-naïve patients aged 3-73 years with anemia and either thrombocytopenia or organomegaly. The primary endpoint was the difference between groups in mean change from baseline to 9 months in hemoglobin concentration. 35 patients were randomized: 34 received study drug (intent-to-treat: 17 per arm), 20 were splenectomized. Baseline characteristics were similar in the two groups. The per-protocol population included 15 patients per arm. The mean treatment difference for hemoglobin concentration from baseline to 9 months (velaglucerase alfa minus imiglucerase) was 0.14 and 0.16 g/dL in the intent-to-treat and per-protocol populations, respectively. The lower bound of the 97.5% one-sided confidence interval in both populations lay within the pre-defined non-inferiority margin of -1.0 g/dL, confirming that velaglucerase alfa is non-inferior to imiglucerase. There were no statistically significant differences in the secondary endpoints. Most adverse events were mild to moderate. No patient receiving velaglucerase alfa developed antibodies to either drug, whereas four patients (23.5%) receiving imiglucerase developed IgG antibodies to imiglucerase, which were cross-reactive with velaglucerase alfa in one patient. This study demonstrates the efficacy and safety of velaglucerase alfa compared with imiglucerase in adult and pediatric patients with GD clinically characterized as Type 1. Differences in immunogenicity were also observed.

Enzyme replacement therapy with velaglucerase alfa in Gaucher disease: Results from a randomized, double-blind, multinational, Phase 3 study

Type 1 Gaucher disease (GD1), resulting from glucocerebrosidase deficiency, leads to splenomegaly, hepatomegaly, anemia, thrombocytopenia, and bone involvement. Current standard treatment is enzyme replacement therapy. Velaglucerase alfa is an enzyme replacement product for GD1, with the same amino acid sequence as naturally occurring human glucocerebrosidase. This multinational, Phase 3 trial evaluated the efficacy and safety of two doses of velaglucerase alfa in 25 treatment-naïve, anemic patients with GD1 (4-62 years of age), randomized to intravenous velaglucerase alfa 60 U/kg (n=12) or 45 U/kg body weight (n=13) every other week for 12 months. The primary endpoint was change from baseline in hemoglobin concentration in the 60 U/kg arm. At 12 months, mean hemoglobin concentrations increased from baseline [60 U/kg: +23.3%; +2.43 g/dL (P<0.001); 45 U/kg: +23.8%; +2.44 g/dL (P<0.001)], as did mean platelet counts [60 U/kg: +65.9%; +50.9 × 10(9) /L (P=0.002); 45 U/kg: +66.4%; +40.9 × 10(9) /L(P=0.01)]. Mean splenic volume decreased from baseline [60 U/kg: -50.4%, from 14.0 to 5.8 multiples of normal (MN) (P=0.003); 45 U/kg: -39.9%, from 14.5 to 9.5 MN (P=0.009)]. No drug-related serious adverse events or withdrawals were observed. One patient developed antibodies. Velaglucerase alfa was generally well tolerated and effective for adults and children with GD1 in this study. All disease-specific parameters measured demonstrated clinically meaningful improvements after 12 months.

Home infusion program for Fabry disease: experience with agalsidase alfa in Argentina

Fabry disease is an X-linked lysosomal storage disorder caused by inherited deficiency of the enzyme a-galactosidase A. Enzyme replacement treatment using agalsidase alfa significantly reduces pain, improves cardiac function and quality of life, and slows renal deterioration. Nevertheless, it is a life-long treatment which requires regular intravenous infusions and entails a great burden for patients. Our objective was to evaluate retrospectively the safety and tolerability of the home infusion of agalsidase alfa in patients with Fabry disease in Argentina. We evaluated all the patients with Fabry disease who received home infusion with agalsidase alfa 0.2 mg/kg between January 2005 and June 2011. The program included 87 patients; 51 males (mean age: 30 years) and 36 females (mean age: 34 years). A total of 5229 infusions (mean: 59 per patient; range: 1-150) were administered. A total of 5 adverse reactions were seen in 5 patients (5.7% of patients and 0.9% of the total number of infusions). All were mild in severity and resolved by reducing the rate of infusion and by using antihistaminics. All these 5 patients were positive for IgG antibodies, but none of them presented IgE antibodies and none suffered an anaphylactic shock. In our group 18 patients were switched from agalsidase beta to agalsidase alfa without complications. Home infusion with agalsidase alfa is safe, well tolerated and is associated to high compliance.

[Guidelines for diagnosis, monitoring and treatment of Fabry disease]

Fabry disease is an X-linked hereditary lysosomal storage disorder caused by deficiency of the enzyme alpha-galactosidase A. Knowledge about this disease, and its medical management, has made remarkable progress in the last decade, including the development of its specific treatment. This guide was developed by medical professionals from various specialties involved in the care of patients with Fabry disease. The discussion and analysis of the available scientific evidence, coupled with the experience of each of the participants, has allowed us to develop the concepts included in this guide in order to provide a useful tool for all professionals who care for patients with Fabry disease.

Brain MRI findings in patients with Fabry disease

BACKGROUND

To evaluate the presence of ischemic and hemorrhagic lesions in brain MRI of patients with Fabry disease (FD).

METHODS

Brain MRI studies in 46 consecutive patients were evaluated using classic sequences as well as GRE-weighted images, for ischemic lesions and chronic microbleed detection. Of the 36 adult patients (15 males, mean age 31.2 years; 21 females, mean age 41.6 years). All had signs or symptoms of FD but lacked history of stroke or TIA.

RESULTS

Ten patients under 20 years of age initially presented a normal MRI. One child developed a hyperintense occipital lesion on T2-weighted imaging during control MRI. Sixteen adult patients (44.4%) had brain MRI evidence of small vessel disease in the basal ganglia, corona radiata, thalamus or brainstem, as well as in the periventricular white matter. Patients with MRI abnormalities were older (45.6 vs 30.9 years, p=0.005), with more vascular risk factors (1.2 vs 0.6 p=0.043). Three women (mean age 59.5 years) presented deep chronic microbleeds identified by GRE. Moreover, Flair and T2-weighted images revealed white matter disease and deep gray matter involvement.

CONCLUSION

44.4% of adult patients with FD without clinical history of CVA or prior dialysis had evidence of small vessel disease on MRI and 11% showed cerebral microbleeds. FD is a treatable disorder that should be routinely included in the differential diagnosis of ischemic and microhemorrhagic lesions in young adults.

Misdiagnosis in Fabry disease

OBJECTIVE

To evaluate the most frequent diagnostic errors in patients with Fabry disease and the types of specialists most often consulted before diagnosis.

STUDY DESIGN

We evaluated 45 consecutive symptomatic patients with Fabry disease confirmed by enzymatic tests in males and genetic studies in females. We interviewed the patients, their mothers, or both regarding symptoms, age at onset, medical consultations, and recommended treatments.

RESULTS

Neuropathic pain was the most frequent initial complaint, and rheumatic fever was the most common diagnosis. Seven patients were treated with penicillin for many years. Ten patients sought medical consultation because of abdominal pain and were diagnosed with food intoxication or nonspecific pain. Six patients sought consultation because of anhidrosis, considered of unclear cause, and angiokeratomas diagnosed as petechiae. Internists and pediatricians were the most frequently consulted specialists. The correct diagnosis was obtained after a mean of 19.7 years.

CONCLUSIONS

Pediatricians as well as internists commonly misdiagnose Fabry disease. Neuropathic pain, hypohidrosis, and recurrent abdominal pain in childhood or adolescence should include Fabry disease in the differential diagnosis to facilitate earlier diagnosis and treatment of these patients.