Migalastat como monoterapia oral para la enfermedad de Fabry

Contexto: la enfermedad de Fabry es una patología de depósito lisosomal poco frecuente, ligada al cromosoma X y causada por la deficiencia o ausencia de la enzima α-galactosidasa-A. La nefropatía, junto con la cardiopatía y el compromiso neurológico de la enfermedad, conduce a una muerte prematura. Objetivo: esta revisión describe la monoterapia oral con migalastat en pacientes con enfermedad de Fabry y mutaciones "amenables". Metodología: una chaperona farmacológica oral denominada migalastat (Galafold®), estabiliza y favorece el pasaje de formas mutadas "amenables" de la enzima hacia los lisosomas, aumentando así su actividad. Resultados: los estudios de fase III Facets y Attract demostraron seguridad y eficacia en comparación con las terapias de reemplazo enzimático disponibles, alcanzando estabilización de la función renal, reducción de la masa ventricular izquierda y estabilización del biomarcador plasmático Lyso-Gb3. Conclusiones: migalastat fue generalmente bien tolerado en ambos estudios. Publicaciones posteriores de extensión evidenciaron resultados similares, confirmando la seguridad y la eficacia, tanto en pacientes que previamente se encontraban con terapia de reemplazo enzimático y han sido rotados a migalastat, como también en pacientes que han iniciado migalastat como primer tratamiento.

Background: Fabry disease is a rare lysosomal storage disorder, linked to the X chromosome, and caused by the deficiency or absence of the enzyme α-galactosidase-A. Nephropathy together with heart disease and neurological involvement lead to premature death. Purpose: This review describes oral migalastat monotherapy in patients with Fabry disease and "amenable" mutations. Methodology: An oral pharmacological chaperone called Migalastat (Galafold®), stabilizes and facilitates the trafficking of "amenable" mutated forms of the enzyme to the lysosomes, thus increasing its activity. Results: The phase III FACETS and ATTRACT studies have demonstrated safety and efficacy compared to available enzyme replacement therapies; achieving renal function stabilization, reduction of left ventricular mass and maintenance of plasmatic Lyso-Gb3 levels. Conclusions: Migalastat was generally well tolerated in both trials. Subsequent extension publications showed similar results, confirming the safety and efficacy both in patients who were previously on enzyme replacement therapy and have been switched to migalastat, as well as in patients who have started migalastat as their first treatment.

Fabry Disease: Switch from Enzyme Replacement Therapy to Oral Chaperone Migalastat: What Do We Know Today?

Fabry disease is a lysosomal storage disorder caused by the deficiency of the α-galactosidase-A enzyme. The result is the progressive accumulation of complex glycosphingolipids and cellular dysfunction. Cardiac, renal, and neurological involvement significantly reduces life expectancy. Currently, there is increasing evidence that clinical response to treatment improves with early and timely initiation. Until a few years ago, treatment options for Fabry disease were limited to enzyme replacement therapy with agalsidase alfa or beta administered by intravenous infusion every 2 weeks. Migalastat (Galafold®) is an oral pharmacological chaperone that increases the enzyme activity of "amenable" mutations. The safety and efficacy of migalastat were supported in the phase III FACETS and ATTRACT studies, compared to available enzyme replacement therapies, showing a reduction in left ventricular mass, and stabilization of kidney function and plasma Lyso-Gb3. Similar results were confirmed in subsequent extension publications, both in patients who started migalastat as their first treatment and in patients who were previously on enzyme replacement therapy and switched to migalastat. In this review we describe the safety and efficacy of switching from enzyme replacement therapy to migalastat in patients with Fabry disease and "amenable" mutations, referring to publications available to date.

Cytokines expression from altered motor thalamus and behavior deficits following sublethal administration of Shiga toxin 2a involve the induction of the globotriaosylceramide receptor.

Encephalopathy associated with hemolytic uremic syndrome is produced by enterohemorrhagic E. coli (EHEC) infection, which releases the virulence factors Shiga toxin (Stx) and lipopolysaccharide (LPS). Neurological compromise is a poor prognosis and mortality factor of the disease, and the thalamus is one of the brain areas most frequently affected. We have previously demonstrated the effectiveness of anti-inflammatory drugs to ameliorate the deleterious effects of these toxins. However, the thalamic production of cytokines involved in pro-inflammatory processes has not yet been acknowledged. The aim of this work attempts to determine whether systemic sublethal Stx2a or co-administration of Stx2a with LPS are able to rise a proinflammatory profile accompanying alterations of the neurovascular unit in anterior and lateral ventral nuclei of the thalamus (VA-VL) and motor behavior in mice. After 4 days of treatment, Stx2a affected the lectin-bound microvasculature distribution while increasing the expression of GFAP in reactive astrocytes and producing aberrant NeuN distribution in degenerative neurons. In addition, increased swimming latency was observed in a motor behavioral test. All these alterations were heightened when Stx2a was co-administered with LPS. The expression of pro-inflammatory cytokines TNFα, INF-γ and IL-2 was detected in VA-VL. All these effects were concomitant with increased expression of the Stx receptor globotriaosylceramide (Gb3), which hints at receptor involvement in the neuroinflammatory process as a key finding of this study. In conclusion, Stx2a to Gb3 may be determinant in triggering a neuroinflammatory event, which may resemble clinical outcomes and should thus be considered in the development of preventive strategies.

Enfermedad de Fabry en Argentina / Fabry disease in Argentina / Doença de Fabry na Argentina

La enfermedad de Fabry es una patología genética debida a la deficiencia de la enzima α-galactosidasa A. En la Facultad de Ciencias Exactas de la Universidad Nacional de La Plata se implementaron estudios de diagnóstico de enfermedades lisosomales y se comenzó por la Enfermedad de Fabry. Se llevó a cabo un estudio dirigido a la detección de pacientes Fabry no diagnosticados mediante un enfoque biomédico multidisciplinario. Se realizó una evaluación nefrológica de los pacientes argentinos detectados y un análisis de sus manifestaciones clínicas durante el tratamiento de reemplazo enzimático. Los pacientes tratados con agalsidasa alfa recibieron sus primeras infusiones en centros médicos y luego la infusión fue domiciliaria. Los datos de los pacientes argentinos fueron registrados en la base de datos FOS, un registro internacional multicéntrico. Los estudios de investigación básica realizados mostraron la existencia de un estado proinflamatorio en células de pacientes Fabry, lo cual podría explicar parte de su fisiopatología. El abordaje de las enfermedades poco frecuentes no es sencillo, sobre todo ante la falta de políticas sanitarias de parte del Estado. Este trabajo permitió lograr múltiples objetivos: la difusión de la Enfermedad de Fabry en Argentina, mayor sospecha clínica en la comunidad médica y mejor accesibilidad al diagnóstico, seguimiento y tratamiento para los pacientes.

A Fabry disease is an X-linked lysosomal disorder that results from a deficiency of the lysosomal enzyme alpha-galactosidase A. The implementation of biochemical and genetic tests for lysosomal diseases was carried out in our institution, the School of Exact Sciences, Universidad Nacional de La Plata. A successful approach for the detection of Fabry patients in Argentina was developed by constitutingan interdisciplinary group of professionals. A nephrological assessment of the Argentine patients detected was made andthe clinical manifestations of Fabry patients were analysed and recorded in a FOS international registry. Patients received their enzyme replacement therapy, and the infusion was offered at home. Research studies carried out by our group showed the existence of a proinflammatory state in cells from Fabry patients, which could be related to the pathophysiology. Approaching rare diseases is not easy, especially when there is a lack of State health care policies. This work led us to achieve objectives such as disseminate knowledge about the disease in our country, enhance clinical suspicion and improve accessibility to diagnosis and treatment for patients.

Doença de Fabry é uma doença genética que resulta da deficiência da enzima α-galactosidase A. Na Faculdade de Ciências Exatas da Universidade Nacional de La Plata foram implementados estudos de diagnóstico de doenças lisossomais e a primeira foi a Doença de Fabry. Realizou-se um estudo orientado à detecção de pacientes Fabry não diagnosticados mediante uma abordagem biomédica multidisciplinar. Foi feita uma avaliação nefrológica dos pacientes argentinos detectados e uma análise de suas manifestações clínicas durante o tratamento de reposição enzimática. Os pacientes tratados com agalsidase alfa receberam suas primeiras infusões em centros médicos, e depois a infusão foi domiciliar. Os dados dos pacientes argentinos se registraram na base de dados FOS, um registro internacional multicêntrico. Estudos de pesquisa básica realizados mostraram a existência de um estado pró-inflamatório em células de pacientes Fabry, o que poderia explicar parte de sua fisiopatologia. A abordagem das doenças pouco frequentes não é simples, principalmente diante da falta de políticas sanitárias de parte do Estado. Este trabalho permitiu alcançar objetivos múltiplos: a difusão da Doença de Fabry na Argentina, maior suspeita clínica na comunidade médica, e melhor acessibilidade ao diagnóstico, seguimento e tratamento para os pacientes.

The Kidney in Fabry Disease: More Than Mere Sphingolipids Overload

Abstract Fabry disease is a rare cause of end-stage renal disease. Renal pathology is notable for diffuse deposition of glycosphingolipid in the renal glomeruli, tubules, and vasculature. Classical patients with mutations in the α-galactosidase A gene accumulate globotriaosylceramide and become symptomatic in childhood with pain, gastrointestinal disturbances, angiokeratoma, and hypohidrosis. Classical patients experience progressive loss of renal function and hypertrophic cardiomyopathy, with severe clinical events including end-stage renal disease, stroke, arrhythmias, and premature death. The pathophysiological mechanisms by which endothelial cells, podocytes, smooth muscle cells, and tubular dysfunction occur in Fabry disease are poorly characterized and understood. This review evaluates the new evidence in pathophysiology of Fabry nephropathy, highlighting the necessity of early identification of individuals with Fabry disease.

L-Rhamnose-binding lectin from eggs of the Echinometra lucunter: Amino acid sequence and molecular modeling.

An L-rhamnose-binding lectin named ELEL was isolated from eggs of the rock boring sea urchin Echinometra lucunter by affinity chromatography on lactosyl-agarose. ELEL is a homodimer linked by a disulfide bond with subunits of 11 kDa each. The new lectin was inhibited by saccharides possessing the same configuration of hydroxyl groups at C-2 and C-4, such as L-rhamnose, melibiose, galactose and lactose. The amino acid sequence of ELEL was determined by tandem mass spectrometry. The ELEL subunit has 103 amino acids, including nine cysteine residues involved in four conserved intrachain disulfide bonds and one interchain disulfide bond. The full sequence of ELEL presents conserved motifs commonly found in rhamnose-binding lectins, including YGR, DPC and KYL. A three-dimensional model of ELEL was created, and molecular docking revealed favorable binding energies for interactions between ELEL and rhamnose, melibiose and Gb3 (Galα1-4Galß1-4Glcß1-Cer). Furthermore, ELEL was able to agglutinate Gram-positive bacterial cells, suggesting its ability to recognize pathogens.

Altered dynamics of a lipid raft associated protein in a kidney model of Fabry disease.

Accumulation of globotriaosylceramide (Gb3) and other neutral glycosphingolipids with galactosyl residues is the hallmark of Fabry disease, a lysosomal storage disorder caused by deficiency of the enzyme alpha-galactosidase A (α-gal A). These lipids are incorporated into the plasma membrane and intracellular membranes, with a preference for lipid rafts. Disruption of raft mediated cell processes is implicated in the pathogenesis of several human diseases, but little is known about the effects of the accumulation of glycosphingolipids on raft dynamics in the context of Fabry disease. Using siRNA technology, we have generated a polarized renal epithelial cell model of Fabry disease in Madin-Darby canine kidney cells. These cells present increased levels of Gb3 and enlarged lysosomes, and progressively accumulate zebra bodies. The polarized delivery of both raft-associated and raft-independent proteins was unaffected by α-gal A knockdown, suggesting that accumulation of Gb3 does not disrupt biosynthetic trafficking pathways. To assess the effect of α-gal A silencing on lipid raft dynamics, we employed number and brightness (N&B) analysis to measure the oligomeric status and mobility of the model glycosylphosphatidylinositol (GPI)-anchored protein GFP-GPI. We observed a significant increase in the oligomeric size of antibody-induced clusters of GFP-GPI at the plasma membrane of α-gal A silenced cells compared with control cells. Our results suggest that the interaction of GFP-GPI with lipid rafts may be altered in the presence of accumulated Gb3. The implications of our results with respect to the pathogenesis of Fabry disease are discussed.

Genomic analysis of Brazilian patients with Fabry disease

Fabry disease is an X-linked lysosomal disorder due to a-galactosidase A deficiency that causes storage of globotriaosylceramide. The gene coding for this lysosomal enzyme is located on the long arm of the X chromosome, in region Xq21.33-Xq22. Disease progression leads to vascular disease secondary to involvement of kidney, heart and the central nervous system. Detection of female carriers based solely on enzyme assays is often inconclusive. Therefore, mutation analysis is a valuable tool for diagnosis and genetic counseling. Many mutations of the a-galactosidase A gene have been reported with high genetic heterogeneity, being most mutations private found in only one family. The disease is panethnic, and estimates of incidence range from about 1 in 40,000 to 60,000 males. Our objective was to describe the analysis of 6 male and 7 female individuals belonging to 4 different Fabry disease families by automated sequencing of the seven exons of the a-galactosidase gene. Sequencing was performed using PCR fragments for each exon amplified from DNA extracted from peripheral blood. Three known mutations and one previously described in another Brazilian family were detected. Of 7 female relatives studied, 4 were carriers. Although the present study confirms the heterogeneity of mutations in Fabry disease, the finding of the same mutation previously detected in another Fabry family from our region raises the possibility of some founder effect, or genetic drift. Finally, the present study highlights the importance of molecular analysis for carrier detection and genetic counseling.