[Mechanism of action of cell therapy in hereditary diseases]. / Mecanismo de acción de la terapia celular en enfermedades hereditarias.

Inherited metabolism disorders are serious childhood diseases that lead to significant cognitive impairment and regression of psychomotor development. The pathophysiology of the neural progressive deterioration is usually associated with severe neuroinflammation and demyelination, and as a consequence, neurodegeneration. At the moment they have no adequate treatment and require early and aggressive therapeutic approaches, which entail high mortality rates and, very frequently, low degrees of functional improvement and survival. Bone marrow transplantation and bone marrow mesenchymal cells grafts are therapeutic and experimental therapies that improve the course of these diseases through different mechanisms of action: enzyme replacement, membrane exchange and regulation of the inflammatory process.

Los trastornos heredados del metabolismo son enfermedades graves de la infancia que cursan con un gran deterioro cognitivo y del desarrollo psicomotor. La fisiopatología del progresivo deterioro del sistema nervioso suele estar asociada a una severa neuroinflamación y desmielinización, y como consecuencia, neurodegeneración. Por el momento no tienen cura y precisan de actitudes terapéuticas precoces y agresivas, que conllevan altas tasas de mortalidad y, muy frecuentemente, escasos grados de mejoría funcional y supervivencia. El trasplante de médula ósea y de células mesenquimales de médula ósea son terapias de elección y experimentales que consiguen mejorar el curso de estas enfermedades mediante diferentes mecanismos de acción: remplazo de enzima deficiente, intercambio de membranas y regulación del proceso inflamatorio.

Mecanismo de acción de la terapia celular en enfermedades hereditarias / Mechanism of action of cell therapy in hereditary diseases

Los trastornos heredados del metabolismo son enfermedades graves de la infancia que cursan con un gran deterioro cognitivo y del desarrollo psicomotor. La fisiopatología del progresivo deterioro del sistema nervioso suele estar asociada a una severa neuroinflamación y desmielinización, y como consecuencia, neurodegeneración. Por el momento no tienen cura y precisan de actitudes terapéuticas precoces y agresivas, que conllevan altas tasas de mortalidad y, muy frecuentemente, escasos grados de mejoría funcional y supervivencia. El trasplante de médula ósea y de células mesenquimales de médula ósea son terapias de elección y experimentales que consiguen mejorar el curso de estas enfermedades mediante diferentes mecanismos de acción: remplazo de enzima deficiente, intercambio de membranas y regulación del proceso inflamatorio.

Inherited metabolism disorders are serious childhood diseases that lead to significant cognitive impairment and regression of psychomotor development. The pathophysiology of the neural progressive deterioration is usually associated with severe neuroinflammation and demyelination, and as a consequence, neurodegeneration. At the moment they have no adequate treatment and require early and aggressive therapeutic approaches, which entail high mortality rates and, very frequently, low degrees of functional improvement and survival. Bone marrow transplantation and bone marrow mesenchymal cells grafts are therapeutic and experimental therapies that improve the course of these diseases through different mechanisms of action: enzyme replacement, membrane exchange and regulation of the inflammatory process.

Diagnóstico y tratamiento de la enfermedad de Pompe / Diagnosis and treatment of Pompe disease

INTRODUCCIÓN: la enfermedad de Pompe es una glucogenosis tipo II con patrón de herencia autosómico recesivo, causada por la deficiencia de la enzima alfa-glucosidasa ácida, que provoca acúmulo de glucógeno en los lisosomas de los macrófagos. El gen está mapeado en el cromosoma 17q25, y han sido detectadas más de 460 mutaciones. Están descritas 3 formas clínicas de la enfermedad, que incluyen, la variedad infantil, la juvenil y la tardía. La variedad infantil se caracteriza por miocardiopatía hipertrófica o infiltrativa, hipotonía, hepatomegalia y macroglosia. En la variedad juvenil hay fiebre recurrente, infecciones respiratorias a repetición y discapacidad motora progresiva. La terapia de reemplazo enzimático modifica el curso clínico de la enfermedad. PRESENTACIÓN DE CASOS: se presentan los elementos al diagnóstico de 4 casos con esta enfermedad, 3 de ellos con la variedad infantil y uno con la variedad juvenil, y se discuten los resultados de estudio molecular. Se informa la evolución clínica de 2 de ellos, luego de 6 meses y un año de tratamiento con la terapia de reemplazo enzimático con alfa-glucosidasa ácida (myozyme), lo que ha llevado a la mejoría de parámetros bioquímicos y clínicos en ambos casos. CONCLUSIONES: en pacientes con enfermedad de Pompe la cuidadosa evaluación clínica para diagnosticar precozmente la enfermedad y el comienzo de la terapia de reemplazo enzimático contribuyen a mejorar las funciones musculares, motoras y cardiovasculares, lo cual impacta en la supervivencia y calidad de vida de estos niños(AU)

INTRODUCTION: Pompe disease is a type II glycogenosis with recessive autosomal inheritance pattern, which is caused by the acid alpha-glucosidase enzyme that brings about buildup of glycogen in macrophage lysosomes. The gene is already mapped in Chromosome 17q25 and has been so far detected over 460 mutations. Three clinical forms of disease were described, including infantile, juvenile and late-onset varieties. The infantile variety is characterized by hpertrophic or infiltratin myocardiopathy, hypotonia, hepatomegaly and macroglossia. The juvenile type comprises recurrent fever, repeated respiratory infections and progressive motor disability. Enzyme replacement therapy changes the clinical course of disease. CASE PRESENTATION: the elements for diagnosis of 4 cases were submitted, 3 of them with infantile form and one with juvenile one. The results of the molecular study were discussed. The clinical progress of 2 of them after 6 monts and one year of treatment with the enzymatic replacement therapy using acid alpha-glucosidase (myozyme), which led to improvement of biochemical and clinical parameters in both cases. CONCLUSIONS: careful clinical assessment of patients with Pompe disease to early diagnose it and the onset of the enzyme replacement therapy help to improve muscle, motor and cardiovascular functions, which has an impact on survival and quality of life of these children(AU)

The Continuous Challenge of Diagnosing patients with Fabry disease in Argentina: Genotype, Experiences, Anecdotes, and New Learnings

Abstract The lysosomal storage disorder Fabry disease (FD) is caused by pathogenic mutations in the α-galactosidase A gene, localized in X chromosome. Deficient enzymatic activity of the product of this gene, the lysosomal hydrolase α-galactosidase A, leads to accumulation of its substrate globotriaosylceramide. Diagnosis of FD starts with clinical suspicion followed by confirmatory laboratory testing. The aim of this work is to report the 14 years' experience and learnings in the diagnosis of patients with Fabry disease in Argentina from a specialized lysosomal diseases diagnosis laboratory and to report the genotype characterization of the 25 families from Argentina with FD detected by us.

Mucopolysacccharidoses: From understanding to treatment, a century of discoveries.

After the first description of a patient recognized as a MPS case was made in 1917, several similar cases were described and identified. Observations reported in the middle of the twentieth century concerning the presence of acid mucopolysaccharides (later called glycosaminoglycans, or GAGs) in tissues and especially in urine of patients were instrumental in providing an identity for these diseases, which became referred as "mucopolysaccharidoses" (MPS). In the late 1960's it was demonstrated that MPS were caused by defects in the breakdown of GAGs, and the specific enzyme deficiencies for the 11 types and subtypes of MPS were identified thereafter. Genes involved in the MPS were subsequently identified, and a large number of disease-causing mutations were identified in each one. Although individually rare, MPS are relatively frequent as a group, with an overall incidence estimated as 1:22,000. The increased excretion of urinary GAGs observed in the vast majority of MPS patients provides a simple screening method, the diagnosis usually being confirmed by the identification of the specific enzyme deficiency. Molecular analysis also plays a role, being helpful for phenotype prediction, prenatal diagnosis and especially for the identification of carriers. As the diseases are rare and diagnosis requires sophisticated methods, the establishment of reference laboratories for MPS identification is recommended. The successful experience of the MPS Brazil Network in providing access to information and diagnosis may be considered as an option for developing countries. The development of therapeutic strategies for MPS, including bone marrow/hematopoietic stem cell transplantation (BMT/HSCT) and enzyme replacement therapy (ERT), changed the natural history of many MPS types. However, some challenges still remain, including the prevention of cognitive decline which occurs in some MPS. Newer approaches, such as intratechal ERT, substrate reduction therapy, read-through, gene therapy and encapsulated modified cells may provide a better outcome for these diseases in the near future. As early diagnosis and early treatment seems to improve treatment outcomes, and as newborn screening is now technically feasible, pilot programs (including one in progress in an area with high-incidence of MPS VI in northeastern Brazil) should provide information about its potential impact in reducing the morbidity associated with MPS diseases.