ABSTRACT
OBJETIVO: Esta revisão teve por objetivo abordar a situação atual do tratamento dos distúrbios do metabolismo intermediário (principalmente dos aminoácidos, ciclo da uréia e ácidos orgânicos) e das doenças relacionadas a duas organelas subcelulares (lisossomos e peroxissomos). FONTES DOS DADOS: Na abordagem do tratamento dos distúrbios do metabolismo intermediário, foi dada prioridade às principais formas de manejo da intoxicação, em virtude da importância para o pediatra do tratamento de quadros agudos e com risco de vida. O artigo apresenta também uma visão geral do tratamento das doenças lisossômicas e peroxissômicas, com ênfase na terapia de reposição enzimática, uma modalidade de tratamento de uso crescente com a qual o pediatra deve se familiarizar. SÍNTESE DOS DADOS: As principais medidas para manejo da intoxicação presente em muitos erros inatos do metabolismo intermediário foram apresentadas (restrição de aporte de substrato através da dieta ou através de inibição enzimática, remoção do produto tóxico, estímulo da atividade enzimática residual, reposição do produto deficiente). O material elaborado sobre terapia para doenças lisossômicas e peroxissômicas inclui tabelas informativas sobre os tratamentos disponíveis. CONCLUSÕES: O tratamento dos erros inatos do metabolismo é uma situação complexa e que deve ser abordada por uma equipe multidisciplinar, na qual o pediatra é peça-chave. Este capítulo contém informações práticas relativas ao manejo de alguns erros inatos do metabolismo e proporciona ao pediatra uma visão geral dos desenvolvimentos recentes ocorrido nessa área da medicina.
OBJECTIVE: To describe the current state of treatment for disorders of intermediate metabolism (primarily of amino acids, urea cycle and organic acids) and for diseases related to two subcellular organelles (lysosomes and peroxisomes). SOURCES: In covering the treatment of disorders of intermediate metabolism, priority was given to the most important methods for managing intoxication, in view of the importance for pediatricians to treat acute and life-threatening cases. The article also provides a general overview of the treatment for lysosomal and peroxisomal diseases, with emphasis on enzyme replacement therapy, which is a treatment modality that is growing in use and with which pediatricians should make themselves familiar. SUMMARY OF THE FINDINGS: The most important measures used to manage the intoxication present in many inborn errors of intermediate metabolism were presented (restriction of substrate build-up by means of diet or enzymatic inhibition, removal of toxic products, stimulation of residual enzyme activity, replacement of the deficient product). The section on treatment for lysosomal and peroxisomal diseases includes tables providing information on the treatments available. CONCLUSIONS: Treating inborn errors of metabolism is a complex task that should be performed by a multidisciplinary team of which the pediatrician is the key member. This article provides practical information relating to the management of some inborn errors of metabolism and provides pediatricians with a general overview of recent developments in this area of medicine.
Subject(s)
Humans , Metabolism, Inborn Errors/therapy , Amino Acid Metabolism, Inborn Errors/diet therapy , Amino Acid Metabolism, Inborn Errors/drug therapy , Enzymes/therapeutic use , Lysosomal Storage Diseases/therapy , Peroxisomal Disorders/therapyABSTRACT
La tirosinemia I es una enfermedad metaból ica de herencia recesiva, causada por la diferencia de la enzima terminal de la vía de degradación de la tirosina,llamada fumarilacetoacetato hidrolasa. Compromete principalmente el hígado, sistema nervioso central y riñones. Objetivo: Dada la baja frecuencia de tirosinemia tipo I en nuestro medio, consideramos importante su revisióna raíz de un caso clínico, para optimizar la sospecha diagnóstica frente a la presentaciónclínica y de laboratorio, e iniciar así su tratamiento en forma precoz, mejorando el pronóstico. Caso clínico: reportamos un lactante de 1 mes 11 días, que ingresó al Hospital Padre Hurtado, con el diagnóstico de síndrome febril sin foco, acompañado de vómitos y distensión abdominal. Al ingreso destacó hematuria macroscópica y masa palpable en fosa renal izquierda. Se realizó ecografía abdominal destacando nefrocalcinosis y nefromegalia bilateral y exámenes de laboratorio que muestran hipercalciuria, hipercalcemia, hipofosfemia, hipoalbuminemia, trnasaminasas, LDH y fosfatasas alcalinas elevadas, bilirrubian con leve aumento de predominio directo, reabsorcióntubular de fosfato disminuida, PTH normal, radiografías con signos de raquitismo, cultivos negativos. El paciente evolucionó con distensión abdominal, evidenciandose ascitis moderada en una nueva ecografía abdominal. En el perfil hepático completo destacó protombina 10 por ciento, TTPK de 112 segundos. Ante la fuerte sospecha de Tirosinemia se solicitan alfa feto proteínas que muestran valor muy elevado y aminoacidemia anormal compatible con el diagnóstico. Conclusiones: La revisión de la literatura en relación a esta patología plantea su amplia gama de presentación clínica y las nuevas opciones de tratamiento que han mejorado el pronóstico de estos pacientes, cuales disponemos en nuestro país y fueron aplicadas en este paciente
Subject(s)
Humans , Male , Infant , Amino Acid Metabolism, Inborn Errors/diagnosis , Tyrosine , Tyrosinemias , Breast-Milk Substitutes , Clinical Evolution , Amino Acid Metabolism, Inborn Errors/physiopathology , Amino Acid Metabolism, Inborn Errors/drug therapy , Hematuria , Nephrocalcinosis , Prognosis , Tyrosine , TyrosinemiasABSTRACT
Background: Propionic aciduria (PA) and Methymalonic aciduria (MMA) result from an inherited abnormality of the enzymes propionyl CoA carboxylase and methylmalonyl CoA mutase respectively. This produces marked increases in the amino acids methionine, threonine, valine and isoleucine (MTVI). Their clinical presentation can be neonatal or late onset forms. Aim: To report 23 children with organic acidurias. Material and methods: Twenty three cases of organic acidurias diagnosed since 1980 (17 PA and 6 MMA) and followed at the Institute of Nutrition and Food Technology, are reported. Results: The average age of diagnosis was 3.9 days for the neonatal form and 8.3 months for the late onset form. The most frequent symptoms were hypotonia, lethargy and vomiting. Neonatal PA had mean ammonemias of 1089ñ678.3 µg/dl. The figure for MMA was 933ñ801.9 µg/dl. Seven children were dialyzed and 30 percent died. 16 children are followed and 81.2 percent have normal weight for age. Seven children required gastrostomy because of anorexia and failure to thrive. The nutritional treatment is based on natural and artificial proteins without MTVI, with periodical controls, amino acid and ammonia quantification. Some patients were submitted to enzyme assays and molecular studies. Conclusions: An early diagnosis and a very strict follow up allows a normal development of children with organic aciduras. There is a relationship between prognosis and the presentation form, the nutritional status and the emergency treatment during acute episodes. The importance of the enzymatic and molecular studies is emphasized because they facilitate treatment, accurate diagnosis and allow an adequate genetic counseling