Conceptos Categóricos

EL SINDROME UREMICO HEMOLITICO Y MANEJO RENAL DE PROTEINAS

EL SINDROME UREMICO HEMOLITICO Y MANEJO RENAL DE PROTEINAS

(especial para SIIC © Derechos reservados)
La fisiopatología de este síndrome es más compleja de lo que se creía ya que la alteración tubular desarrollada conlleva fallas en el mecanismo de endocitosis de proteínas, las cuales se suman a las eliminadas por las alteraciones a nivel de la barrera de filtración.
Autor:
Federico Ochoa
Columnista Experta de SIIC

Institución:
Universidad de Buenos Aires


Artículos publicados por Federico Ochoa
Coautores
Abril Seyahian* Elsa Zotta** 
Farmacéutica, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina*
Médica, Universidad de Buenos Aires, Buenos Aires, Argentina**
Recepción del artículo
25 de Julio, 2017
Aprobación
15 de Mayo, 2018
Primera edición
21 de Mayo, 2018
Segunda edición, ampliada y corregida
25 de Octubre, 2018

Resumen
El síndrome urémico hemolítico (SUH) está definido por la tríada de anemia hemolítica microangiopática, trombocitopenia e insuficiencia renal aguda. En Argentina constituye la primera causa de insuficiencia renal aguda en pediatría. Aproximadamente, del 2% al 4% de los pacientes mueren durante la fase aguda de la enfermedad, y solo un tercio del 96% restante que sobrevive lo hace con secuelas renales, como la persistencia de la proteinuria. Un individuo adulto sano filtra alrededor de 5000 mg/día de proteínas, si bien la excreción en orina es escasa (150 mg/día). La escasa cantidad de proteínas excretadas indica la presencia de un mecanismo de reabsorción a nivel del túbulo proximal. Por lo tanto, la reabsorción tubular renal desempeña un papel muy importante ya que, ante una función glomerular normal, es el principal mecanismo encargado de evitar la depleción proteica corporal. Desde hace aproximadamente 30 años se sabe que la albúmina es reabsorbida en el túbulo proximal. La reabsorción proteica se produce por un mecanismo de endocitosis mediada por el receptor dependiente de clatrina y por endocitosis de fase líquida. Clásicamente se ha descrito que el mecanismo básico del daño renal en el SUH típico y en el atípico es una microangiopatía trombótica, pero de diferentes causas. Sin embargo, debe tenerse en cuenta que la fisiopatología de esta enfermedad es más compleja de lo que se creía, ya que la alteración tubular que surge va a evolucionar en fallas en el mecanismo de endocitosis de proteínas que se suman a las eliminadas por las alteraciones a nivel de la barrera de filtración glomerular.

Palabras clave
proteinuria, megalina, cubilina, FCRN, podocito, endocitosis, diafragma de filtración, síndrome urémico hemólitico, SUH atípico, insuficiencia renal


Artículo completo

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Abstract
Hemolytic uremic syndrome (HUS) is defined by the triad of hemolytic anemia microangiopathic, thrombocytopenia and acute renal failure. In Argentina it constitutes the first cause of acute renal failure in Pediatrics. Approximately 2-4% of patients die during the acute phase of the disease, and only a third of the remaining 96% survive with renal sequelae, such as the persistence of proteinuria.
A healthy adult filters around 5000 mg/day of proteins, with an excretion in urine of 150 mg/day. The little quantity of proteins excreted indicates the presence of a reabsorption mechanism at the level of the proximal tubule. Therefore, the tubular reabsorption plays a very important role since it is the main mechanism responsible for preventing the depletion of protein.
For approximately 30 years, it has been known that albumin is reabsorbed in the proximal tubule. Protein reabsorption occurs by a clathrin-dependent receptor mediated endocytosis mechanism and by fluid phase endocytosis. The basic mechanism of renal damage in typical and atypical HUS has been described as a thrombotic microangiopathy, but of different causes. However, the pathophysiology of this disease is more complex than what was believed since the emerging tubular alteration will ewvolve into failures of the protein endocytosis mechanism that are added to the alterations at the level of the glomerular filtration barrier.

Key words
proteinuria, megalin, cubilin, FCRN, podocyte, endocytosis, slit diaphragm, hemolytic uremic syndrome, atypic hus, renal failure


Clasificación en siicsalud
Artículos originales > Expertos de Iberoamérica >
página   www.siicsalud.com/des/expertocompleto.php/

Especialidades
Principal: Anatomía Patológica, Nefrología y Medio Interno
Relacionadas: Pediatría, Trasplantes



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Enviar correspondencia a:
Elsa Zotta, 1121, Paraguay 2155, Buenos Aires, Argentina
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