Reserva funcional renal mediante la depuración de ácido dietilen-triamino-pentaacético marcado con tecnecio-99m en niños que padecieron síndrome urémico-hemolítico Translated title: Renal functional reserve in children with a history of hemolytic uremic syndrome through technetium-99m diethylene-triamine-penta-acetic acid clearance

Abstract

Normalmente, la ingesta de carga proteica aumenta el fltrado glomerular, lo que implica reserva funcional renal. Cuando disminuye el número de nefronas pueden observarse fltrados glomerulares normales por hiperfltración, lo que implica pérdida de reserva funcional, temprano indicador de daño renal y, probablemente, factor contribuyente a su progresión. Determinamos el fltrado glomerular mediante la curva de desaparición plasmática del ácido dietilen-triamino-pentaacético marcado con tecnecio-99m, en pacientes con proteinuria y depuración de creatinina normal, que padecieron síndrome urémico-hemolítico con antelación mayor de 1 año. En 33 niños, de 2-16 años de edad, se determinó la reserva funcional renal mediante fltrado glomerular basal y tras carga proteica. Considerando normal un aumento superior al 20%, 16 pacientes mostraron no tener reserva funcional renal. Esta prueba, por su seguridad y fácil realización, resulta particularmente útil en pacientes que necesitan especial control y tratamiento.

Translated abstract

Protein loads in normal subjects increase glomerular fltration rate (GFR), which implies a renal functional reserve (RFR). Patients who have suffered a loss in the number of nephrons may show normal values of GFR due to hyperfltration of remnant nephrons, with subsequent loss of RFR. This could be an early sign of renal damage, and probably a contributory factor to renal damage progress. The objective of this study is to determine the RFR through technetium-99m diethylene-triamine-penta-acetic acid (99m Tc-DTPA) clearance in patients who have recovered from hemolytic uremic syndrome. Renal functional reserve was determined in 33 children from 2 to 16 years old, with normal values of proteinuria, serum creatinine and creatinine clearance after over a year of having suffered hemolitic uremic syndrome. For that purpose 99m Tc-DTPA clearance was determined in basal condition and following protein load. In 17 patients DTPA clearance increased 20% or more after protein load compared to basal condition, and they were considered to have normal RFR, a probably index of totally recovered renal function; in the remaining 16 patients the increases were lower than 20%, and were considered to have no RFR, condition that was postulated as a contributing factor to renal damage progress. There was not signifcant diferences either in age or basal GFR between both groups. Being the test easier than inuline clearance and more accurate than creatinine clearance, it proves particularly useful for early diagnosis of patients that need special follow-up and treatment.