Renal function during and after childhood acute poststreptococcal glomerulonephritis

Abstract 

It is still debatable whether acute poststreptococcal glomerulonephritis (APSGN) can lead to permanent renal impairment. The clinical, immunological, and histological findings during the acute disease have been described thoroughly, however, the hemodynamic events are still poorly understood. In this retrospective study, the inulin and p-aminohippurate clearances were measured to evaluate glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) within a month of onset of the disease (acute stage) in 26 children, and 2–12 months after onset (follow-up) in 22 children with APSGN. During the acute stage, the mean GFR was 77±23 (SD) ml/min per 1.73 m², the mean ERPF 537±138 ml/min per 1.73 m², and the filtration fraction (FF) 14%±3%, compared with values for controls of 115±11 ml/min per 1.73 m², 607±72 ml/min per 1.73 m², and 19%±2%, respectively (n=42). At follow-up, GFR was 114±15 ml/min per 1.73 m², ERPF 600±68 ml/min per 1.73 m², and FF 19%±3%. Thus, during the disease both GFR and ERPF fell below values for controls, but later were restored. The GFR, however, was more reduced than the ERPF, as indicated by the reduced FF. This might reflect a relative hyperperfusion of individual nephrons, which might start processes later deleterious to the nephrons. This finding, however, needs to be further investigated and we have therefore started a long-term follow-up of these patients.