Reflux nephropathy: Effects of antimicrobial therapy on the evolution of the early pyelonephritic scar

The importance of vesicoureteric reflux (VUR) and its extension into the pyelotubular system of the kidney (intrarenal reflux) in the genesis of segmental renal scarring during childhood (nonobstructive chronic pyelonephritis; reflux nephropathy) is now well established [1–3]. Papillary morphology determines the distribution of intrarenal reflux (IRR) and subsequent scar formation [3–6]. There is still considerable controversy whether scarring may occur following intrarenal reflux of sterile urine [7, 8] or whether urinary infection is an essential prerequisite [3, 9]. Germane to this argument is the clinical observation that most patients with reflux nephropathy have renal scars when first seen and the development of completely new scars is a distinctly rare event [10]. The finding of sterile urine in the presence of established scarring does not mean that infection never occurred or that it is unimportant in the pathogenesis of the scarring process. The possibility exists that scarring may develop very quickly in the presence of reflux of infected urine, perhaps even during the first episode of urinary tract infection. The present experimental study was undertaken to see how quickly parenchymal damage and scarring might occur in the presence of reflux of infected urine and to establish how treatment might modify the response