Discussion DR. ERIC G. NEILSON (Chief, Renal Electrolyte Section, Hospital of the University of Pennsylvania, and Associate Professor of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania): This young woman has acute interstitial nephritis. Perhaps the most famous case of interstitial nephritis was Admiral John Paul Jones, who died in 1792 with severe renal failure and hypertension [11. His autopsy revealed advanced interstitial nephritis, presumably from leadcontaminated water consumed aboard ship. An abbreviated history describing our understanding of the interstitial lesion is outlined in Table 1. Since the advent of the percutaneous renal biopsy, this lesion has been recognized with increasing frequency.

Interstitial nephritis often occurs as a primary process and accounts for approximately 15% of the lesions in acute renal failure [2], and up to 25% ofthe lesions in chronic renal failure [3]. Interstitial nephritis also can develop as a secondary process following glomerular or vascular injury. Interstitial nephritis, therefore, is a final common pathway to all forms of end-stage renal disease and is the most common and pivotal lesion in nephrology. The importance of this form of injury is partially underscored by a previously unrecognized literature on structure-function relationships associated with interstitial damage. Various morphometric correlations strongly suggest that changes in tubular function and glomerular filtration corre-late more strongly with the presence of progressive deterioration in interstitial architecture than with changes in glomerular tuft integrity (Fig. 1)[4—6].