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Tubulointerstitial disease may be acute or chronic. Acute disease is most commonly associated with medications, infectious agents, and systemic rheumatologic disorders. Interstitial edema, infiltration with polymorphonuclear neutrophils, and accompanying ATN can be seen. (See Acute Kidney Injury, above, and Table 22–9.) Chronic disease is associated with insults from an acute factor or progressive insults without any obvious acute cause. Interstitial fibrosis and tubular atrophy are present, with a mononuclear cell predominance. The chronic disorders are described below.
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