Because urinary tract infection may be associated with reflux, it is best to wait several weeks after treating a urinary tract infection before trying to diagnose reflux nephropathy. Many persons with such mild reflux undergo spontaneous remission with time. The incidence of this form of renal damage has greatly declined with the ability to precisely deliver high-dose radiation to a given abdominal port and with better shielding of the kidneys from radiation exposure. Current cases usually occur in patients who received high-dose, diffuse abdominal radiation, often in combination with radiomimetic chemotherapeutic agents. There is often no clear clinical or pathologic distinction between these entities, however.
Some patients manifest mild or severe hypertension or isolated proteinuria after radiation exposure.
On histopathologic examination, kidneys affected by radiation nephritis typically show damage to all structural components. There may be various degrees of proliferative glomerulonephritis as well as glomerulosclerosis, tubular degeneration and atrophy, fibrinoid necrosis and intimal proliferation of the small arteries and arterioles, and interstitial edema and fibrosis. The pathogenesis of radiation nephritis remains unknown. The only treatment for radiation nephritis entails control of hypertension. Preventing the development of radiation nephritis by appropriate delivery of radiation, with shielding of the kidneys, is crucial.