Radiation nephropathy: Dose, management, and population risk

Radiation nephropathy is renal injury caused by a sufficient dose of irradiation. It can result from external beam irradiation or internal irradiation as might occur from therapeutic radioisotopes. Its usual clinical presentation is as chronic kidney disease occurring some months after irradiation, and it can evolve to end-stage-renal-disease. While the immediate cellular injury from irradiation depends on radiolysis of water and oxidative DNA damage, there is no conclusive evidence for chronic persistent oxidative stress or inflammation as the cause of the multi-tissue scarring that ensues. Antagonists of the renin-angiotensin system are effective treatments for experimental radiation nephropathy but their preferential value in human clinical medicine is unproven.

RADIOPROTECTIVE PROPERTIES OF POLYPHENOLIC COMPOUNDS OF EDIBLE AND AROMATIC PLANTS

The proliferation of nuclear technologies threatens by the negative impact of ionizing radiation on the human body and requires the search of new effective means for prevention from radiation damage. Informational search in scientific editions and search databases on radioprotective effects of food and aromatic plants, radiation nephropathy and promising herbal drugs for its prevention has been carried out. Methods of analysis, systematization, comparison, generalization of information data have been applied. An overview of the results of experimental phytochemical and clinical studies of domestic and foreign scientists on radioprotective effects of biologically active substances of food and aromatic herbs has been carried out. It is revealed that plant polyphenolic compounds, due to their antioxidant properties, are able to neutralize free radicals and thus leading to a stop of radio-induced chain oxidation reactions in cells, to scavenge and neutralize of lipoperoxyl radicals, chelate ions of metals, as well as to exhibit antimutagenic activity. Radiotherapy might cause several radiation-induced kidney injuries, including radiation nephropathy. Search of promising herbal substances for prevention and alleviation of radiation nephropathy is under active investigation in recent years. Preventive inclusion of radioprotective agents, containing polyphenolic compounds, before irradiation seems to be an obvious renoprotective strategy. The prospect for further phytochemical, pharmacodynamic and toxicological studies of properties of polyphenolic compounds in food and aromatic plants with an objective to create new effective remedies for the prevention and treatment of radiation damage is shown.

Chronic tubulointerstitial nephritis

Chronic tubulointerstitial nephritis is usually asymptomatic, presenting with slowly progressive renal impairment. Urinalysis may be normal or show low-grade proteinuria (<1.5 g/day) and/or pyuria. Diagnosis depends on renal biopsy, which reveals variable cellular infiltration of the interstitium, tubular atrophy, and fibrosis. There are many causes including sarcoidosis, drugs (prescribed and nonprescribed), irradiation, toxins, and metabolic disorders. Analgesic nephropathy—characterized by renal papillary necrosis and chronic interstitial nephritis and caused by the prolonged and excessive consumption of combinations of analgesics, mostly including phenacetin. Nonsteroidal anti-inflammatory drugs—the most frequent cause of permanent renal insufficiency after acute interstitial nephritis. Aristolochic acid nephropathy—(1) Chinese herb nephropathy—caused in most cases (but perhaps not all) by aristolochic acid, and is associated with a high incidence of urothelial malignancy. (2) Balkan endemic nephropathy—a chronic, familial, noninflammatory tubulointerstitial disease of the kidneys that is associated with a high frequency of urothelial atypia, occasionally culminating in tumours of the renal pelvis and urethra. 5-Aminosalicylic acid—used in the treatment of chronic inflammatory bowel disease and causes clinical nephrotoxicity in approximately 1 in 4000 patients/year. Chronic interstitial nephritis in agricultural communities (CINAC) —nonproteinuric chronic kidney disease that presents in young, agricultural workers in Central America and Sri Lanka in the absence of any clear aetiology. Lithium—the most common renal side effect is to cause nephrogenic diabetes insipidus. Radiation nephropathy—preventive shielding of the kidneys in patients receiving radiation therapy generally prevents radiation nephropathy, but total body irradiation preceding bone marrow transplantation leads 20% to develop chronic renal failure in the long term. Nephropathies induced by toxins (including lead and cadmium) or by metabolic disorders (chronic hypokalaemia and chronic urate nephropathy).