genitourinary disorders
Metabolic Nephropathies
Acute urate nephropathy
This disorder is not a true form of acute tubulointerstitial nephritis but rather an intraluminal obstructive uropathy caused by uric acid crystal deposition within the lumen of renal tubules; acute oliguric or anuric kidney injury results. Themost common causeof acute urate nephropathy is Tumor Lysis and Cytokine Release Syndromes after treatment of lymphoma, leukemia, or other Other causes of acute urate nephropathy include seizures, treatment of solid tumors, rare primary disorders of urate overproduction (hypoxanthine-guanine phosphoribosyltransferase deficiency), and disorders of urate overexcretion due to decreased proximal tubule reabsorption (Fanconi-like syndromes). Disorders of urate overproduction and overexcretion are rare. Typically, no symptoms are present. Diagnosis is suspected when acute kidney injury occurs in patients with marked hyperuricemia (>15 mg/dL). Urinalysis results may be normal or may show urate crystals. Prognosis for complete recovery of renal function is excellent if treatment is initiated rapidly. In patients with normal cardiac and renal function, treatment is usually withallopurinolplus aggressive IV hydration with normal saline.Allopurinolis given to help prevent urate nephropathy. In the event that acute urate nephropathy does occur, urate oxidase (rasburicase), which catalyzes urate to a much more soluble compound, is usually given. Patients should be carefully monitored for adverse effects, including anaphylaxis and hemolysis. Hemodialysis may be recommended to remove excess circulating urate in severe cases where diuresis cannot be induced with a loop diuretic and IV saline. Alkalinization with a Prevention of acute urate nephropathy is indicated for patients at high risk (eg, those at risk of tumor lysis syndrome). Prevention is by use ofallopurinol2 to 3 times a day plus saline loading to maintain a urine output>2.5 L/day before chemotherapy or radiation therapy. Urate oxidase is also indicated for the prevention of acute urate nephropathy secondary to tumor lysis syndrome in high-risk patients. 