1/3. Elitek-rasburicase: an effective means to prevent and treat hyperuricemia associated with tumor lysis syndrome, a Meeting Report, Dallas, texas, January 2002.Renal precipitation of uric acid associated with tumor lysis syndrome (TLS) is a major complication in the management of leukemia, lymphoma, and other drug-sensitive cancers. Management of hyperuricema has historically consisted of administration of allopurinol, hydration, alkalinization to maintain pH between 7.0 and 7.3, and in some cases diuresis. allopurinol, a xanthine analogue, blocks xanthine oxidase and formation of uric acid. urate oxidase converts uric acid to allantoin, which is 5-10 times more soluble than uric acid. Homo sapiens cannot express urate oxidase because of a nonsense mutation. urate oxidase was initially purified from aspergillus flavus fungus. Treatment with this nonrecombinant product had been effective in preventing renal precipitation of uric acid in cancer patients, but was associated with a relatively high frequency of allergic reactions. This enzyme was recently cloned from A. flavus and is now manufactured as a recombinant protein. Clinical trials have shown this drug to be more effective than allopurinol for prevention and treatment of hyperuricemia in leukemia and lymphoma patients. This drug has been approved in europe as well as the US and several clinical trials are in progress to further determine its clinical utility in other patient subsets. The purpose of this meeting was to discuss usefulness of recombinant urate oxidase, also known as rasburicase, Fasturtec, and Elitek, for the management of TLS in certain cancer patients.- - - - - - - - - - ranking = 1keywords = cancer (Clic here for more details about this article) |
2/3. Renal manifestations of a mutation in the uromodulin (Tamm Horsfall protein) gene.BACKGROUND: uromodulin (Tamm Horsfall glycoprotein) is the most abundant protein found in normal human urine. Its function has yet to be determined. Identifying mutations in the uromodulin gene may be helpful in understanding the function of uromodulin. There has been 1 report of 4 families suffering from mutations in the uromodulin gene, resulting in the autosomal dominant transmission of hypouricosuric hyperuricemia and chronic renal failure. This case report describes another family with similar clinical manifestations. methods: A family was identified with clinical characteristics of hypouricosuric hyperuricemia and renal failure occurring in a mother and daughter. Clinical characteristics were identified, and laboratory studies were obtained in the proband and the proband's daughter. A genetic analysis was performed to evaluate for mutations in the uromodulin gene. RESULTS: The proband suffered from hyperuricemia at an early age and progressive renal failure with end-stage renal disease developing at age 49 years. The proband's daughter suffered from hyperuricemia, a reduced fractional excretion of uric acid, and mild renal insufficiency. A g.2105G > A mutation in exon 4 of the uromodulin gene resulting in a substitution of tyrosine for cysteine was identified in both the proband and the proband's daughter. The clinical characteristics were similar to those of other patients suffering from uromodulin mutations and to those of patients suffering from medullary cystic kidney disease type 2 and familial juvenile hyperuricemic nephropathy. CONCLUSION: uromodulin associated kidney disease results in hyperuricemia and renal failure. The specific uromodulin mutation found in this family is consistent with the hypothesis that mutations disrupt highly conserved cysteine residues in the uromodulin protein. Potential mechanisms for these pathologic changes are discussed. The authors would appreciate referral of other families for screening for mutations.- - - - - - - - - - ranking = 104.97222869997keywords = kidney (Clic here for more details about this article) |
3/3. hypersensitivity syndrome and pure red cell aplasia following allopurinol therapy in a patient with chronic kidney disease.OBJECTIVE: To report a rare case of combined hypersensitivity syndrome and pure red cell aplasia (PRCA) following allopurinol therapy. CASE SUMMARY: A 43-year-old woman with underlying mesangioproliferative glomerulonephritis developed fever, generalized morbilliform rash, leukocytosis with marked eosinophilia, and hepatic dysfunction 3 weeks after starting allopurinol therapy (300 mg/day for 3 days followed by 200 mg/day) for hyperuricemia and arthritis. The clinical findings were judged to be a probable drug reaction according to the Naranjo probability scale. The drug-induced hypersensitivity syndrome (DHS) resolved after withdrawal of allopurinol and initiation of systemic corticosteroid therapy. However, there was progressive worsening of anemia with reticulocytopenia; PRCA was suspected. PRCA was judged to be a possible drug reaction according to the Naranjo probability scale. The patient refused blood transfusion and bone marrow biopsy. Recombinant human erythropoietin was initiated in addition to prednisolone 15 mg daily. Eleven days later (approximately 7 wk after allopurinol withdrawal), both the hemoglobin level and reticulocyte count began to rise. The patient consented to a bone marrow study at that time, which confirmed the presence of dysplasia involving only the erythroid lineage. DISCUSSION: allopurinol may induce DHS, aplastic anemia, and, in rare instances, PRCA. We report the first case of PRCA concurrent with allopurinol-induced DHS in a patient with chronic kidney disease. Discontinuation of allopurinol is the first step in the treatment of such cases. The slow recovery of PRCA might be partly attributed to her underlying chronic kidney disease. CONCLUSIONS: To minimize serious DHS, proper indications for treatment and dosage adjustment should be closely observed when starting allopurinol therapy in patients with chronic kidney disease.- - - - - - - - - - ranking = 367.40280044991keywords = kidney (Clic here for more details about this article) |