Renal dysfunctions secondary to ifosfamide treatment in children

With the increasing use of ifosfamide in pediatric tumors, nephrotoxicity became the point of interest since it may cause chronic morbidity. In this study, the renal glomerular and tubular functions of 25 cases with solid tumors aged between 2-17 years (median 9) who were treated with ifosfamide, were investigated. For this purpose, routine blood urea, creatinine, calcium, phosphorus, electrolytes, urinary creatinine, phosphorus, glucose, protein and urinary retinol binding protein as well as microglobulin were evaluated. Except for two patients who had hypophosphatemia, phosphaturia, and proteinuria, all the cases had normal blood biochemistry, creatinine clearance, tubular phosphate reabsorption; and none had proteinuria, hematuria, or glycosuria. In spite of these findings, urine beta 2 microglobulin and retinol binding protein were found to be high in 11 patients and this elevation persisted during the following one year in 8 cases whose treatments were stopped and their levels increased in three patients who continued to receive fosfamide therapy. In correlation with the increasing cumulative dose of ifosfamide (32-126 g/m2), urinary retinol binding protein or beta 2 microglobulin of patients who are treated with ifosfamide may predict the existence of renal toxicity even if other routine renal function tests are normal. Thus, the periodic evaluation of urinary beta 2 microglobulin and retinol binding protein in patients receiving chemotherapy containing ifosfamide is recommended.