Renal tubular calcification in six nephrotic children with acute renal insufficiency

Summary: A review of 42 primary nephrotic children who underwent kidney biopsies found that six patients had calcification of the renal tubules (aged 2-9 years). These six patients showed significant increases in weight gain, blood pressure, urinary protein, serum urea nitrogen and urinary calcium/creatinine, and significant decreases in serum phosphate, % tubular reabsorption of phosphate and creatinine clearance as compared with 36 nephrotic patients without tubular calcification. Furthermore, these patients received high dose furosemide, and five of six patients received methylprednisolone pulse therapy to treat progressive renal dysfunction. the interval before the first kidney biopsy and after both the onset of the nephrotic syndrome, and the start of glucocorticoid therapy, including methylprednisolone pulse therapy and furosemide, ranged from 1 to 5 months excluding one patient (33 months). Although one patient received haemodialysis, renal insufficiency was resolved from 10 to 18 days after its onset. Glucocorticoid therapy, including methylprednisolone pulse therapy and high dose furosemide in primary nephrotic children with acute renal insufficiency, induced calcification of the renal tubules.