Early diagnosis of juvenile renal osteodystrophy.

Renal osteodystrophy has assumed growing importance as a major and frequently disabling complication of chronic renal failure in children since the advent of successful hemodialysis and renal transplantation programs. The frequency and severity of renal osteodystrophy appears greatest in younger children with congenital diseases of the kidney and urinary tract, who experience long intervals of chronic renal failure prior to reaching end-stage. Twenty-nine children with varying degrees of chronic renal failure were studied to learn: (1) how early renal osteodystrophy can be diagnosed; and (2) how the various clinical, biochemical, and hormonal abnormalities correlate with abnormal bone histomorphometry as determined from percutaneous transilial bone biopsies. Results showed: (1) marked-to-moderate reductions in GFR (mean = 35 ml/minute/1.73 m2; range 11 to 65 ml/minute/1.73 m2); (2) elevations of serum PTH concentrations in all patients with a GFR < 45 ml/minute/1.73 m2; (3) abnormal bone histomorphometry in all patients with elevated PTH concentrations; (4) "early" renal osteodystrophy (elevated PTH concentrations and abnormal bone histomorphometry but normal serum chemistry values and radiographs) in one quarter of the patients; (5) poor correlations of serum chemistry values and radiographs with bone histomorphometry; and (6) a wide range of histologic abnormalities including predominant osteomalacia (n = 7), predominant hyperparathyroidism (n = 6), or a mixed picture (n = 11).