Renal transplantation is the treatment of choice for patients with
end-stage renal disease. It corrects most of the metabolic abnormalities that cause
renal osteodystrophy. Nevertheless,
renal osteodystrophy persists in many transplant recipients. The aim of this study was to investigate frequency and histomorphometric pattern of
bone disease after
renal transplantation. Bone biopsy specimens were taken from the iliac crest of 57 patients, including 28 women (26-70 years old) and 29 men (27-67 years old). Indications for biopsy were
hypercalcemia, elevation of
parathyroid hormone, and, in 19 cases, without suspected bone abnormalities based on laboratory parameters. The mean time of dialysis prior to
renal transplantation was 43 months (range, 6-91 months in women and 10-111 months in men) and the mean interval between
transplantation and bone biopsy was 53.5 months (range, 4-191 months in women and 5-90 months in men). Fourteen patients were treated with either
25-hydroxyvitamin D3 and/or 1-alpha hydroxyvitamin D3 or
1,25 dihydroxyvitamin D3, 3 with
phosphate-binding agents. The immunosuppression consisted of
cyclosporine,
azathioprine, and
prednisolone. The cumulative dosage of
corticosteroids was 5569+/-5305 mg. For static and dynamic histomorphometry, we used American Society of Bone and
Mineral Research nomenclature. Mild
osteitis fibrosa and
osteitis fibrosa, the most frequent forms of
renal osteodystrophy, were observed in 13. (22.8%) and 14 patients (24.6%), respectively. Mixed uremic osteodystrophy was found in 7 patients (12.3%), adynamic renal
bone disease in 3 patients (5.3%), and
osteomalacia in 2 patients (3.5%). In 13 patients (22.8%), reduced bone mass and structural damage without typical signs of
renal osteodystrophy, such as endosteal
fibrosis or osteoclasia, were detected, and 5 patients (8.7%) showed normal histomorphometric parameters. We concluded that
renal osteodystrophy, especially forms with high bone turnover, persisted in many patients after successful
renal transplantation. This finding may be due to preexisting conditions, such as duration of dialysis and degree of
hyperparathyroidism.
Bone disease is increased by
corticosteroid and immunosuppressive therapy after
renal transplantation and requires close monitoring.