Role of osteoclastic dysfunction in the development of renal bone disease

A 47-year-old-man was referred for treatment for end-stage renal failure. He had been diagnosed with type II adult onset osteopetrosis before the deterioration of his renal function. He presented with anaemia, severe hypocalcaemia, secondary hyperparathyroidism and azotaemia. An iliac bone biopsy revealed increased bone volume, disturbed osteoid calcification, active osteoclastic bone resorption and fibrous transformation in the bone marrow space. Incomplete osteoclastic dysfunction strongly suggested hypocalcaemia and secondary hyperparathyroidism, and the osteoclastic bone resorption also indicated secondary hyperparathyroidism, even though bone resorption was potentially suppressed. The present case shows that evidence of the involvement of osteoclastic dysfunction in the development of renal bone disease can be found in bone histology.