Relationships between histomorphometric features of bone formation and bone cell characteristics in vitro in renal osteodystrophy

To determine whether abnormal bone cell recruitment or differentiation may be involved in the development of aplastic bone lesion in renal osteodystrophy we have compared histomorphometric parameters of bone formation and in vitro behavior of osteoblastic cells isolated from the trabecular bone surfaces in 37 dialysis patients with osteitis fibrosa, normal bone formation rate, or aplastic bone lesion. The bone cell responses to human PTH-(1–34) (20 nmol/L), as evaluated by intracellular cAMP production, and to 1,25-dihydroxyvitamin D (10 nmol/L), as assessed by osteocalcin synthesis, were not different from normal in patients with low, normal, or high bone formation rates. Osteoblastic cells isolated from patients with a high bone formation rate and markedly elevated serum iPTH and osteocalcin values had a higher than normal DNA replication in primary culture. The peak of [3H]thymidine incorporation, the maximal DNA synthesis, and the area under the growth curve were 4.4- to 6.3-fold increased in osteitis...