Microstructural analysis of severe bone lesions in seven thalassemic patients treated with deferoxamine

Osteochondrodystrophic lesions, mainly affecting long bane metaphyses, can be radiologically evident in homozygotic thalassemic patients treated with deferoxamine, and their incidence rate varies among authors. The clinical a nd radiological appearance of these lesions is described in the literature, but microstructural data are still lacking. The aim of our research was to evaluate the microstructure of five tibial biopsy specimens from thalassem ic patients with bone lesions (5 cases out of 180 patients followed for the last 10 years, i.e., 2.8%) and two bone biopsy specimens from thalassemic patients with no radiological alteration of the long bones. As control, bon e tissue taken from autoptic tibiae of two subjects with no skeletal pathol ogy was used. Using microradiography and X-ray diffraction (XRD), we found a reduced and irregular mineralization of the bone (compared with controls) in thalassemi c subjects. Bone tissue microhardness was also significantly reduced. Never theless, bone apatite lattice was unaltered and no 'foreign' crystallograph ic phase was recorded by XRD. In conclusion, all the patients shared a simi lar picture of abnormal bone, even with no radiological evidence of lesion.