Bone density and metabolism in thalassaemia

Twenty-seven thalassaemic, patients (13 F, 14 M, aged 8.1-14.9 yr), regular ly transfused and chelated with desferrioxamine (30-40 mg/kg/day) were stud ied. Every patient was submitted to auxological evaluations, dual X-ray abs orptiometry to measure bone mineral density (BMD), and to the determination of bone metabolic markers of osteoclastic activity (total urinary hydroxyl ysylpyridinoline crosslinks, carboxyterminal pyridinoline crosslinked telop eptide of type I collagen [ICTP]) and of osteoblastic activity (bone Gla pr otein [BGP] and carboxy-terminal propeptide of type I procollagen [PIPC]), The evaluations were repeated after 1 year, during which 13 patients contin ued desferrioxamine chelation while 14 underwent deferiprone chelation (75 mg/kg/day in 3 doses). The data demonstrate widespread bone alterations consisting of osteoporosis , growth failure and bone age delay. Lumber spine (L2-L4) BMD areal values (Z score) inversely correlated with age, as did height SDS of both male and female patients, indicating osteoporosis progressing with age in parallel with growth insufficiency. No clear-cut alterations in bone mineral metabol ism were found in basal state and after 1 year. Extensive MR imaging studies are needed to define the contribution of resid ual bone marrow hyperplasia to thalassaemic. osteopathy suggested by subtle radiological signs as enlargement of bone marrow cavities with thinning of the cortical bone and abnormalities of the trabecules of spongy bone.