Treatment of patients with ␤-thalassemia major has improved dramatically during the past 40 years; however, the current clinical status of these patients remains poorly characterized. We performed a cross-sectional study of 342 patients in the Registry of the National Institutes of Health-sponsored Thalassemia Clinical Research Network. Evidence of hepatitis C exposure was present in 35% of tested patients, was associated with age, and had a rate of spontaneous viral clearance of 33%. Ferritin levels ranged from 147 to 11 010 ng/mL (median, 1696 ng/mL). Median hepatic iron content was 7.8 mg/g dry weight and 23% of patients had values of 15 mg/g dry weight or higher. No patients 15 years or younger and 5% of patients aged 16 to 24 years had heart disease requiring medication. Ten percent had cirrhosis on biopsy. Endocrinologic complications were common among adults. Seventy-four (22%) patients had recent implantable central venous access devices (CVADs) placed. Among 80 episodes of bacteremia in 38 patients, 90%were attributable to the CVAD. Among 330 patients who had received deferoxamine chelation therapy, 224 (68%) reported no complications. We conclude that hepatitis C, iron-related organ dysfunction, and complications of iron chelation therapy are strongly age-dependent in North American patients with ␤-thalassemia.

Adults with β thalassemia major frequently have low BMD, fractures, and bone pain. The purpose of this study was to determine the prevalence of low BMD, fractures, and bone pain in all thalassemia syndromes in childhood, adolescence, and adulthood, associations of BMD with fractures and bone pain, and etiology of bone disease in thalassemia. Patients of all thalassemia syndromes in the Thalassemia Clinical Research Network, ≥6 yr of age, with no preexisting medical condition affecting bone mass or requiring steroids, participated. We measured spine and femur BMD and whole body BMC by DXA and assessed vertebral abnormalities by morphometric X-ray absorptiometry (MXA). Medical history by interview and review of medical records, physical examinations, and blood and urine collections were performed. Three hundred sixty-one subjects, 49% male, with a mean age of 23.2 yr (range, 6.1–75 yr), were studied. Spine and femur BMD Z-scores < −2 occurred in 46% and 25% of participants, respectively. Greater age, lower weight, hypogonadism, and increased bone turnover were strong independent predictors of low bone mass regardless of thalassemia syndrome. Peak bone mass was suboptimal. Thirty-six percent of patients had a history of fractures, and 34% reported bone pain. BMD was negatively associated with fractures but not with bone pain. Nine percent of participants had uniformly decreased height of several vertebrae by MXA, which was associated with the use of iron chelator deferoxamine before 6 yr of age. In patients with thalassemia, low BMD and fractures occur frequently and independently of the particular syndrome. Peak bone mass is suboptimal. Low BMD is associated with hypogonadism, increased bone turnover, and an increased risk for fractures.

SummaryThis study aimed to determine differences in the rates of growth, endocrineand calcium-related abnormalities in the various thalassemia syndromes in North America treated with current therapies. Medical history, physical examinations and blood and urine collections were obtained from patients with all thalassemia syndromes age 6 years and older in the Thalassemia Clinical Research Network. 361 subjects, 49% male, mean age 23AE2 years (range 6AE1-75 years) were studied. Approximately 25% of children and adults, regardless of the thalassemia syndrome, had short stature. Overall growth in children was mildly affected. Final height was close to midparental height (z = )0AE73 ± 1AE24). Patients with beta thalassemia major (TM) had higher rates of hypogonadism, multiple endocrinopathies, worse hyperglycaemia, subclinical hypoparathyroidism and hypercalciuria. Hypogonadism remained the most frequent endocrinopathy and was frequently under-treated. 12AE8% of the subjects had 25 vitamin D concentrations less than 27 nmol/l and 82% less than 75 nmol/l, regardless of the thalassemia syndrome. Adolescents had lower 25 vitamin D levels than children and adults. Compared to patients with other thalassemia syndromes, those with beta TM suffered from higher rates of multiple endocrinopathies, abnormal calcium metabolism and hypercalciuria. Vitamin D abnormalities were high among adolescents.