History of myocardial iron loading is a strong risk factor for diabetes mellitus and hypogonadism in adults with ß thalassemia major.

Endocrinopathies are common complications of transfusional hemosiderosis among patients with ß thalassemia major (TM). Previous studies had shown associations between some endocrinopathies and iron overload of the myocardium, liver and/or endocrine organs as assessed by MRI techniques. This retrospective analysis of 92 patients with TM (median age 36 yr) from a tertiary adult thalassemia unit in UK aimed to determine independent risk factors associated with endocrinopathies among these patients. Unlike previous studies, longitudinal data on routine measurements of iron load [worst myocardial and liver T2* values since 1999, worst LIC by MRI-R2 since 2008 and average 10-yr serum ferritin (SF)] up to April 2010 together with demographic features and age of initiating chelation were analyzed for associations with endocrinopathies. The most common endocrinopathies in this cohort were hypogonadism (67%) and diabetes mellitus (DM) (41%), and these were independently associated with myocardial T2* <20 ms (P < 0.001 and P = 0.008, respectively) and increased age (P = 0.002 and P = 0.016, respectively). DM and hypogonadism were independently associated with average SF >1250 µg/L (P = 0.003) and >2000 µg/L (P = 0.047), respectively. DM was also associated with initial detection of abnormal myocardial T2* at an older age (30 yr vs. 24 yr, P = 0.039). An abnormal myocardial T2* may therefore portend the development of DM and hypogonadism in patients with TM.

Prospective study of histomorphometry, biochemical bone markers and bone densitometric response to pamidronate in ß-thalassaemia presenting with osteopenia-osteoporosis syndrome.

This study aimed to evaluate bone remodelling disorders in thalassaemia by using pamidronate (PD) infusion with or without hormone replacement therapy (HRT) as a diagnostic-therapeutic tool. In this prospective study, 24 adult thalassaemia major (TM) and 10 thalassaemia intermedia (TI) patients received either PD and HRT or HRT only (controls) for 3 years. Eugonadal patients with TI had PD only. Bone remodelling was assessed by dual energy X ray absorptiometry (DXA scan), type 1-collagen biochemical bone markers (BBM) and histomorphometry of iliac crest biopsy before and after PD. As a group, thalassaemics had a significant improvement in spinal and femoral bone mineral density Z scores following PD (P < 0·01) compared to the controls. Although BBM were comparable pre-therapy, they were significantly lower in the PD cohort (P < 0·001) compared to the control group. All patients had osteopenia, diminished osteoid formation and bone volume on histomorphometry pre-therapy with high turnover bone disease (HTO) in TM and low-turnover disease (LTO) in TI. In TM, bone volume improved significantly, whereas TI patients showed little or no response to PD. In conclusion, histomorphometry data suggest that TM patients have a distinct pathology of high turnover bone disease compared to TI patients, who have low-turnover disease.

Monitoring chelation therapy to achieve optimal outcome in the treatment of thalassaemia.

Effective management of iron overload in thalassaemia requires monitoring both for iron toxicity and the effects of excessive chelation. Careful monitoring together with adherence to established regimens using desferrioxamine (DFO) results in a 78% survival rate at 40 years of age at UCLH, with steadily improving survival as progressive cohorts receive chelation earlier in life. By contrast, survival is considerably below this in non-specialist centres. The prognostic significance of the measures being used in monitoring should be known so that decisions about chelation management are evidence-based. Serum ferritin measurement, although easy to perform frequently, is subject to variability and falsely high or falsely low values in relation to body iron are frequently obtained. However, there is evidence that persistently high ferritin values above 2500 microg/l have poor prognostic significance in patients treated with DFO. Liver iron predicts total body iron in a more predictable way than serum ferritin in thalassaemia. Liver iron concentrations of 15 mg/g dry weight appear to predict those patients who develop heart failure in subjects treated with DFO. The prognostic significance of this measurement or indeed other measurements of iron overload in patients treated with other chelation regimens is not known. Recent advances with MRI imaging have aroused interest in its use for monitoring patients with thalassaemia. A recent publication suggests a relationship between left ventricular ejection fraction and cardiac T2*, the value of which shortens with increasing iron concentrations in the liver and hence by inference in the heart. The prognostic value of this technique has not yet been demonstrated in prospective studies and hence changes in therapy based on this measurement alone should be considered with caution at this time. The value of monitoring to decrease morbidity from iron overload is also discussed, particularly with reference to the estimation of iron deposition in the pituitary.

Value of sequential monitoring of left ventricular ejection fraction in the management of thalassemia major.

Regular monitoring of left ventricular ejection fraction (LVEF) for thalassemia major is widely practiced, but its informativeness for iron chelation treatment is unclear. Eighty-one patients with thalassemia major but no history of cardiac disease underwent quantitative annual LVEF monitoring by radionuclide ventriculography for a median of 6.0 years (interquartile range, 2-12 years). Intraobserver and interobserver reproducibility for LVEF determination were both less than 3%. LVEF values before and after transfusion did not differ, and exercise stress testing did not reliably expose underlying cardiomyopathy. An absolute LVEF of less than 45% or a decrease of more than 10 percentage units was significantly associated with subsequent development of symptomatic cardiac disease (P <.001) and death (P =.001), with a median interval between the first abnormal LVEF findings and the development of symptomatic heart disease of 3.5 years, allowing time for intervention. In 34 patients in whom LVEF was less than 45% or decreased by more than 10 percentage units, intensified chelation therapy was recommended (21 with subcutaneous and 13 with intravenous deferoxamine). All 27 patients who complied with intensification survived, whereas the 7 who did not comply died (P <.0001). The Kaplan-Meier estimate of survival beyond 40 years of age for all 81 patients is 83%. Sequential quantitative monitoring of LVEF is valuable for assessing cardiac risk and for identifying patients with thalassemia major who require intensified chelation therapy.