Risk factors for endocrine complications in transfusion-dependent thalassemia patients on chelation therapy with deferasirox: a risk assessment study from a multi-center nation-wide cohort.

Transfusion-dependent patients typically develop iron-induced cardiomyopathy, liver disease, and endocrine complications. We aimed to estimate the incidence of endocrine disorders in transfusiondependent thalassemia (TDT) patients during long-term iron-chelation therapy with deferasirox (DFX). We developed a multi-center follow-up study of 426 TDT patients treated with once-daily DFX for a median duration of 8 years, up to 18.5 years. At baseline, 118, 121, and 187 patients had 0, 1, or ≥2 endocrine diseases respectively. 104 additional endocrine diseases were developed during the follow-up. The overall risk of developing a new endocrine complication within 5 years was 9.7% (95% Confidence Interval [CI]: 6.3-13.1). Multiple Cox regression analysis identified three key predictors: age showed a positive log-linear effect (adjusted hazard ratio [HR] for 50% increase 1.2, 95% CI: 1.1-1.3, P=0.005), the serum concentration of thyrotropin showed a positive linear effect (adjusted HR for 1 mIU/L increase 1.3, 95% CI: 1.1-1.4, P<0.001) regardless the kind of disease incident, while the number of previous endocrine diseases showed a negative linear effect: the higher the number of diseases at baseline the lower the chance of developing further diseasess (adjusted HR for unit increase 0.5, 95% CI: 0.4-0.7, P<0.001). Age and thyrotropin had similar effect sizes across the categories of baseline diseases. The administration of levothyroxine as a covariate did not change the estimates. Although in DFX-treated TDT patients the risk of developing an endocrine complication is generally lower than the previously reported risk, there is considerable risk variation and the burden of these complications remains high. We developed a simple risk score chart enabling clinicians to estimate their patients' risk. Future research will look at increasing the amount of variation explained from our model and testing further clinical and laboratory predictors, including the assessment of direct endocrine magnetic resonance imaging.

The Link of Pancreatic Iron with Glucose Metabolism and Cardiac Iron in Thalassemia Intermedia: A Large, Multicenter Observational Study.

In thalassemia major, pancreatic iron was demonstrated as a powerful predictor not only for the alterations of glucose metabolism but also for cardiac iron, fibrosis, and complications, supporting a profound link between pancreatic iron and heart disease. We determined for the first time the prevalence of pancreatic iron overload (IO) in thalassemia intermedia (TI) and systematically explored the link between pancreas T2* values and glucose metabolism and cardiac outcomes. We considered 221 beta-TI patients (53.2% females, 42.95 ± 13.74 years) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. Magnetic Resonance Imaging was used to quantify IO (T2* technique) and biventricular function and to detect replacement myocardial fibrosis. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Pancreatic IO was more frequent in regularly transfused (N = 145) than in nontransfused patients (67.6% vs. 31.6%; p < 0.0001). In the regular transfused group, splenectomy and hepatitis C virus infection were both associated with high pancreatic siderosis. Patients with normal glucose metabolism showed significantly higher global pancreas T2* values than patients with altered OGTT. A pancreas T2* < 17.9 ms predicted an abnormal OGTT. A normal pancreas T2* value showed a 100% negative predictive value for cardiac iron. Pancreas T2* values were not associated to biventricular function, replacement myocardial fibrosis, or cardiac complications. Our findings suggest that in the presence of pancreatic IO, it would be prudent to initiate or intensify iron chelation therapy to prospectively prevent both disturbances of glucose metabolism and cardiac iron accumulation.

The Close Link of Pancreatic Iron With Glucose Metabolism and With Cardiac Complications in Thalassemia Major: A Large, Multicenter Observational Study.

OBJECTIVE: We systematically explored the link of pancreatic iron with glucose metabolism and with cardiac complications in a cohort of 1,079 patients with thalassemia major (TM) enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) project. RESEARCH DESIGN AND METHODS: MRI was used to quantify iron overload (T2* technique) and cardiac function (cine images) and to detect macroscopic myocardial fibrosis (late gadolinium enhancement technique). Glucose metabolism was assessed by the oral glucose tolerance test (OGTT). RESULTS: Patients with normal glucose metabolism showed significantly higher global pancreas T2* values than patients with impaired fasting glucose, impaired glucose tolerance, and diabetes. A pancreas T2* <13.07 ms predicted an abnormal OGTT. A normal pancreas T2* value showed a 100% negative predictive value for disturbances of glucose metabolism and for cardiac iron. Patients with myocardial fibrosis showed significantly lower pancreas T2* values. Patients with cardiac complications had significantly lower pancreas T2* values. No patient with arrhythmias/heart failure had a normal global pancreas T2*. CONCLUSIONS: Pancreatic iron is a powerful predictor not only for glucose metabolism but also for cardiac iron and complications, supporting the close link between pancreatic iron and heart disease and the need to intensify iron chelation therapy to prevent both alterations of glucose metabolism and cardiac iron accumulation.

MRI multicentre prospective survey in thalassaemia major patients treated with deferasirox versus deferiprone and desferrioxamine.

We prospectively assessed the efficacy of deferasirox versus deferiprone or desferrioxamine as monotherapy in thalassaemia major (TM) patients by magnetic resonance imaging (MRI). We selected the patients enrolled in the Myocardial Iron Overload in Thalassaemia network who received only one chelator between two MRIs (deferasirox = 235, deferiprone = 142, desferrioxamine = 162). Iron overload was measured by T2* technique and biventricular function by cine images. Among the patients with baseline myocardial iron, in all three groups there was a significant improvement in global heart T2* values. The deferiprone and desferrioxamine groups showed a significant improvement in left ventricular ejection fraction (LVEF). Only the deferiprone group showed a significant improvement in right ventricular ejection fraction (RVEF). The improvement in global heart T2* was significantly lower in the deferasirox versus the deferiprone group. The improvement in the LVEF was significantly higher in the deferiprone and desferrioxamine groups than in the deferasirox group and the improvement in the RVEF was significantly higher in the deferiprone than in deferasirox group. Among the patients with baseline hepatic iron, the changes in hepatic iron were comparable in deferasirox versus the other groups. Deferasirox monotherapy was less effective than deferiprone in improving myocardial siderosis and biventricular function and less effective than desferrioxamine in improving the LVEF.

The effect of desferrioxamine chelation versus no therapy in patients with non transfusion-dependent thalassaemia: a multicenter prospective comparison from the MIOT network.

We prospectively assessed by magnetic resonance imaging (MRI) the advantages of desferrioxamine (DFO) with respect to the absence of chelation therapy in non transfusion-dependent thalassaemia (NTDT) patients. We considered 18 patients non-chelated and 33 patients who received DFO alone between the two MRI scans. Iron overload was assessed by the T2* technique. Biventricular function parameters were quantified by cine sequences. No patient treated with DFO had cardiac iron. At baseline, only one non-chelated patient showed a pathological heart T2* value (< 20 ms) and he recovered at the follow-up. The percentage of patients who maintained a normal heart T2* value was 100% in both groups. A significant increase in the right ventricular ejection fraction was detected in DFO patients (3.48 ± 7.22%; P = 0.024). The changes in cardiac T2* values and in the biventricular function were comparable between the two groups. In patients with hepatic iron at baseline (MRI liver iron concentration (LIC) ≥ 3 mg/g/dw), the reduction in MRI LIC values was significant only in the DFO group (- 2.20 ± 4.84 mg/g/dw; P = 0.050). The decrease in MRI LIC was comparable between the groups. In conclusion, in NTDT patients, DFO therapy showed no advantage in terms of cardiac iron but its administration allowed an improvement in right ventricular function. Moreover, DFO reduced hepatic iron in patients with significant iron burden at baseline.