Cardiac iron across different transfusion-dependent diseases

Daily labile plasma iron as an indicator of chelator activity in Thalassaemia major patients

Labile plasma iron (LPI), a non-transferrin-bound component of plasma iron detected in iron overload disorders is a potential source of cellular iron accumulation and ensuing oxidative damage. Periodic monitoring of LPI over a 24 h time-span was used to compare the ability of chelation to control daily LPI levels in 40 Thalassaemia major patients (9-11/group) who had been receiving one of three different chelation protocols for more than a year: Group I. deferrioxamine overnight, Group II. deferiprone daily, Group III. deferrioxamine and deferiprone sequentially. An additional group (Group IV) was treated with desferasirox for up to 6 months. The patterns of daily LPI recrudescence showed significant individual variations, especially in patients treated with deferrioxamine or deferiprone, although these patterns were maintained over 6-9 months of treatment in all groups. Group data analysis showed that the proportion of patients whose daily LPI were maintained within the normal range (<0.45 micromol/l) varied with treatment: 6/10 with deferrioxamine, 5/11 with deferiprone, 9/10 with deferrioxamine + deferiprone and 8/10 at the onset and 10/10 after 6 months treatment with deferasirox. Although the clinical significance and therapeutic value of LPI remain to be established, monitoring of daily LPI level may provide an analytical basis for assessing chelation efficacy in preventing daily LPI recrudescence.

Elevated serum parathormone levels are associated with myocardial iron overload in patients with beta-thalassaemia major

OBJECTIVES

Despite advances in conventional treatment, iron-induced cardiomyopathy is still the most frequent cause of death among patients with beta-thalassaemia major. Recent studies have correlated increased myocardial iron content to decreased levels of vitamin D in thalassaemic patients. The aim of this study was to measure parathormone (PTH) and metabolites of vitamin D and consequently to investigate whether these parameters predispose to myocardial iron overload in patients with beta-thalassaemia major.

METHODS

In 62 patients (29 M and 33 F, mean age: 22.79 +/- 6.18 yr) with beta-thalassaemia major levels of intact parathormone (iPTH) and vitamin D metabolites [25(OmicronH)D(3) and 1,25(OmicronH)(2)D(3)] were measured in serum. Additionally, estimation of myocardial iron content was performed by magnetic resonance imaging, whereas mean serum ferritin concentrations were calculated for 1 yr prior to the study.

RESULTS

Results showed markedly decreased levels of serum 25(OH)D(3) in 37 patients (60%), whereas 7 patients (11%) had borderline 25(OH)D(3) levels (between 50 and 75 nmol/L). Serum iPTH levels were significantly higher in patients having increased myocardial iron compared to those having normal myocardial iron (44.04 +/- 22.09 pg/mL vs. 31.39 +/- 14.30 pg/mL, P = 0.017). Multivariant regression analysis identified PTH levels as the major predictor of increased myocardial iron.