Iron overload status in patients with non-transfusion-dependent thalassemia in China

Abstract

Background: Iron overload is one of the main factors that increase morbidity and mortality in patients with non-transfusion dependent thalassemia (NTDT).

Aim: This study aimed at investigating the prevalence and severity of iron overload in Chinese NTDT patients.

Methods: we analyzed serum ferritin (SF), liver iron concentration (LIC) and cardiac T2* in 178 Chinese NTDT in this cross-sectional study.

Results: The median SF level was 996.00(27.15-19704.00) ng/ml and the median LIC value was 8.90(0.60-43.00) mg Fe/g dry weight (dw). The youngest patient with liver iron overload was 5 years old with 5.6 mg Fe/g dw in LIC. The median cardiac T2* was 33.06(7.46-75.08) ms. 6 patients had cardiac T2*⩽20ms. The patients with β thalassemia intermedia and HbE/β thalassemia showed a statistically significant lower Hb and higher values of SF and LIC than those of hemoglobin H disease patients. On multivariate logistic regression analysis, patients in ⩾ age 30-year old had a significant higher risk for iron overload (OR: 77.75, 95% CI: 8.76-690.49) in the age group. The detailed analysis of proportions of different LIC indicate in > 30-year old group, 76.8% patients suffered from moderate and severe LIC.

Conclusion: Our study provides a strong support for the novel findings that Chinese NTDT patients have a high prevalence of iron overload. The first assessment of MRI LIC should be performed as early as 5 years old. Then, NTDT patients > 30 years old may suffer with a high burden of iron overload.

Keywords: Chinese thalassemic patients; iron overload; non-transfusion-dependent thalassemia.

Figure 1.

Correlation among age, Hb, serum ferritin and LIC in NTDT patients. (a) Correlation between SF and liver iron concentration (r = 0.83, p < 0.001). The dotted line represents reference range for LIC of 3.0 mg Fe/g dw, and the solid line represents SF of 800 ng/ml, (b) LIC was positively associated with age correlation (r = 0.41, p < 0.001). The dotted line represents reference range for LIC of 3.0 mg Fe/g dw, and the solid line represents age of 5 year, (c) correlation between Hb and liver iron concentration (r = -0.19, p = 0.01) and (d) correlation between Hb and serum ferritin (r = -0.07, p = 0.38).

Figure 2.

Blox-plot demonstrating the distribution trend between LIC and age groups.

Figure 3.

Shift in proportion of patients with severe, moderate, mild and normal LIC values. The proportion of severe LIC in ⩾ 30-year old NTDT group is significantly higher than that in other groups (p = 0.001).