Abstract. Introduction: Chronic blood transfusion is the mainstay of care for individuals with β-thalassemia major (BTM). However, it causes iron-overload that requires monitoring and management by long-term iron chelation therapy in order to prevent endocrinopathies and cardiomyopathies, that can be fatal. Hepatic R2 MRI method (FerriScan®) has been validated as the gold standard for evaluation and monitoring liver iron concentration (LIC) that reflects the total body iron-overload. Although adequate oral iron chelation therapy (OIC) is promising for the treatment of transfusional iron-overload, some patients are less compliant with it and others suffer from long-term effects of iron overload.
Objective: The aim of our study was to evaluate the prevalence of endocrinopathies and liver dysfunction, in relation to LIC and serum ferritin level, in a selected group of adolescents and young adult BTM patients with severe hepatic iron overload (LIC from 15 to 43 mg Fe/g dry weight).
Patients and Methods: Twenty-four selected BTM patients with severe LIC, due to transfusion-related iron-overload, followed at the Hematology Section, National Center for Cancer Care and Research, Hamad Medical Corporation of Doha (Qatar), from April 2015 to July 2017, were retrospectively evaluated. The prevalence of short stature, hypogonadism, hypothyroidism, hypoparathyroidism, impaired fasting glucose (IFG), diabetes, and adrenal insufficiency was defined and assessed according to the International Network of Clinicians for Endocrinopathies in Thalassemia (ICET) and American Diabetes Association criteria.
Results:
Patients have been transfused over the past 19.75 ± 8.05 years (ranging from 7 to 33 years). The most common transfusion frequency was every 3 weeks (70.8%). At the time of LIC measurements, the mean age of patients was 21.75 ± 8.05 years, mean LIC was 32.05 ± 10.53 mg Fe/g dry weight (range: 15 to 43 mg Fe/g dry weight). Their mean serum ferritin level was 4,488.6 ± 2,779 µg/L. The overall prevalence of growth failure was 26.1% (6/23), IFG was 16.7% (4/24), sub-clinical hypothyroidism was 14.3% (3/21), hypogonadism was 14.3% (2/14), diabetes mellitus was 12.5% (3/24), and biochemical adrenal insufficiency was 6.7% (1/15). The prevalence of hepatitis C positivity was 20.8% (5/24). No case of clinical hypothyroidism, adrenal insufficiency or hypoparathyroidism was detected in this cohort of patients. The prevalence of IFG impaired fasting glucose was significantly higher in BTM patients with very high LIC (>30 mg Fe/g dry liver) versus those with lower LIC (p = 0.044). LIC was correlated significantly with serum ferritin levels (r = 0.512; p = 0.011), lactate dehydrogenase (r = 0.744; p = 0.022) and total bilirubin (r = 0.432; p = 0.035).
Conclusions: A significant number of BTM patients, with high LIC and endocrine disorders, still exist despite the recent developments of new oral iron chelating agents. Therefore, physicians’ strategies shall optimize early identification of those patients in order to optimise their chelation therapy and to avoid iron-induced organ damage. We believe that further studies are needed to evaluate if serial measurements of quantitative LIC may predict the risk for endocrine complications. Until these data are available, we recommend a close monitoring of endocrine and other complications, according to the international guidelines.
Outcome of iron reduction therapy in ex-thalassemics