Evolution of Thalassaemia Management Four Decades in Thalassaemia Care – Our Achievements and Challenges
Iron Chelation became an Integral Part of Treatment
Iron chelation with subcutaneous deferoxamine Fig. 11 was started in Hong Kong in the late 1970s and early 1980s. Since then, regular blood transfusion together with subcutaneous deferoxamine has become the standard management. Deferoxamine is not a simple treatment as the drug has a short half-life and it must be infused underneath the skin continuously over 10 to 12 hours a day using a syringe driver.Fig. 12 Complications due to iron overload still occurred in a significant number of patients. This was partly due to poor compliance with the demanding chelator injection, partly related to efficiency of the chelator, and related to lack of tools to monitor iron overload except serum ferritin. Deferoxamine injection is relatively safe, and patients most often develop skin reactions at the injection site. Other drug associated complications such as skeletal dysplasia was occasionally observed.
Deferiprone Fig. 13 was the first oral chelator which came to local clinical practice in the late 2000s after quite a few overseas clinical studies which brought controversies. The drug is effective but can cause liver dysfunction in some patients and reduction of normal white cell count called agranulocytosis is occasional patients. Deferiprone was shown in a randomized controlled study to significantly reduce ferritin levels in poorly chelated Hong Kong Chinese patients when combined with deferoxamine. Therefore, combination therapy of deferoxamine with deferiprone has been frequently used in poorly chelated patients.
The use of validated MRI software to assess organ iron is one the major innovations which has transformed thalassaemia care as clinicians can now adjust iron chelation regimen based on degree of iron overload in specific organs. It was introduced to Hong Kong in 2009.
Deferasirox Fig. 14 is another oral iron chelator which was available in Hong Kong public hospitals since 2010. It was recommended for first-line treatment in children aged between 2-6 years, and for second-line treatment for children older than 6 years, who are not responding optimally to combined deferoxamine with deferiprone. Renal tubular dysfunction has been observed to be a frequent but reversible adverse effect.
Now we have more choices of iron chelators for thalassaemia patients and different combination regimens may be applied according to needs of patients and their tolerability to individual drugs.Fig. 15
