Beta thalassemia intermedia Flashcards
Why is there such heterogeneity for the disease?
More imbalance = more ineffective erythropoiesis = symptoms
What are the genotypes that can give rise to beta thal intermedia?
2 thalassemic genes that are mild
1 thalassemic gene that is bad
Explain how 2 thalassemic genes can give rise to an intermedia picture
they have ameliorating factors such as: Inheritance of alpha thal compound heterozygosity mutation inheriting particularly mild B gene coinheritence of increases of HbF
Explain how 1 thalassemic gene can give rise to an intermedia picture
Coinheritance of triplicated alpha genes (more imbalance)
Inheritance of “dominant beta thal” which is a rare mutation coding for hyperunstable Hb
Coinheritance of HbE
What is a new attempt to predict the clinical severity and genotype?
Soluble transferrin receptor levels to reflect EPO activity
Paolo Richi et al 2016
When would a splenectomy be an alternative approach to raise Hb?
If hypersplenic with bulky/painful spleen
Can make a difference if there is no safe transfusion available/alloantibodies make it difficult/if chelation is not available
High blood consumption when transfusing
What are the risks of a splenectomy?
Increased spontaneous iron loading (Porter et al 2016)
Increased risk of extra medullary haematopoietic masses (Masrouha kz et al 2016)
Thrombosis risk increased
septic risk around 10%
Lifelong penicillin and immunisations
What are the downsides to regular transfusions?
They are inconvenient, require venous access, iron overload is common, transfusion transmitted infection and alloantibody formation
What organs are particularly susceptible to iron loading?
Heart
Endocrine glands
Liver
What are other common transfusion indications?
Pulmonary HTN
Ankle ulceration
What are 2 kinds of iron chelators?
Deferriprone/Ferriprox
Deferasirox/Exjade
