Thalassaemia is a type of anaemia that leads to a decrease in haemoglobin levels, causing red blood cells to become fragile and short-lived. It should not be confused with iron-deficiency anaemia, since normally, iron deficiency isn't a symptom of thalassemia.
Professor John Porter, renowned consultant haematologist based in London, provides an expert insight into thalassaemia, including how is it different from the more common iron-deficiency anaemia.
What is thalassaemia?
Thalassaemia is a type of congenital and hereditary anaemia very common in the Mediterranean region. It results in a decrease in haemoglobin levels due to an alteration in its synthesis or formation, or more specifically, the globin fraction of the haemoglobin chain. This makes the red blood cells fragile with a low survival rate as they circulate through the bloodstream.
How is thalassaemia diagnosed?
Thalassaemia diagnosis, as in any anaemic syndromic process, involves a complete anamnesis, investigating both the patient's family and personal history, as well as a thorough and systematised clinical examination.
Subsequently, a haematologist will identify the relevant laboratory tests which can include: a haemogram; biochemistry tests with profile of iron metabolism, folic acid and vitamin B12; and (if necessary) a study of erythrocyte haemoglobins to confirm the diagnosis of thalassaemia.
A morphological study of a patient's blood sample by the haematologist is also very useful. It can identify red blood cells of different morphology and smaller size, since they are not formed properly. Among them, there is a particular form of red blood cells that are a characteristic of thalassaemia although not specific to this condition.
What are the different types of thalassaemia?
Thalassaemia is categorised firstly as alpha or beta thalassaemia, and then depending on the level of the deficit, it is classified as major-intermediate-minor or thalassaemic trait.
Traditionally and indirectly, certain analytical data may be oriented to a greater or lesser extent toward anaemia of one type or another. Typically, thalassaemia are translated into the blood count by an increase in the number of red blood cells (above normal) with decreased haemoglobin levels and a small erythrocyte size, which is reflected by a laboratory parameter called the mean corpuscular volume (MCV).
From the mid to late 20th century - when electrophoresis techniques or quantification of different types of haemoglobin were perfected - a formula was used that correlated the total number of red blood cells with haemoglobin levels and erythrocyte size which was called Index of England, a term which is nowadays practically disregarded outside the pure academic scope.
What are the signs and symptoms of thalassaemia?
The signs and symptoms of thalassaemia are virtually indistinguishable from any other anaemic syndrome.
Among other symptoms, thalassaemia can cause:
- paleness or jaundice due to raised bilirubin by the increased destruction of red blood cells
- discreet enlargement of the liver and spleen
What's the difference between thalassaemia and iron-deficiency anaemia?
The diagnostic approach to thalassaemia is a source of confusion, not only among the general population, but also sometimes within the same medical group. Most iron-deficiency anaemias are often mistaken for thalassaemia.
As a general rule, thalassaemia will show a normal or increased iron metabolism, since the accelerated destruction of red blood cells releases metabolites into the bloodstream. Among these is iron that will be deposited as ferritin in the liver.
In some cases, thalassaemia may be accompanied by intrinsic iron deficiency if the study of the ferric profile performed confirms this.
Where thalassaemia is suspected, the confirmatory diagnosis will be made by electrophoresis sequencing the different haemoglobin bands of the red blood cell.
How is thalassaemia treated?
Thalassaemia treatment will depend on the degree of the condition, ranging from simply observing the patient to treatment with vitamin supplements such as folic acid, or even in the most extreme cases, transplantation of haematopoietic progenitors.
Professor John Porter is an esteemed consultant haematologist with over 45 years' experience. If you require expert diagnosis and treatment of thalassaemia, don't hesitate to book an appointment with him via his Top Doctors profile today.