Have you ever donated your blood? If so, are you aware of its role in hemoglobinopathies? One of the genetically inherited blood disorders is thalassemia. The inherited blood disorders that occur due to defect in haemoglobin synthesis are haemoglobinopathies. They cause damage to the structure of the haemoglobin. Defect in haemoglobin synthesis leads to a disease called thalassemia.
Defect in the structure of haemoglobin synthesis results in sickle cell anaemia. One of the most serious hemoglobinopathies is thalassemia. Every year, India has reported 10,000 major cases of thalassemia. And also, the awareness of thalassemia is very low across the country. Hence, this article highlights the various types, investigations, and management and care measures for thalassemia.
WHAT IS THALASSEMIA?
Thalassemia is an inherited blood disorder that limits the body. It does not produce adequate amounts of oxygen to the haemoglobin. This affects the functions of important organs of the body. The word thalassemia is derived from the Greek word Thalassa. Further, people inherit this condition.
This is an inherited disorder from parents. It occurs due to interlinked or cross-linked marriages. Parents become carriers to their children. Moreover, there is also a genetic inheritance pattern for this condition. Hence, the public should have a better awareness of this condition.
EPIDEMIOLOGY OF THALASSEMIA:
Thalassemia is more prevalent in regions like Africa, the Middle East, the Mediterranean, India, Asia, and the Far East. However, the main cause includes inter-ethnic mixing. Leading to these types of conditions across the world. Further, in areas affected by malaria, this is common. The thalassemic red cells provide immunity against the malarian parasite.
HISTORY OF THALASSEMIA:
Firstly, this condition was first reported in Italy in the year 1925 by a Detroit physician. Further, he studied a group of Italian children with features like severe anaemia, poor growth, huge abdominal organs, and early childhood death. Further, in 1946 they found that the cause for this condition was due to defect in the haemoglobin structure. Consequently, in 1960, they found that blood transfusion showed excellent results in children suffering from thalassemia. Hence, they found that this will be one of the best treatment options for this condition.
PATHOGENESIS OF THALASSEMIA:
Thalassemia occurs due to defect in α, β chains of haemoglobin, a protein tetramer molecule. Further, it contains four sets of chains, two α, and two β chains. Further, if a defect occurs in one of the genes it affects haemoglobin synthesis. Also, the erythrocytes accumulate excess haemoglobin. Subsequently, this compromises the entire functions of the body.
The spleen recognizes abnormal erythrocytes. Further, the bone marrow destroys these erythrocytes. This leads to the premature death of the erythrocytes, therefore resulting in hypochromic microcytic anaemia in thalassemia. Hence, thalassemia patients have anaemia as well.
THE GENES INHERITED:
HBB, HBA1, HBA2 are the inherited genetic variants of thalassemia.
NORMAL HAEM LEVELS:
|Infants||9.5 – 13 g/dl|
Thalassemia patients have low levels of haemoglobin.
TYPES OF THALASSEMIA:
|TYPES OF THALASSEMIA|
|α type or minor type|
|β type or major or Cooley anaemia|
|Thalassemia intermedia ( variant of β type)|
α TYPE OR THE MINOR VARIANT:
This type affects the α globulin variant of haemoglobin. Moreover, the defect in the α globin gene causes this variant.
Firstly, when only one defective gene has been inherited the occurrence of the disease is nil. Further, the thalassemia trait occurs if we inherit 2 genes. Moreover, these patients have a mild degree of anaemia, microcytosis, splenomegaly (enlargement of the spleen), etc.
When all the α variants of the haemoglobin get affected, it results in a condition termed hydrops fetalis. Infants are affected during birth. Generalized fatal oedema, is not only a manifestation of this type. Further, it’s seen in conditions like severe Rh incompatibility, etc.
β VARIANT COOLEYS ANEMIA OR MAJOR TYPE:
Firstly, in the β variant, we inherit one defective gene resulting in this major variant of thalassemia. Also, in the β type of haemoglobin, we inherit 2 defective genes.
Due to severe microcytic hypochromic anaemia, this condition is detected due in the 1st year of life. Further, fetal haemoglobin production usually ceases between 3-4 months of age. Hence, the red blood cells (RBC’s) produced are extremely fragile and survive for only a few days.
To maintain an adequate level of oxygen in the blood, the rate of hematopoiesis gets increased (production of haemoglobin), resulting in massive bone marrow enlargement. Further, it leads to enlargement of organs, swollen lymph nodes, enlargement of the upper and lower jaws etc.,
THE CHIPMUNK FACES:
This is a classical feature of thalassemia. They have a prominent frontal bone, and enlargement of the jaws that results in a characteristic feature called “chipmunk faces”. Due to this classic feature, the patient’s face resembles a chipmunk.
HAIR ON END APPEARANCE:
The classical radiographic feature for this type includes “hair on end appearance”. Moreover, the prominent frontal bones, give a radiographic appearance in the skull termed the hair-on-end appearance. To clarify, sickle cell anaemia is a major cause.
Firstly, the variant of the β or the major type. Moreover in this, there is reduced availability of the β chains of haemoglobin. Hence, this leads to moderate to severe anaemia. Further, there is an array of complications such as bone deformities and splenomegaly.
β THALASSEMIA AND MALARIA:
The thalassemia RBC offers protection against a malaria parasite called plasmodium falciparum. And also, reduces the malarial effect. Most importantly, this RBC is immune to malaria.
GENERAL CLINICAL MANIFESTATIONS:
- Fatigue, weakness
- Shortness of breath
- Facial bone formities
- Swollen abdomen (due to enlargement of the internal organs such as spleen, liver)
- Dark colored urine
- Leg ulcers
- Gall bladder stones such as cholelithiasis etc.
|TYPE OF INVESTIGATION||PROCEDURE AND RESULTS|
|Complete blood count (CBC)||This test detects any kind of infection in the blood. In this test, the quality of haemoglobin is measured. These patients usually have defects in their chains of haemoglobin.|
|Reticulocyte count||In this test, the numbers of reticulocytes are measured in the bone marrow. Usually, reticulocytes are produced in the bone marrow. Therefore, this test also plays an important role. The normal reticulocyte count: 0.5-1.5 per cent.|
|Iron studies||This is usually taken from a complete blood count. Serum iron, transferrin, and ferritin were detected.|
|Haemoglobin electrophoresis||This test usually identifies a different kind of haemoglobin in the blood. Most importantly, detects the different globin chains in the blood.|
|Genetic testing||This usually detects the β variant of thalassemia. Usually, genes like, HBB, HBA1, and HBA2 are inherited genetically in this condition.|
|Radiograph||The lateral skull radiograph is usually taken for this condition. The trabecular pattern was detected in this position.|
|Ultrasound||This procedure uses high-frequency waves to scan the body. There will be enlargement of the spleen, the liver in these patients. Hence to detect these kinds of abnormalities abdominal ultrasound is preferred.|
Firstly, blood transfusion is one of the best treatment modalities for this condition. Further, patients should undergo a transfusion every 21 days.
The main goal of blood transfusion is to maintain the viability and function of the red blood cells. Further, selecting a donor with good levels of RBC and haemoglobin plays a crucial role.
Moreover, the cells are subjected to filtration post-transfusion. Further, this procedure is performed to remove the target antibodies.
BONE MARROW TRANSPLANTATION:
Bone marrow transplantation is one of the costliest treatment modalities. Patients suffering from thalassemia have defective production of erythrocytes. Hence, HLA donor with normal levels of haemoglobin usually selected so that will be capable of erythrocytes production in these patients.
IRON CHELATION THERAPY:
In order, to remove the iron overload iron chelation therapy is performed. Mostly done for iron overload cases, after 1 year of blood transfusion in β thalassemia patients.
Supplements such as vitamin B12, folic acid supplements improve the nutritional status of the body.
HYPERBARIC OXYGEN THERAPY:
To clarify, oxygen levels increase by this therapy.
WORLD THALASSEMIA DAY:
We celebrate World thalassemia day on May 8. The purpose is to, encourage thalassemia patients, to lead a confident life. Further, this is done to increase the awareness of thalassemia among the public. Awareness insists on inter-ethnic marriages. Also, if both the parents have thalassemia, there is a 50 % chance for the child to develop a minor variant. Further, a 25% chance for the child to develop a major variant. Moreover, at the time of pregnancy perform a postnatal diagnostic test.
To sum up, thalassemia is one of the inherited blood disorders affecting the synthesis of haemoglobin. Hence, the public should be well aware of this anaemic disease and its cause. Hence, donate blood saves a life. These can make changes in the lives of thalassemic patients.