Thalassemia What we need to know

02.11.2022

Thalassemia belongs to the group of hereditary hemolytic anemias. Hemolytic anemias are a large group of diseases, which differ from each other in their causes, clinical picture and features of treatment. These diseases are united by the main pathological process of enhanced hemolysis of erythrocytes.

Table of Contents

Hemolysis means the breakdown of erythrocytes. Normal erythrocytes live 100-200 days. In case of hemolytic anemia, their life span is reduced to 12-14 days. Normally, erythrocytes are broken down only in the spleen, and during the disease, enhanced breaking down may take place in the blood vessels.

what causes

Erythrocytes, red blood cells, carry oxygen to all cells. Their main component is hemoglobin, which consists of iron and two pairs of protein chains - alpha and beta globins. In thalassemia, due to a deficiency or defect in the genes responsible for globin production, the protein chains cannot be produced in sufficient quantities or are abnormal.

Depending on the globin defect, two main types of thalassemia are distinguished - alpha and beta. Both alpha and beta thalassemia may be major or minor. In thalassemia major, the defective gene is passed on to the child from both parents, and in thalassemia minor, only from one. In this case, the person is an asymptomatic carrier of the disease. In alpha or beta thalassemia minor, the red blood cells are small, but there are no symptoms.

How is it revealed? symptoms

Violation of hemoglobin synthesis leads to enhanced breakdown of erythrocytes and anemia.

The clinical range of thalassemia varies from asymptomatic to severe and depends on the type of disease and the severity of the anemia. Anemia is manifested by weakness, exhaustion, dizziness, shortness of breath, rapid heart rate, headache, muscle cramps, difficulty concentrating, paleness or yellowing of the skin and mucous membranes, facial bone deformities, growth retardation in children - abdominal enlargement, darkening of urine, which is a sign of the breakdown of erythrocytes, loss of appetite decrease.

Most people born with thalassemia have health problems a few months after birth. Less severe cases may not be seen until late childhood or even adulthood. The main health problems associated with thalassemia are:

Blood transfusion – regular blood transfusion for treatment and prevention of anemia; In severe cases, they are needed about once a month
Chelation therapy – drug treatment to remove excess iron from the body, which accumulates as a result of regular blood transfusions; Some people with thalassemia accumulate iron without blood transfusions and require treatment.

The body tries to fill the loss by producing more erythrocytes. They are mainly formed in the bone marrow (the dark, spongy substance in the middle of the bones). It expands over time due to more than normal loads, which causes the bones to expand and become brittle.

Blood is also produced in the spleen. It is located on the left side of the abdominal cavity, under the ribs. Its main functions are filtering the blood and fighting infections. In the case of thalassemia, the spleen produces red blood cells in a stronger way and becomes enlarged due to excessive load, and it can no longer effectively deal with infections, so people are more prone to infectious diseases. In case of strong enlargement, the spleen is excised.

Diagnosis

Thalassemia is suspected when its signs appear in early childhood. The mild form is diagnosed as a result of a routine blood test. The disease is suspected even when the patient belongs to a high-risk ethnic group. By examination, the doctor checks for enlargement of the spleen.

Blood tests are used for diagnostics, which reveal abnormalities in the number, size, color or shape of red blood cells. General blood analysis shows a decrease in hemoglobin and erythrocytes - anemia. Under the microscope, erythrocytes are small in size and abnormal in shape, and hemoglobin electrophoresis shows the abnormal form of the protein. In addition, DNA analysis may be performed to detect gene mutations. There are also newer studies, with the help of which safe testing can be done in the early stages of pregnancy (Veragen (100 monogenic diseases)) methods determine whether the fetus has mutated genes. Also, if there is a risk of transmitting the disease to the child, couples can consult a specialist before the birth and manage the pregnancy properly

There are two main types of tests available to prevent fetal syndromes during pregnancy (prenatal period): screening tests and diagnostic tests. Screening and diagnostic tests determine whether a fetus has a low or high chance of developing various syndromes.

If screening tests show that you are at high risk of having a baby with thalassemia, it is recommended that you also have a diagnostic test to determine if the fetus has the genetic disorder.

1. Screening Tests – A prenatal screening test can determine if your baby is more or less likely to have birth defects, many of which are genetic disorders. These tests include blood tests, specific ultrasounds, and prenatal cell-free DNA screening.

2. Diagnostic tests – after the screening test, the final answer is given by the diagnostic test, which checks the genetic material of the fetus and therefore can also find out whether the fetus has a genetic disorder. Invasive and non-invasive prenatal diagnostic tests ((NIPT) Verasity, Veragen) are the only, safe and effective way to confirm the diagnostics.

Be aware that some diagnostic tests, such as chorionic villus sampling and amniocentesis, carry a small risk of miscarriage.

Learn more about prenatal diagnostics → (https://synevo.ge/prenatal-screening/)

Treatment

The type of treatment for thalassemia depends on the severity of the disease. The more severe it is, the less hemoglobin there is in the body and the more severe the anemia. In case of thalassemia major of moderate severity, blood transfusions are performed periodically. This procedure is carried out even in the presence of aggravating factors, for example, in the presence of an infectious or other disease. In case of severe form, relatively frequent blood transfusion is required - on average once every few weeks.

As a result of regular transfusion, iron gradually accumulates in the blood, which can damage the heart, liver and other organs. Iron may accumulate even without regular transfusions. Removing excess iron is vital. For this, chelation therapy is carried out, which involves binding excess iron and expelling it from the body with the help of special drugs (deferasirox, deferiprone or injectable deferoxamine). In case of minor thalassemia, blood transfusion is usually not required. Folic acid supplements are also used to treat thalassemia major. Folic acid is involved in the development of red blood cells.

The treatment of choice for especially severely ill children is stem cell transplantation, also known as bone marrow transplantation. The procedure involves infusions of stem cells from a compatible donor, usually a sister or brother.