Thalassemia is a special, genetically dependent disease that affects one of the main structural units of blood - red blood cells. It is important to emphasize that thalassemia does not deform erythrocytes, but develops in the presence of deformed red blood cells. The most dangerous and most an important feature of thalassemia is the risk of developing the most powerful destruction of damaged red blood cells - the development of the hemolytic crisis.
It is also important to know that thalassemia is even a disease associated with a genetic defect, but it does not have such a high capacity for development, such as other similar diseases. In addition, the risk of developing this disease will be high only in those patients who showed signs of thalassemia in both parents. In the presence of a confirmed diagnosis of thalassemia only in the father or mother, the risk of its development in the offspring will be extremely small, since the gene for the development of this disease will simply be suppressed by healthy genes.
Thalassemia is an "endemic" disease, inherent only in certain peoples and nations (especially the peoples of the African continent, the Latin American coast and the nations of the Mediterranean). There is an opinion that such specificity of this disease emerged as the primary compensatory protective function of the organism, where its purpose was to protect the body from a parasite circulating in certain areas, circulating in the bloodstream, the malarial plasmodium.
In general, thalassemia is a disease that requires constant monitoring and supportive treatment. Patients with established thalassemia become on dispensary records, which will be periodically carried out throughout their life.
The basis of the manifestation of thalassemia is the hemoglobin defect of erythrocytes. Normally hemoglobin consists of two components - two chains (alpha chain and beta chain). For the correctness of the compilation of these structures, special places (loci) in the human genetic code are responsible. Synthesis of the normal beta chain corresponds to the loci of chromosome 14, and, respectively, for the creation of the alpha chain - the same loci, but in 11 chromosomes.
With thalassemia, there is a gene mutation-deletion (loss of one of the chromosome regions). As a result, some chromosome loci are lost, which contain information on the correct structure of hemoglobin.
Further pathological processes of the onset of thalassemia are based on failures in the processes of protein biosynthesis, thanks to which hemoglobin chains appear. To do this, from the DNA chain to a special "carrier" - the RNA chain, through the sequence of its constituents, information about the future structure of the created protein must be copied. After this, such a chain with "stored information" is sent to the "protein factory" of the cell - the ribosome and, extending through it like a chain, triggers the assembly of the protein.
In thalassemia, the genetic code, because of the mutations described above, contains deliberately incorrect information, and, accordingly, the structure of the protein itself is pathological. Here we can distinguish the following main pathological moments: the synthesis of one fraction of the chain is usually inhibited, and the other chain, on the contrary, is synthesized in excess. Also, the destruction of the membrane structures of the erythrocyte itself, as well as the oxidation of that fraction of the chain, which is reproduced in excess. As a result of all these reactions, the erythrocyte loses its structure and can not perform its functions: it becomes brittle and, at the slightest contact with the vessel wall, collapses.
The destruction of erythrocytes leads to the release of their pigments and their further deposition in structures and tissues. This condition is called hemosiderosis . During its course, iron-containing pigments accumulate in cells and destroy them. Then such cells are replaced with a connective tissue and the function of the organ where the pigment has deposited is gradually lost until it completely stops.
In addition, this "wrong" red blood cell does not do its main function anymore - delivering oxygen to the tissues that need it and removing carbon dioxide from them. As a consequence, hypoxia of these tissues develops and their death gradually decreases.
Thalassemia is usually distinguished by fractions of hemoglobin, which are affected, and also by the principle of its genetic manifestations. Isolate thalassemia with alpha chain (alpha-thalassemia) and thalassemia with beta-chain damage (beta-thalassemia). Beta-thalassemia is also divided into two subspecies, which are due to their genetic manifestation: homozygous thalassemia (large thalassemia) and heterozygous (small thalassemia).
With a large thalassemia, the pathological gene will manifest itself all 100%, so the clinical picture will be extremely rich and bright. With heterozygous thalassemia, some of the clinical signs will not develop, due to partial inhibition (inhibition) of the manifestations of the "mutant" gene.
Symptoms of thalassemia
The first signs of thalassemia will appear in the newborn period. Thalassemia in children is an extremely severe and severe disease. Due to the fact that in the body with thalassemia the process of tissue hypoxia is started - the bone structures of the child do not form normally, there is a disruption of development and psyche.
Since thalassemia is accompanied by a large hemolysis, the skin will have a characteristic "hemolytic" color. It is important to note that such jaundice will have its own special lemon or "canary" color, which is explained by the application of jaundice to anemic pallor.
Another possible sign of thalassemia will be an objective palpable enlargement of the spleen and liver. The spleen accumulates the decaying erythrocytes and, with a large number of them, increases, so-called "working hypertrophy" of the organ occurs. The increase in the liver is explained by hemosiderosis and massive deposition of its enzymes in the liver cells. In the future, the liver will, on the contrary, decrease, and acquire a more dense consistency.
These signs will also add typical common signs of anemia: weakness, loss of strength, loss of appetite, severe dizziness , which may be accompanied by syncope. Another bright sign of developing anemia - against a background of complete well-being with adequate physical exertion, patients begin to notice a sharp development of severe shortness of breath. This process is also explained by the increasing hypoxia of the body, which it tries to eliminate, causing itself to breathe more often. But this sign can be adequate only if there is a normal function of the cardiovascular and respiratory systems.
A large form of thalassemia is a subspecies of thalassemia with a high lethal outcome - such a child can die already in the first year of life. With long-term treatment and less active form, life expectancy is higher, but such patients with thalassemia suffer from extensive hemosiderosis: gastritis , myocardial dystrophic lesions and joint damage occur.
There is a whole range of diagnostic measures aimed at detecting thalassemia. The main principle of the diagnosis of thalassemia: the determination of characteristic hematological changes, the disruption of the normal structure of the erythrocyte and the identification of the hereditary nature of the disease.
Possible hereditary nature of the development of the disease is usually determined by the collection of an anamnesis of life and a patient with a suspected thalassemia. Another important criterion for diagnosis in thalassemia will be the ethnic belonging of the patient - belonging to the peoples of the Mediterranean region, to the peoples of Africa, Latin America, and the Caucasus (these peoples have the most thalassemia, as mentioned above).
In the blood with thalassemia, the following characteristic changes will occur: a decrease in the color index and the level of hemoglobin. In addition, with thalassemia, it is possible to determine the highly characteristic form of the erythrocytes themselves: due to the broken structure of hemoglobin, it will be "target-like", oblate (instead of a normal biconcave form). Also, because due to the permanent disintegration of red blood cells, the percentage of their relative content in blood sharply decreases, then the organism automatically starts the formation of new ones, and therefore a certain number of future precursors of red cells-reticulocytes can be found in the blood. Absolutely for the same reasons the red hematopoietic germ in the bone marrow with a high number of normoblasts, erythroblasts (these are all cells of the erythrocyte series) will be enlarged (hyperplasticized).
Also, thalassemia will be characterized by signs of extensive hemolytic damage: an increase in the indices of the indirect part of bilirubin, an extremely high level of iron in the blood serum (formed due to the breakdown and release of the red blood cell hemosiderin into the blood) and a visual indicator: hemolytic jaundice. It should be noted that only carrying out all of the above diagnostic methods in one complex will allow suspect a probable presence of thalassemia in the patient.
Thalassemia is a disease belonging to the so-called class of "congenital diseases". And this means that it is impossible to completely cure it, since it is impossible to inhibit the activity of the pathological gene and the subsequent production of abnormal hemoglobin chains.
The greatest attention in the treatment of thalassemia is given to periodic transfusions (transfusions) of the donor erythrocyte mass. The main principle of such treatment is that the constant compensation of the lost volume of red blood cells does not allow to develop a sharp decrease in the level of hemoglobin and to develop subsequent severe complications.
The first transfusion of blood components in thalassemia begins with a 6-month-old child. The first cycle is also the most intensive: in 2 weeks of the cycle, in general, about 8 transfusions should be performed. Further, the frequency of procedures decreases to the optimum frequency, which will amount to 1 blood transfusion in about 3 or 4 weeks. The main indicator that should be looked at when assigning blood transfusion and assessing the results of its conduct is the level of hemoglobin. In patients with thalassemia, it should be above 100 grams per liter. In addition, you need to know the formula for calculating the amount of erythrocyte mass used for each patient, it is about 15-20 ml of mass per kilogram of body weight of the patient.
Donor erythrocytes do not contain defective hemoglobin structures, and therefore do not hemolyse and function during their normal life span. This makes it possible to compensate for such an important function for the body as oxygenation of its tissues and to prevent the development of tissue hypoxia.
Since thalassemia is accompanied by massive destruction of erythrocytes containing irregularly formed hemoglobin, the main plan for thalassemia therapy will be another important symptom - hemosiderosis or a massive deposition of decayed erythrocytes in tissues. For his treatment, use the scheme Desferalom therapy. Desferal is a special preparation from a number of chelate preparations that can create certain complexes with pathological substances and remove them from the body. It is Desferal aimed at the capture of hemosiderin, which plays a major role in the development of hemosiderosis in thalassemia. For his appointment, it is important to adhere to the following scheme: the course of his appointment should be at least 3 weeks, and a single dose should be up to 3 grams per day. In order to confirm the effectiveness of this therapy at the end of each of its courses, control is carried out: an intramuscular injection is made and the number of its chelates (complexes) in urine is counted. With effective treatment of hemosiderosis with thalassemia, this parameter should not be higher than 1, 1 mg. Also, with thalassemia, you can designate a complex: Desferal + Ascorbic acid. Ascorbic acid has the effect of potentiating (enhancing) the action of Desferal.
If thalassemia continues to progress, then in this case it is necessary to remove the spleen. Such an operation is performed with a large number of congenital anemia (including thalassemia) and is considered one of the effective methods of stopping massive destruction of red blood cells. In addition, such removal is also a preventive method: in the body the spleen performs the function of a "depot" or a storehouse of old and dying red blood cells and the processes of their decay are carried out precisely in it. Therefore, a very large number of erythrocytes and circulating blood are always contained in the spleen. In case of massive decays of the erythrocyte structure, the spleen can burst, which leads to a drop in hemoglobin to its "lethal" level, blood loss and subsequent death.
There is also one more new method of treating thalassemia, and it is he, in combination with other methods, that can significantly improve a patient's life. This is bone marrow transplantation. Namely the donor erythrocyte germ. Such a new germ is genetically healthy, which means it will also synthesize healthy red blood cells with a normal hemoglobin structure.