Polycythemia is a disease characterized by an increase in erythrocyte volume in the bloodstream. This disease can be both primarily conditioned, and secondarily arising as a result of exposure to certain underlying causes. Both the primary and secondary polycythemia are quite serious diseases, which can lead to serious consequences.
So the primary or true polycythemia manifests itself in the appearance of a tumor substrate in the bone marrow and increased production of red blood cells. Therefore, in advanced stages, this lesion increases in size and displaces all other substrates from the bone marrow - the progenitors of the future blood cells.
Secondary polycythemia occurs in completely different situations, but one of the leading polycythemia is the general hypoxia (oxygen starvation) of the body. Thus, secondary polycythemia is an indicator of certain pathological processes in the body, arising as a compensatory reaction.
True polycythemia is a disease with a purely tumor origin. Fundamental in this disease is that the red bone marrow is affected by stem cells, or rather, the progenitor cells of blood cells (also called polipotent stem cells). As a result, the number of erythrocytes and other uniform elements (platelets and leukocytes) sharply increases in the body. But since the body is adapted to a certain norm of their content in the blood, any excess of the limits will entail certain violations in the body.
True polycythemia differs quite malignant course and is difficult to treat. This is explained by the fact that it is practically impossible to influence the main cause of the appearance of a true polycythemia - a mutated stem cell with high mitotic activity (the ability to divide).
A bright and characteristic sign of polycythemia will be the plethoric syndrome. It is caused by a high content of erythrocytes in the channel. This syndrome is characterized by a purplish-red coloration of the skin with a strong itching.
True polycythemia has three main stages, which are arranged according to the activity of the process. The first stage is the height stage. At this stage, the first changes in the bone marrow will be formed, and the altered hemopoiesis will be formed. The stage of sweeping is almost impossible to detect clinically. Most often at this stage, the diagnosis of the true polycythemia is randomized, for example, when carrying out blood tests to diagnose another disease.
After the stage of swelling, the stage of clinical manifestations follows: all clinical signs of this disease, plague syndrome, skin itch , enlarged spleen will appear here. After the stage of clinical manifestations, the final stage will appear - anemic. With it, all the same clinical signs will be revealed, plus diagnostic symptoms of bone marrow "devastation" (thanks to the constant bone marrow hyperplasia).
It is important to note that true polycythemia is a formidable disease due to its complications. An increased number of erythrocytes and platelets will lead to increased thrombosis and the development of thrombotic damage to the body. In addition, the overall blood pressure increases, which can lead to persistent arterial hypertension and hemorrhagic strokes, followed by intracranial hemorrhage and death.
Polycythemia of the cause
In polycythemia, the main manifestation will be an increase in the blood flow, in the course of various reasons, the number of red blood cells. The reasons for this mechanism will depend on the type of polycythemia. There are polycythemia of absolute and relative type.
With absolute polycythemia, there is a direct increase in the volume of red blood cells in the bloodstream. The absolute polycythemia includes true polycythemia, polycythaemia in hypoxic conditions and obstructive pulmonary diseases, hypoxia associated with renal and adrenal lesions. For all these states, there is an increased synthesis of red blood cells.
With true polycythemia, erythrocytes intensively synthesize tumor hyperplastic areas of the bone marrow, hypoxia will cause a retrograde increase in the number of erythrocytes in the blood, and with certain kidney lesions, the synthesis of erythropoietin, the main hormone responsible for triggering the formation of new red blood cells, can increase.
With a relative polycythemia, erythrocyte volumes will increase due to a decrease in plasma volume. In normal plasma is approximately 5% more than the blood cells. With loss of plasma, this ratio is violated, the plasma becomes smaller. The main paradox is that with relative polycythemias, the number of red blood cells does not change literally - it remains within the normal range. But due to the decrease in plasma blood in the ratio of plasma: uniform elements, they become larger - their "relative" number increases.
So to relative polycythemia include such infectious diseases as cholera, dysentery and salmonellosis. They have severe vomiting and diarrhea, which leads to a loss of significant internal water supplies, including plasma, by the body. In addition, to reduce the volume of plasma and the development of relative polycythaemia can lead to burns, as well as human exposure to high temperatures, which will cause increased sweating.
It is also necessary to pay special attention to the two most common causes of polycythemia: a tumor lesion of the red bone marrow and effects on the synthesis of red blood cells of hypoxia.
Tumor lesion of the red bone marrow is fundamental for the development of primary or true polycythemia. With this type of polycythemia, a mutation occurs at the genome level of the stem cell, and it begins to divide uncontrollably, creating new tumor clones. It is important to note here that these polypotent stem cells are the "alpha and omega" of all future blood cells: red blood cells, leukocytes and platelets. These polypotent cells undergo a certain differentiation during their growth and form three main sections of hematopoiesis in terms of the number of elements: erythrocyte, platelet and leukocyte. Then, from each sprout, future uniform elements are gradually born.
But with true polycythemia, the polypotent stem cell already has a genetic defect, and it synthesizes exactly the same defective posterior progenitor cells of hematopoiesis. As a result, these cells are part of the hematopoietic sprouts and, like their ancestors, divide intensively, creating a huge number of uniform elements. Thus, two pathological processes are formed with true polycythemia: excess of normal levels of erythrocytes and simultaneous hyperplasia (increase in size) of affected hemopoiesis.
The effect of hypoxia on the body has a number of pathological phenomena on it, among which the development of secondary polycythaemia plays an important role. The reason for the secondary polycythemia in hypoxia is explained by the fact that the body tries to compensate for the lack of oxygen in the body, synthesizing new red blood cells. This is due to the effects of hypoxia on the kidneys, during which the latter produces a special substance - erythropoietin. It is erythropoietin that triggers the processes of differentiating the polypotent stem cell into reticulocytes (the precursors of erythrocytes) and the further formation of new erythrocytes. Therefore, under the influence of hypoxia on hematopoiesis, the following connection can be traced: the stronger its effect on the body, the more erythropoietin will be synthesized by the kidneys, and the more the erythrocyte part of the bone marrow will work, synthesizing new red blood cells.
The main and, perhaps, the most important sign of polycythemia will be the so-called "plethora syndrome". This syndrome is caused by an increase in the volume of all blood elements and total abundance.
The basis of the plethoric syndrome will be the complaints of the patients themselves, as well as violations that can be determined with the help of objective research.
Among patients' complaints, the main indicators of the plethora syndrome will be permanent headaches that will alternate with dizziness. In addition, the plethoric syndrome will always accompany patients' complaints of itching. Its origin is explained by the fact that with true polycythemia there is a massive synthesis of mast cells by special substances - prostaglandins and histamines, which, acting on histamine receptors, will lead to the appearance of strong, sometimes even intolerable skin itching. By the way, one of the classic and characteristic polycythaemias is the specific nature of this skin itch - it can increase several times, after contact of the skin with water (with baths, showering or even with simple washing). But it is important to know that the plethora is a sign of a strictly true polycythemia. In secondary polycythemia, skin coloring will not undergo such significant changes.
In addition to the above complaints, patients will also indicate changes in the hands. These changes are called erythromelalgia. The skin of the brushes will be a characteristic "red-cyanotic" color. In addition, a change in the color of the hands and fingers will be accompanied by strong pain in the affected areas, which will occur with every contact with any surface. The cause of this condition is the same as in the case of plethoric cutaneous itching - the production of a high number of histamines.
Objectively, you can determine the presence of patients with polycythemia of a specific color - the skin will be cyanotic red, sometimes even cherry. Also, there will be significant changes from the cardiovascular system. The most characteristic of them will be: excess of blood pressure and development of thrombosis. A characteristic sign of changes in blood pressure in polycythemia will be an increase in systolic blood pressure above 200 mm Hg.
The second syndrome with polycythemia will be myeloproliferative syndrome. This symptom complex is more typical for the true or primary polycythemia. This syndrome is accompanied by an increase in the spleen or liver. Its main reason is that the spleen in the body fulfills the function of the so-called "depot" or "storehouse" for red blood cells. Normally, in the spleen, erythrocytes, ending their life cycle, are destroyed. But since in polycithemia the number of erythrocytes can sometimes exceed the norm by a factor of tens, the amount of red blood cells accumulating in the spleen is enormous. As a result, there is hyperplasia of the spleen tissue and its increase. To the enlargement of the spleen in the syndrome of myeloproliferation, patients' complaints about weakness, fatigue, and pain in the tubular bones and in the left hypochondrium are also added. Painful symptoms are explained just by the growth of the tumor-altered hematopoiesis and hyperplastic spleen.
In addition, with any polycythemia may appear symptoms that are associated with an increase in the viscosity of the blood. These include small and large thromboses, the development of strokes and heart attacks, as well as separation of thrombus and subsequent development of pulmonary embolism .
But in addition to the symptoms of polycythaemia described above, which are directly related to the pathogenesis of this disease, namely, the increase in the number of red blood cells in the bloodstream and the subsequent changes, there are also symptoms - signs of major diseases that led to the development of secondary polycythemia. Such symptoms can be cyanosis (acrocyanosis and common cyanosis) with the primary causes of secondary polycythemia from the respiratory system (most often to its appearance can lead to chronic obstructive pulmonary disease) and the effects of general body hypoxia. Symptoms of renal dysfunction or tumor damage, which can also cause secondary polycythemia, can also be detected.
In addition, we must not forget about the effect of infectious agents on the main mechanism of polycythemia development. The main possible signs for infectious conditioned secondary polycythemia are profuse diarrhea and vomiting, which will lead to a sharp decrease in the volume of plasma, which means a nonspecific increase in the number of red blood cells.
Polycythemia of newborns
The first signs of polycythemia development can also be observed in newborns. Polycythemia of the newborn arises as a response of the child's organism to the intrauterine hypoxia suffered by it, which could develop due to placental insufficiency. In response, the body of the baby, trying to correct hypoxia, begins to synthesize an increased number of red blood cells. Exactly the same oxygen deficiency as the triggering factor of neonatal hypoxia can also be observed in the presence of a newborn "blue" congenital heart disease or pulmonary disease.
In addition to respiratory conditioned polycythemia in newborns, as well as in adults, true polycythemia can develop. Especially this risk can be affected by twins.
This disease occurs in the first weeks of a newborn's life and its first signs are a significant increase in hematocrit (up to 60%) and an increase in hemoglobin levels by 22 times.
In neonatal polycythemia, there are several stages of clinical course: the initial stage, the stage of proliferation and the stage of exhaustion.
At the initial stage polycythemia practically does not manifest itself and develops without any clinical manifestations. In addition, the presence of polycythemia in a child at this stage can only be determined by examining the parameters of peripheral blood: hematocrit, hemoglobin and the level of erythrocytes.
The stage of proliferation has a much more vivid clinic. In this stage, the child shows enlarged liver and spleen. Developing pletoric phenomena: the skin becomes a characteristic "pleatorically red" shade, the child's concern when touching the skin. Thrombosis is added to the plethoric syndrome. In the analyzes there will be a change in the number of platelets, erythrocytes and leukocyte shifts. In addition, the performance of all blood cells can increase - this phenomenon was called panmelosis.
At the stage of exhaustion, the child will still have signs of an increase in the spleen and liver, there will be a significant loss of body weight, asthenia and malnutrition.
Such clinical changes are very difficult for the newborn and can lead to irreversible changes and subsequent death. In addition, the true polycythemia of the newborn can lead to sclerosis in the bone marrow, because due to the constant growth of tumor cells in the bone marrow, the normal working hemopoietic tissue is displaced and its connective tissue replaced. In addition, this phenomenon can lead to disruption of the production of certain types of leukocytes, responsible for the immune protection of the child's body. As a result, the newborn can develop severe bacterial infections, which are the cause of their death.
For the correct treatment of polycythaemia, it is important to determine the root cause, which has become a starting factor in the development of this pathology. It is the difference in the effect on the main triggering factor polycythemia and will be fundamental in the treatment regimen. So, for example, in the secondary polycythaemia, they are engaged in eliminating its original cause, and with true polycythemia try to work on tumor cells and to curtail the consequences of increased production of cells-shaped blood cells.
True polycythemia is quite difficult to treat. It is difficult to work on tumor cells and stop their activity. In addition, the age-determining factor in the administration of polycythemia therapy directed at suppressing the metabolism of tumor cells is age. Thus, patients with a true polycythemia who are under the age of 50, the appointment of certain drugs is strictly prohibited, they are prescribed only to those patients, whose age is from 70 years. Most often for the suppression of the tumor process used drugs myelosuppressors: Hydroxyurea, Hydrea, Hydroxycarbamide.
But in addition to directly affecting the tumor in the bone marrow, it is also important to fight the consequences of the increased content of blood cells. With a high number of red blood cells, the bleeding procedure is extremely effective. In addition, this procedure is the leading in the treatment of true polycythemia. The main goal, which is pursued in the appointment of bleeding with true polycythemia, is a decrease in hematocrit to 46%. A single volume of blood, which is usually removed during the procedure, corresponds to approximately 500 ml. In the presence of certain pathologies (for example, a violation of the function of the cardiovascular system), this volume is reduced to 300-350 ml.
Before the first bleeding procedure, patients are assigned a number of studies aimed at determining hemoglobin indices, establishing the exact number of erythrocytes, hematocrit, and determining the clotting indices. All these indicators are necessary for the correct calculation of the frequency of the procedure, the volume of blood seizures and the calculation of targets (especially hematocrit).
Before starting the first bleeding, the patient is prescribed drugs - antiaggregants: Aspirin or Curantil. By the way, these same drugs are prescribed for use within a few weeks after the end of the procedure. Before the bloodletting itself, the patient is also given the administration of rheopolyglucin with heparin to improve the aggregate state of the blood. Usually the procedures are carried out with the order of 1 every two days.
Another more modern method of treating true polycythemia is cytophrasis. This procedure is that the patient connects to a special device with cleaning filters. By catheterizing the veins of both hands, the circulatory system of the patient is closed on this apparatus in such a way that blood from one vein enters the apparatus, passes through the filters and returns to another vein. This apparatus centrifuges the incoming blood into it and "screened out" a portion of the red blood cells, returning the patient plasma. Thus, this device removes an excessive amount of red blood cells from the bloodstream in patients with true polycythemia.
As already mentioned above, secondary polycythemia is cured when the main cause that elicits polycythemia is cured and eliminated. When hypoxic root causes of polycythemia are prescribed intense oxygen therapy, as well as elimination of the hypoxic factor, if any. In polycythemia, which develop due to infectious diseases, first eliminate the most infectious agent by prescribing antibiotics, and when large volumes of fluid are lost, replacing intravenous infusions of colloidal solutions are performed.
The prognosis of polycythemia directly depends on its type and timeliness of treatment. True polycythemia is a disease with a more severe prognosis: due to the difficulty in its therapy and the constant increase in the number of red blood cells, such patients are forced to continue the courses of hemoexfusion therapy. In addition, these patients are at high risk of thromboembolic complications, stroke and hypertension. The prognosis of secondary polycythemia depends on its primary disease. In addition, the effectiveness of its elimination depends on early diagnosis and the appointment of adequate treatment.