The concept of primary thrombocytosis
Primary thrombocytosis - a hematologicloss relating to mieloprolifera-tive syndrome, in which there is disruption of the stem cells are characterized by an autonomous proliferation of one or more germs of hematopoiesis in bone marrow. The result is an excessive number of cells in the peripheral blood and, in some cases, liver and spleen. These diseases, affecting mainly those over 60 years old, quite rare in children and young people. For example, the prevalence of thrombocytosis in childhood is about 0.09 cases per million children aged 0 to 14 years.
Symptoms of the disease
Symptoms are variable manifestations of the disease andmainly diagnosed by chance based on total blood analysis carried out at the general examination of the patient. The most common symptoms - a headache. The diagnosis is sometimes put before the thrombotic or hemorrhagic complications. In fact, these patients have an increased incidence of complications associated with impaired platelet aggregation.
Diagnostic criteria of primary thrombocytosis are:
- number of platelets over 600 g / l
- hematocrit less than 40% of blood or normal weight
- Normal ferritin levels or normal amount of red blood cells with an average volume of normal erythrocyte
- medullary normal karyotype
- the absence of medullary fibrosis (1/3 or less in the absence of enlarged spleen and elevated white blood cell count)
- no morphological abnormalities or cytogenetic changes, indicating the presence of myeloproliferative syndrome
- no reason to reactive thrombocytosis
Diagnostic criteria for primary thrombocytosisbased on the totality of the symptoms and biological data with the presence of features of bone marrow myelogram with a pronounced increase in the megakaryocytic germ, which is responsible for platelet production. A bone marrow biopsy allows to establish the increase in bone marrow cells.
The mechanisms of primary thrombocytosis
The mechanisms of primary thrombocytosis isnot known. There is a theory of clonal bone marrow (ie, associated with the proliferation of cellular pathological clone). The disease is most severe in the case of clonality with a particularly high risk of thrombosis.
Treatment of primary thrombocytosis
Currently, the primary treatmentthrombocytosis apply such medical preparations as Hydrea or gidrokosiurea (hydroxyurea) - antimitotics is used for many years. These drugs play a role in reducing the risk of thrombosis, decreasing the viscosity of blood by limiting interaction of leukocytes with the vascular wall and reduce the level of red blood cells. The mechanism of action is associated with inhibition antimitotics maturation of megakaryocytes in the bone marrow (in low doses) and inhibits platelet adhesion (at higher doses).
Interferon-alpha is also an effective means oftreatment of thrombocytosis, but it is administered only parenterally, that is, without going through the intestines, the side effects of the drug, (flu-like syndrome, psychiatric disorders), was forced to abandon its widespread use today.