Trombotsitы - Thrombocytopenia

Thrombocytopenia may be caused by the following factors:

1. rapid, early and massive loss of platelets from the action on them auto- and antibodies isoimmune (idiopaticheskaya trombotsitopenicheskaya purpura, drug immune thrombocytopenia, thrombocytopenia in systemic connective tissue diseases and others.);
2. increased platelet maceration in the spleen and the portal vein (splenomegaly, cirrhosis, etc.. d.);
3. intense diminution of platelets from the blood stream as a result of disseminated intravascular coagulation, massive thrombus formation, intensive aggregation of platelets (trombogemorragichesky syndrome, thromboembolism, trombogemoliticheskaya trombotsitopenicheskaya purpura, or Moschcowitz'disease, gemolitikouremichesky syndrome, or illness Gasser, and etc.);
4. violation platelet in bone marrow (gipoplasticheskaya anemia, Acute leukemia, radiation sickness, multiple tumor metastasis to bone marrow, violation of maturation of megakaryocytes due to lack trombotsitopoetina).

In the first three cases, the life span of platelets dramatically shortened and myelogram revealed normal or increased amounts of megakaryocytic cell number, and blood - immature, excessively large basophilic platelets. In the latter case, the content of megakaryocytes in the myelogram sharply reduced, and dominated by small blood, functionally defective cells (in acute leukemia along with it can be detected in the blood of large fragments promegakariotsitov); Life labeled platelet transfusion in the absence of splenomegaly remains normal.

Gipermegakariotsitoz bone marrow and peripheral blood thrombocytosis observed in chronic myeloproliferative disorders - essential thrombocytosis (platelet count may be increased to 2000-4000 in the G 1 l and more), polycythemia vera, in the early stages of chronic myeloid leukemia and osteomyelofibrosis. As a temporary phenomenon hyperthrombocytosis can develop after splenectomy, Pregnancy, after injection of adrenaline and significant physical exertion. For some women, the number of these cells in the blood during the premenstrual and menstrual periods is noticeably reduced (to 100 T in 1 l).

Antigenic structure corresponds to that of platelet red blood cells (Systems ABO and CDE-Rh) and leukocytes (по системе HL-A), When platelet transfusions weight of these factors are taken into account, although transfusions are out of the antigenic structure of platelets is not accompanied by a pronounced shortening of life expectancy of these cells. In autoimmune thrombocytopenia and isoimmune such transfusions increase the titer of anti-platelet antibodies, and practically useless, as the input donor platelets, even on a strictly selected group antigens accessories, stored in the patient's blood only 30-90 min.