From Big Medical Encyclopedia

THROMBOCYTOPENIA (thrombocyte [yu] + Greek penia poverty; a synonym a thrombocytopenic syndrome) — the morbid condition which is characterized by the lowered maintenance of thrombocytes in blood — less than 150 Ltd companies in 1 mkl (150-109/l).

T. can be an independent disease (see the Purpura a thrombocyte to a penicha from Kai) or a symptom of a row patol. the states (as acquired and hereditary), it can be caused by the increased destruction of thrombocytes, their increased consumption or insufficient education (is more often the reason of T. the increased destruction of thrombocytes is).

In most cases T. happen acquired, however there is a group of hereditary T., the thrombocytes connected with structural inferiority (see), leads edges to shortening of duration of their life. At hereditary T. change of various functional properties of thrombocytes is quite often observed that gives the grounds to carry them to group of trombo-tsitopatiya (see). Carry T to hereditary., caused by the defect of membranes of thrombocytes which is combined with disturbance of a functional condition of thrombocytes, napr, Mei's syndrome — Hegglina, or anomaly of thrombocytes of Mei — Hegglina, Bernard's syndrome — Sulye (see Trombotsitopatiya), hereditary thrombocytopenia of Viskott — Aldrich in combination with defect of immune system (see Viskott — Aldrich a syndrome), hereditary T., the activities of enzymes of glycolysis caused by disturbance (see) or a tricarbonic acid cycle (see. Tricarboxylic acids cycle), hereditary T., the formations of thrombocytes caused by disturbance in connection with decrease in maintenance of trombotsitopoetin (see).

The acquired T. distinguish depending on the pathogeny and the reasons causing damage of thrombocytes or megacaryocytes, carry To the acquired trombotsitopeniye: 1) immune T. — alloimmun-

ny, or isoimmune at which antibodies are formed at hemotransfusions (see Hemotransfusion) or get to an organism of a fruit from mother; transimmune T., connected with penetration through a placenta of maternal autoantibodies; heteroimmune; autoimmune;

2) thrombocytopenia, caused by oppression of proliferation of cells of marrow and observed at an idiopathic form of an ailasti-chesky syndrome (see. Hypoplastic anemia), at a radial illness (see) and impact of cytostatic drugs on marrow; 3) thrombocytopenia, connected with vegetative mutation of progenitors of a myelopoiesis (see the Hemopoiesis), arising at Markiafava's disease — Mika of l and (see. Hemolitic anemia) and hemoblastoses (see); 4) thrombocytopenia of consumption, observed at fibrinferments (see), extensive hemorrhages, the expressed splenomegaly (see); 5) thrombocytopenia, developing owing to substitution of marrow a tumor, napr, at metastasises of cancer in marrow, at hemoblastoses (see); 6) thrombocytopenia,

caused by a bruise of thrombocytes at hemangiomas (see Kazabakh — Merritt a syndrome), the expressed splenomegaly, in the presence of artificial valves of heart; 7) thrombocytopenia at deficit of B12 vitamin (see Cyanocobalamine) or folic acid (see).

Most often in a wedge, practice immune T meet., connected with impact on thrombocytes of antibodies. Among them the largest specific weight belongs to autoimmune T., to-rye it is possible to divide into three groups depending on against what antigen antibodies are directed: against the antigen of thrombocytes, antigen of megacaryocytes (which is absent in thrombocytes) or the general antigen for thrombocytes, leukocytes and erythrocytes. Autoimmune T. can be idiopathic (see the Purpura thrombocytopenic) when the reason of an autoaggression is not established, and symptomatic when the lowered maintenance of thrombocytes in blood is a consequence of a basic disease and is considered as one of its symptoms.

All forms T. are characterized, as a rule, by painless spotty hemorrhages. At the majority of T. hemorrhages in skin or different types of bleedings from mucous membranes are noted (from gums, nasal, went. - kish., etc.).

At sick T. at a blood analysis decrease in number of thrombocytes up to total disappearance is noted, the normal or increased maintenance of plasma blood-coagulation factors (see. Coagulant system of blood), decrease in consumption of a prothrombin (see), disturbance of retraction (see) blood a clot (sometimes retraction is absent). At the expressed T. at most of patients a bleeding time (see) it is increased. Because of the increased fragility of capillaries connected with narusheniyekhm angiotrofichesky function of thrombocytes (see), tests on capillary resistance, napr, can test (see Valjdman test), are sharply positive. In diagnosis of hereditary T. plays an essential role morfol. analysis of thrombocytes (their size, structure), definition of their functional properties, and also existence of other displays of hereditary pathology inherent nek-eye of T. So, at Bernard's syndrome — Sulye the sizes of thrombocytes are considerably increased (several times more than normal), because of defect of membranes release of a factor of 3 thrombocytes is reduced and there are no receptors for a factor of Vil-lebranda (see the Angiogemophilia) in this connection there is no aggregation of thrombocytes under the influence of Ristocetinum; at Mei's syndrome — Hegglina the increased thrombocytes are found, the quantity of thrombocytes is reduced to 80 Ltd companies — 120 000 in 1 mkl (80 — 120*109/l), in neutrophils the large blue inclusions located excentricly — little bodies Business are defined.

In marrow at the majority of the hereditary and acquired T. the quantity and the sizes of megacaryocytes are increased; young forms of megacaryocytes with one kernel, narrow cytoplasm and with a small amount of granules are found. At most of patients with T. shortening of life expectancy of thrombocytes and the accelerated education them in marrow is noted. However T come to light., characterized by trace amount of megacaryocytes in marrow and the lowered formation of thrombocytes. So, at hereditary T., the trombotsitopoetrsh connected with disturbance of development, the quantity of megacaryocytes is reduced or they are absent. At autoimmune T. in the period of an aggravation, especially against the background of a heavy infection when the quantity of antibodies can sharply increase, megacaryocytes can temporarily disappear. There are T., at to-rykh trace amount of thrombocytes at safe marrow is constantly observed, normal soot-

carrying between the hemopoietic marrow and fatty tissue. At these T. antibodies are probably directed against antigen of megacaryocytes. At various options of an An-lastichesky syndrome (see. Hypoplastic anemia) is found trace amount of megacaryocytes

or they are absent. At the same time in marrow considerable dominance of fatty tissue over hemopoietic is noted. At Viskott's syndrome — Aldrich the inefficient thrombocytopoiesis — the increased destruction of thrombocytes in marrow is revealed at their sufficient development. At patients with gemangiomamp, with artificial valves of heart stress rupture of thrombocytes can be observed.

At Markiafava's disease — Mika-whether (see. Hemolitic anemia) in marrow as a result of vegetative mutation the thrombocytes, erythrocytes and neutrophils with a defective membrane which are easily collapsing in blood under the influence of a complement (see) are formed.

T. in combination with macrocytic hyperchromic anemia it is observed at deficit of B12 vitamin or folic to - you as a result of disturbance of cell fission of marrow. At the same time in some cases the maintenance of thrombocytes, up to total disappearance is sharply reduced; bleeding, as a rule, does not arise. T. at metastasises of cancer in marrow and hemoblastoses complicates a current of a basic disease. T. at hemoblastoses can result from substitution of normal marrow patol. a clone of the hemopoietic cells or owing to chemotherapeutic influence or ionizing radiation. At the same time at a certain stage T. can be the only manifestation it is hidden the proceeding basic disease, napr, an acute leukosis. In these cases of T. arises owing to vegetative mutation of progenitors of a myelopoiesis.

Special group T. makes so-called. T. consumption, most often connected with massive hemorrhages or fibrinferments (the B. olypy quantity of thrombocytes is spent for formation of blood clots), especially at a syndrome of the disseminated intravascular coagulation (see. Hemorrhagic diathesis).

Treatment of T. depends on a basic disease. E.g., at hemoblastoses, an aplastic syndrome (especially in need of performing surgery) introduction of trombotsitny weight is shown (see). At immune T. appoint glyukokortigsoida; introduction of trombotsitny weight is contraindicated. At autoimmune T. effek

a tivna a splenectomy (see). Treatment of hereditary T. depends on their pathogeny: at deficit trombotsito-

ioetin the transfusion of plasma of donors is recommended, at defects of membranes of thrombocytes when duration of their life is shortened, make a splenectomy.

Symptomatic treatment of T., followed by hemorrhages, includes transfusion of trombotsitny weight. Appoint also Adroxonum, synthetic progestins. At nasal bleedings widely use an absorbable gelatin sponge, ok-sitsel (the oxidized cellulose), Adroxonum, local cryotherapy, a tamponade of a nose.

The forecast depends on a basic disease.

Thrombocytopenia at children — the most common form of hemorrhagic diathesis. Allocate primary and secondary, or symptomatic, T. K primary carry idiopathic T. (see a Werlhof's disease), hereditary, isoimmune T. and inborn transimmune T.

On modern representations Verlgof's disease at children, or idiopathic T., it is caused by quantitative and qualitative insufficiency of a platelet link of a hemostasis (see). This disease with hereditary predisposition; it is characterized by existence at patients of a hereditary trombotsptopa-tiya, against the background of a cut the postponed viral infections (acute respiratory viral infections, measles, a rubella and others), preventive inoculations, physical and mental injuries, and also other factors can lead to emergence of immunopathological process — proliferation of lymphocytes, sensibilized to autotrombotsita, and synthesis of antithrombocytic autoantibodies. Because reason of development of idiopathic T. immunopathological process is, allocation of immune and not immune forms of a disease is irrational. At patients of idiopathic T. bleeding is caused quantitative (thrombocytopenia) and qualitative (trombotsitopatiya) inferiority vascular trombo - the cytic mechanism of a hemostasis. The vascular endothelium deprived of angiotrofichesky function of thrombocytes a cut normal in days is spent for implementation apprx. 35 Ltd companies of thrombocytes from 1 mkl blood (35*109/l), is exposed to dystrophy that leads to increase in permeability of vessels (spontaneous hemorrhages). Disturbances of the coagulative mechanism of a hemostasis (decrease in rates of a thromboplastinopoiesis, accelerated fibrpno-liz) are secondary in relation to insufficiency of a platelet link. Signs of a trombotsitopatiya (disturbance of adhesion and aggregation of thrombocytes) are noted at patients during the entire periods of a disease, including after a splenectomy at normal quantity of thrombocytes in blood. At a cytochemical research are found decrease in maintenance of a glycogen in megacaryocytes and thrombocytes, it is reduced not activities of a lactate dehydrogenase, a malate dehydrogenase, a suktsinatdegidro-genaza, glyukozo-6-fosfatdegidroge-nazy and increase in acid phosphatase in megacaryocytes and thrombocytes that demonstrates disturbance in them of metabolism, preferential energy balance. Qualitative inferiority of thrombocytes is expressed also in decrease in contents in them arachidonic to - you, necessary for synthesis is simple of the lan-din stimulating aggregation of thrombocytes. Decrease in content of enzymes in thrombocytes is observed at remission, according to various researchers, of 6 weeks till 1 year. Therefore in the absence of vital indications the splenectomy needs to be carried out not earlier than 6 months — 1 years from the beginning of a disease.

At children on a current allocate acute and hron. forms of idiopathic T. Chronic forms (duration of a disease more than 6 months) subdivide into forms with a rare recurrence, with a frequent recurrence and forms, continuously recurrent. Allocate several periods of a disease — crisis, a wedge, remission (lack of bleeding at the remaining thrombocytopenia) and kliniko-hematologic remission. Crosby (W. The N of Crosby, 1975) suggested to distinguish on a wedge, a picture dry (at patients the skin hemorrhagic syndrome) and wet purpuras (a purpura in combination with bleedings is noted).

Idiopathic T. at children prior to the beginning of the period of puberty it is observed equally often at boys and girls, and among children and re pubertal and pubertal age of the girl are ill twice more often than boys. The disease, as a rule, develops after the postponed viral infections. There are skin hemorrhages, hemorrhages in mucous membranes, bleedings. Are characteristic to iolikhromnoyet hemorrhages (at the same time on skin it is possible to find hemorrhages of different coloring — from reddish-bluish to green and yellow), their polymorphism (along with ecchymomas of different size petechias), asymmetry and spontaneity of emergence (preferential appear at night). Bleedings from mucous membranes are typical (nasal, gingival, from a hole removed - tooth, at girls of pubertal age — uterine). The melena, hamaturia and other types of bleeding are seldom observed. The moderate splenomegaly can be found approximately in 30% of sick children. Forecast, as a rule, favorable.

Hereditary T. can develop as a result of insufficient formation of thrombocytes (hypoplastic T. about an autosomal recessive - nym a mode of inheritance) or the increased their destruction (see Viskot-ta — Aldrich a syndrome). Hypoplastic T. (at hypo - or an amegaka-riotsitoza) are usually combined with other malformations, it is especially frequent with an aplasia of beam bones. Bleeding (a purpura, nasal, intestinal and other bleedings) and the lowered maintenance of thrombocytes in blood in typical cases appear in the first days of life. The hypoplasia of a megakariotsi-tare sprout can be a symptom of hypoplastic anemia, chromosomal anomalies (trisomies on the 13th, 15th, 18th couples of chromosomes). The forecast is adverse, more than a half of patients dies about one year.

Hereditary T. depending on the size of thrombocytes subdivide on microcytic, macrocytic and normotsitarny. From them syndromes of Viskot-ta — Aldrich (see Viskott — Aldrich a syndrome), Bernard — Sulye and Mei — Hegglina are most studied (see Trombotsito-pati and).

Among isoimmune T. it is possible to allocate posttransfusion T., observed after transfusions of whole blood or trombotsitny weight (see Incompatibility immunological) and inborn T., edges usually arises in the presence at a fruit of platelet antigen of PIAI and absence it at mother (in population such persons make 2 — 5%). In a sensibilized organism of mother antithrombocytic antibodies are synthesized, to-rye get through a placenta and cause trombotsitoliz in a fruit. The disease is diagnosed at 1 on 5000 — 10 000 newborns. At isoimmune inborn T. during the first hours lives at the child appear petekhialny and melkopyatnisty hemorrhages on skin. At a heavy current there can be hemorrhages on mucous membranes, bleedings (nasal, umbilical, pulmonary), intracranial hemorrhages, a melena, and also a moderate splenomegaly. The disease lasts ©t 2 to 12 weeks, sometimes longer. The diagnosis the wedge, pictures and data establish on the basis a lab. researches, napr, a positive agglutination test of thrombocytes of the child in blood serum of mother (see. And gglt also on a tion).

Inborn transimmune T. is passing (tranzitorny) thrombocytopenia of the newborns who were born from mothers sick with a Werlhof's disease. It is observed at 30 — 50% of newborns, mothers to-rykh are ill a Werlhof's disease. The disease is connected with penetration of antithrombocytic autoantibodies of mother into an organism of a fruit. In half of cases usually in the first days of life of the child petechias, small ecchymomas on a back, a breast, konechn appearawns, hemorrhages on mucous membranes, nasal bleedings, a melena are more rare. Bleeding, as a rule, insignificant, but in some cases there can be intracranial hemorrhages. The diagnosis the wedge, pictures and data establish on the basis of the anamnesis, a lab. researches (in mother find antithrombocytic autoantibodies, and in the child and mother — lymphocytes, sensibilized to autotrombotsita). Recovery usually occurs in 5 — 12 weeks. In 1 — 3% of cases transition to a Werlhof's disease is noted.

Secondary, or symptomatic, T. at children develop more often than primary and can be observed during the acute period inf. diseases (it is especially frequent at perinatal viral infections), at the allergic states proceeding with hyperreactivity of immediate type; collagenoses and other autoimmune processes; at a syndrome of the disseminated intravascular coagulation; at diseases of system of blood (leukoses, hypoplastic and B12-scarce anemias); at the diseases which are followed by a splenomegaly and a hypersplenism, napr in connection with portal hypertensia at cirrhoses of a liver (see); at inborn hemangiomas (see) and disbolism, napr, diseases to Gosha (see Gosha a disease), Nimanna — Peak (see Nimann — Peak a disease).

Treatment of children, sick T., depends on genesis of a disease. Newborns with hard proceeding isoimmune forms T. during 2 weeks feed with donor breast milk, then put to a breast (control of number of thrombocytes in blood of the child is necessary). At other T. children are fed usually according to age; restrictions in the mode are necessary, as a rule, only in the period of hemorrhagic crisis.

At T. appoint aminocaproic acid on 0,05 — ODES of to 1 kg of weight 4 times the day and drugs improving adhesive agrega-tsionnuyu activity of thrombocytes (etamsylate, Adroxonum, pantothenate of calcium, ATP in combination with drugs of magnesium, phytotherapy). In the period of hemorrhagic crisis aminocaproic to - that needs to be entered intravenously, kapelno, 1 — 2 time a day. Corticosteroid therapy is shown at a generalized hemorrhagic syndrome, and also at hemorrhages in internals. Prednisolonum is applied within 3 — 4 weeks on 1,5 — 2 mg on 1 kg of weight a day with a further dose decline and drug withdrawal. At inefficiency of corticosteroid therapy the planned splenectomy is shown (see); the emergency splenectomy is made at hemorrhage in a brain. According to different researchers, approximately at 80% of the children sick with idiopathic T., the splenectomy leads to kliniko-hematologic remission or considerable reduction of bleeding. Existence at the patient of the spleniculus which is not removed during operation is the most frequent reason of a palindromia after a splenectomy. The splenectomy is undesirable at children up to 5 years (especially about one year) since it can lead to sensitization to an infection. At heavy hemorrhagic crisis resort to transfusion of trombotsitny weight.

At inborn isoimmune T. zamenny transfusions of whole blood of mother or injection of the trombotsitny weight allocated from blood of mother are effective. At hereditary (in particular hypoplastic) T. it is possible to make transplantation of marrow (see), compatible on antigens of the HLA system.

Bibliography: Barkagan 3. C. Hemorrhagic diseases and syndromes, M., 1980; Idelson JI. I. Autoimmune cytopenias, Rubbed. arkh., t. 51, No. 9, page 132, 1979; Mazurin A. V. A Werlhof's disease (Verl-gof's disease) at children, M., 1971; Father yan A. V. and Shabalov N. P. Hemorrhagic diathesis at children, L., 1982; The Guide to hematology, under the editorship of A. I. Vorobyov and Yu. I. Loriye, page 472, M., 1979; Savchenko V. G. The pathogeny and diagnostic methods of an idiopathic Werlhof's disease, Rubbed. arkh., t. 51, No. 9, page 122, 1979; McMillan R. Chronic idiopathic thrombocytopenic purpura, New Engl. J. Med., Y. 304, p. 1135, 1981; Ochs H. D. a. o. The Wiskott — Aldrich syndrome, studies of lymphocytes, granulocytes, and platelets, Blood, v. 55, p. 243, 1980; Weiss H. J. Congenital disorders of platelet function, Sem. Hemat., v. 17, p. 228, 1980.

JI. I. Idelson; A. V. Mazurin, H. P. Shabalov (ped.) .