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Erythrocyte aplasia

This disease meets less than aplastic anemia, but its chronic form is especially often observed at elderly persons. Etiological classification of a chronic form of an erythrocyte aplasia is provided in the table. Refractory normokhromny anemia without such symptoms of aplastic anemia as the raised bleeding is characteristic of it. Poorly expressed splenomegaly can take place. At secondary forms of an erythrocyte aplasia signs of defeat of connecting fabric, lymphoma symptoms, etc. can be observed. Communication of an erythrocyte aplasia with a thymoma, especially at women is firmly proved. The picture of blood is characterized by sharply expressed reticulocytopenia without any disturbances granulo-and a thrombocytopoiesis. In marrow which cellularity is often normal either total absence of erythroblasts, or a small number of proerythroblasts is found. The marrowy lymphocytosis is sometimes noted. At immunological research can come to light hypo - or a hypergammaglobulinemia; sometimes antibodies to erythrocytes and paraproteins are found.

Clinical classification of a chronic erythrocyte aplasia

Idiopathic
allegedly autoimmune genesis *
the pathogeny is not clear
Connected with:
thymoma *
autoimmune disease * (for example, system lupus erythematosus, autoimmune hemolitic anemia, thyroiditis, etc.)
cancer *, lymphoma *, myeloma
drugs?
preleukemic dysplasias
heavy food deficit

* At some patients humoral autoantibodies to erythroidal cells and erythropoetin are revealed. In a small number of cases also limfotsitotoksichesky antibodies are found. It is remarkable that the chronic renal failure though is followed by hemopoiesis suppression, seldom leads to morphologically expressed erythroidal aplasia.

Pathogeny

The acute self-limited erythrocyte aplasia occurs generally at children and young adults and is caused probably by an infection parvoviruses. At people 50 years are more senior this syndrome often is characterized by slow development and a tendency to transition to a chronic form, though cases of spontaneous remission meet. Sometimes the clonal disturbance caused by a mutation of a stem hemopoietic cell is the cornerstone of the specified pathology and patients of this group months or years later can have a miyeloblastny leukosis. Generally erythroidal sprout is surprised, however at a blood analysis and marrow symptoms of a granulotsitarny and megakariotsitarny dysplasia often come to light, and there can be other forms of cytopenias later.

Chromosomal anomalies also demonstrate existence of a preleukosis. This form of an erythrocyte aplasia is not exposed to spontaneous remission. Other big group of chronic cases is a consequence of autoimmune disorders of cells of an erythroidal row. Experimental data demonstrate that suppression of an erythrogenesis in some cases is caused by antibodies or cell-bound immune complexes. Sometimes a target for the IgG-antibodies which are attached to a cellular surface are erythroblasts; occasionally as antigen erythropoetin acts.

The hemopoiesis oppression mediated by cellular immune mechanisms is described. Other clinical or serological signs of autoimmune disorders, for example the positive skin test for hypersensitivity of the slowed-down type or antibodies to unstriated muscles can be found in such patients. The specified syndrome can be also observed within such limfoproliferativny diseases as a chronic lymphoid leukosis, a nekhodzhkinsky lymphoma and a myeloma. The mechanism of communication of an erythrocyte aplasia with a thymoma described many years ago remains not clear; approximately in 50% of cases of an erythrocyte aplasia came to light as well a thymoma. The most probable explanation consists in that, as the tumor, and anemia are secondary phenomena in relation to chronic immunological disturbances; the thymus gland tumor usually precedes development of an erythrocyte aplasia, and after surgical removal of a thymoma in some cases there comes remission of an aplasia.

Treatment of an erythrocyte aplasia

As well as at other cytopenias it is necessary to identify and whenever possible to eliminate an exogenous factor to which influence the patient is exposed. It is supposed that the erythrocyte aplasia is caused by a number of medicines, including many of those which are the reason of aplastic anemia. In the presence of indirect clinical or serological certificates of the autoimmune nature of an illness it is possible to try to resort to immunodepressive therapy. The thymoma whenever possible should be removed in the surgical way as at 30% of the operated patients there comes remission and according to some information immunodepressive therapy appears more effective after a thymectomy. Sometimes androgens give good effect, and after achievement of remission the maintenance therapy is not required.

Use various forms of immunodepressive therapy. At a small number of patients corticosteroids give good effect, but usually happens it is necessary to use cytotoxic drugs like Cyclophosphanum (150 mg a day) or such antimetabolites as Azathioprinum (100 mg a day). These drugs inevitably cause a miyelodepressiya of this or that degree. Occasionally remission came after use of anti-lymphocytic globulin in the form of an independent course or after chemotherapy. There are casuistic messages on remission after a plasma exchange, occasionally effective is a splenectomy.

 
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