Juvenile dermatomyositis (DMJ)

Juvenile dermatomyositis is a multisystem inflammatory disease in the target organs affected are the muscles, which presents a nesupurativ inflammation and skin type.
Juvenile dermatomyositis is different clinical and anatomical pathology of the adult form. Compared with other autoimmune diseases such as Henoch purpura Schönlein-, juvenile chronic arthritis (JRA), systemic lupus erythematosus (SLE) disease is lower freceventa. The incidence of this disease is higher in girls 0, 3-05/100. 000 children.
Etiology:
Juvenile dermatomyositis is an autoimmune disease of unknown etiology. Various experimental studies could not reveal any microorganism that is incriminated in the pathogenesis of disease is excluded as the etiology of viral or bacterial infectious nature. There are data that specifies the mechanisms of immune intervention in disease pathology. Presence of certain abnormalities in immune response control is suggestive for the involvement of cellular immunity in causing disease. Acetic demonstration was done for the next investigation. Thus, dermatomyositis was experimentally reproduced by transfer of lymphocytes sensitized. It was noted that patients with dermatomyositis lymphocytes incubated in normal muscles, autologous muscle cells secrete toxic limfokine. The reaction of patients with dermatomyositis T limfocitelot react as antigens as foreign to their own muscle.Can not tell whether immune deficiency is represented by the inability of T lymphocytes to recognize antigens own muscle or muscle antigen if the structure is similar to that of an antigen starin, unidentified.
Assumptions under which there would be involved in disease etiology and humoral immunity. He pointed to some patients present hipergamaglobulinemiei polyclonal, and 20% of cases are presented rheumatoid factor (RF) and ANA. In the vascular wall to reveal the presence of focal deposits of complement, Ig G and Ig M.Do not know the nature of the antigen that combines with immunoglobulins to achieve immune complexes. In patients with dermatomyositis occurring antibodies against striated muscle myoglobin purified from, they are considered specific antibodies and called MSA5 (Myositis-specific autoantibodies).
Of genetically juvenile dermatomyositis has not been Demonstration that it belongs to hereditary diseases, family. It was noted frequently coexisting histocompatibility antigen HLA DQA 1-0501. The carriers of this antigen is disease incidence rate of 11, 5%.
In terms of histopathological damage is associated with the vascular muscle. It is a thickening of the intima reamarca vascular wall, and the presence of perivascular mononuclear cell infiltrates. Vasculitis affecting small vessels, arterioles, venules, capillaries that irrigate the muscles and subcutaneous tissues. Thus, striated muscle loses its structure and areas of degeneration occurs, with interstitial edema and proliferation of connective tissue. The skin appears thickened areas of epidermis and dermis edema.Gastrointestinal vasculitis and stroke will cause mucosal tissue ulceration. During the chronic disease form calcium deposits, with areas of inflammation around.