Mechanisms of immune damage in XXXX .

@entity6875 @entity1 @entity2694 @entity137
We have studied the role of immunologically mediated @entity137 in the orbital tissue damage of @entity6875 . @entity137 ( @entity137 ) against eye muscle (EM) cells and @entity2694 ( @entity2694 ) was demonstrated in a small proportion of @entity1 , all of whom had severe, recent disease. Antibody-mediated (complement-dependent) @entity137 against @entity2694 was found in only a few @entity1 . No @entity1 showed lysis above background with EM targets. @entity137 activity against @entity2694 was absorbed by preincubation of serum with thyroid cells, eye muscle cells, and @entity2694 , as well as thyroid, eye muscle and orbital connective tissue membranes. Both EM and @entity2694 were able to express class II MHC HLA-DR antigens when stimulated by gamma interferon, phytohemagglutinin or activated T lymphocytes. DR-positive target cells were much more susceptible to lysis, in both @entity137 and lymphocyte-mediated @entity137 , than DR negative cells. When DR-positive @entity2694 and EM were used as targets in @entity137 assays, the degree of lysis determined as 51Cr release given by serum from @entity1 with @entity6875 was enhanced, but only in those @entity1 showing positive tests with DR-negative targets. Intrathyroidal T lymphocytes obtained from a @entity1 with @entity6875 were more cytotoxic against DR-positive @entity2694 and EM than equal numbers of her peripheral blood T lymphocytes. @entity137 and lymphocyte-mediated @entity137 against @entity2694 and eye muscle cells are thus associated with target cell HLA-DR antigen expression and are likely to be mechanisms for in vivo tissue damage in @entity6875 . The identity of the mononuclear cell subpopulation effecting cell-mediated @entity137 against orbital target cells, and the possible significance of reaction of cytotoxic antibodies against orbital, thyroid-shared antigens are unclear.
