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Query: UMLS:C0039483 (giant cell arteritis)
 3,204 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Giant cell arteritis (GCA) is a spontaneous vasculitic syndrome that specifically targets the walls of medium and large arteries. Vascular lesions are characterized by patchy granulomatous infiltrates composed of T cells, macrophages, histiocytes, and giant cells. To test the hypothesis that a locally residing antigen recruits T cells into the vessel walls, we have analyzed T cell receptor (TCR) molecules of tissue infiltrating T cells. A total of 638 CD4+ T cell clones were isolated from temporal artery specimens of three patients with GCA. Analysis of TCR molecules for the usage of V beta 1-V beta 20 revealed that all TCR V beta elements were represented, demonstrating that interleukin 2 (IL-2)-responsive T cells infiltrating the tissue are highly diverse. To detect expanded T cell specificities, we made use of the patchy character of the inflammatory disease and compared the TCR repertoire of T cells established from independent vasculitic foci of the same artery. Sequence analysis of TCR V beta chains documented that individual TCR specificities were present in multiple copies, indicating clonal expansion. T cells with identical beta chains were isolated from distinct inflammatory foci of the same patient. These specificities represented only a small fraction of tissue-infiltrating T cells and involved the V beta 5.3 gene segment in the two patients sharing the HLA-DRB1*0401 allele. The third complementarity determining region of clonally expanded TCR beta chains was characterized by a cluster of negatively and positively charged residues, suggesting that the juxtaposed antigenic peptide is charged. The sharing of identical T cell specificities by distinct and independent regions of the granulomatous inflammation suggests that these T cells are disease relevant and that their repertoire is strongly restricted. These data suggest that an antigen residing in the arterial wall is recognized by a small fraction of CD4+ T cells in the inflammatory process characteristic for GCA.
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PMID:Distinct vascular lesions in giant cell arteritis share identical T cell clonotypes. 811 87

Two inflammatory vascular diseases often show multinucleated macrophages: Takayasu's disease and Horton's disease. Takayasu's disease is a segmentary panarteritis most prominent in the adventitia. Lesions show an inflammatory infiltrate close to the external elastic lamina. Progressive stenosis of the artery, sometimes complicated by calcifying atheroma is the typical course. Horton's disease or temporal arteritis is another segmentary arteritis. Lesions show a mixed inflammatory infiltrate partly localized in the adventitia where there are T CD4+ lymphocytes secreting II-2 and IFN-gamma and also macrophages expressing TGF beta 1, IL-6 and IL-1 beta, and partly situated in the interior part of the wall, around the internal elastic lamina, and mostly made of macrophages and giant cells which produce TNF, collagenase and nitric oxide that are responsible for destruction of the wall. The variety and subtleness of some lesions do not always make a precise diagnosis possible. But any inflammatory vascular lesion, even slight, can reveal a systemic vasculitis.
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PMID:[Pathology of giant cell arteritis]. 992 94