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

Macrophages represent a critical component in the inflammatory lesions of giant cell arteritis. By combining immunohistochemistry and in situ hybridization, we have analyzed the functional heterogeneity of tissue-infiltrating macrophages in patients with untreated vasculitis. 20% of macrophages in temporal artery tissue synthesized IL-6-specific mRNA and produced IL-6 and IL-1 beta proteins. IL-6 and IL-1 beta production was not limited to CD68+ cells in the lymphoid aggregates but was a feature of CD68+ cells dispersed throughout the tissue. 50% of tissue-infiltrating CD68+ cells synthesized 72-kD type IV collagenase. Only a small subset of CD68+ cells produced cytokines as well as collagenase, indicating functional specialization or distinct differentiation stages of CD68+ cells in the inflamed tissue. Activation of CD68+ cells was not restricted to tissue-infiltrating cells. Expression of IL-6 and IL-1 beta was found in 60-80% of circulating monocytes of patients with untreated giant cell arteritis, whereas collagenase production was restricted to tissue macrophages. IL-6 and IL-1 beta production by the majority of circulating monocytes was a shared feature of patients with giant cell arteritis and polymyalgia rheumatica but was not found in rheumatoid arthritis. These data suggest that giant cell arteritis has two components of disease, an inflammatory reaction in vessel walls and a systemic activation of monocytes. Systemic monocyte activation can manifest independently without vasculitis as exemplified in patients with polymyalgia rheumatica.
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PMID:Functional profile of tissue-infiltrating and circulating CD68+ cells in giant cell arteritis. Evidence for two components of the disease. 808 54

Giant cell arteritis (GCA) is a common disease in the elderly. It is characterized by focal inflammatory lesions dominated by T lymphocytes and macrophages. The etiology of GCA is, however, still unknown. The aim of the present study was to determine whether lesional T cells represent clonal proliferations, and to characterize adhesion receptors that could be important for recruitment of T cells and antigen receptors involved in their activation. Temporal artery biopsies were obtained from 13 patients presenting with clinical signs of GCA. Immunohistochemistry was used to characterize cell surface receptors on CD3+ T cells in situ in the lesions of eight patients with biopsy-verified GCA. The overwhelming majority of T cells in GCA lesions expressed the TCR alpha beta receptors. In sections from three of eight patients, a small proportion of cells expressing TCR gamma delta was also seen. Almost all T cells expressed the integrin receptors, LFA-1 and VLA-1, as determined by double-staining. To characterize the clonal composition of the lesional T cell population, cells were isolated by collagenase digestion of two lesions and T cells cloned by limiting dilution in the presence of mitogenic antibodies, IL-2 and autologous feeder cells. Rearrangements of the T cell receptor (TCR) genes of the clones were analysed by Southern hybridization using probes for TCR gamma and beta genes. T cell clones established from GCA lesions exhibited heterogeneous rearrangement patterns, indicating a polyclonal origin of the cells. We conclude that GCA lesions contain T lymphocytes that are of polyclonal origin and express integrin-type adhesion receptors. This supports the hypothesis that GCA involves an inflammatory response during which polyclonal T cells adhere to arterial tissue components and accumulate in the developing lesions.
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PMID:T lymphocytes in giant cell arteritic lesions are polyclonal cells expressing alpha beta type antigen receptors and VLA-1 integrin receptors. 838 21

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