Rheumatoid Arthritis Support

The vessels with HEV characteristics appear in human tissue in association with long-standing chronic inflammation. In rheumatoid arthritis, it has been observed that the level of sulfate incorporation as well as the ‘plumpness’ (or ‘tallness’) of the endothelium in areas of lymphocytic infiltration in the synovial membrane are closely related to the concentration of the lymphocytes in the perivascular infiltrates. Similarly, expression o MECA-79 and HECA-452 on these vessels is most pronounced in association with extensive lymphoid infiltrates. Therefore, the development of bona fide HEVs in the synovial membrane of patients with rheumatoid arthritis is likely to facilitate large-scale influx of lymphocytes, leading to amplification and maintenance of chronic inflammation. The development of HEVs after prolonged inflammatory stimulus is not restricted to diseased synovium, but can also occur in other tissues, particularly the gut and thyroid. During chronic inflammation of the gut in inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) or the thyroid in autoimmune thyroiditis (Graves’ disease and Hashimoto’s thyroiditis), areas of dense lymphocytic infiltration contain vessels with plump endothelium expressing MECA-79 and HECA-452. These observations suggest that HEVs could play an important role in the pathogenesis of these diseases by mediating abnormal lymphocyte recruitment to the gut or the thyroid. MECA-79+ venules with plump endothelium have also been detected in other sites of chronic inflammation, including many cutaneous inflammatory lesions. The presence of MECA-79+ HEV-like vessels in many different human chronic inflammatory diseases indicates that L-selectin is likely to play a major role in lymphocyte emigration at chronic inflammatory sites.


Adapted from the Wikipedia article High endothelial venules, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki