Cellular immunity in polymyalgia rheumatica and giant cell arteritis: lack of response to muscle or artery homogenates.

Peripheral blood lymphocyte functions were evaluated in 20 patients with active polymyalgia rheumatica (PMR) and/or giant cell arteritis (GCA) by determining the percent of E-rosette-forming cells and by measuring the uptake of tritiated thymidine by peripheral blood lymphocytes after exposure to common infectious antigens and to homogenates of homologous and heterologous artery, muscle, and elastin. Although lymphocytes from patients with PMR and/or GCA were stimulated slightly by artery and muscle homogenates, no differences in lymphocyte responses were found when the results were compared with 22 normal controls and 16 patients with rheumatoid arthritis. The hypothesis that GCA results from a cellular immune reaction to normal or diseased arterial wall antigens is not supported by these studies.