[A new serologic reaction in patients with polymyalgia rheumatica and/or giant cell arteritis].

Fresh sera from patients with active polymyalgia rheumatica and/or giant cell arteritis are fixing the complement components C4 and C3 to structures of the medulla of rat kidney tissue as demonstrated by the indirect immunofluorescent technique. This PMR-associated reaction is also a useful tool in monitoring disease activity, as it becomes negative under effective treatment with steroids.