Polymyalgia rheumatica and giant cell arteritis: circulating immune complexes.

Circulating immune complexes (CIC) were detected in a large population of patients with polymyalgia rheumatica (PMR) alone, PMR-giant cell arteritis (GCA), and GCA alone. CIC were found in the majority of patients studied. A direct correlation was observed between levels of CIC material and the erythrocyte sedimentation rate. The presence of immune complexes in the sera of patients with these disorders do not have diagnostic significance but may play an important role in their pathogenesis.