Immunofluorescence study of immune complexes in polymyalgia rheumatica.

Two elderly patients with polymyalgia rheumatica (PMR), one with and the other without temporal arteritis (TA), are presented. Immunofluorescence study of muscle biopsy specimens showed IgG, IgA, and fibrinogen deposits in the perifascicular area in the perimysium. This finding suggests that immune complexes play a role in the pathogenesis of this condition and that the pathophysiology of PMR involves an interstitial inflammatory process.