Study Methods & Results
Researchers retrospectively compared clinical, laboratory and pathological characteristics of 67 patients at the onset of PMR or peripheral arthritis, and their treatments and outcomes, to those of a random group of 65 patients with PMR or peripheral arthritis who did not develop late GCA. Researchers included patients with prior peripheral arthritis (isolated or with PMR) because peripheral arthritis is frequently associated with PMR and may sometimes form part of the rheumatic spectrum of GCA. Researchers also compared the characteristics and outcomes of patients with late GCA with those of a random sample of patients with more usual GCA (65 with concurrent PMR or peripheral arthritis and 65 without). The entire cohort of 132 patients with PMR or peripheral arthritis (67 late GCA patients and 65 controls) was followed for an average of 38.5 months.
Patients with late GCA represented 7.4% of all GCA patients in the hospital-based inception cohort. GCA was diagnosed an average of 27 months after PMR or peripheral arthritis. Permanent visual loss developed in 10 patients, including eight of 48 (17%) who developed cranial arteritis. Patients with either form of GCA—usual or late—experienced similar outcomes.
At disease onset, patients with late GCA and controls were indistinguishable, except for a higher proportion of women in the late GCA group. The groups were similar in terms of baseline erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels, as well as proportions of patients experiencing long-lasting remission, relapses and resistant PMR or peripheral arthritis.