C-reactive protein in giant cell (cranial, temporal) arteritis.

A controlled study of C-reactive protein in patients with and without temporal arteritis was performed. C-reactive protein was elevated in 10 of 11 patients with biopsy-proven temporal arteritis before treatment. It was positive in 14 of 32 control patients with negative temporal artery biopsies. This difference is statistically significant. C-reactive protein was elevated in 6 to 9 (depending on the adequacy of therapy) of 34 patients with temporal arteritis after corticosteroids were started. C-reactive protein and erythrocyte sedimentation rate are positively correlated in untreated arteritis. Clinical correlation showed C-reactive protein was more sensitive than the erythrocyte sedimentation rate in following the adequacy of corticosteroid dosages in temporal arteritis probably because many more noninflammatory factors influence erythrocyte sedimentation than influence C-reactive protein.