Relationship between histological subtypes and clinical characteristics at presentation and outcome in biopsy-proven temporal arteritis. Identification of a relatively benign subgroup.

Temporal arteritis (TA) may offer major complications, whilst high dosage of prednisone may result in serious side effects. We tried to identify a subgroup of TA, which can be treated with a lower dosage of prednisone. Retrospectively, clinical and laboratory data were studied at presentation, as well as the outcome in 44 consecutive patients with biopsy-proven temporal arteritis. These data were related to three particular histological subgroups, (a) classical giant cell arteritis, (b) atypical arteritis, and (c) 'healed arteritis', defined according to Allsop and Gallagher (The American Journal of Surgical Pathology 5:317-332, 1981). At presentation in subgroup c, erythrocyte sedimentation rate was lower and the level of haemoglobin was higher than in the other two subgroups. During follow-up in the healed arteritis group, reactivation, recurrence, or early death were not observed, whilst prednisone dosage after 2 and 3 years was lower compared to subgroup b. Major complications (permanent blindness and cerebrovascular accident) were only observed in subgroups a and b. We believe that the healed arteritis subgroup represents a relatively benign subgroup with a mild clinical presentation and a good prognosis. Therefore, a much lower initial prednisone dosage (15 mg/day) is suggested for patients in subgroup c than in the other two subgroups (40-60 mg/day).