Objectives: To examine the frequency and features of patients with biopsy-negative giant cell arteritis (GCA), establish differences with biopsy-proven GCA, and identify the optimal set of predictors for a positive temporal artery biopsy (TAB) in patients with GCA.
Methods: Retrospective study of an unselected population of patients with GCA diagnosed at the reference hospital for a defined population between 1981 and 1998. Patients were classified into biopsy-proven GCA if a TAB was positive for GCA, or biopsy-negative GCA if they fulfilled the American College of Rheumatology 1990 criteria for the classification of GCA (Hunder GG, et al Arthritis Rheum 1990; 33:1122-8) despite having a negative TAB.
Results: One hundred ninety Caucasian patients were diagnosed with GCA. Twenty-nine of them (15.3%) had a negative TAB. In these biopsy-negative patients, headache and polymyalgia rheumatica were frequent presenting symptoms. In contrast, jaw claudication, abnormal temporal artery on physical examination, and constitutional syndrome (asthenia, anorexia, and weight loss of 4 kg or more) were less common. They also had lower biologic markers of inflammation. The best predictive model of biopsy-proven GCA included a history of constitutional syndrome (OR = 6.1), an abnormal temporal artery on physical examination (OR = 3.2), and the presence of visual complications (OR = 4.9).
Conclusions: In GCA, a subset of patients have a high likelihood of having a negative TAB. This subset seems to have less severe ischemic complications than that of biopsy-proven GCA. In patients without visual manifestations, abnormal temporal artery on examination or constitutional syndrome the risk of having an abnormal TAB is low.