Search

Objective: To develop and validate updated classification criteria for giant cell arteritis (GCA). Methods: Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 6 phases: 1) identification of candidate items, 2) prospective collection of candidate items present at the time of diagnosis, 3) expert panel review of cases, 4) data‐driven reduction of candidate items, 5) derivation of a points‐based risk classification score in a development data set, and 6) validation in an independent data set. Results: The development data set consisted of 518 cases of GCA and 536 comparators. The validation data set consisted of 238 cases of GCA and 213 comparators. Age ≥50 years at diagnosis was an absolute requirement for classification. The final criteria items and weights were as follows: positive temporal artery biopsy or temporal artery halo sign on ultrasound (+5); erythrocyte sedimentation rate ≥50 mm/hour or C‐reactive protein ≥10 mg/liter (+3); sudden visual loss (+3); morning stiffness in shoulders or neck, jaw or tongue claudication, new temporal headache, scalp tenderness, temporal artery abnormality on vascular examination, bilateral axillary involvement on imaging, and fluorodeoxyglucose–positron emission tomography activity throughout the aorta (+2 each). A patient could be classified as having GCA with a cumulative score of ≥6 points. When these criteria were tested in the validation data set, the model area under the curve was 0.91 (95% confidence interval [95% CI] 0.88–0.94) with a sensitivity of 87.0% (95% CI 82.0–91.0%) and specificity of 94.8% (95% CI 91.0–97.4%). Conclusion: The 2022 American College of Rheumatology/EULAR GCA classification criteria are now validated for use in clinical research. [ABSTRACT FROM AUTHOR]

Objective: To develop and validate new classification criteria for Takayasu arteritis (TAK). Methods: Patients with vasculitis or comparator diseases were recruited into an international cohort. The study proceeded in 6 phases: 1) identification of candidate criteria items, 2) collection of candidate items present at diagnosis, 3) expert panel review of cases, 4) data‐driven reduction of candidate items, 5) derivation of a points‐based classification score in a development data set, and 6) validation in an independent data set. Results: The development data set consisted of 316 cases of TAK and 323 comparators. The validation data set consisted of an additional 146 cases of TAK and 127 comparators. Age ≤60 years at diagnosis and imaging evidence of large‐vessel vasculitis were absolute requirements to classify a patient as having TAK. The final criteria items and weights were as follows: female sex (+1), angina (+2), limb claudication (+2), arterial bruit (+2), reduced upper extremity pulse (+2), reduced pulse or tenderness of a carotid artery (+2), blood pressure difference between arms of ≥20 mm Hg (+1), number of affected arterial territories (+1 to +3), paired artery involvement (+1), and abdominal aorta plus renal or mesenteric involvement (+3). A patient could be classified as having TAK with a cumulative score of ≥5 points. When these criteria were tested in the validation data set, the model area under the curve was 0.97 (95% confidence interval [95% CI] 0.94–0.99) with a sensitivity of 93.8% (95% CI 88.6–97.1%) and specificity of 99.2% (95% CI 96.7–100.0%). Conclusion: The 2022 American College of Rheumatology/EULAR classification criteria for TAK are now validated for use in research. [ABSTRACT FROM AUTHOR]