Validation of the 2022 American College of Rheumatology/EULAR classification criteria for Takayasu arteritis.

Objectives: The present study validates the 2022 ACR/European Alliance of Associations for Rheumatology (EULAR) classification criteria for Takayasu's arteritis (TAK), compared with the 1990 ACR TAK classification criteria.

Methods: The fulfilment of 2022 ACR/EULAR and 1990 ACR TAK criteria from four referral centres was assessed for TAK compared with extracranial giant cell arteritis (EC-GCA) and other controls. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), likelihood ratio of a positive test (LR+) or negative test (LR-), and area under receiver operating characteristics curve (AUC) were calculated.

Results: Among 504 patients with TAK (404 females) and 222 controls (151 females, 144 patients with EC-GCA), the 2022 ACR/EULAR criteria had better sensitivity (95.83% vs 82.94%) and NPV, but poorer specificity (63.51% vs 90.54%), PPV, LR+, LR- and AUC at the pre-determined cut-offs than the 1990 ACR criteria. The 2022 ACR/EULAR criteria had greater specificity (76.06% vs 57.62%) and AUC (0.845 vs 0.771), with similar sensitivity (93% vs 96.53%) in males as in females. The 2022 ACR/EULAR criteria performed similarly with only EC-GCA as controls (sensitivity 95.83%, specificity 60.42%, AUC 0.781). Sensitivity remained similar, whereas specificity was higher for 40-60 years vs <40 years. Cut-offs of ≥6 (sensitivity 91.87%, specificity 82.88%) and ≥7 (sensitivity 86.71%, specificity 86.49%), or removing the point for female sex (sensitivity 92.64%, specificity 81.08%) greatly improved the balance between sensitivity and specificity.

Conclusion: The poor specificity of the 2022 ACR/EULAR TAK criteria in real-life settings was improved by increasing the cut-off to 6 or 7, or removing the point for female sex.