How would you approach a rising PR3 in a patient with limited GPA who is currently asymptomatic on methotrexate?

This is an important question because ANCA testing is frequently used in the monitoring of disease activity in AAV. Unfortunately, ANCA is a much better diagnostic test than a disease activity biomarker. Multiple studies have looked at the utility of ANCA in monitoring disease activity finding that there is a modest correlation between ANCA rises and disease activity. For example, data from the RAVE trial demonstrated that an increase in PR3-ANCA elevated the risk of future relapse (HR 5) and th...