Table 3.

Future direction of research regarding ANCA type in AAV.

Topic	Research Question
Genetics and Pathogenesis	• Can unique genetic risk factors be used to identify patients at risk of MPO- or PR3-ANCA+ AAV before the onset of clinical symptoms or findings?
Risk Factors	• Are there modifiable risk factors for AAV that differ according to ANCA type? • How do certain drugs induce an MPO-ANCA+ AAV?
Organ Involvement	• Why might fibrotic lung disease and bronchiectasis be more common in MPO-ANCA+ AAV? • Why is renal disease more severe at presentation in MPO-ANCA+ AAV? • Why does PR3-ANCA+ AAV tend to affect the upper airway more often?
Remission Induction	• Should remission induction treatment decisions be influenced by ANCA type? • Should clinical trials be powered to detect significant differences in treatment arms stratified by ANCA type?
Remission Maintenance	• Should maintenance strategies (continuous vs. tailored immunosuppression) be driven by ANCA type? • Does monitoring PR3- or MPO-ANCA+ titer predict flares depending on treatment strategy used?
Long-Term Outcomes	• Are MPO-ANCA+ patients at higher risk for chronic lung disease like pulmonary fibrosis or chronic respiratory symptoms? • Should cardiovascular disease risk be managed differently in patients who are MPO-ANCA+?