MPO and anti-neutrophil cytoplasmic antibody-associated vasculitis: The true prevalence of clinically significant AAV in SSc is around 1.6%.2 Patients with SSc-AAV are more likely to be female,23 and more likely to be lcSSc (especially with MPO-ANCAvasculitis).2,22 There is increased prevalence of ATA in the overlapcohort (58.8%–77.7% compared to 20%–30% in SSc alone9), but other associated antibodies include anti-U1 RNP and anti-U3 RNP.2 However, given the rarity of SSc-AAV, the absolute numbers are stillextremely low.