MPO and Hypertension: Additionally, the adjusted odds of kidney involvement were 2.4 (95% CI 1.3 to 4.7, p=0.008) times higher in participants who were seropositive for MPO-ANCA versus PR3-ANCA, which was attributable to certain clinical manifestations, specifically hypertension, proteinuria and haematuria/the presence of RBC casts.