Myeloperoxidase ANCA is more common than proteinase-3 ANCA, and glomerulonephritis is the most common clinical presentation of ANCA-associated vasculitis in SSc.
The ratio between PR3-ANCA and MPO-ANCA varies in glomerulonephritis with respect to age, gender, renal function and geographic latitude/UV radiation levels.
Patients with PR3- as compared to MPO-ANCA were younger (58 versus 64 years, <i>p</i> = 0.001), had a higher percentage of males (62 versus 41%, <i>p</i> < 0.001), had a lower percentage with a sclerozing glomerulonephritis pattern (4 versus 16%, <i>p</i> < 0.001), and had a significantly higher cumulative ESRD-free survival (90 versus 80%, <i>p</i> = 0.007) at 1-year follow-up.