MPO and systemic sclerosis: COVID-19 = coronavirus disease 2019; HTN = hypertension; DM = diabetes mellitus; NA = not available; SSC = systemic sclerosis; HF = heart failure; IHD = ischemic heart disease; OM = otitis media; M = male; F = female; AKI = acute kidney injury; GN = glomerulonephritis; AIN = acute interstitial nephritis; fGN = fibrous glomerulonephritis; ATN = acute tubular necrosis; NR: not reported; ANCA = antineutrophil cytoplasmic antibody; p-ANCA = perinuclear antineutrophil cytoplasmic antibody; MPO-ANCA = myeloperoxidase antineutrophil cytoplasmic antibody; PEX = plasma exchange