CASE REPORT A 40-year-old man with Hepatitis C and a history of cocaine abuse presented with multiple stages of painful rashes on his extremities and ears. On examination, the patient had several areas of purpuric macules and retiform purpura to his legs and ears (Figures 1 and 2), as well as large ulcerations with erythematous borders on bilateral lower extremities (Figure 3). Laboratory studi...

OBJECTIVES Recently published findings suggested that antineutrophil cytoplasmic antibodies (ANCA), particularly those with a cytoplasmic (C-ANCA) labelling pattern and targeting proteinase 3 (anti-PR3), might be markers of tuberculosis (TB). This is a critical issue, because C-ANCA/anti-PR3 were considered to be a highly specific hallmark of Wegener's granulomatosis or microscopic polyangiitis...

BACKGROUND Neutrophil recruitment into glomerular tissues and reduced capillary wall integrity has been implicated in the development of vasculitic glomerulonephritis (VGN). This study investigated the stages and mechanisms through which neutrophil serine proteases (SPs), proteinase 3 (PR3) or elastase contribute to endothelial dysfunction. METHODS Protease-induced damage to endothelium and a...

BACKGROUND Subacute bacterial endocarditis (SBE) occasionally exhibits positive cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA) of the anti-proteinase-3 (PR-3) type. Clinically, it mimics ANCA-associated vasculitis, such as Wegener's disease with glomerulonephritis. Lung abscesses are the most common manifestation of lung involvement. We herein report a case of culture-negative SBE st...

Two important cytokines mediating inflammation are tumor necrosis factor alpha (TNFalpha) and IL-1beta, both of which require conversion to soluble forms by converting enzymes. The importance of TNFalpha-converting enzyme and IL-1beta-converting enzyme in the production of circulating TNFalpha and IL-1beta in response to systemic challenges has been demonstrated by the use of specific convertin...

The aim of this study was to investigate the inhibitory effects of human leukocyte elastase (HLE), cathepsin G (Cat G), and proteinase 3 (PR3) on the activation of endothelial cells (ECs) and platelets by thrombin and to elucidate the underlying mechanisms. Although preincubation of ECs with HLE or Cat G prevented cytosolic calcium mobilization and prostacyclin synthesis induced by thrombin, th...

Protease-activated receptors (PARs) compose a family of G protein-coupled receptors activated by proteolysis with exposure of their tethered ligand. Recently, we reported that a neutrophil-derived serine proteinase, proteinase 3 (PR3), activated human oral epithelial cells through PAR-2. The present study examined whether other neutrophil serine proteinases, human leukocyte elastase (HLE), and ...

A 77-year-old man developed severe renal insufficiency due to proteinase 3 anti-neutrophil cytoplasmic antibody (PR3-ANCA)-associated vasculitis, and was started on hemodialysis (HD). Because his renal insufficiency appeared to be irreversible, he was maintained on oral prednisolone (PSL) at 5 mg/day. However, a disease flare-up with alveolar hemorrhage occurred. Serology revealed elevated leve...

Anti-neutrophil cytoplasmic antibodies (ANCA) are a group of autoantibodies, predominantly IgG, involved in the pathogenesis several autoimmune disorders, detected either through indirect immunofluorescence or enzyme-linked immunosorbent assay. By means immunofluorescence, main patterns C-ANCA (cytoplasmic) and P-ANCA (perinuclear), while proteinase 3 (PR3) myeloperoxidase (MPO) represent autoa...