ANCA positive for?
Correct Answer: Wegener granulomatosis
Description: Antineutrophil cytoplasmic antibodiesAntineutrophil cytoplasmic antibodies (ANCA) are IgG antibodies directed against the cytoplasmic constituents of granulocytes and are useful in the diagnosis and monitoring of systemic vasculitis. Two common patterns are described by immunofluorescence: cytoplasmic fluorescence (c-ANCA), which is caused by antibodies to proteinase-3 (PR3); and perinuclear fluorescence (p-ANCA), which is caused by antibodies to myeloperoxidase (MPO) and other proteins such as lactoferrin and elastase. These antibodies are not specific for vasculitis and positive results may be found in autoimmune liver disease, malignancy, infection (bacterial and human immunodeficiency virus, HIV), inflammatory bowel disease, rheumatoid ahritis, SLE and pulmonary fibrosis. In granulomatosis with polyangiitis (also known as Wegener's granulomatosis (WG)), the vasculitis is characterised by granuloma formation, mainly affecting the nasal passages, airways and kidney. A minority of patients present with glomerulonephritis. The most common presentation of WG is with epistaxis, nasal crusting and sinusitis, but haemoptysis and mucosal ulceration may also occur. Deafness may be a feature due to inner ear involvement, and proptosis may occur because of inflammation of the retro-orbital tissue . This causes diplopia due to entrapment of the extra-ocular muscles, or loss of vision due to optic nerve compression. Disturbance of colour vision is an early feature of optic nerve compression. Untreated nasal disease ultimately leads to destruction of bone and cailage. Migratory pulmonary infiltrates and nodules occur in 50% of patients. Patients with WG are usually proteinase-3 (PR3) antibody-positive . Ref - Harrison's internal medicine 20e p
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