A 43-year-old man is hospitalized with recent-onset oliguria and a high serum creatinine level. He has been seen in clinic several times for an intranasal ulcer that has failed to heal. This patient's condition is most likely associated with antibodies against which of the following?

Question

A 43-year-old man is hospitalized with recent-onset oliguria and a high serum creatinine level.  He has been seen in clinic several times for an intranasal ulcer that has failed to heal.  This patient's condition is most likely associated with antibodies against which of the following?

Quizplus · Accepted Answer

Nasal mucosal ulcerations and glomerulonephritis are most characteristic of granulomatosis with polyangiitis (Wegener). Cytoplasmic-staining antineutrophil cytoplasmic antibodies (c-ANCAs) are virtually pathognomonic for granulomatosis with polyangiitis, with a better than 90% specificity and sensitivity. Proteinase 3-ANCA (also known as c-ANCA) may also be useful as a quantitative measure of disease activity. (Choice A) Goodpasture syndrome is sometimes called anti-glomerular basement membrane (GBM) antibody disease. Presenting clinical manifestations of Goodpasture syndrome are hemoptysis, radiographic focal pulmonary consolidations, and a glomerulonephritis that may rapidly progress to renal failure. Upper respiratory tract ulceration is not characteristic. (Choice B) Smooth muscle cell antibodies are commonly seen in patients with autoimmune hepatitis. (Choice D) Antierythrocyte antibodies can produce hemolysis of an intravascular and/or extravascular type. Hemoglobinemia from intravascular hemolysis can end in acute renal failure, although this is predominantly seen after transfusion reactions only when other conditions, such as hypovolemia and/or acidemia, coexist. Hemolytic anemia would not cause isolated ulceration of mucosa. (Choice E) Platelet antibodies can often cause thrombocytopenia by binding to platelets. Neither these autoantibodies, nor thrombocytopenia is known to cause acute renal failure. (Choice F) Antimitochondrial antibodies are seen in primary biliary cholangitis (cirrhosis). Educational objective: Necrotizing vasculitis of the upper and lower respiratory tract (causing nasal ulcerations, sinusitis, hemoptysis) and rapidly progressive glomerulonephritis-producing a variable degree of renal failure-is characteristic of granulomatosis with polyangiitis (Wegener). This disease is associated with C-ANCAs, which may target neutrophil proteinase 3.

A 43-Year-Old Man Is Hospitalized with Recent-Onset Oliguria and a High