ABSTRACT
We present a case of an aged male with myeloperoxidase anti-neutrophil cytoplasmic autoantibody (MPO-ANCA)-associated vasculitis with onset of brain infarction that demonstrated immunohistochemically MPO-positive capillaries at autopsy. The patient initially presented with gait difficulty and right-sided weakness. Since an imaging study revealed brain infarction, he was admitted to our hospital and medicated by antiplatelet agents. Continuous fever and elevated serum C-reactive protein (CRP), hematuria of glomerular origin, renal dysfunction, and high serum titer of MPO-ANCA were detected. Systemic toxicoderma appeared, and skin biopsy revealed small-vessel vasculitis; thus, he was diagnosed with MPO-ANCA-associated vasculitis. Steroid therapy (methylprednisolone 30 mg/day) was started, and general status improved. However, he died of shock 6 days after the start of the therapy. Autopsy revealed massive retroperitoneal hemorrhage with necrotizing small-vessel vasculitis in systemic organs including retroperitoneum, skin, brain, testes, and kidneys. Immunohistochemically, infiltration of MPO-positive white blood cells into the capillaries was occasionally observed, along with the features of MPO-positive capillaries. Cerebrovascular involvement of MPO-ANCA-associated vasculitis is rare compared with renal and pulmonary manifestations, having been reported to occur in up to 4 % of patients. Furthermore, as we have recently reported, MPO-immunopositive capillaries may appear only during the hyperacute stage of the disease. Therefore, the present case represents the unique combination of these two rare manifestations.
ABSTRACT
We present a case of a middle-aged woman with myeloperoxidase anti-neutrophil cytoplasmic autoantibody (MPO-ANCA)-associated vasculitis that demonstrated immunohistochemically positive MPO capillaries of the pleura. The patient initially presented with proteinuria and microscopic hematuria at the age of 38. Acute progressive glomerulonephritis and pulmonary hemorrhage occurred 4 years later, and a high serum titer of MPO-ANCA was detected therefore a diagnosis of microscopic polyangiitis was made. Steroid-pulse therapy was performed and the pulmonary shadow improved, but the renal failure did not improve, thus, hemodialysis was initiated. Thereafter, an 18-year asymptomatic phase followed, but high serum levels of MPO-ANCA persisted during this period. Chronic pulmonary hemorrhage was discovered at the age of 60, and video-assisted thoracoscopic surgery was performed. Resected tissue revealed diffuse aloveolar hemorrhage accompanied by marked hemosiderin deposition, whereas MPO-immunopositive capillaries were identified only in the pleura. To our knowledge, this is the first report demonstrating MPO-positive capillaries in a disease other than glomerulonephritis. Judging from this unique case, MPO-positive endothelial cells may appear only during the hyperacute stage before hemorrhage, and may diminish thereafter, thus, may be associated with the trigger of microscopic polyangiitis.
