Microscopic Polyangiitis in a Patient with Diffuse Alveolar Hemorrhage and No Biochemical Renal Impairment

無臨床腎功能異常之顯微性多血管炎合併瀰漫性肺泡出血

丁文穎(Wen-Ying Ting) ； 林芳綺(Fang-Chi Lin) ； 賴信良(Shinn-Liang Lai)

《胸腔醫學》 30卷5期 (2015/10) Pp. 300-306

摘要

顯微性多血管炎是一種自體免疫疾病，其特徵為全身小血管發炎，且血清中存在抗嗜中性球細胞質抗體。在顯微性多血管炎，抗嗜中性球細胞質抗體引發的壞死性血管炎常常造成壞死性腎絲球腎炎以及肺部微血管炎。雖然急進性腎絲球腎炎是顯微性多血管炎最重要的臨床表現，但是肺部微血管炎造成的瀰漫性肺泡出血才是患者需要住院的主要原因。瀰漫性肺泡出血臨床症狀變異很大，可能只有胸部X光異常卻無症狀，也可能呼吸衰竭。及早診斷及時治療可以改善顯微性多血管炎患者的預後。我們報告一名44歲男性，住院主訴咳血一個月，尿液鏡檢發現血尿，生化檢查卻無明顯的腎功能異常。經由支氣管肺泡灌洗術發現瀰漫性肺泡出血，隨後抗嗜中性球細胞質抗體陽性，診斷為顯微性多血管炎。之後病人接受anti-CD20單株抗體rituximab治療，臨床症狀及胸部X光異常顯著改善。希望藉此病例提醒臨床醫師，凡疑似瀰漫性肺泡出血之病人，無論其腎功能是否有顯著異常，仍應將顯微性多血管炎列入鑑別診斷。

關鍵字

顯微性多血管炎 ； 抗嗜中性球細胞質抗體 ； 瀰漫性肺泡出血

並列摘要

Microscopic polyangiitis (MPA) is an autoimmune disease characterized by inflammation of the small vessels and the presence of circulating anti-neutrophil cytoplasmic antibodies (ANCA). Resulting from an injury orchestrated by ANCA, MPA usually manifests as necrotizing glomerulonephritis (GN) and necrotizing pulmonary capillaritis. The major clinical feature of MPA is rapidly progressive GN; however, diffuse alveolar hemorrhage (DAH) that originates from pulmonary capillaritis is often the main reason for hospitalization. The clinical presentation of DAH is highly variable, ranging from asymptomatic radiographic abnormalities to fatal respiratory failure. Some patients may experience a variable degree of hemoptysis, accompanied by dyspnea, chest tightness and anemia. Early diagnosis and prompt therapy will lead to a good prognosis for patients with MPA. We describe a 44-year-old male with MPA presenting with hemoptysis for 1 month. DAH was detected by the presence of numerous hemosiderin-laden alveolar macrophages in bronchoalveolar lavage. The renal function at diagnosis was normal though microscopic hematuria was observed. The patient was successfully treated with rituximab, a monoclonal chimeric antibody targeting CD20, a cellsurface protein expressed on B-lymphocytes.

並列關鍵字

microscopic polyangiitis ； anti-neutrophil cytoplasmic antibodies ； diffuse alveolar hemorrhage