顯微性多血管炎（microscopic polyangitis）是一種影響全身中小型血管的壞死性發炎疾 病。臨床上，罹患該疾病病患常見腎絲球腎炎與肺微血管炎。非特異性症狀，包括發燒、 體重減輕與肌肉骨骼疼痛使這個疾病不易被診斷。顯微性多血管炎的治療，以醣質類固醇 與免疫抑制劑為主；接受合併治療約有 75%病患疾病可完全緩解，但仍有 50%病患在長期 後續追蹤中，疾病多次再發。對於治療反應不佳病患，以 cyclophosphamide  脈衝式治療， 被證實與傳統低劑量口服治療效果相當，並且有較少的嚴重不良反應。本文報告─76 歲男 性重症病患，呼吸衰竭與腎臟衰竭轉入加護病房，因為血清中出現抗骨髓過氧化 抗體而 被診斷顯微性多血管炎。因廣泛性肺出血，開始使用類固醇加上 cyclophosphamide  脈衝式 治療。Cyclophosphamide 脈衝式治療可以被用於罹患全身性威脅器官功能疾病病患，但因 這些病患感染與白血球低下風險較高，應該接受嚴密追蹤與適當處置。

Microscopic  polyangiitis  (MPA)  is  a  necrotizing  vasculitis  affecting  small  and  medium-sized arteries and venules. Clinically, glomerulonephritis and pulmonary capillaritis are common in patients with microscopic polyangiitis. Non-specific symptoms, including fever, weight loss, and musculoskeletal pain make diagnose of this disease is difficult. The mainstay of MPA treatment is combination of glucocorticoid  and  immunosupressant.  Patients  with  vasculitis  syndrome  who  had  undergone  this therapy showed that 75% achieved completed remission. Despite the dramatic remissions induced by this therapeutic regimen, long-term follow-up of these patients has revealed about 50% of remissions are later associated with one or more relapses. In refractory cases, efficacy of pulse cyclophosphamide was proved to be equivalent to low-dose oral therapy, and with much less severe toxic effects. We report a
76-year-old male, transferred to medical intensive care unit due to respiratory and renal failure. MPA was diagnosed on the basis of presence of myeloperoxidase anti-neutrophilic cytoplasmic antibodies in plasma. Glucocorticoids and pulse cyclophosphamide were started due to diffusive pulmonary hemorrhage. Pulse cyclophosphamide with oral glucocorticoids can be used to induce remission in patients with generalized organ-threatening diseases. Patients should be closely monitored because they have higher risks of infection and leukopenia.