Nada A K, Torres V E, Ryu J H, Lie J T, Holley K E
Division of Nephrology and Internal Medicine, Mayo Clinic, Rochester, MN 55905.
Mayo Clin Proc. 1990 Jun;65(6):847-56. doi: 10.1016/s0025-6196(12)62575-0.
Between 1978 and 1988, three patients at our institution had an initial diagnosis of idiopathic pulmonary fibrosis but later were correctly diagnosed as having pulmonary-renal syndrome and microscopic polyarteritis. These cases involved elderly patients with progressive dyspnea and nonproductive cough, bilateral dry crackling rales, bilateral interstitial infiltrates evident on a chest roentgenogram, and restrictive findings on pulmonary function testing. In two patients, lung biopsy specimens were obtained, and an initial diagnosis of nonspecific pulmonary fibrosis was made. All three patients eventually had microhematuria and renal insufficiency. A revised diagnosis of small-vessel pulmonary-renal vasculitis was based on the demonstration of segmental necrotizing glomerulonephritis in renal biopsy specimens in two patients, thrombotic microangiopathy consistent with healed vasculitis on postmortem examination of the kidney in one patient, and subsequent detection of small-vessel vasculitis on review of the two lung biopsy specimens. Anti-neutrophil cytoplasmic antibodies with perinuclear staining on indirect immunofluorescence microscopy were positive in the two patients in whom determinations were performed. The clinical manifestations of vasculitis were notably scarce--no involvement of the skin, nervous system, or gastrointestinal tract; no episodes of fever; and minimal or absent musculoskeletal symptoms. These cases illustrate the importance of a high index of suspicion for the diagnosis of systemic vasculitis in elderly patients and the need to consider a vasculitis in the differential diagnosis of idiopathic pulmonary fibrosis, especially if an active urinary sediment is present.
1978年至1988年间，我院有3例患者最初被诊断为特发性肺纤维化，但后来被正确诊断为肺肾综合征和显微镜下多动脉炎。这些病例涉及老年患者，有进行性呼吸困难和干咳、双侧干性啰音、胸部X线片显示双侧间质浸润以及肺功能测试显示限制性改变。其中2例患者获取了肺活检标本，最初诊断为非特异性肺纤维化。所有3例患者最终均出现镜下血尿和肾功能不全。修订后的诊断为小血管肺肾血管炎，依据为2例患者肾活检标本显示节段性坏死性肾小球肾炎，1例患者肾脏尸检显示符合愈合性血管炎的血栓性微血管病，以及对2例肺活检标本复查后发现小血管血管炎。2例进行检测的患者间接免疫荧光显微镜检查显示核周型抗中性粒细胞胞浆抗体阳性。血管炎的临床表现明显缺乏——未累及皮肤、神经系统或胃肠道；无发热发作；肌肉骨骼症状轻微或无。这些病例说明了对老年患者系统性血管炎诊断保持高度怀疑的重要性，以及在特发性肺纤维化的鉴别诊断中考虑血管炎的必要性，特别是当出现活动性尿沉渣时。
