Kitching A Richard, Hutchinson Paul, Atkins Robert C, Holdsworth Stephen R
Centre for Inflammatory Diseases, Monash University Department of Medicine, Monash Medical Centre, Clayton, Victoria, Australia.
Nephrol Dial Transplant. 2004 Feb;19(2):365-70. doi: 10.1093/ndt/gfg553.
Most cases of pauci-immune crescentic glomerulonephritis (PICGN) are associated with serum anti-neutrophil cytoplasmic antibodies (ANCA). This article studied the sensitivity and specificity of serum ANCA, determined by flow cytometry and indirect immunofluorescence (IIF), to identify patients with acute PICGN.
577 adults presenting for first biopsy of their native kidneys with serum taken for ANCA (flow cytometry and IIF) determination were studied. A positive ANCA was defined using a flow cytometric ANCA assay as a screening test, followed by a slide-based indirect IIF technique. Pathological confirmation of acute PICGN was used to assess the sensitivity and specificity of this combined approach and its positive predictive value (PPV) and negative predictive value (NPV) in patients presenting for renal biopsy due to abnormal urinary sediment.
Forty-nine patients were found to have acute PICGN on renal biopsy. Of these 47 were ANCA positive (sensitivity 95.9%). Overall 93 of the renal biopsy patients were ANCA positive, (specificity 91.3%). A further seven patients (two ANCA positive) had advanced sclerosing disease consistent with PICGN but without evidence of current disease activity. The PPV and NPV of ANCA, assessed by flow cytometry and slide IIF, in predicting that patients presenting with undifferentiated renal disease would have acute PICGN was 50.5 and 99.8%, respectively.
Flow cytometric screening of serum for ANCA in patients undergoing renal biopsy has a high NPV for determining those with acute PICGN. It may provide a rapid, simple screening test for this lesion in laboratories using diagnostic flow cytometry and may complement IIF/ELISA in evaluating ANCA positive patients.
大多数寡免疫性新月体性肾小球肾炎（PICGN）病例与血清抗中性粒细胞胞浆抗体（ANCA）相关。本文研究了通过流式细胞术和间接免疫荧光法（IIF）检测血清ANCA以识别急性PICGN患者的敏感性和特异性。
对577例首次进行肾活检并采集血清用于ANCA（流式细胞术和IIF）检测的成年人进行了研究。使用流式细胞术ANCA检测作为筛查试验来定义ANCA阳性，随后采用基于玻片的间接IIF技术。急性PICGN的病理确诊用于评估这种联合方法在因尿沉渣异常而进行肾活检的患者中的敏感性、特异性及其阳性预测值（PPV）和阴性预测值（NPV）。
49例患者经肾活检确诊为急性PICGN。其中47例ANCA阳性（敏感性95.9%）。总体而言，93例肾活检患者ANCA阳性（特异性91.3%）。另外7例患者（2例ANCA阳性）患有与PICGN一致的晚期硬化性疾病，但无当前疾病活动的证据。通过流式细胞术和玻片IIF评估的ANCA在预测未分化肾病患者患有急性PICGN方面的PPV和NPV分别为50.5%和99.8%。
对接受肾活检的患者进行血清ANCA的流式细胞术筛查在确定急性PICGN患者方面具有较高的NPV。它可为使用诊断流式细胞术的实验室提供一种快速、简单的针对该病变的筛查试验，并且在评估ANCA阳性患者时可补充IIF/ELISA。
