Sinclair D, Saas M, Stevens J M
Department of Chemical Pathology, Queen Alexandra Hospital, Portsmouth PO6 3 LY, UK.
J Clin Pathol. 2004 Feb;57(2):131-4. doi: 10.1136/jcp.2003.8052.
Most positive antineutrophil cytoplasmic antibody (ANCA) results are associated with non-vasculitic conditions, and guidelines have been proposed for the judicious use of this test. The outcome of applying similar guidelines in a routine laboratory is reported.
All immunology requests (6500) over six months were selected, and those requesting ANCA were studied for the appropriateness of the clinical data supporting the request, the presence of ANCA in those samples tested, and the final diagnosis. Antibodies were detected by indirect immunofluorescence.
ANCA testing was requested in 287 samples. Application of a "gating policy", which refuses analysis on requests that are not supported by clinical data suggestive of systemic vasculitis, made clinicians more selective about the patients for whom they requested ANCA testing. The percentage of "appropriate" screens for systemic vasculitis was relatively high (212 of 287 requests: 72.5%). Only one of the remainder, for whom ANCA testing was initially refused, developed an ANCA related systemic vasculitis in the two years after the study, but the delay in reporting her positive ANCA was only two days. Most of the samples tested were negative (155 of 212), but most (42 of 57) of the patients with positive ANCA results were found to have a systemic vasculitis.
A gating policy to select requests supported by clinical data suggestive of systemic vasculitis makes ANCA testing more clinically relevant and cost effective. Studies where guidelines can be proposed and their effects measured are important in the light of clinical governance and evidence based medicine.
大多数抗中性粒细胞胞浆抗体（ANCA）检测结果呈阳性与非血管炎疾病相关，并且已经提出了合理使用该检测的指南。本文报告了在常规实验室应用类似指南的结果。
选取六个月内所有的免疫学检测申请（6500份），对申请ANCA检测的样本，研究其支持检测申请的临床数据的恰当性、检测样本中ANCA的存在情况以及最终诊断结果。通过间接免疫荧光法检测抗体。
287份样本申请了ANCA检测。应用“筛选策略”，即拒绝分析那些没有提示系统性血管炎临床数据支持的检测申请，使得临床医生在申请ANCA检测的患者选择上更加具有选择性。针对系统性血管炎的“恰当”筛查比例相对较高（287份申请中有212份：72.5%）。其余最初被拒绝进行ANCA检测的患者中，只有一人在研究后的两年内发生了与ANCA相关的系统性血管炎，但报告其ANCA阳性的延迟仅为两天。大多数检测样本为阴性（212份中有155份），但ANCA检测结果呈阳性的患者中大多数（57份中有42份）被发现患有系统性血管炎。
采用筛选策略选择有提示系统性血管炎临床数据支持的检测申请，可使ANCA检测在临床上更具相关性且更具成本效益。鉴于临床治理和循证医学，能够提出指南并衡量其效果的研究很重要。
