Centro de Pesquisas Aggeu Magalhães, FIOCRUZ, Recife, Pernambuco, Brazil.
J Immunol Methods. 2013 Jan 31;387(1-2):245-53. doi: 10.1016/j.jim.2012.11.002. Epub 2012 Nov 8.
The aim of this study was to compare the techniques of indirect immunofluorescence assay (IFA) and flow cytometry to clinical and laboratorial evaluation of patients before and after clinical cure and to evaluate the applicability of flow cytometry in post-therapeutic monitoring of patients with American tegumentary leishmaniasis (ATL). Sera from 14 patients before treatment (BT), 13 patients 1 year after treatment (AT), 10 patients 2 and 5 years AT were evaluated. The results from flow cytometry were expressed as levels of IgG reactivity, based on the percentage of positive fluorescent parasites (PPFP). The 1:256 sample dilution allowed us to differentiate individuals BT and AT. Comparative analysis of IFA and flow cytometry by ROC (receiver operating characteristic curve) showed, respectively, AUC (area under curve)=0.8 (95% CI=0.64-0.89) and AUC=0.90 (95% CI=0.75-0.95), demonstrating that the flow cytometry had equivalent accuracy. Our data demonstrated that 20% was the best cut-off point identified by the ROC curve for the flow cytometry assay. This test showed a sensitivity of 86% and specificity of 77% while the IFA had a sensitivity of 78% and specificity of 85%. The after-treatment screening, through comparative analysis of the technique performance indexes, 1, 2 and 5 years AT, showed an equal performance of the flow cytometry compared with the IFA. However, flow cytometry shows to be a better diagnostic alternative when applied to the study of ATL in the cure criterion. The information obtained in this work opens perspectives to monitor cure after treatment of ATL.
本研究旨在比较间接免疫荧光法(IFA)和流式细胞术与临床和实验室评估患者在临床治愈前后的技术,并评估流式细胞术在治疗后监测美洲皮肤利什曼病(ATL)患者中的适用性。评估了 14 名治疗前(BT)患者、13 名治疗后 1 年(AT)患者和 10 名治疗后 2 年和 5 年患者的血清。流式细胞术的结果表示为 IgG 反应性水平,基于阳性荧光寄生虫的百分比(PPFP)。1:256 的样本稀释允许我们区分 BT 和 AT 个体。通过 ROC(接受者操作特征曲线)对 IFA 和流式细胞术进行比较分析,AUC(曲线下面积)分别为 0.8(95%CI=0.64-0.89)和 AUC=0.90(95%CI=0.75-0.95),表明流式细胞术具有等效的准确性。我们的数据表明,ROC 曲线确定的最佳截断点为 20%。该测试的灵敏度为 86%,特异性为 77%,而 IFA 的灵敏度为 78%,特异性为 85%。通过比较分析治疗后 1、2 和 5 年的技术性能指标进行的治疗后筛选表明,流式细胞术与 IFA 的性能相当。然而,当应用于治愈标准中的 ATL 研究时,流式细胞术显示出更好的诊断替代方法。这项工作获得的信息为监测 ATL 治疗后的治愈开辟了前景。