Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients.
Use of a Chagas Urine Nanoparticle Test (Chunap) to Correlate with Parasitemia Levels in T. cruzi/HIV Co-infected Patients.
复制标题
DOI：
10.1371/journal.pntd.0004407
复制
发表时间：
2016-02
影响因子：
3.8
通讯作者：
Chagas/HIV Working Group in Bolivia and Peru
中科院分区：
文献类型：
--
作者：
Castro-Sesquen YE;Gilman RH;Mejia C;Clark DE;Choi J;Reimer-McAtee MJ;Castro R;Valencia-Ayala E;Flores J;Bowman N;Castillo-Neyra R;Torrico F;Liotta L;Bern C;Luchini A;Chagas/HIV Working Group in Bolivia and Peru
早期诊断艾滋病毒患者的复发性恰加斯病可能挽救生命。在拉丁美洲，诊断是通过显微镜检测T。血液中的克氏寄生虫;缺乏灵敏度的诊断试验。本研究评价T.通过Chunap（查加斯尿纳米颗粒试验）测定的尿中的克氏抗原与T. cruzi/HIV合并感染患者。T. 55例HIV患者尿中检出克氏抗原（T. cruzi感染和24株T. cruzi血清学阴性）使用水凝胶颗粒浓缩，并通过蛋白质印迹和校准曲线定量。通过显微镜观察血液中的寄生虫来确定恰加斯病的再活化。查加斯病血清学阳性患者的寄生虫血症水平分类如下：查加斯病的高寄生虫血症或再激活（通过显微镜检查可检测到寄生虫血症）、中度寄生虫血症（通过显微镜检查不可检测但通过qPCR可检测到）和阴性寄生虫血症（通过显微镜检查和qPCR不可检测到）。Chunap法的阳性率为：复活者100%（7/7），中度原虫血症者91.7%（11/12），阴性原虫血症者41.7%（5/12）。Chunap特异性为91.7%。线性回归分析表明，寄生虫血症水平与尿T。Cruzi抗原浓度（P<0.001）。选择> 105 pg的截止值来确定查加斯病再激活的患者（7/7）。CD 4+淋巴细胞计数低于200/mL的患者的抗原尿水平高36.08倍（95% CI：7.28至64.88）（p = 0.016）。HIV载量和CD 8+淋巴细胞计数无显著差异。Chunap显示了早期发现查加斯病重新激活的潜力。通过适当的调整，这种诊断测试可用于监测锥虫病在T。cruzi/HIV合并感染患者。艾滋病毒感染者的查加斯病复发是一种严重的临床疾病，与高死亡率有关。因此，早期诊断和治疗可以挽救生命。虽然没有公认的标准来识别有再激活风险的患者，但寄生虫血症水平通常被认为是最好的预测因子。显微镜在拉丁美洲用于检测寄生虫血症水平。然而，这具有低灵敏度，这通常导致诊断和治疗的延迟。定量PCR仅用于流行区的研究。尿液中的抗原（抗原尿）与动物模型中的寄生虫血症水平相关，以及在先天性恰加斯病的情况下。我们相信抗原尿也可以用来预测T. cruzi/HIV合并感染患者。在这项研究中，Chunap（查加斯尿纳米颗粒试验）用于T的浓缩和定量。T.尿液中的克氏抗原。cruzi/HIV合并感染患者。T.尿中的克氏抗原仅在查加斯病再激活的患者中观察到。这项研究表明，抗原尿水平与寄生虫血症水平高度相关，可以作为一种非侵入性技术用于监测T。cruzi/HIV合并感染患者。
Early diagnosis of reactivated Chagas disease in HIV patients could be lifesaving. In Latin America, the diagnosis is made by microscopical detection of the T. cruzi parasite in the blood; a diagnostic test that lacks sensitivity. This study evaluates if levels of T. cruzi antigens in urine, determined by Chunap (Chagas urine nanoparticle test), are correlated with parasitemia levels in T. cruzi/HIV co-infected patients. T. cruzi antigens in urine of HIV patients (N = 55: 31 T. cruzi infected and 24 T. cruzi serology negative) were concentrated using hydrogel particles and quantified by Western Blot and a calibration curve. Reactivation of Chagas disease was defined by the observation of parasites in blood by microscopy. Parasitemia levels in patients with serology positive for Chagas disease were classified as follows: High parasitemia or reactivation of Chagas disease (detectable parasitemia by microscopy), moderate parasitemia (undetectable by microscopy but detectable by qPCR), and negative parasitemia (undetectable by microscopy and qPCR). The percentage of positive results detected by Chunap was: 100% (7/7) in cases of reactivation, 91.7% (11/12) in cases of moderate parasitemia, and 41.7% (5/12) in cases of negative parasitemia. Chunap specificity was found to be 91.7%. Linear regression analysis demonstrated a direct relationship between parasitemia levels and urine T. cruzi antigen concentrations (p<0.001). A cut-off of > 105 pg was chosen to determine patients with reactivation of Chagas disease (7/7). Antigenuria levels were 36.08 times (95% CI: 7.28 to 64.88) higher in patients with CD4+ lymphocyte counts below 200/mL (p = 0.016). No significant differences were found in HIV loads and CD8+ lymphocyte counts. Chunap shows potential for early detection of Chagas reactivation. With appropriate adaptation, this diagnostic test can be used to monitor Chagas disease status in T. cruzi/HIV co-infected patients. Reactivation of Chagas disease in people living with HIV is a serious clinical condition that is associated with high mortality. Hence, early diagnosis and treatment can be lifesaving. Although there are not well accepted criteria to identify patients at risk of reactivation, parasitemia levels are usually considered as the best predictor. Microscopy is used in Latin America for detection of parasitemia levels. However, this has low sensitivity, which usually leads to a delay in diagnosis and treatment. Quantitative PCR is used only for research proposes in endemic areas. Antigens in urine (antigenuria) are correlated with parasitemia levels in animal models, as well as in cases of congenital Chagas disease. We believe that antigenuria can also be used for prediction of parasitemia levels in T. cruzi/HIV co-infected patients. In this study, Chunap (Chagas urine nanoparticle test) was used for concentration and quantification of T. cruzi antigens in urine of T. cruzi/HIV co-infected patients. Values of more than 105 pg of T. cruzi antigens in urine were observed only in patients with reactivation of Chagas disease. This study shows that antigenuria levels are highly correlated to levels of parasitemia and can be used as a non-invasive technique for monitoring parasitemia levels in T. cruzi/HIV co-infected patients.