YRG Centre for AIDS Research and Education, Voluntary Health Services, Chennai, India.
Johns Hopkins University School of Medicine, Baltimore, USA.
J Int Med Res. 2020 Sep;48(9):300060520955028. doi: 10.1177/0300060520955028.
CD4+ T lymphocyte count remains the most common biomarker of immune status and disease progression in human immunodeficiency virus (HIV)-positive individuals. VISITECT®CD4 is an instrument-free, low-cost point-of-care CD4 test with a cut-off of 350 CD4 cells/μL. This study aimed to evaluate VISITECT®CD4 test's diagnostic accuracy.
Two hundred HIV-positive patients attending a tertiary HIV centre in South India were recruited. Patients provided venous blood for reference and VISITECT®CD4 tests. An additional finger-prick blood sample was obtained for VISITECT®CD4. VISITECT®CD4's diagnostic performance in identifying individuals with CD4 counts ≤350 cells/μL was assessed by calculating sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) taking flow cytometry as the reference.
The overall agreement between VISITECT®CD4 and flow cytometry was 89.5% using venous blood and 81.5% using finger-prick blood. VISITECT®CD4 showed better performance using venous blood [sensitivity: 96.6% (95% confidence interval: 92.1%-98.9%), specificity: 70.9% (57.1%-82.4%), PPV: 89.7% (83.9%-94.0%) and NPV: 88.6% (75.4%-96.2%)] than using finger-prick blood [sensitivity: 84.8% (77.9%-90.2%), specificity: 72.7% (59.0%-83.9%), PPV: 89.1% (82.7%-93.8%) and NPV: 64.5% (51.3%-76.3%)].
VISITECT®CD4 performed well using venous blood, demonstrating its potential utility in decentralization of CD4 testing services in resource-constrained settings.
CD4+T 淋巴细胞计数仍然是人类免疫缺陷病毒(HIV)阳性个体免疫状态和疾病进展的最常见生物标志物。VISITECT®CD4 是一种无仪器、低成本的即时护理 CD4 检测,其截断值为 350 CD4 细胞/μL。本研究旨在评估 VISITECT®CD4 检测的诊断准确性。
本研究招募了 200 名在印度南部一家三级 HIV 中心就诊的 HIV 阳性患者。患者提供静脉血用于参考和 VISITECT®CD4 检测。另外采集指尖血样用于 VISITECT®CD4 检测。通过计算灵敏度、特异性、阳性预测值(PPV)和阴性预测值(NPV),以流式细胞术为参考,评估 VISITECT®CD4 在识别 CD4 计数≤350 个细胞/μL 的个体中的诊断性能。
使用静脉血时,VISITECT®CD4 与流式细胞术的总体一致性为 89.5%,使用指尖血时为 81.5%。使用静脉血时,VISITECT®CD4 表现更好[灵敏度:96.6%(95%置信区间:92.1%-98.9%),特异性:70.9%(57.1%-82.4%),PPV:89.7%(83.9%-94.0%)和 NPV:88.6%(75.4%-96.2%)],而使用指尖血时[灵敏度:84.8%(77.9%-90.2%),特异性:72.7%(59.0%-83.9%),PPV:89.1%(82.7%-93.8%)和 NPV:64.5%(51.3%-76.3%)]。
VISITECT®CD4 在使用静脉血时表现良好,表明其在资源有限的环境中分散 CD4 检测服务具有潜在的应用价值。