Comparison of two commercial tests (Immy vs. Dynamiker) for cryptococcal capsular antigen

Abstract INTRODUCTION Lateral flow assay is an advanced method useful in the early diagnosis of cryptococcal meningitis. We aimed to compare two commercial tests for cryptococcal capsular antigen in the sera of asymptomatic patients with human immunodeficiency virus in Barranquilla, Colombia. METHODS Thawed (n=162) previously collected serums (2016-2019) were processed using IMMY and Dynamiker cryptococcal antigen lateral flow assay. RESULTS Compared to IMMY’s results, Dynamiker’s sensitivity, specificity, positive predictive value, negative predictive value, and kappa index were 100%, 89.9%, 48.3%, 100.0%, and 0.61, respectively. CONCLUSIONS The Dynamiker test had excellent sensitivity, acceptable specificity, and a low detection threshold for cryptococcal antigen in the tested samples.

摘要
引言 侧流免疫层析试验（Lateral flow assay）是一种可用于隐球菌性脑膜炎早期诊断的先进检测方法。本研究旨在对比哥伦比亚巴兰基亚地区人类免疫缺陷病毒（human immunodeficiency virus, HIV）无症状感染者血清中两款商用隐球菌荚膜抗原侧流免疫层析检测试剂的性能。
方法 对2016至2019年收集并解冻的162份既往留存血清样本，分别采用IMMY与Dynamiker公司的隐球菌抗原侧流免疫层析试验进行检测处理。
结果 以IMMY的检测结果作为参照标准，Dynamiker检测的灵敏度、特异度、阳性预测值、阴性预测值及Kappa值分别为100%、89.9%、48.3%、100.0%和0.61。
结论 在所检测的样本中，Dynamiker检测试剂对隐球菌抗原具备优异的灵敏度、可接受的特异度以及较低的检测下限。