Tortosa-Carreres Jordi, Lloret-Sos Carmen, Sahuquillo-Arce Jose Miguel, Garrido-Jareño Marta, Fornals-López Ana, Pérez-Cataldo Gabriela, Alba-Redono Amparo, Martínez-Triguero María Luisa, Aguado-Codina Cristina, Pascual-Costa Rosa María, Laiz-Marro Begoña, López-Hontangas Jose Luis
Laboratory Department, Hospital Univeritari i Politècnic la Fe, Av Fernando Abril Martorell 106, València, 46026, Spain.
Microbiology Department, Hospital Univeritari i Politècnic la Fe, Av Fernando Abril Martorell 106, València, 46026, Spain.
Eur J Clin Microbiol Infect Dis. 2025 Aug 13. doi: 10.1007/s10096-025-05223-4.
VirClia provides an automated platform for detecting antibodies against Bartonella henselae and Coxiella burnetii.
To assess the diagnostic performance of VirClia and identify potential sources of interference.
A retrospective study was conducted using two independent datasets from routine clinical samples tested simultaneously by IFA and VirClia. Diagnostic performance was evaluated using Cohen's kappa and ROC curves, with IFA as the reference standard. For C. burnetii (n=1628), IgG against Phase I, Phase II, and their combination (positive if either reactive) was analyzed. For B. henselae (n=955), IgG and IgM were assessed independently. Two thresholds were defined per parameter: one ensuring 90% sensitivity and another ≥90% specificity. Intermediate values were considered within a gray zone, assumed to require IFA confirmation. The potential reduction in IFA use was estimated assuming that values outside this zone would not need confirmation. False positives (FP) were defined as VirClia values above the high-specificity threshold with a negative IFA result. Logistic regression was used to assess associations between FP results and sex, age, and symptoms. The presence of autoantibodies in FP cases was also evaluated.
Applying gray zone thresholds-using the manufacturer's upper cut-off (1.1) and a sensitivity-driven lower limit-yielded estimated IFA reductions of 56% for B. henselae IgG, 42% for IgM, and 79% for C. burnetii (combined phases). FP results for C. burnetii were significantly associated with extractable nuclear antigens and older age.
VirClia demonstrates strong diagnostic performance and may reduce IFA dependency when a gray zone strategy is implemented.
VirClia提供了一个用于检测抗汉氏巴尔通体和伯纳特立克次体抗体的自动化平台。
评估VirClia的诊断性能并确定潜在的干扰源。
使用来自常规临床样本的两个独立数据集进行回顾性研究，这些样本同时通过间接荧光抗体试验（IFA）和VirClia进行检测。以IFA作为参考标准，使用科恩kappa系数和ROC曲线评估诊断性能。对于伯纳特立克次体（n = 1628），分析了针对I期、II期及其组合的IgG（如果任一反应性为阳性）。对于汉氏巴尔通体（n = 955），分别评估了IgG和IgM。每个参数定义了两个阈值：一个确保90%的敏感性，另一个≥90%的特异性。中间值被视为处于灰色区域，假定需要IFA确认。假设该区域外的值不需要确认，估计了IFA使用的潜在减少。假阳性（FP）定义为VirClia值高于高特异性阈值且IFA结果为阴性。使用逻辑回归评估FP结果与性别、年龄和症状之间的关联。还评估了FP病例中自身抗体的存在情况。
应用灰色区域阈值——使用制造商的上限（1.1）和敏感性驱动的下限——汉氏巴尔通体IgG的估计IFA减少量为56%，IgM为42%，伯纳特立克次体（组合阶段）为79%。伯纳特立克次体的FP结果与可提取核抗原和年龄较大显著相关。
当实施灰色区域策略时，VirClia表现出强大的诊断性能，并可能降低对IFA的依赖。
