Govrins Miriam, Vahedi-Shahandashti Roya, Lass-Flörl Cornelia
Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria.
Mycoses. 2025 Aug;68(8):e70103. doi: 10.1111/myc.70103.
Diagnosing invasive aspergillosis (IA) remains challenging despite the availability of various tests due to the limited sensitivity and variability in accuracy depending on the clinical context. Laboratory-based definitions consider different mycological criteria, such as culture and galactomannan (GM) positivity, equivalent in diagnostic weight. However, a more detailed analysis is essential for reliably distinguishing true infection from colonisation.
This laboratory-based pilot study aimed to evaluate the diagnostic reliability of culture positivity by comparing it with fungal microscopy, GM testing, and Aspergillus-specific PCR in bronchoalveolar lavage fluid (BALF) samples, all of which were culture-positive for Aspergillus.
Ninety-two Aspergillus fumigatus culture-positive BALF specimens were obtained from mixed patient populations, displaying various risk factors for IA. The multi-assay approach used direct microscopy, GM, and Aspergillus-specific PCR. The diagnostic value of each test was assessed utilising a composite score based on mycological findings and clinical suspicion.
Among 92 culture-positive BALF samples, positivity rates for microscopy, GM, and PCR were 12.0% (n = 11), 27.2% (n = 25), and 28.3% (n = 26), respectively. Notably, in 58.7% (n = 54) of cases, culture positivity was not supported by any other mycological test. Direct microscopy showed the strongest correlation with other diagnostic methods, whereas GM and PCR showed moderate agreement.
Based on our data, the current practice of weighing all mycological parameters equally should be reconsidered, with greater emphasis on microscopy and multimodal diagnostics rather than on culture alone, particularly in non-neutropenic patients.
尽管有各种检测方法，但侵袭性曲霉病（IA）的诊断仍然具有挑战性，因为其敏感性有限，且准确性因临床背景而异。基于实验室的定义认为不同的真菌学标准，如培养和半乳甘露聚糖（GM）阳性，在诊断权重上是等效的。然而，进行更详细的分析对于可靠地区分真正的感染与定植至关重要。
这项基于实验室的初步研究旨在通过将支气管肺泡灌洗液（BALF）样本中的培养阳性结果与真菌显微镜检查、GM检测和曲霉特异性PCR进行比较，评估培养阳性的诊断可靠性，所有这些样本的曲霉培养均为阳性。
从混合患者群体中获取了92份烟曲霉培养阳性的BALF标本，这些患者表现出各种IA危险因素。多检测方法采用直接显微镜检查、GM检测和曲霉特异性PCR。根据真菌学检查结果和临床怀疑，利用综合评分评估每项检测的诊断价值。
在92份培养阳性的BALF样本中，显微镜检查、GM检测和PCR检测的阳性率分别为12.0%（n = 11）、27.2%（n = 25）和28.3%（n = 26）。值得注意的是，在58.7%（n = 54）的病例中，其他真菌学检测均未支持培养阳性结果。直接显微镜检查与其他诊断方法的相关性最强，而GM检测和PCR检测的一致性中等。
根据我们的数据，应重新考虑目前对所有真菌学参数同等加权的做法，尤其应更加强调显微镜检查和多模式诊断，而不是仅依赖培养，特别是在非中性粒细胞减少患者中。
