Department of Pathology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
J Clin Lab Anal. 2022 Feb;36(2):e24209. doi: 10.1002/jcla.24209. Epub 2022 Jan 8.
Fungal rhinosinusitis (FRS) encompasses a various spectrum of diseases. Histopathology is the "reference method" for diagnosing FRS, but it cannot determine the genus and species. Moreover, in more than 50% of the histopathologically proven cases, the culture elicited no reliable results. This study was an attempt to evaluate the diagnostic efficiency of semi-nested polymerase chain reaction (PCR) from formalin-fixed paraffin-embedded (FFPE) functional endoscopic sinus surgery (FESS) in FRS patients.
One hundred ten specimens were subjected to DNA extraction and histopathology examination. The amplification of the β-globin gene by conventional PCR was used to confirm the quality of extracted DNA. The semi-nested PCR was performed using ITS1, ITS2, and ITS4 primers during two steps. Sequencing the internal transcribed spacer region (ITS1-5.8S-ITS2) to identify causative agents was performed on PCR products.
Sixty-four out of 110 samples were positive by histopathology evidence, of which 56 samples (87.5%) were positive by PCR. Out of 46 negative samples by histopathological methods, five samples (10.9%) yielded positive results by PCR. Sensitivity, specificity, positive predictive value, and negative predictive value of the semi-nested PCR method were reported 87.5%, 89.2%, 92.7%, and 85.2%, respectively. The kappa factor between PCR and histopathological methods was 0.76, indicating substantial agreements between these two tests.
Due to the acceptable sensitivity and specificity of the present method, it might be used to diagnose fungal sinusitis infections along with microscopic techniques. This method is recommended to confirm the diagnose of suspected fungal sinusitis with negative histopathology results.
真菌性鼻-鼻窦炎（Fungal Rhinosinusitis，FRS）包含了一系列疾病。组织病理学是诊断 FRS 的“参考方法”，但它无法确定真菌的属和种。此外，在超过 50%的经组织病理学证实的病例中，培养无法得出可靠的结果。本研究旨在评估半巢式聚合酶链反应（PCR）从福尔马林固定石蜡包埋（FFPE）功能性内镜鼻窦手术（FESS）标本中诊断 FRS 患者的真菌病原体的诊断效率。
110 个标本进行 DNA 提取和组织病理学检查。采用常规 PCR 扩增β-球蛋白基因，以确认提取 DNA 的质量。采用 ITS1、ITS2 和 ITS4 引物进行两步半巢式 PCR。对 PCR 产物进行内部转录间隔区（ITS1-5.8S-ITS2）测序，以鉴定病原体。
64 个样本经组织病理学证实为阳性，其中 56 个样本（87.5%）PCR 阳性。46 个组织学阴性样本中，有 5 个样本（10.9%）PCR 阳性。半巢式 PCR 方法的敏感性、特异性、阳性预测值和阴性预测值分别为 87.5%、89.2%、92.7%和 85.2%。PCR 和组织病理学方法之间的 Kappa 系数为 0.76，表明这两种方法具有高度一致性。
由于本方法具有可接受的敏感性和特异性，它可能与显微镜技术一起用于诊断真菌性鼻窦炎感染。建议对组织学检查结果阴性的疑似真菌性鼻窦炎患者使用该方法来确认诊断。
