Department of Pathology, Beijing Chest Hospital, Capital Medical University, Beijing Tuberculosis and Thoracic Tumor Research Institute, Beijing, China.
Am J Clin Pathol. 2023 Jul 5;160(1):62-71. doi: 10.1093/ajcp/aqad012.
The present study used immunohistochemistry (IHC) to detect antigen Ag85B in tissue sections and aimed to evaluate its validity in histopathologic diagnosis of tuberculosis (TB).
In total, 204 patients with confirmed TB and 40 other diseases were included in the present study. Ziehl-Neelsen (Z-N) stains, IHC (anti-Ag85B), and quantitative fluorescence polymerase chain reaction were used to detect acid-fast bacilli, Mycobacterium tuberculosis (MTB) antigen, and MTB DNA.
Immunohistochemistry was significantly more sensitive than Z-N stains (93.1% vs 67.2%; P < .001). The sensitivity of Z-N stains significantly correlated with anti-TB treatment history. The sensitivity of Z-N stains was lower in rifampicin (RIF)-resistant TB compared with RIF-sensitive TB (52.8% vs 69.0%; P = .091) and those without treatment history (52.8% vs 84.0%; P = .015). However, IHC was not significantly affected by treatment history (P = .410). Moreover, expression patterns of Ag85B were dependent on treatment history and commonly showed weak scattered spots in RIF-susceptible TB. Conversely, strong brown rods were often found in those with RIF-resistant TB.
Immunohistochemistry is a simple, sensitive technique for the diagnosis of TB, especially for those patients with treatment history. The expression pattern of Ag85B is a potential marker for evaluating anti-TB treatment response.
本研究采用免疫组织化学（IHC）方法检测组织切片中的抗原 Ag85B，旨在评估其在结核病（TB）组织病理学诊断中的有效性。
本研究共纳入 204 例确诊为 TB 的患者和 40 例其他疾病患者。采用 Ziehl-Neelsen（Z-N）染色、IHC（抗 Ag85B）和定量荧光聚合酶链反应检测抗酸杆菌、结核分枝杆菌（MTB）抗原和 MTB DNA。
与 Z-N 染色相比，IHC 具有更高的敏感性（93.1% vs 67.2%；P <.001）。Z-N 染色的敏感性与抗结核治疗史显著相关。与 RIF 敏感型 TB（69.0%）相比，RIF 耐药型 TB（52.8%）和无治疗史的患者（52.8%）的 Z-N 染色敏感性较低（P =.091）。然而，IHC 不受治疗史的显著影响（P =.410）。此外，Ag85B 的表达模式取决于治疗史，RIF 敏感型 TB 中通常表现为弱阳性的点状分布，而 RIF 耐药型 TB 中则常表现为强阳性的棕色棒状分布。
IHC 是一种简单、敏感的 TB 诊断技术，尤其适用于有治疗史的患者。Ag85B 的表达模式可能是评估抗结核治疗反应的潜在标志物。
