Karimi Shirin, Shamaei Masoud, Pourabdollah Mihan, Sadr Makan, Karbasi Mehrdad, Kiani Arda, Bahadori Moslem
Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Clinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Int J Mycobacteriol. 2016 Dec;5 Suppl 1:S234-S235. doi: 10.1016/j.ijmyco.2016.11.001. Epub 2016 Nov 11.
OBJECTIVE/BACKGROUND: The histological diagnosis of Mycobacterium tuberculosis (MTB) has long been a diagnostic challenge in the anatomical pathology field despite availability of different laboratory methods. Immunohistochemistry (IHC) could not only confirm granulomatous tissue involvement but also demonstrate MTB antigen immunolocalization. This study tries to clarify the details of IHC staining for MTB with pAbBCG.
A total of 50 patients undergoing simultaneous biopsy and tissue culture with positive tissue culture for MTB during 2005-2009 were selected from the MRC Department at Masih Daneshvari Hospital, Tehran, Iran. Using the archives of the Pathology Department of this hospital, which is a referral center for pathological lung lesions, hematoxylin and eosin slides of the selected patients were evaluated. Twenty-three confirmed TB granulomatous tissue samples with adequate tissue and number of granulomas were chosen and studied by Ziehl-Neelsen and IHC staining with pAbBCG.
A total of 23 cases were evaluated, of which 17 (73.9%) were males. The types of tissue obtained from study cases were as follows: pleura (9 cases, 39.1%), lymph node (cervical, axillary, and thoracic [9 cases, 39.1%]), and lung tissues (5 cases, 21.7%). IHC staining was positive in all samples, whereas Ziehl-Neelsen staining was positive in nine cases of 23 (39.1%). IHC showed positive coarse granular cytoplasmic and round, fragmented bacillary staining. In this study, epithelioid cells clearly showed more positive staining at the periphery rather than at the center of granuloma. There is also positive staining in endothelial cells, fibroblasts, plasma cells, macrophages, and lymphocytes outside the granuloma.
Detection of TB in tissue slides is still based on the histological pattern of the granuloma, which has several differential diagnoses with different treatments. Presence of mycobacterial antigens and tissue morphology can be evaluated using the IHC technique. Considering the criteria of positive IHC staining of TB granulomatous reactions, this stain not only highlights the presence of mycobacterial antigens for tissue diagnosis, but also could morphologically localize their distribution in different cells. Pathologists must be familiar with adequate staining pattern, elimination of background staining, and type of selected antibody. This method is especially important for application in countries with high prevalence of TB as a technique with early diagnostic value in tissue specimens. Early diagnosis using this technique can reduce related morbidity and mortality and decrease the rate of complications due to misdiagnosis and mistreatment of TB.
目的/背景：尽管有多种实验室方法，但结核分枝杆菌（MTB）的组织学诊断长期以来一直是解剖病理学领域的一项诊断挑战。免疫组织化学（IHC）不仅可以确认肉芽肿组织受累情况，还能显示MTB抗原的免疫定位。本研究旨在阐明用抗卡介苗多克隆抗体（pAbBCG）对MTB进行免疫组织化学染色的细节。
从伊朗德黑兰马西·达内什瓦里医院MRC科选取2005年至2009年间同时进行活检和组织培养且MTB组织培养呈阳性的50例患者。利用该医院病理科的存档资料（该医院是肺部病理病变的转诊中心），对所选患者的苏木精和伊红染色切片进行评估。选择23例确诊的结核肉芽肿组织样本，这些样本组织充足且肉芽肿数量合适，采用萋-尼染色和用pAbBCG进行免疫组织化学染色研究。
共评估了23例病例，其中17例（73.9%）为男性。研究病例获取的组织类型如下：胸膜（9例，39.1%）、淋巴结（颈部、腋窝和胸部[9例，39.1%]）和肺组织（5例，21.7%）。所有样本免疫组织化学染色均为阳性，而萋-尼染色在23例中有9例（39.1%）为阳性。免疫组织化学显示阳性的粗颗粒状胞质以及圆形、碎片化的杆菌染色。在本研究中，上皮样细胞在肉芽肿周边比在中心明显显示出更多阳性染色。在肉芽肿外的内皮细胞、成纤维细胞、浆细胞、巨噬细胞和淋巴细胞中也有阳性染色。
组织切片中结核的检测仍基于肉芽肿的组织学模式，其有多种不同治疗方法的鉴别诊断。可使用免疫组织化学技术评估分枝杆菌抗原的存在和组织形态。考虑到结核肉芽肿反应免疫组织化学染色阳性的标准，这种染色不仅突出了用于组织诊断的分枝杆菌抗原的存在，还能在形态学上定位其在不同细胞中的分布。病理学家必须熟悉适当的染色模式、背景染色的消除以及所选抗体的类型。作为一种在组织标本中具有早期诊断价值的技术，该方法在结核病高流行国家的应用尤为重要。使用该技术进行早期诊断可降低相关的发病率和死亡率，并降低因结核病误诊和误治导致的并发症发生率。
