title: Histopathological findings in immunohistological staining of the granulomatous tissue reaction associated with tuberculosis.
abstract: Purpose. The histological diagnosis of Mycobacterium tuberculosis (MTB) remains a diagnostic challenge despite different methods. Immunohistochemistry (IHC) not only could confirm granulomatous tissue involvement but also can demonstrate MTB antigen immunolocalization. This study tries to clarify the details of immunohistochemical staining for MTB with pAbBCG. Materials/Methods. Twenty-three confirmed TB granulomatous tissue samples were studied by Ziehl-Neelsen and immunohistochemistry (IHC) staining with pAbBCG. Samples were selected from the archive of the Department of Pathology, National Research Institute of Tuberculosis and Lung Disease, Tehran, Iran. Results. IHC staining was positive in all samples, whereas Ziehl-Neelsen was positive in 9 cases out of 23 (39.1%). Tissue types used were pleural tissue, lymph nodes, and lung tissue. IHC showed positive coarse granular cytoplasmic and round, fragmented bacillary staining. In this study, epithelioid cells clearly showed more positive staining at the periphery of the granuloma rather than the center of granuloma. There is also positive staining in endothelial cells, fibroblasts, plasma cells, lymphocytes, and macrophages outside the granuloma. Conclusion. Considering the criteria of positive immunohistochemical staining of TB granulomatous reactions, this stain not only highlights the presence of mycobacterial antigens for tissue diagnosis, but also could morphologically localize its distribution in different cells.
authors: Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Shirin
authors: S
authors: Karimi
authors: Clinical Tuberculosis and Epidemiology Research Center, NRITLD, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Masoud
authors: M
authors: Shamaei
authors: Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Mihan
authors: M
authors: Pourabdollah
authors: Tracheal Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Makan
authors: M
authors: Sadr
authors: Pediatric Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Mehrdad
authors: M
authors: Karbasi
authors: Tracheal Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Arda
authors: A
authors: Kiani
authors: Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Moslem
authors: M
authors: Bahadori