%0 Journal Article
%T Histopathological Findings in Immunohistological Staining of the Granulomatous Tissue Reaction Associated with Tuberculosis
%A Shirin Karimi
%A Masoud Shamaei
%A Mihan Pourabdollah
%A Makan Sadr
%A Mehrdad Karbasi
%A Arda Kiani
%A Moslem Bahadori
%J Tuberculosis Research and Treatment
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/858396
%X 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. 1. Introduction Histological diagnosis of tuberculosis (TB) has long been an important issue in anatomical pathology. On the other hand, extrapulmonary TB comprises 10¨C15% of infections with Mtb. Following HIV prevalence increase, extrapulmonary TB is rising as well [1, 2]. Considering the limitations in sensitivity and specificity of Ziehl-Neelsen staining [3], mycobacterial evaluation, mycobacterial culture, and molecular and serological techniques [4¨C6], histomorphological analysis appears to be the only feasible technique for field diagnosis of TB in some patients [7, 8]. Granulomatous reactions, and in some cases, nongranulomatous reactions such as the presence of foamy macrophages [9] or mycobacterial spindle cell pseudotumour [10] in some types of mycobacterial infections are indicative of TB only if the presence of TB bacilli has been confirmed in the tissue. Recently, it has been stated that PCR results are acceptable only if the presence of TB bacilli can be confirmed in the tissue [11]. Detection of beaded bacilli (which are more commonly observed in the necrotic zone) by
%U http://www.hindawi.com/journals/trt/2014/858396/