Immunohistochemical techniques and their applications in the histopathology of the respiratory system.

Abstract

Subsequent to the first report in the 1940s on incubation of tissue sections with fluorescein-conjugated antibodies for localization of antigens, a great number of modifications were introduced to improve the validity of immunohistochemistry which has become a growingly popular tool. The use of immunoenzymatic techniques eliminates the need for expensive fluorescence microscopy equipment, the lack of permanency of preparations and the lack of electron density required in ultrastructural localization of antigens. Regardless of the technique, it is also important to choose a correct fixation which allows the proper preservation of antigens and morphology and the penetration of antibodies through the entire thickness of the preparation. A variety of immunohistochemical techniques have been applied to study several components of the lung, such as collagen, surface active material, lung specific antigens, and enzymes and the detection of tumor markers, immunoglobulins and infectious agents in the respiratory system which is reviewed. The large surface area and the multiplicity of cell types provided by the respiratory tract epithelium of humans for exposure to microbial as well as toxic substances in the environment make this organ system very vulnerable but a good early indicator of adverse health effects. Immunohistochemistry provides valuable information complementary to the immunochemical and biochemical characterization of this barrier.

Immunohistochemical diagnosis of human infectious diseases: a review

“…The examination of hematoxylin and eosin-stained tissue sections is the first step in the diagnosis of any infectious disease from tissue samples before any other staining in histopathology [ 6 ]. The principal immunohistochemical methods are direct, indirect, PAP, alkaline phosphatase and avidin-biotin techniques [ 17 , 27 ], which use antigen-antibody complexes to locate cellular antigens in paraffin sections, frozen tissues, post-mortem tissues and cell preparations.…”

Respiratory Tract

“…114 Other useful antigens, which can be demonstrated in the lung, include surfactants, lysozyme, immunoglobulins and those of microorganisms that infect the lung. 136 Electron microscopy is particularly useful for the detailed characterization of injury to the cells of the alveolar epithelium and endothelium ( Figure 6.1).…”

Immunohistochemistry of Pancreatic Neoplasia

“…The origin of IHC goes back to the early 1940s when fluorescein-conjugated antibodies were used to demonstrate the expression of bacterial antigens in infected tissues (1). The developments in technology and usage of paraffin blocks in the 1970s further enhanced the application of IHC in various biochemical fields.…”

“…IHC is also used in drug development to test drug efficacy by detecting either the activity and/or the up- or down-regulation of therapeutic targets. In the case of breast cancer, IHC has been routinely used to distinguish the usual ductal hyperplasia (UDH) from atypical ductal hyperplasia (ADH)/low-grade carcinoma in situ, subtyping lesions as ductal versus lobular or basal versus luminal, helping to distinguish true microinvasion from mimics (“pseudoinvasion”), predicting the likelihood of response to anti-hormonal and other therapeutic agents, improving sentinel node staging, and finally, helping to recognize metastatic carcinoma of an unknown primary site as originating in the breast (1). Further, IHC has been commonly used to check the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status in breast cancer patients to classify patient subtype (2).…”