Immunohistochemistry as an important tool in biomarkers detection and clinical practice

Abstract

The immunohistochemistry technique is used in the search for cell or tissue antigens that range from amino acids and proteins to infectious agents and specific cellular populations. The technique comprises two phases: (1) slides preparation and stages involved for the reaction; (2) interpretation and quantification of the obtained expression. Immunohistochemistry is an important tool for scientific research and also a complementary technique for the elucidation of differential diagnoses which are not determinable by conventional analysis with hematoxylin and eosin. In the last couple of decades there has been an exponential increase in publications on immunohistochemistry and immunocytochemistry techniques. This review covers the immunohistochemistry technique; its history, applications, importance, limitations, difficulties, problems and some aspects related to results interpretation and quantification. Future developments on the immunohistochemistry technique and its expression quantification should not be disseminated in two languages-that of the pathologist and another of clinician or surgeon. The scientific, diagnostic and prognostic applications of this methodology must be explored in a bid to benefit of patient. In order to achieve this goal a collaboration and pooling of knowledge from both of these valuable medical areas is vital.

Keywords: immunohistochemistry; pathology; review.

Figure 1.

Number of scientific publications using the immunohistochemistry technique, found on the Medline database, between 1960 and 2006. The plot indicates the frequency in which the term “immunohistochemistry” appears in the title or abstract of the manuscripts. (Adapted from Werner et al27).

Figure 2.

Histogenetic diagnosis of neoplasias using immunohistochemistry technique. A) Expression of cytoqueratin AE1/AE3 in lung carcinosarcoma (IHC-peroxidase—X200); B) chromogranin expression in gastric neuroendocrine carcinoma (IHC-peroxidase—X100); C) HMB 45 immunostainning in murine melanoma (IHC-peroxidase—X400).

Figure 3.

Heparanase expression in the diagnosis of broncopulmonar carcinoid tumors. Optical microscopy at X400 power: A) negative expression of heparanase (absence of staining—peroxidase—in cell’s cytoplasm) in bronchial mucosa not compromised by neoplasm; B) positive expression of heparanase (presence of cytoplasm full of peroxidase—brownish areas) in broncopulmonar carcinoid tumor. (Adapted from: de Matos et al87).