IMMUNOHISTOCHEMISTRY TEST (IHC TEST)

What is an immunohistochemistry test (IHC Test)?

Immunohistochemistry is a test used to diagnose cancer by detecting specific kinds of antibodies attached to antigens in a cell. This test helps to identify tumors; also, it can distinguish whether or not the tumor is benign or malignant

Why does the doctor prescribe an Immunohistochemistry (IHC) test?

• A doctor may prescribe this test when he suspects cancer or tumor in some parts of the body
• To determine the stage and grade of a tumor and identify the cell type and origin of a metastasis
• To find the site of the primary tumor.
• To detect many types of cancer, for example, adenocarcinomas (colon, breast, Prostate) and skin.
• To predict response to treatment in two significant tumors, i.e., carcinoma of breast and Prostate.
• To confirm infectious agents in tissues
• Many doctors recommend it to differentiate melanoma from diseases it mimics

What are the components of the IHC test?

IHC tests detect four proteins in the tumor, which helps the body cells to work correctly. This test is based on the principle of antigen-antibody reaction. Each antibody recognizes and attaches to antigens that match it. To detect the attachment of the antibodies to the cells, certain chemicals are added that make the cells change color only if a specific antibody is present. These antibodies will be linked to an enzyme or a fluorescent dye. After the antibodies bind to the antigen in the tissue sample, the enzyme or dye gets activated, and the antigen can then be seen under a microscope. Presence of changes in the protein of the tumor will give a positive or negative result.

Procedure & prerequisites

Tissue samples for biopsy are collected in a non-breakable plastic container

Reference Range

Negative Test

If the test is negative, it means that the laboratory did not find any changes in the proteins of the tumor, indicating that

• A person is not affected by a particular disorder,
• Is not a carrier of a specific genetic mutation
• Does not have an increased risk of developing a particular disease.

Sometimes a negative test requires further investigation.

Positive Test

If the test is positive, the result means that the laboratory found a particular change in the proteins of the tumor. It indicates that a person may have an inherited genetic condition, and further genetic testing is recommended.