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Updated: Aug 11, 2026
Immunohistochemical Analysis in the Rat Central Nervous System and Peripheral Lymph Node Tissue Sections
Published on: November 14, 2016
Nonspecificity of Immunohistochemistry for Mycobacteria Species Using a Rabbit Polyclonal Antibody
Justin T Kelley1, Lauren Kroll-Wheeler2, Steven Hrycaj2
1From the Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee (Kelley).
Context.—:
Recent publications have featured immunohistochemistry (IHC) as a sensitive tool for detecting Mycobacterium tuberculosis and nontuberculous mycobacteria, but performance is limited to cases suspected to have mycobacterial infection.
Objective.—:
To examine cross-reactivity of a polyclonal antimycobacterial antibody with various types of pathogens, tissues, and inflammatory patterns.
Design.—:
Surgical pathology files during a period of 6 years were searched, and 40 cases representing a variety of pathogens, tissue types, and inflammatory responses were retrieved. Cases were stained with a rabbit polyclonal antimycobacterial antibody (Biocare Medical, Pacheco, California). The cases and associated histochemical stains, culture, and molecular results were reviewed by 3 pathologists.
Results.—:
All 8 cases of mycobacterial infection previously diagnosed by other methods were positive for mycobacteria by IHC. In addition, multiple bacterial and fungal organisms and 1 case of Leishmania amastigotes were also immunoreactive with the mycobacterial IHC.
Conclusions.—:
Although highly sensitive for mycobacteria, the polyclonal antibody shows significant cross-reactivity with other organisms. This is a sensitive but nonspecific stain that can be used as an alternative confirmation method for mycobacteria, but attention should be paid to inflammatory reaction and organism morphology when IHC is positive to avoid misdiagnosis.
