Cell-mediated immune response in equine babesiosis.

The research paper presents a study that successfully develops a skin test to detect Babesia equi infection in donkeys, exploring the role of cell-mediated immunity in combating the infection.

Background on Equine Babesiosis

• Babesia equi is a tick-borne parasite that causes Babesiosis, a serious disease impacting the equine population worldwide.
• The disease affects the red blood cells, often leading to severe anemia.
• Understanding the immune response to this parasite in the equine population is critical for the development of effective methods for infection detection, treatment, and prevention.

Development of the Intradermal Skin Test

• In this study, the authors developed an intradermal skin test to demonstrate delayed cutaneous hypersensitivity reaction, which is a part of the body’s immune response, in Babesia equi infection in donkeys.
• The skin reaction to the presence of B. equi antigen was successfully elicited not just in infected donkeys, but also in those that had been vaccinated or served as carriers.
• The test could provoke a response in both fully healthy donkeys and those that had undergone splenectomy – a surgical removal of the spleen.

Examination of the Skin Reaction

• A detailed histopathological examination of the skin biopsy from the test revealed the infiltration of mononuclear cells and the accumulation of oedematous fluid in the deeper layers of the dermis.
• The infiltration of mononuclear cells is an indication of the immune system’s response to infection, while the presence of oedematous fluid likely relates to inflammation caused by the hypersensitivity reaction.

Development and Use of Leucocyte Migration Inhibition Test

• Apart from the skin test, another method called the leucocyte migration inhibition test (LMIT) was also developed in the study.
• Leucocyte migration inhibition refers to the prevention of white blood cells’ movement, and the test serves as an in vitro—outside the body—measure of the cell-mediated immunity to B. equi antigen.
• The test’s specificity was established, proving its effectiveness for assessing cell-mediated immunity.

Correlation between Cell-Mediated Immunity and Protection

• The results of both the intradermal skin test and the leucocyte migration inhibition test demonstrated a relationship between cell-mediated immunity and protection against the Babesia equi infection.
• This implies the importance of cell-mediated immunity in an organism’s defensive response to Babesiosis.