Tocilizumab Successful in Slowing Down Tuberculosis Bacillus Infection in Adult Patients

Immunologists have found that a drug used to fight arthritis also stops the process that allows the tuberculosis bacillus to infect and hijack blood stems.

About a quarter of the world population is a carrier of Koch’s bacillus, bacteria which can cause tuberculosis. Most of those who are infected have latent tuberculosis (TB), meaning that they don’t become ill. However, this latent TB can turn in active tuberculosis when the immune system becomes weaker, such as in elderly patients or patients living with HIV.

TB is mostly known as a lung disease and pulmonary TB is the infectious form, but TB can affect all tissues and organs. It is still unknown how the disease spreads through the body, although researchers suspected that the bacillus hides in the bone marrow. It is known that blood stem cells are often manipulated into becoming a host.

In this study, the research team used blood stem cells from bone marrow and umbilical cord blood of healthy donors. They then put these blood stem cells in a test tube and exposed the to the TB bacillus. As a result, 2 processes took place: the bacillus infected and started multiply in the blood stem cells.

At the same time, the blood stem cells transformed themselves into a specific type of white blood cell. White blood cells typically defend the body against infections, but in this case they were hijacked by the bacillus and became ideal host cells.

The researchers then did a large-scale computer analysis of databases with genes that are important for both TB and blood stem cells. To their surprise, this analysis led them to a medicine against arthritis known as tocilizumab. When administered in the test tube, the transformation of the blood stem cells into host cells ceases and the multiplication of TB bacilli slows down.

The study authors noted that running tests in the lab is not the same as actually treating patients. Further research and testing will be needed to explore the potential of their findings.

Reference

• Anti-arthritis drug also stops tuberculosis bacillus from multiplying in blood stem cells [press release]. KU Leuven website. Published October 22, 2019. https://nieuws.kuleuven.be/en/content/2019/arthritis-tuberculosis. Accessed January 2, 2020.