Tuberculosis tricks body's immune system to spread

Tuberculosis (TB) tricks the immune system into attacking the body's lung tissue so the bacteria are allowed to spread to other people, new research suggests.
Researchers from the University of Southampton in the UK propose that current ideas about how tuberculosis develops in patients may be incomplete and that, in fact, infection causes autoimmunity, where the immune system reacts incorrectly to its own tissue.
Tuberculosis kills more people than any other infectious disease, and the causative bacterium, Mycobacterium tuberculosis, is becoming increasingly resistant to antibiotics used to treat the infection.
The research team conducted a review of published studies and found evidence suggesting that an autoimmunity process develops in TB.

"We are not disputing that the immune system mainly targets the bacteria to fight it off, but we are suggesting that there is more to the story," said Professor Paul Elkington, from Southampton, who led the project.
"It seems that TB tricks the immune system into damaging our own lung tissue, which therefore makes the person highly infectious through coughing and the TB then spreads by aerosol droplets to other individuals," said Elkington.

"There is also a group of patients who develop a range of symptoms, such as eye inflammation, joint inflammation and skin rashes, that are not explained by current TB disease concepts," he said.

"These symptoms are usually associated with diseases like rheumatoid arthritis and Crohn's disease, which led us to believe autoimmunity plays a key role in the TB disease process," Elkington said.
Elkington highlights that more research is needed to investigate the hypothesis but if it is proved, the discovery could have major implications for the design of new vaccines and drug treatments.
The study was published in the journal Trends in Immunology.