Gene Boosts Risk of Tuberculosis
People with active TB five times likelier to have this gene variation, study finds
MONDAY, Dec. 12, 2005 (HealthDay News) -- A minor genetic change that increases the risk of developing active tuberculosis has been identified by researchers at the University of Texas Health Center.
They analyzed patients in Korea and Mexico and concluded that people who have a small change in the gene that encodes a protein called MCP-1 are more likely to develop TB when they're infected with TB-causing bacteria.
The change, which involves the gene's DNA sequence differing by only a single nucleotide (the building blocks of DNA), results in increased production of MCP-1. People with active TB were five times more likely to have this gene variation than people who were infected but remained healthy, the researchers said.
The finding appears in the Dec. 19 issue of the Journal of Experimental Medicine.
MCP-1 helps attract immune cells to sites of infection in the body and is important to early immune response to the TB-causing bacteria. However, exceedingly high levels of MCP-1 can inhibit production of another immune protein called interleukin-12, which is needed to activate immune cells that fight off the infection, the researchers said.
The American Lung Association has more about tuberculosis.