Cannabis may offer some hope to people with autoimmune disorders like lupus and rheumatoid arthritis. It seems to decrease inflammation in the body by suppressing certain parts of the immune system. Researchers are hoping that these new study results will lead to new treatments down the road.

Previous studies have hinted at immune system abnormalities among cannabis users. Such as in the function of immune system cells called T lymphocytes and natural killer cells that help the body fight infections, and no direct link with lowered immunity has yet been shown.

In this study, researchers tested the blood of 29 cannabis smokers - 13 people who used it occasionally and 16 "regular" users (weekly or daily use). These results were compared with a group of 32 nonsmokers.

Researchers found that cannabis smokers had fewer immune-enhancing natural killer cells and lymphocytes, and higher levels of proteins (called interleukin-10) that may promote tumor growth. Such changes can dampen the immune system's response to infection, increasing susceptibility to infections and promoting growth of tumors.

They also say this finding could lead to new treatments for people with autoimmune disorders. Current treatments suppress the immune system, which calms the abnormal immune response in people with such conditions. Cannabis lowers levels of the inflammation-promoting protein interleukin-2 and raises levels of the anti-inflammatory protein interleukin-10.

Source: The Journal of the American Medical Association, April 16, 2003 as reported by WebMD.