Smoking discovery implicated in autoimmune diseases

May 2 (UPI) -- Researchers have found a link between reduced levels of a cell involved in the development of autoimmune diseases and smoking tobacco.

A study by researchers in Denmark have found that smokers have reduced levels of mucosal-associated invariant T, or MAIT, cells, which are associated with autoimmune diseases.

Researchers analyzed the relationship between reduced MAIT cells in smokers and an increased risk in developing certain diseases like multiple sclerosis, or MS.

The study was published in the Journal of Leukocyte Biology.

"It is clear that smoking is detrimental to overall health and can predispose to many diseases," John Wherry, deputy editor of the Journal of Leukocyte Biology, said. "These new studies shed light on how smoking can also influence the immune system, an effect that may have implications in autoimmunity and also in other settings such as cancer and chronic inflammatory diseases."

Researchers analyzed circulating immune cell phenotypes, quantified antigen-induced proliferation and cytokine secretion in smokers and nonsmokers in a cohort of 100 healthy participants.

The study found that the frequencies of MAIT cells were decreased in healthy individuals and patients with MS and that T cells from smokers were not more easily activated when they encountered foreign- and self-antigens.

"We believe that our study represents an important contribution to the understanding of systemic immune cell alterations in smokers," Dr. Cecilie Ammitzboll, a researcher from the Danish Multiple Sclerosis Center in Copenhagen, Denmark, said in a press release. "From our findings we hope that focused research in specific cell populations might reveal pathogenic mechanisms contributing to the understanding of diseases associated with smoking."