A team from the University of Michigan used mice to reveal the particular gene group known as “human leukocyte antigen” (HLA) that are already linked to autoimmune disorders also initiates the cells that destroy the bones as part of rheumatoid arthritis.
The HLA gene family is an inherited group that helps in making proteins that help the immune system against viruses and bacteria. Scientists already know that the presence of one particular subset of these genes puts an individual at risk of developing rheumatoid arthritis but the reason for this was not known.
The Michigan team decided to test a theory that suggests the link between the specific HLA genes and autoimmune disorders is down to the HLA genes wrongly identifying tissue as foreign and turning the immune system on the body.
Their conclusion dismisses that theory and reveals instead that a subset of HLA genes is actually the cause of arthritis because it switches on both the cells that cause inflammation and those that destroy bone, known as osteoclasts.
The study, reported in the Journal of Immunology, is regarded as a major breakthrough in figuring out why some genes are linked to a greater risk of rheumatoid arthritis. The results could lead to improvements in treatment of the disorder and other autoimmune diseases by developing drugs that block the genes’ pathway.
Rheumatoid arthritis is a debilitating condition that causes inflammation in the joints, bone degeneration, joint deformity and pain, and can cause decreased mobility.