Scientists identify "common diseases" gene
risk factor behind a number of common diseases such as
cardiovascular disease, rheumatism and Multiple Sclerosis (MS), of
which up to a quarter of the population could be affected.
The gene is the first identified gene to link autoimmune diseases with cardiovascular diseases and represents a viable target for which drug treatments and therapies can be based upon.
The discovery also reveals a new area of application for statins, drugs usually taken to lower cholesterol levels. Statins have been shown to reduce activity in this gene variant and thus produce anti-inflammatory effects. Statins have now been tested on MS patients and have been demonstrated to be beneficial in this very way.
"This gene variant can therefore be one of the single largest genetic causes of complex diseases with inflammatory components," said Fredrik Piehl, associate professor at Karolinska Institutet and researcher at the CMM.
"There is also a chance that other diseases are also affected by this gene variant. The discovery can now lead to more reliable diagnostics and better treatments for a great number of patients," he added.
The gene variant was first identified in an animal model and then studied in a number of patient groups to ascertain if there was a link to human diseases. The researchers discovered that people with the variant ran a 20-40 per cent greater risk of developing rheumatism, MS or a myocardial infarction. The gene variant is also common, an estimated 20-25 per cent of the population carry it.
The disease-associated gene variant leads to a reduction in the production of a number of immune defence proteins. Some viruses and bacteria have also been observed to influence the gene in an attempt to evade the immune defence system, a strategy employed, for example, by the viruses that cause AIDS, herpes and hepatitis.
Major histocompatibility complex class II (MHCII) molecules play a pivotal role in the induction and regulation of immune responses. These MHC class II-expressing T cells (MHC2TA) are found in a wide repertoire of clinical scenarios, including autoimmune diseases, inflammation, infection, and oncogenic transformation.
Although the exact function of MHC class II on T cells is not completely resolved, activated human T cells are known to exhibit characteristics of antigen presenting cells.
The article, entitled: "MHC2TA is associated with differential MHC molecule expression and susceptibility to rheumatoid arthritis, multiple sclerosis and myocardial infarctionâ." will be published on the Nature Genetics website
