London, August 2 : Scientists at the Oklahoma Medical Research Foundation have identified a gene mutation that may cause the immune system to remain active even after fighting an infection, and thus lead to damage in the body.
The researchers say that this effect may result from a variation of the gene called TNFAIP3.
"TNFAIP3 can be thought of as a critical brake mechanism for the immune system. When the gene doesn't function properly, the immune system redlines," Nature magazine quoted Dr. Patrick Gaffney, the senior author on the study and associate member of OMRF's Arthritis and Immunology Research Program, as saying.
He said that his team has observed that the immune system has trouble turning itself off in lupus patients with the gene variant, while normal versions of TNFAIP3 produce a protein (called A20) in healthy individuals that regulates and shuts off the immune response.
"We suspect that the variant either doesn't make enough of the protein, or it makes a less effective protein. Our data adds TNFAIP3 to a growing list of lupus-associated genes that may help us diagnose and treat our patients," he said.
A research article in the journal Nature Genetics describes lupus as a chronic "autoimmune" disease in which the body's immune system attacks healthy tissues and organs.
Its symptoms range from skin rashes and joint pain to strokes, seizures and organ failure.
Though lupus is a multi-genic disease, the researchers believe that the TNFAIP3 variant may work in concert with other mutant genes to cause it in some patients.
"Every single lupus-associated gene we discover is just as important as the others. Each gene can set off new opportunities and new projects for us. You never know which gene is going to give you the best chance to develop new therapeutics or better diagnostics," Dr. Kathy Moser, another researcher associated with the study.
Gaffney said that he and his colleagues would continue studying the TNFAIP3 variant for links to any other gene variations.
"We also want to know exactly what effect the gene variation has on A20 protein production and function," he said.