The connection between lupus and arthritis
Arthritis is a common symptom of lupus (systemic lupus erythemaosus). Inflammatory arthritis is also the hallmark of rheumatoid arthritis. The arthritis of lupus tends to be less destructive than the arthritis of rheumatoid arthritis. However, there is a genetic link between rheumatoid arthritis and lupus, and a person may experience features of both these two distinct diseases.
When a person has two independent diseases, it’s called comorbidity. According to one article, the lupus/rheumatoid arthritis comorbidity might be based in genetics.
Just one gene in your body may cause both lupus and arthritis.
What is lupus?
Lupus is an autoimmune disease that attacks joints and internal organs, including the heart, lungs, brain, and kidneys. People with lupus often have a characteristic facial rash. This rash as well as other body rashes can worsen with sun exposure.
Lupus can also cause more serious health conditions, such as seizures. Some people with lupus also have low red blood cell counts. This can lead to anemia or low white blood cell counts that weaken your immune system and expose you to infections.
What is arthritis?
Arthritis, by definition, is inflammation of the joints. It can cause everything from simple morning stiffness to swelling and pain. According to a CDC report, 25.6 percent of people with arthritis suffer severe joint pain, and 37.7 percent say that the pain affects their daily activities.
This inflammatory condition is associated with redness and swelling of the joints. If you have arthritis, your joints might have a limited range of motion. This can prevent full extension and flexion of the joints and lead to pain, discomfort, and ultimately disability.
The genetic link
A 2007 study showed a genetic link between lupus and rheumatoid arthritis. That link has to do with mutations of the gene STAT4.
People who carry a mutated version of this gene have twice the risk of developing lupus. They also have a 60 percent higher risk of developing rheumatoid arthritis.
Scientists don’t know what causes the STAT4 gene to mutate. They do know that when it happens, the risk of developing autoimmune disorders increases. According to the U.S. National Library of Medicine’s Genetics Home Reference, mutations of the STAT4 gene also increase the risk of juvenile idiopathic arthritis and systemic scleroderma. The latter is a disease characterized by tightening and hardening of the skin and the supporting connective tissue.
Unfortunately, there’s no easy way to know whether you carry a variant of STAT4. Genetic testing is still in its early stages, and it might take decades before scientists develop accurate tests that are available to the public.
So far, all the research involving the STAT4 gene has been done at universities or medical centers. These studies are paving the way to learning how genes and autoimmune diseases are connected. One day, they might also lead to new, more effective forms of treatment.
What can be done?
The genetic connection between lupus and rheumatoid arthritis means that both diseases could respond to similar treatments. Depending on your symptoms, you might need to combine a number of treatments to help you control flare-ups and reduce organ damage.
Both rheumatoid arthritis and and the arthritis of lupus might require drugs to help prevent damage to the joints and reduce painful swelling. Any treatment plan for arthritis should include physical therapy, which will include basic stretches, exercises to ease joint stiffness, and instructions on joint protection.