What Are Common Causes & Risk Factors for Lupus?
Lupus is a serious chronic autoimmune disease that can damage any part of the body. Doctors do not yet know exactly what causes lupus. They do know that some complex mix of genetics, stress, environmental exposure, and lifestyle may increase someone’s chance of developing lupus. The current medical theory is that some people inherit a predisposition for lupus and then something in their environment actually triggers the disease.
Risk factors for lupus
Gender, age, and ethnicity are risk factors for lupus. For example, women ages 15 to 44 are 9 to 10 times more likely to develop lupus than men. Women of color, particularly black women, are diagnosed with lupus at significantly higher rates than white women. Men, children, and seniors are less likely to develop lupus but it does happen.1,3
Family history of lupus
Between 20 percent and 50 percent of people with lupus have a parent or a sibling with lupus. In those with no family history of lupus, there are likely to be other autoimmune diseases such as rheumatoid arthritis or scleroderma. In identical twins, if one develops lupus, the other has a 30 increased risk of developing the disease, but only 24 percent actually do.1,3,5
There is no single gene that creates a high risk for lupus, except for the rare TREX1 mutation. That is why doctors believe that some combination of genes makes a person more likely to develop lupus if they are also exposed to the right environmental conditions.
Scientists have identified nearly 100 genetic mutations that seem to be linked to lupus. One genetic variant is found on the chromosome TNFAIP3, which regulates a protein that can cause inflammation. The TNFAIP3 mutation occurs most often in Koreans and Europeans with lupus.1,2 Other genes associated with lupus control mannose-binding protein, C-reactive protein, and cytokines; genes that direct complement receptors and antibody receptors; and genes that code Fcy-receptors.6
Having genes that predispose you to lupus does not mean that you will develop the disease.
Researchers believe that lupus develops due to a combination of genetics, lifestyle, and environment. In other words, someone may be genetically susceptible to lupus and exposure to certain risk factors increases their chance of developing the disease. However, doctors don’t know how genes and the environment interact so that one person develops lupus and another does not. A wide variety of environmental triggers are being studied, including:1-5
- Crystalline silica exposure
- Pesticide exposure, especially among agricultural workers
- Viruses and infections such as the Epstein-Barr virus
- Ultraviolet (UVA and UVB) light from the sun and fluorescent light bulbs
- Stress. Physical exhaustion and emotional stress seem to trigger the disease and flares.
- Pollution, such as air particulates and bisphenol A (BPA)
- Heavy metal exposure
- Hormones. Since most people with lupus are female, and many report more
Symptoms just before a menstrual period or during pregnancy, scientists speculate that estrogen may play a role in the severity of lupus.
Drug-induced lupus occurs when someone takes high doses of certain medicines, including hydralazine and diltiazem (for high blood pressure), procainamide (for cardiac arrhythmia), isoniazid (for malaria), sulfa drugs and minocycline (antibiotics), and TNF inhibitors (for inflammation). The symptoms of drug-induced lupus are similar to SLE lupus except that the symptoms tend to go away when the drug is stopped. This is a rare form of lupus and only occurs in about 10 percent of cases.2,3
Remember, having a risk factor for lupus does not mean that you will get lupus. It just means that you may be more likely to develop lupus if the right (for you) combination of genetics and life events take place.