Causes of Lupus

The exact cause of lupus is still unknown. Researchers have explored hormones, genetics, and environmental triggers as the culprit for lupus. Recently, research has also focused on epigenetics or the role of the environment in activating specific genetic markers.

These possible causes are examined in detail below.

Hormones

About nine out of ten cases of lupus are of women. Lupus also manifests in women during the child-bearing age. Hormones are said to be the leading cause of lupus in women. The onset of menstruation until pre-menopause is said to expose women to high estrogen levels. Lupus also flares mostly before menstrual periods and during pregnancy. Still, some other studies suggest that it’s not just hormones but sex as well. The female X chromosome carries CD40 which contributes to the development of lupus. Patients also experience more flares during pregnancy and researchers still have not discovered whether estradiol or progesterone cause this.

Genetics

Studies on what specific genes set off lupus are still ongoing. There may be around 50 to 100 genes that make you susceptible for lupus. In identical twins where one has developed lupus, the remaining twin has a 30% chance of getting it too. If you have a family member or relative who has lupus, your risk is 10% higher especially if other members of the family have other autoimmune diseases.

People of color are also at higher risk of getting lupus. African-Americans, Asians, Hispanic/Latino, Native Americans, native Hawaiians, and Pacific Islanders might share similar genes that predispose them to lupus. It has also been observed that some lupus patients come from more diverse backgrounds although the link is not established.
Epigenetics can also explain why some people who have higher risks for lupus never really develop it especially in the case of identical twins.

Environment

Some environmental factors are known to activate flares. It follows that these environmental agents are investigated too, but there is no definite link established yet. If someone who is predisposed to lupus is in an environment that has known triggers, their chances of manifesting the disease are certainly higher. Here are some environmental agents:

  • UV rays both from artificial and natural light can elicit skin rashes and lesions of susceptible people.
  • Cigarette smoking has a link to lupus and other autoimmune diseases. Smoking is thought to damage DNA and increase anti-dsDNA antibodies, responsible for attacking the body’s own cells.
  • Exposure to certain substances like silica, solvents, pesticides, and heavy metals. Although it’s not yet clear how exactly they trigger lupus, silica has been linked to the increase of pro-inflammatory cytokines.

Others

Drug-induced lupus is normally caused by drugs like hydralazine, minocycline, quinidine, chlorpromazine, methyldopa, and minocycline to name a few. Unlike SLE, symptoms for drug-induced lupus disappear when the patient stops taking the drugs.

References:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728979/

https://www.ncbi.nlm.nih.gov/books/NBK459474/

https://www.webmd.com/lupus/understanding-lupus-prevention#1

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4965307/

https://resources.lupus.org/entry/what-causes-lupus