Autoimmune Disease: Lupus Overview

Lupus is a chronic autoimmune disease that causes inflammation. This inflammation can affect many different parts of the body, including the skin, joints, brain, heart, blood vessels, and kidneys.¹ There are several types of lupus, although systemic lupus erythematosus (SLE) is the most common.² SLE affects each person differently, and its effects can also change over time, making it difficult to diagnose and treat. Signs and symptoms include constitutional symptoms (e.g., fatigue, fever, weight loss) and mucocutaneous involvement (e.g., skin lesions, oral and nasal ulcers).³ The central nervous system can also be affected; the signs and symptoms of neuropsychiatric SLE range from mild cognitive dysfunction to seizures and stroke.⁴ People with SLE have an increased risk of death, with common causes being infections and cardiovascular and renal disease.³

The complex and potentially life-threatening nature of this autoimmune disorder disproportionately impacts women and communities of color.^{3 , 5} While the etiology of SLE is still unclear, it seems to have a strong genetic component. It is most commonly diagnosed in women aged 15 to 45 years,⁶ which suggests that some of the genes on the X chromosome are involved in its development.³ There is also evidence that hormones such as estrogen can play a role, as the use of estrogen-containing contraceptives and hormone replacement therapy can cause SLE symptoms to flare up. Certain environmental factors (e.g., smoking) can also increase the risk of SLE.³

SLE can cause serious pregnancy complications, including spontaneous abortion, maternal thrombosis, and pre-eclampsia. In addition, certain maternal antibodies can cross the placenta and cause fetal heart block and a rare condition called neonatal lupus in the infant. SLE can also trigger other health problems in women, such as coronary artery disease and renal disease.^{2 , 3}

Because SLE is a heterogenous disease and the signs and symptoms overlap with those of other conditions, it can be difficult to diagnose. The vast majority of people with SLE will have a positive antinuclear antibody (ANA) test result; however, people with other conditions and healthy people can have positive ANA results as well, so this test should be followed by further testing for specific antibodies.^{3 , 7} There is currently no definitive cure for SLE, but antimalarials, corticosteroids, immunosuppressants, and other drugs can help manage symptoms and prevent organ damage.^{3 , 7} B cells are known to play a role in the pathophysiology of SLE, with autoreactive B cells producing autoantibodies and pro-inflammatory cytokines. Accordingly, some strategies for managing SLE include the use of B cell-depleting therapies.⁸ Research on potential treatments for SLE is ongoing, and some therapies, such as chimeric antigen receptor T (CAR-T) cell therapy, are showing potential.⁹

The Lupus Clinical Trials Unit at the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) conducts research on many aspects of SLE, including genes that are associated with a higher risk of lupus, biomarkers that help predict flares in people with lupus, and sex differences in immune and inflammatory systems. NIAMS also funds and supports researchers at other organizations who are working to better understand the causes of this condition.¹⁰