Systemic lupus erythematosus (SLE) is an autoimmune inflammatory rheumatic disease, more specifically a systemic connective tissue disease (collagenosis) that can affect numerous organs, including joints, kidneys, skin, mucous membranes and blood vessel walls. According to the German Rheumatism League, almost one in 1,000 women and one in 10,000 men are affected in Germany; mostly young women between 20 and 40 years. Symptoms are varied, with lupus kidney inflammation being the most common dangerous organ involvement. 40 to 60 percent (depending on race) of people with SLE will develop lupus nephritis in their lifetime.
Early diagnosis and therapy can prevent a further loss of kidney function up to and including the need for dialysis. Virtually all patients with SLE receive hydroxychloroquine (except in the case of glucose-6-phosphate dehydrogenase deficiency). Non-steroidal anti-inflammatory drugs (NSAIDs) are also used for mild illness. In severe cases, corticosteroids are given, in active phases often as a prednisolone boost, immunosuppressants such as methotrexate, azathioprine, mycophenolate mofetil and mycophenolic acid, and antimalarials. The antibody belimumab has also been approved for active lupus nephritis since 2021. In 2022, the antibody anifrolumab came on the market. It is not yet approved for lupus nephritis, but is intended as an add-on treatment for adult patients with moderate to severe, active autoantibody-positive SLE who are already receiving standard therapy.