What Is Lupus Nephritis?

Lupus nephritis is a serious kidney condition that develops as a complication of systemic lupus erythematosus (SLE), an autoimmune disorder in which the body's immune system mistakenly attacks its own tissues. When this autoimmune response targets the kidneys, it leads to inflammation and damage known as lupus nephritis. This condition affects a significant number of SLE patients and can result in impaired kidney function if not diagnosed and treated early.

Understanding the Connection Between SLE and Kidney Damage

Systemic lupus erythematosus triggers the production of autoantibodies—antibodies that target the body's own cells and proteins. In lupus nephritis, these immune complexes circulate in the bloodstream and eventually settle in the kidneys, particularly in the glomeruli, which are responsible for filtering waste and excess fluids from the blood. This accumulation causes inflammation, disrupting normal kidney function and potentially leading to proteinuria (excess protein in urine), hematuria (blood in urine), and high blood pressure.

Key Immune Markers Associated With Lupus Nephritis

Patients with lupus nephritis often show distinct immunological abnormalities in blood tests. Common indicators include elevated levels of antinuclear antibodies (ANA) and anti-double-stranded DNA (anti-dsDNA) antibodies. Additionally, complement proteins such as C3 and C4 are typically reduced, signaling active immune system involvement. These markers not only help in diagnosing the disease but also assist doctors in monitoring disease activity and treatment response over time.

Clinical Features and Systemic Impact

Besides kidney-specific symptoms, individuals with lupus nephritis frequently experience systemic manifestations. Anemia is a common finding due to chronic inflammation and possible involvement of bone marrow function. Fatigue, swelling in the legs or around the eyes, and unexplained weight gain may also occur as a result of fluid retention caused by declining kidney performance.

Because lupus nephritis presents differently in each patient, treatment plans are highly individualized. They often involve corticosteroids and immunosuppressive medications to control inflammation and prevent further immune-mediated injury. Advances in medical therapy have significantly improved outcomes, allowing many patients to achieve remission and maintain a good quality of life.