What is Lupus Nephritis?
Lupus nephritis is a serious kidney inflammation caused by systemic lupus erythematosus (SLE), an autoimmune disease in which the body’s immune system attacks its own tissues. When lupus affects the kidneys, it can impair their ability to filter waste and regulate fluids, electrolytes, and blood pressure.
What Causes Lupus Nephritis?
Lupus nephritis occurs when autoantibodies (immune proteins that mistakenly target the body’s own cells) attack the kidneys, particularly the glomeruli - the filtering units. This leads to inflammation, swelling, and scarring that reduce kidney function. Genetic factors, infections, hormones, and environmental triggers (like sunlight or certain medications) can contribute to its development.
What are the Signs and Symptoms of Lupus Nephritis?
The common signs and symptoms of lupus nephritis include the following:
- Swelling (edema) in the legs, ankles, or around the eyes
- Foamy or frothy urine (indicating protein loss)
- Blood in urine (hematuria)
- High blood pressure
- Fatigue
- Weight gain due to fluid retention
How is Lupus Nephritis Diagnosed?
Lupus nephritis is diagnosed through a combination of clinical evaluation, laboratory tests, and kidney biopsy.
Doctors start by checking for signs of kidney involvement in people with lupus, such as protein or blood in the urine and changes in kidney function. Common diagnostic tests include:
- Urinalysis – to detect protein, red blood cells, or cellular casts in the urine.
- Blood tests – to assess kidney function (creatinine, blood urea nitrogen) and measure lupus-related antibodies such as ANA, anti-dsDNA, and complement levels (C3, C4).
- Kidney biopsy – a small tissue sample from the kidney is examined under a microscope to confirm the diagnosis, determine the type and severity of lupus nephritis, and guide treatment.
These tests together help doctors accurately identify and classify the condition for proper management.
How is Lupus Nephritis Treated?
Lupus nephritis is treated with the goal of reducing kidney inflammation, preventing further damage, and preserving kidney function. Treatment depends on the severity and type of kidney involvement, as confirmed by biopsy results.
Main treatments include the following:
- Corticosteroids (e.g., prednisone) – to quickly reduce inflammation in the kidneys.
- Immunosuppressive medications – such as mycophenolate mofetil (CellCept), cyclophosphamide, or azathioprine- to control the overactive immune response.
- Biologic therapies – drugs like belimumab or rituximab may be used in resistant cases to target specific immune cells.
- Blood pressure control – with medications such as ACE inhibitors or ARBs, which also help reduce protein loss in urine.
- Lifestyle and supportive care – including limiting salt and protein intake, avoiding smoking, and maintaining a healthy weight.
With early detection and effective treatment, many patients achieve remission. However, severe or untreated lupus nephritis can lead to chronic kidney disease or end-stage renal failure, requiring dialysis or a kidney transplant.
