Lupus nephritis

Lupus nephritis is an inflammation of the kidneys caused by systemic lupus erythematous (SLE) or lupus, which is an autoimmune disorder. It mostly affects on joints, skin, kidneys, heart, lungs, blood, or brain.

The kidneys play an important role in body’s functioning. If they are impaired, they cannot remove wastes from your blood. The antibodies produced by the lupus attacks on the glomeruli of the kidney, making them unfunctional. Untreated lupus nephritis can lead to permanent damage of the kidney. It occurs mostly in ages between 20 and 40.

Causes of Lupus Nephritis

Lupus nephritis is caused by SLE. The body’s own immune system develops antibodies and attacks in different areas in the body. It attacks on the filtering structures of kidney (glomeruli) and reduces their functioning leading to accumulation of waste products in the body.

Signs and Symptoms of Lupus Nephritis

  • The common symptoms of lupus nephritis include: dark urine, blood in urine, foamy or frothy urine, increased urination (especially at night), edema in the feet, ankles, and legs, weight gain, high blood pressure, pain in mid-back or flank, and vomiting.

Staging of Lupus Nephritis

Upon diagnosis of lupus nephritis, the severity of damage is represented by staging. The stages of lupus nephritis include:

Stage 1: No evidence of lupus nephritis.
Stage 2: Very mild lupus nephritis and is easily treated with corticosteroids.
Stage 3: Earliest stage of advanced lupus. High amounts of corticosteroids are required for the treatment.
Stage 4: Advanced stage of lupus. The risk of kidney failure is high. High amounts of corticosteroids and immune suppression medications are required for the treatment.

The diagnostic tests for lupus nephritis include:

Blood Tests: Blood tests are required to check the levels of waste products, such as creatinine and urea. If the test shows increased levels of waste products in the blood, it may indicate lupus nephritis.
24-Hour Urine Collection: This test is used to measure the kidney’s ability to filter wastes. It is used to determine the amount of protein that appears in urine over 24 hours.
Urine Tests: Urine tests are required to measure the functioning of kidney. Urine tests help in identifying the levels of protein, red blood cells, and white blood cells.
Iothalamate Clearance Testing: A contrast dye is used to observe the filtering property of kidneys. Radioactive iothalamate is injected into the blood, and the doctor will test how quickly it is excreted in urine and blood. It is considered as the most accurate test of kidney filtration speed.
Kidney Biopsy: Biopsies are the most accurate way to diagnose the level of kidney disease. A long needle through will be inserted through the stomach and into the kidney. A sample of kidney tissue will be taken for analysis.
Ultrasound: Sound waves are used to create detailed images of the kidney. The images help in identifying abnormal size and shape of a kidney.

Treatment for lupus nephritis is based on the stage and severity of nephritis. The goal of treatment is to improve kidney functioning and delay or prevent kidney failure. There is no cure for lupus nephritis. The medications include:

Immunosuppressive Drugs: These are medications are used to suppress the immune system, such that it stops attacking and damaging the kidneys. Cyclophosphamide, azathioprine, and mycophenolate are some of the medications used in the treatment.
Corticosteroids: These drugs are used to decrease the inflammation in the kidneys. Prednisone is one of the corticosteroids used for the treatment.
Blood Pressure Medications: The increased blood pressure can be lowered by medications such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs).
Hydroxychloroquine: It is used for treating SLE.
Diuretics: help the kidneys in removing waste fluids from the body.

Dialysis and kidney transplant are required for patients with kidney failure due to lupus nephritis.