What is the definition of Lupus (Systemic Lupus Erythematosus) nephritis?

From the Guidelines

Lupus nephritis is defined as kidney inflammation caused by systemic lupus erythematosus (SLE), an autoimmune disease, affecting approximately 20-60% of patients with SLE, with the goal of treatment being to preserve kidney function and reduce morbidity and mortality associated with chronic kidney disease (CKD) and kidney failure, as stated in the kdigo 2024 clinical practice guideline for the management of lupus nephritis 1.

Key Points

• Lupus nephritis occurs when the immune system mistakenly attacks the kidneys, causing inflammation in the glomeruli, which are the kidney's filtering units.
• The condition can range from mild to severe and is classified into six different classes based on the pattern and severity of kidney damage observed under microscopic examination.
• Symptoms may include foamy urine, blood in urine, high blood pressure, swelling in the legs, ankles or around the eyes, and increased protein in urine.
• Diagnosis typically involves blood tests, urine tests, and often a kidney biopsy to determine the specific class of nephritis.
• Treatment aims to reduce inflammation, suppress the immune system, and prevent permanent kidney damage, with common medications including corticosteroids, immunosuppressants, and medications to control blood pressure, as recommended by the american college of rheumatology guidelines for screening, treatment, and management of lupus nephritis 1 and the joint european league against rheumatism and european renal association-european dialysis and transplant association (eular/era-edta) recommendations for the management of adult and paediatric lupus nephritis 1.

Treatment Recommendations

• The ultimate goals of treatment in lupus nephritis are long-term preservation of renal function, prevention of disease flares, avoidance of treatment-related harms, and improved quality of life and survival, as stated in the eular/era-edta recommendations 1.
• Initial treatment may include mycophenolic acid (MPA) or low-dose intravenous cyclophosphamide (CY) in combination with glucocorticoids, with the goal of achieving complete renal response with UPCR <50 mg/mol and normal or near-normal renal function.
• Subsequent treatment may involve immunosuppression with either MPA or azathioprine (AZA) for at least 3 years, in combination with low-dose prednisone, with gradual drug withdrawal attempted after improvement.

From the FDA Drug Label

The patients had a clinical diagnosis of SLE according to American College of Rheumatology classification criteria; biopsy-proven lupus nephritis Class III, IV, and/or V; and had active renal disease at screening requiring standard therapy

Lupus nephritis is defined as biopsy-proven lupus nephritis Class III, IV, and/or V with active renal disease. Key characteristics include:

• Clinical diagnosis of SLE according to American College of Rheumatology classification criteria
• Biopsy-proven lupus nephritis
• Active renal disease at screening requiring standard therapy 2

From the Research

Definition of Lupus Nephritis

• Lupus nephritis (LN) is a form of glomerulonephritis that constitutes one of the most severe organ manifestations of the autoimmune disease systemic lupus erythematosus (SLE) 3.
• It is associated with significant morbidity and mortality in SLE patients, as up to 20% of patients progress to end-stage renal disease (ESRD) 4.
• LN is a common manifestation of SLE that can lead to irreversible renal impairment 5.

Clinical Manifestations and Diagnosis

• The clinical manifestations of LN are variable, ranging from asymptomatic proteinuria to a myriad of manifestations associated with nephritic and nephrotic syndromes and ESRD 4.
• Urinalysis is a useful screening test in LN, and quantification of proteinuria can be performed with either a urine protein-to-creatinine ratio or 24-h urine sample collection for protein 4.
• Renal biopsy remains the gold standard for diagnosis of LN 4.

Treatment and Management

• Treatment of LN usually involves immunosuppressive therapy, typically with mycophenolate mofetil or cyclophosphamide and with glucocorticoids 3.
• Combined with high-dose prednisone, mycophenolate mofetil (MMF) has emerged as a first-line immunosuppressive treatment 6.
• A combination of medium-dose prednisone, methylprednisolone pulses, cyclophosphamide, and hydroxychloroquine is at least as effective in achieving remission of lupus nephritis as regimes containing high-dose prednisone and causes less toxicity 7.