Systemic Manifestations of Rheumatic Diseases: Renal Implications in Lupus and Vasculitis

Rheumatic diseases such as systemic lupus erythematosus (SLE) and vasculitis can have profound effects on renal function. These disorders often lead to complications such as glomerulonephritis, proteinuria, and ultimately renal failure, posing significant challenges in patient management.

Renal Manifestations of Lupus

Lupus nephritis, a serious complication of SLE, results from immune complex deposition in the glomeruli, leading to inflammation and progressive kidney damage. Clinical manifestations include:

• Proteinuria: Indicative of glomerular dysfunction and frequently associated with nephrotic syndrome.
• Hematuria: Due to glomerular inflammation and capillary damage.
• Hypertension: Resulting from renal impairment and secondary hyperaldosteronism.

Renal Involvement in Vasculitis

Vasculitis, particularly ANCA-associated vasculitis (AAV), can lead to rapidly progressive glomerulonephritis. Major types include:

• Granulomatosis with Polyangiitis (GPA): Affects small blood vessels leading to necrotizing glomerulonephritis.
• Microscopic Polyangiitis (MPA): Associated with crescentic glomerulonephritis and renal dysfunction.
• Eosinophilic Granulomatosis with Polyangiitis (EGPA): Less frequently impacts renal function but may cause interstitial nephritis.

Diagnosis and Management

Diagnosis typically involves:

• Serologic tests (ANA, ANCA)
• Urinalysis (proteinuria, hematuria assessment)
• Renal biopsy (histopathologic confirmation)

Management strategies include immunosuppressive therapy with corticosteroids, cyclophosphamide, or mycophenolate mofetil, aimed at controlling inflammation and preventing progression to renal failure.