Lupus Nephritis — Advanced

Class IV lupus nephritis is diffuse proliferative disease, defined by involvement of more than half of the glomeruli. It may show endocapillary proliferation, necrosis, crescents, and subendothelial deposits, and it carries substantial risk of kidney dysfunction. Classes I and II are mesangial, while class V is membranous.

Active systemic lupus commonly produces rising anti-dsDNA titers and falling complement, particularly C3 and C4, although these markers are imperfect. They should be interpreted with proteinuria, urinary sediment, blood pressure, eGFR, and clinical context rather than used alone to diagnose renal activity.

Class V lupus nephritis is the membranous form of lupus nephritis, with subepithelial immune deposits and a nephrotic presentation being common. It can coexist with a proliferative class, in which case management must reflect the proliferative component and the overall clinical severity.

Rapidly rising creatinine with hematuria and cellular casts is a kidney emergency pattern consistent with active proliferative lupus nephritis or another rapidly progressive GN. Kidney biopsy helps determine the class, activity, and chronicity and guides treatment; delaying evaluation risks preventable irreversible scarring.

Active proliferative lupus nephritis generally requires glucocorticoids plus an additional immunosuppressive agent such as mycophenolate or cyclophosphamide, with regimen selection based on severity, comorbidity, fertility considerations, and local protocols. Supportive care alone is inadequate for organ-threatening inflammation.

Hydroxychloroquine reduces lupus disease activity and flare risk and is generally continued unless contraindicated. It does not directly remove glomerular immune deposits or replace induction therapy for proliferative nephritis. Dose adjustment and ophthalmologic monitoring are important, especially in kidney impairment.

Persistent proteinuria, active urinary sediment, hypertension, and falling eGFR together suggest ongoing renal injury and higher progression risk. A transient symptom or an isolated normal laboratory value does not exclude lupus nephritis, so trends and the complete renal assessment are essential.

Immunosuppression increases the risk of bacterial, viral, and opportunistic infection and can affect fertility and pregnancy. Prevention includes vaccination planning, screening and prophylaxis when indicated, blood-count and liver monitoring, and shared reproductive counseling before therapy.

When worsening proteinuria or kidney function could represent active inflammation, chronic scarring, thrombotic microangiopathy, or a different lesion, repeat biopsy can clarify the mechanism. This distinction matters because active lesions may respond to immunosuppression, whereas chronic scarring is not reversed by escalating therapy.

After induction response, maintenance treatment with mycophenolate or another appropriate immunosuppressant reduces relapse risk while limiting cumulative toxicity. Long-term care also includes hydroxychloroquine when appropriate, blood-pressure and proteinuria control, infection prevention, reproductive planning, and serial assessment of renal activity.