## **Core Concept**
Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease that can affect various parts of the body, including the kidneys, leading to lupus nephritis. The World Health Organization (WHO) classification of lupus nephritis is based on histopathological findings. Membranous glomerulonephritis is one of the patterns observed in SLE.

## **Why the Correct Answer is Right**
The WHO classification system for lupus nephritis includes several classes based on biopsy findings. Class IV is characterized by diffuse proliferative lupus nephritis, Class III by focal lupus nephritis, and Class V by membranous lupus nephritis. Membranous glomerulonephritis in SLE is associated with the deposition of immune complexes on the subepithelial side of the glomerular basement membrane, leading to thickening of the membrane. This pattern is specifically designated as Class V lupus nephritis according to the WHO.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is incorrect because it does not correspond to the correct classification for membranous glomerulonephritis in SLE.
- **Option B:** This option is incorrect as it does not accurately represent the WHO classification for membranous changes in SLE.
- **Option C:** Although not explicitly provided, typically, Class III and IV involve proliferative changes rather than membranous changes.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that membranous nephropathy (Class V lupus nephritis) in SLE often presents with nephrotic syndrome and has a relatively better prognosis compared to proliferative lupus nephritis but requires careful management.

## **Correct Answer:** .