A32-year old African-American male presents with recurrent edema of the feet and periorbital swelling. He has a history of high risk sexual behavior. The blood pressure was 110/85 mm Hg. Results of the laboratory investigations are as follows : HBs Ag : Negative Blood glucose : Normal HIV ELISA : Positive 24-hour urine protein : 3.9 g Urine microscopy : Fatty casts, oval fat bodies. An H and E stain of the renal biopsy is most likely toshow-

**Core Concept**
The patient's presentation of recurrent edema, periorbital swelling, and laboratory findings of proteinuria, fatty casts, and oval fat bodies, in the context of a positive HIV ELISA result, suggests an HIV-associated kidney disease, specifically HIV-associated nephropathy (HIVAN). HIVAN is a common cause of chronic kidney disease in individuals with HIV infection, particularly those of African descent.

**Why the Correct Answer is Right**
HIVAN is characterized by the presence of collapsing glomerulopathy, which is a specific histopathological pattern seen in the renal biopsy. This pattern is characterized by the collapse of the glomerular tuft, leading to a "collapsed" appearance. The presence of HIVAN is often associated with the HIV-1 subtype B, which is more prevalent in individuals of African descent. The patient's high-risk sexual behavior and positive HIV ELISA result further support the diagnosis of HIVAN.

**Why Each Wrong Option is Incorrect**
**Option A:** Focal segmental glomerulosclerosis (FSGS) is a common cause of nephrotic syndrome, but it is not specifically associated with HIV infection.
**Option B:** Membranous nephropathy is a cause of nephrotic syndrome, but it is not typically associated with HIV infection.
**Option C:** Acute tubular necrosis (ATN) is a cause of acute kidney injury, but it is not typically associated with HIV infection or the specific histopathological pattern seen in HIVAN.

**Clinical Pearl / High-Yield Fact**
HIVAN is a common cause of chronic kidney disease in individuals with HIV infection, particularly those of African descent. It is essential to consider HIVAN in the differential diagnosis of patients with kidney disease and a history of high-risk sexual behavior or HIV infection.

**Correct Answer:** C. Collapsing glomerulopathy is a specific histopathological pattern seen in HIVAN.

✓ Correct Answer: A. Segmental sclerosis of some of the glomeruli