In reflux nephropathy, glomerular lesion is?
**Core Concept**
Reflux nephropathy is a type of kidney disease characterized by damage to the kidney due to abnormal reflux of urine from the bladder back into the kidneys. This condition is often seen in children with vesicoureteral reflux, where urine flows back into the ureters and then into the kidneys, causing damage to the glomeruli.
**Why the Correct Answer is Right**
The glomerular lesion in reflux nephropathy is primarily due to the damage caused by the abnormal reflux of urine. The repeated exposure of the glomeruli to the acidic and potentially toxic components of the urine leads to scarring and fibrosis in the glomeruli. This results in a decrease in the number of functioning nephrons, leading to chronic kidney disease. The mechanism involves the activation of various inflammatory pathways and the release of pro-inflammatory cytokines, which further exacerbate the damage.
**Why Each Wrong Option is Incorrect**
**Option A:** Glomerular mesangial cell proliferation is not a characteristic feature of reflux nephropathy.
**Option B:** Tubulointerstitial fibrosis is more commonly seen in chronic kidney disease due to other causes, such as diabetes or hypertension.
**Option C:** Focal segmental glomerulosclerosis is a type of glomerular injury seen in other conditions, such as minimal change disease or focal segmental glomerulosclerosis syndrome.
**Clinical Pearl / High-Yield Fact**
Reflux nephropathy is often associated with hypertension and proteinuria, and early detection and management are crucial to prevent progression to end-stage renal disease.
**Correct Answer:** C. Focal segmental glomerulosclerosis.