Wire loop lesions are seen in
**Core Concept**
Wire loop lesions are a characteristic histopathological feature of certain autoimmune diseases, particularly lupus nephritis. They are formed by the deposition of immune complexes and complement components within the glomerular basement membrane, leading to its thickening and distortion.
**Why the Correct Answer is Right**
The formation of wire loop lesions is a result of the activation of the complement system, which leads to the deposition of C3 and other complement components within the glomerular basement membrane. This process causes the basement membrane to thicken and become distorted, resulting in the characteristic "wire loop" appearance under light microscopy. The immune complexes that trigger this response are typically composed of antibodies directed against antigens such as DNA or histones.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because wire loop lesions are not typically associated with conditions such as membranous nephropathy, which is characterized by a different histopathological appearance.
**Option B:** This option is incorrect because wire loop lesions are not a feature of conditions such as diabetic nephropathy, which is characterized by glomerular hypertrophy and mesangial expansion.
**Option C:** This option is incorrect because wire loop lesions are not typically associated with conditions such as focal segmental glomerulosclerosis, which is characterized by a different histopathological appearance.
**Clinical Pearl / High-Yield Fact**
Wire loop lesions are a classic histopathological feature of lupus nephritis and are often seen in conjunction with other changes such as mesangial proliferation and glomerular crescents. A high index of suspicion for lupus nephritis should be maintained in patients with a history of SLE who present with new-onset nephrotic syndrome or rapidly progressive glomerulonephritis.
**Correct Answer:** D. Lupus nephritis.