WBR231
Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
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Exam Type | ExamType::USMLE Step 1 |
Main Category | MainCategory::Pathology |
Sub Category | SubCategory::Renal |
Prompt | [[Prompt::A 68 year old Caucasian male patient presents to his physician for his annual check-up. Patient’s past medical history is significant for hypertension controlled on lisinopril and advanced diabetes mellitus type II poorly controlled on daily insulin injections. Routine work-up reveals elevated serum creatinine. A renal biopsy under light microscopy similar to the patient’s biopsy is shown in the image below. The following findings could be best explained by which of the following pathologic processes? |
Answer A | AnswerA::Amorphous pink deposits of amyloid in renal cortex |
Answer A Explanation | [[AnswerAExp::Amyloidosis is characterized by amyloid deposition that is positive for Congo red stain.]] |
Answer B | AnswerB::Immune response mediated by CD4 and CD8 lymphocytes |
Answer B Explanation | [[AnswerBExp::Immune response mediated by CD4 and CD8 lymphocytes describes the mechanism of renal rejection following transplantation.]] |
Answer C | AnswerC::Cystic distribution throughout the renal parenchyma |
Answer C Explanation | [[AnswerCExp::Polycystic kidney disease is characterized by cystic distribution throughout the renal parenchyma.]] |
Answer D | AnswerD::Immune complex deposition activating the complement pathway |
Answer D Explanation | [[AnswerDExp::The pathogenesis of several primary glomerulonephritides, including post-infectious glomerulonephritis and membranoproliferative glomerulonephritis, is characterized by immune complex deposition that activates the complement pathway.]] |
Answer E | AnswerE::Non-enzymatic glycosylation of proteins |
Answer E Explanation | AnswerEExp::Diabetic nephropathy is a common microvascular complication in advanced diabetes mellitus. Renal biopsy under light microscopy would reveal characteristic eosinophilic nodules in the glomerular tuft called “Kimmelsteil-Wilson” lesion. |
Right Answer | RightAnswer::E |
Explanation | [[Explanation::Diabetic nephropathy is a common microvascular complication in advanced diabetes mellitus. Renal biopsy under light microscopy would reveal characteristic eosinophilic nodules in the glomerular tuft called “Kimmelsteil-Wilson” lesion. Chronic hyperglycemia leads to accumulation of advanced glycosylation end products (AGEs) that trap extravasated immunoglobulins, albumin, LDL, and other proteins via cross-linking to the extra vascular matrix.
Educational objective: Diabetic nephropathy is a microvascular complication of uncontrolled diabetes mellitus. It is characterized by Kimmelsteil-Wilson lesions, which are eosinophilic nodules in glomerular tufts. The pathogenesis of diabetic nephropathy is believed to be due to accumulation of advanced glycosylation end products (AGEs). Reference: Kalia K, Sharma S, Mistry K. Non-enzymatic glycosylation of immunoglobulins in diabetic nephropathy. Clin Chim Acta. 2004;347(1-2):169-76. |
Approved | Approved::No |
Keyword | |
Linked Question | Linked:: |
Order in Linked Questions | LinkedOrder:: |