Renal Pathology 5: Vascular Disease (Dobson)

Question 1

Nephrosclerosis

Answer 1

sclerosis of renal arterioles and small arteries; strongly associated with aging and HTN; causes cortical scarring and shrinking; thickened walls/narrowed lumens leads to focal parenchymal ischemia; resembles “grain leather”

Question 2

HTN secondary to renal stenosis is caused by what?

Answer 2

increased production of renin from the ischemic kidney

Question 3

Fibromuscular dysplasia (FMD)

Answer 3

focal irregular thickening in medium and large muscular arteries including renal, carotid and vertebral vessels; cause is unknown; medial and intimal hyperplasia leads to luminal stenosis; “string of beads” appearance on angiography

Question 4

“string of beads” appearance on angiography

Answer 4

Fibromuscular dysplasia (FMD); focal irregular thickening in medium and large muscular arteries that leads to to luminal stenosis

Question 5

Thrombotic microangiopathy

Answer 5

encompasses a spectrum of clinical syndromes that includes thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) - can be typical and atypical

Question 6

Typical HUS

Answer 6

acquired; Shiga toxin-mediated by intestinal infection with E. coli ( 0157:H7 most common); children and older adults are at higher risk; managed by dialysis; long term prognosis is poor

Question 7

Clinical presentation of typical HUS

Answer 7

Prodrome of influenza-like or diarrheal symptoms then sudden onset of bleeding (hematemesis and melena), severe oliguria and hematuria, hemolytic anemia, prominent neurological changes and HTN

Question 8

Atypical HUS

Answer 8

inherited deficiency of complement-regulatory proteins, most commonly Factor H (breaks down alternative pathway C3 convertase) and protects cells from damage caused by uncontrolled complement activation; tx: irradiation to the kidney

Question 9

Thrombotic Thrombocytopenic Purpura (TTP)

Answer 9

deficiency of ADAMTS13 (plasma protease that cleaves vWF multimers into smaller sizes; pentad: fever, neurological symptoms, microangiopathic hemolytic anemia, thrombocytopenia, and renal failure

Question 10

Deficiency of ADAMTS13

Answer 10

Thrombotic Thrombocytopenic Purpura (TTP); plasma protease that cleaves vWF multimers into smaller sizes; pentad: fever, neurological symptoms, microangiopathic hemolytic anemia, thrombocytopenia, and renal failure

Question 11

Bilateral renal artery disease

Answer 11

diagnosed by arteriography; common cause of chronic ischemia with renal insufficiency in older adults; surgical revascularization can prevent further decline in renal fxn

Question 12

Sickle Cell Nephropathy

Answer 12

Sickle cell disease patients that have sickling in the vasa recta; decrease concentrating ability and increase thrombosis; can be cortical scarring and patchy papillary necrosis

Question 13

“flea-bitten” appearance

Answer 13

Malignant nephrosclerosis; petechial hemorrhage that have a “flea-bitten” appearance.

Question 14

Clinical presentation of malignant nephrosclerosis

Answer 14

systolic >200 and diastolic >120 mmHg, papilledema, retinal hemorrhages, encephalopathy, cardiovascular abnormalities and renal failure

Question 15

Treatment for TTP

Answer 15

can be treated in most patients with plasmapheresis; removes autoantibodies and provides functional ADAMTS13