Diabetic Nephropathy

Question 1

First sign of diabetic nephropathy?

Answer 1

Microalbuminuria

Question 2

Histological signs of diabetic nephropathy?

Answer 2

Increased mesangial matrix

Glomerular collapse and sclerosis

Question 3

Describe the 5 stages of kidney disease in DN?

Answer 3

1) Asymptomatic; increased GFR
2) Glomerular damage-> microalbuminemia
3) Protein loss over 300mg/day; BUN and Cr rise
4) Decreased GFR; BUN and Cr rise
5) GFR less than 10

Question 4

Explain glomerular hyperfiltration

Answer 4

Glucose is an osmotic diuretic that increases filtration, thereby causing glomerular hypertrophy and increasing glomerular pressure. The kidney becomes hypertrophic and the glomerular failure is accelerated, resulting in glomerulosclerosis and ultimately, reduced GFR.

So inc GFR and size first, then decrease.

Question 5

What role do AGEs play in diabetic nephropathy?

Answer 5

Nonenzymatic glycosylation of the GBM and afferent/efferent arterioles causes damage through hyaline arteriosclerosis

Question 6

Explain the pathogenesis through glycosylation

Answer 6

AGEs glycoslyate GBM and arterioles, causing increase in permeability to protein and hyaline sclerosis

Question 7

What is the treatment goal for diabetic nephropathy?

Answer 7

Lower BP to under 130/80

Question 8

What is the treatment for diabetic nephropathy?

Answer 8

ACEi (-prils)
ARB (-sartans)
Beta blockers

Question 9

What is a good prognosis marker?

Answer 9

Proteinuria level; baseline is good predictor of ESRD onset

Question 10

What are some complications of diabetes nephropathy?

Answer 10

Pyelonephritis risk
Tubular acidosis type IV
Neurogenic bladder
At risk for nephrotoxic drugs

Question 11

What type of diabetic nephropathy is most common?

Answer 11

Diffuse (global) glomerular

Question 12

What are the microscopic features of diffuse diabetic glomerulopathy?

Answer 12

Mesangial thickening

BM thickening

Question 13

What type of diabetic glomerulopathy is of later onset and is seen only about 10 years after having diabetes?

Answer 13

Nodular

Question 14

What are the features of nodular diabetic glomerulopathy?

Answer 14

Kimmelstiel-Wilson nodules and hyaline sclerosis of afferent and efferent arterioles

BM thickening of capsule and capillaries

Question 15

What are Kimmelstiel WIlson nodules and where are they found?

Answer 15

Spherical hyaline deposits of mucopolysaccharides, lipids, or fibrillary proteins in the mesangium in periphery of glomerulus

They squeeze capillaries shut

Question 16

What are the two types of exudative lesions seen in diabetic nephropathy?

Answer 16

Fibrin caps - crescentic deposits of leaked plasma proteins - subendo or subepi
–> not specific to diabetes

Capsular drops - deposits of plasma protein and BM in parietal part of capsule
–> specific to diabetes

Question 17

Which kind of injury correlates well with ESRD?

Answer 17

Nodular glomerulosclerosis