Diabetes Nephropathy

Question 1

T or F: DN is the most common cause of ESRD

Answer 1

T

Question 2

T or F: Development is strongly genetic

Answer 2

T: only 17 % risk if no family history

Question 3

Describe the early changes assc with DN (pathogenesis, clinical, histo)

Answer 3

hyperfiltraion resulting in glomerular hypertrophy

clinically manifests as microalbuminemia

histo: inc mesangial matrix, glomerular collapse, glomerularsclerosis

Question 4

Describe the progression of DN.

Answer 4

microalbuminemia –> proteinuria –> inc Sr Cr –> ESRD

Question 5

What is the clinical defn of DN?

Answer 5

long standing DM (+/-retinopathy)
Macroalbuminemia
HTN

Question 6

What usually develops at the same time as DN?

Answer 6

retinopathy

Question 7

What are the 5 stages of DN kidney disease?

Answer 7

1. hyperfiltration (inc GFR)
2. microalbuminemia
3. more proteinuria, more Sr Cr, inc BUN, +/- HTN
4. GFR <10 ml/min

Question 8

How long can it take to get to ESRD?

Answer 8

long time (avg 23 yrs)

Question 9

What causes the damage in DN?

Answer 9

inc blood glc, inc Ang II causes hyperfiltration –> inc glomerular pressure –> hypertrophy of epithelium and endothelium –> accerlation of cell failure and premature glomerulosclerosis

Question 10

Is there inflammation assc with progression of DN?

Answer 10

no, TGF-B secreted by the tubuloepithelial cells causes thickening of GBM, hypertrophy, mesangial matrix expansion

Question 11

What are AGEs? What is their role in DN? How are they formed?

Answer 11

advanced glycosylation products –> accelerates cell injury

*long term hyperglycemia forms them from non-enzymatic glycosylation of capillary BM

Question 12

Are AGEs normal?

Answer 12

yes, there are just more of them in DN pts

Question 13

What is the tx for DN? Why?

Answer 13

CONTROL DM!! (slows progression)

ARBs and ACE-Is (only drugs that dec glomerular pressure = relax both aff and eff tone)

Question 14

What is a good marker for the progression of DN towards ESRD?

Answer 14

degree of proteinuria

Question 15

What are some complications of DN?

Answer 15

pyelonephritis
papillary necrosis
RTA type 4
neurogenic bladder

Question 16

What are the 3 main types of DN? (and their subtypes)

Answer 16

1. glomerular: diffuse and nodular
2. papillary: pyelonephritis and papillary necrosis
3. tubulointersitial: tubular BM thickening and intersitial fibrosis

Question 17

What is the most common type of DN?

Answer 17

diffuse

**earlier and less severe

Question 18

Describe the appearance of diffuse DN histologically

Answer 18

thickening of GBM and mesangial matrix expansion

Question 19

When does nodular type appear?

Answer 19

> 10 yrs of DM

= correlates with ESRD/need for dialysis

Question 20

What are the histological features of nodular DN

Answer 20

kimmelsteil wilson nodules and hyaline sclerosis od afferent and efferent arterioles

Question 21

What are kimmelstiel wilson nodules?

Answer 21

spherical hyaline deposits of mucopolysacchairdes, lipids, and fibrillary proteins within the mesangium or glomerular tuft

*they eventually squeeze capillaries shut

Question 22

What are the 2 types of exudative lesions and which one occurs only in DN?

Answer 22

fibrin caps
capsular drops (only DN)

Question 23

What are fibrin caps and capsular drops?

Answer 23

firbin caps: crescentric deposits of condened leaked plasma proteins overlying the peripheral capillaires (can be subspi or sub endo)

Capsular drops: deposits of partly plasma proteins and BM in parietal later of Bowman’s capsule (protrudes into urinary space)

Question 24

The end stage of DN looks just like __disease_ (describe gross and microscopic appearance too)

Answer 24

hypertensive nephropathy

• gross, diffuse fine granularity of cortical surface
• *microscpoic: fibrosis and sclerosis –> globally sclerotic glomeruli, dilated tubules, tubules resembling thyroid follicles and interstitial fibrosis