Fogo, Ch. 21 - Other transplant disease

Question 1

Recite three patterns of calcineurin-inhibitor toxicity.

Can CsA and tacrolimus toxicity be distinguished morphologically?

Answer 1

Acute tubulopathy, arteriolopathy, and TMA.

No.

Question 2

Describe the morphologic features of CIT-mediated acute tubulopathy.

Answer 2

Tubular vacuolization (fluid, actually ER). Loss of brush border.

Question 3

Describe the morphologic features of CIT-mediated arteriolopathy.

Answer 3

Can be acute or chronic.

Smooth muscle vacuolization to necrosis. Beaded hyaline deposits. Progressive scarring and fibrosis.

Question 4

Describe the morphologic features of CIT-mediated TMA.

Answer 4

Resembles usual TMA (intimal thickening, trapped RBCs). Only seen with very high levels of CNI.

Question 5

What is the main entity on the differential for CIT?

Answer 5

Acute rejection (can present with endarteritis)

Question 6

What 3 conditions can be caused by BK virus?

Answer 6

Hemorhagic cystitis

Ureteral stenosis

Acute interstitial nephritis

Question 7

Describe the LM (and IHC!) findings in BK polyomavirus infection.

Answer 7

Plasma cell infiltrate, tubular cytopathic effect with viral inclusions (Decoy cells).

SV40 antigen in tubular epithelial cells.

Question 8

Describe the IF/EM findings in BK polyomavirus infection.

Answer 8

IF: IgG, C3/C4d

EM: 30-40nm viral particles (called “haufen” in aggregate).

Question 9

What is the outlook for BK infection?

How is it clinically followed?

Answer 9

Poor functioanl response. Cidofovir isn’t very helpful, must reduce immunosuppression.

Followed with serum BK tests (urothelial shedding is benign).

Question 10

What are the most common primary kidney diseases to recur in transplant?

Which have the biggest impact on graft survival?

Answer 10

Most common: DDD, MIDD, diabetic nephropathy

Most concerning: FSGS, aHUS, MPGN