1. Transplantation - Immunosuppression A Case-based Approach January 20, 2009
Paul D. Greig, MD, FRCS(C)
Professor of Surgery
University of Toronto

2. Saint Cosmas & Saint Damian perform the first transplant 280 CE

3. Sir Peter Medawar
( )
Recognized that lymphocytes were the “immunocompetent cells” that were responsible for rejection – Nobel prize, 1960
Alexis Carrel ( ) “I have started research into the procedure of vascular anastomoses in order to be able to transplant certain organs…” 1901

4. Joseph E. Murray, MD First successful organ transplant: 1954, Brigham Hospital, Boston, Mass. Kidney transplant between dizygotic twins (recipient received sub-lethal dose of total body X-radiation)

5. The Pioneers of Liver Transplantation
Sir Roy Calne Thomas E. Starzl, MD

10. Liver Transplant at the University of Toronto
Year

11. Transplantation - Immunosuppression
Case 1
52 y.o. male
Hepatitis C +ve cirrhosis, ascites (paracentesis q 2-3 weeks)
Liver transplant
conventional vascular reconstruction
conventional biliary reconstruction: CBD-CBD
? Initial postoperative immunosuppression

12. Transplantation - Immunosuppression
Question 1
why is immunosuppression necessary?
Corollary
what are the immunologic mechanisms of allograft rejection?
what are the targets of the allo-immune response?
what are the “steps” of this response?

17. Transplantation - Immunosuppression
Question 2a
what are the immunosuppression options?
Corollary
what points in the allo-immune response are the targets of current immunosuppressive drugs?
What are the current (new) immunosuppressive drugs available?
What is the mechanism of action of each of these drugs?

18. Transplantation - Immunosuppression IMMUNOSUPPRESSIVE DRUGS
Newer Drugs
Neoral
Tacrolimus
Mycophenolate Mofetil
Sirolimus
anti- IL2R antibodies
Traditional Drugs
Steroids
Cyclosporine A
Azathioprine
Anti-lymphocyte antibodies:
polyclonal or monoclonal (OKT3)

20. Transplantation - Immunosuppression
Question 2b
what are the toxicities of these immuno-suppression drugs?
Option
balance the immunosuppressive activity with toxicity with different combinations
summary of each drug:

21. Transplantation - Immunosuppression CORTICOSTEROIDS
Mechanism of action
inhibition of cytokine production by APCs
Toxicity
infection, poor wound healing,osteoporosis, aseptic necrosis, hypertension, DM, hyperlipidemia, obesity,cushinoid facies
Currently
minimize dose, alternate day therapy
early steroid withdrawal

22. Transplantation - Immunosuppression MICROEMULSION CYCLOSPORINE A NEORAL
Mechanism of Action
inhibits calcineurin --> inhibits IL2 production
Microemulsion CsA (NEORAL)
improved absorption, avoid IV dosing
Toxicity
Nephotoxicity, hypertension
Neurotoxicity (tremor, headache, direct CNS)
DM, hyperlipidemia, hirsutism, gingival hyperplasia
Currently
10 agent
? Optimal monitoring using C2 (peak level) not C0 (trough levels)

23. Transplantation - Immunosuppression TACROLIMUS, formerly FK506 - PROGRAF
Advantages
lower incidence of acute rejection than CsA?
useful for refractory or chronic rejection
less hyperlipidemia, hirsutism, gingival hypertorphy than CsA
Toxicity
same as Cyclosporine A, possibly higher incidence
More DM,
Currently
primary immunotherapy, esp. those at high risk
for steroid resistant or refractory rejection

24. Transplantation - Immunosuppression AZATHIOPRINE
Mechanism of action
antimetabolite, inhibits PRPP amidotransterase
Toxicity
marrow: esp. neutropenia, thrombocytopenia
liver: cholestasis
Currently
routine “triple therapy”
added to reduce calcineurin inhibitor
added for rejection despite adequate calcineurin inhibitor levels

25. Transplantation - Immunosuppression MYCOPHENOLATE MOFETIL CELLCEPT or MYFORTIC
Advantages
no nephro- or neuro-toxicity
MoA more lymphocyte-specific than azathioprine
reduced acute rejection
Toxicity
marrow, GI tract
Currently
primary “triple immunotherapy”
add to CsA or FK monotherapy following rejection or to reduce dose for CNI toxicity

26. Transplantation - Immunosuppression RAPAMYCIN SIROLIMUS or EVEROLIMUS
Advantages
No neuro-toxicity
Less nephro-toxicity
synergistic with CsA and with FK (despite competition for FKBP)
? effective without calcineurin inhibitor
Toxicity
Hyperlipidemia
Impaired wound healing
Currently
“BLACK BOX WARNING” regarding HAT following liver transplantation

27. Transplantation - Immunosuppression Toxicities - in - Common
Infection
esp. viral and fungal
Malignancy
all cancers with time
importance of surveillance
Lymphoproliferative Disease (LPD)
+ Epstein Bar Virus (EBV-LPD)
--> monoclonal LPD --> lymphoma

28. IMMUNOSUPPRESSION Individual Toxicities
Obesity
HBP
Nepro
Neuro DM
Lipids
Marrow
GIT
Inf’n
Steroids
+++ +
Calcineurin Inhibitors
Cyclosporin A ++
Tacrolimus
TOR Inhibitor
Sirolimus
Antimetabolites
Azathioprine
Mycophenolate
Antilymphocyte Ab
ALG
OKT3
IL2R-Ab

29. Transplantation - Immunosuppression “Standard Combinations”
Calcineurin-inhibitor based
Corticosteroids
Solumedrol 500 mg pre-op, then taper form 200 mg/d to 20 mg/d during 1st week
Cyclosporin A (NEORAL)
CsA mg/kg/d divided BID, orally OR
Tacrolimus (PROGRAF)
FK mg/kg/d divided BID, orally
Third agent
MMF (Cellcept) 2 gm/d divided BID
Azathioprine 1-2 mg/kg/d

30. Transplantation - Immunosuppression
Question 2c
Do all patients require the same degree and type of immunosuppression?
Rephrased:
what are the risk factors for acute rejection?
Who needs more immunosuppression, who needs less?
What are the risk factors for toxicity?
Any alternates without Nephro/Neuro-toxicity?

31. Transplantation - Immunosuppression Risk Factors for Acute Rejection
Increased Risk
ABO incompatibility (preformed anti- A or B antibodies)
presensitized (+ve crossmatch)
From previous blood transfusions or pregnancy
high PRA
Variable levels of preformed antibody
previous immunologic graft loss (chronic rej’n)
underlying autoimmune disease
PSC, Autoimmune CAH
younger patients
Lower risk
Uremia
Malnourished patient
older patient
critically ill

32. Transplantation - Immunosuppression Risk Factors for Early Toxicity
Increased Risk
renal failure
Rx: avoid CsA or FK by using antibody therapy * days, introduce low dose CN-inhibitor with MMF or Azathioprine
preop coma, postop depressed LOC
Rx same as above
CMV -ve recipient of CMV +ve organ
Rx, lower immunosuppression or antiviral prophylaxis
EBV naïve recipient
surveillance

33. Transplantation - Immunosuppression Risk Factors for Early Toxicity
Options for patients at Increased Risk
in general: it is the nephro- or neuro-toxicity
avoid (or minimize calcuneurin (IL2) inhibition
i.e. avoid cyclosporin or tacrolimus
use anti-lymphocyte antibodies
for days
combine with MMF or Aza
introduce low dose CsA or Tac ~ POD 7

34. Transplantation - Immunosuppression Anti-Lymphocyte Antibodies
Polyclonal Products: RATS, ATG, ALS
cocktail of anti-bodies to antigens on activated t-cells
Toxicity: Fever
2. Cross-react with platelets (thrombocytopenia)
Monoclonal Antibody: OKT3
murine antibody to the CD3 receptor
Toxicity: Cytokine storm
2. Anti-murine antibodies
Anti-IL2R Antibodies
anti-CD25 antibody to the a-chain of IL2R
chimerized or humanized
toxicity: fever
? Efficacy without CNI

35. IMMUNOSUPPRESSIVES BACKGROUND
What’s The Problem?
Toxicity
major barrier to effective immunosuppression
variable spectrum of toxicities
specific to each drug
objective
juggle the toxicities of the available agents to achieve the lowest doses necessary for each patient
problem
no objective measure of the net immunosuppressive effect in any one individual

36. Transplantation - Immunosuppression Toxicities - in - Common
Infection
esp. viral and fungal
Malignancy
all cancers with time
importance of surveillance
Lymphoproliferative Disease (LPD)
+ Epstein Bar Virus (EBV-LPD)
--> monoclonal LPD --> lymphoma

37. IMMUNOSUPPRESSION Individual Toxicities
Obesity
HBP DM
Nephro
Neuro
Lipids
Marrow
GIT
Inf’n
Steroids
+++ +
Calcineurin Inhibitors
Cyclosporin A ++
Tacrolimus
TOR Inhibitor
Sirolimus
Antimetabolites
Azathioprine
Mycophenolate
Antilymphocyte Ab
ALG
OKT3
IL2R-Ab

38. Transplantation - Immunosuppression Standard Combinations
Corticosteroids
Solumedrol 500 mg pre-op, then taper form 200 mg/d to 20 mg/d during 1st week
Cyclosporin A (NEORAL)
CsA mg/kg/d divided BID, orally OR
Tacrolimus (PROGRAF)
FK mg/kg/d divided BID, orally
Third agent
MMF (Cellcept) 2 gm/d divided BID
Azathioprine 1-2 mg/kg/d
Sirolimus (Rapammune)

39. Transplantation - Immunosuppression
Case 1
52 y.o. male, HCV+ve, Liver transplant
Steroids: methylprednisilone or prednisone
500, 100, 80, 60, 40, 20 -->7.5 mg/d by POM4
Calcineurin (IL2) inhibition
Tacrolimus 5 mg bid, adjust to ng/ml
POD 20:
Bili: 13 --> 28, ALP 96 --> 170
AST 35 --> 125, ALT > 140
DDx?

40. Transplantation - Immunosuppression
Case 1
DDx:
Hepatic artery thrombosis
U/S liver & Doppler, CT & arterial phase, Angiogram

41. Transplantation - Immunosuppression
Case 1
DDx:
Hepatic artery thrombosis
U/S liver & Doppler, CT & arterial phase, Angiogram
Biliary Stenosis, Leak
U/S, MRCP, ERCP

42. Transplantation - Immunosuppression
Case 1
DDx:
Hepatic artery thrombosis
U/S liver & Doppler, CT & arterial phase, Angiogram
Biliary Stenosis, Leak
U/S, ERCP
Infection
CMV --> CMV antigenemia, Liver Bx
recurrent HCV --> Biopsy

43. Transplantation - Immunosuppression
Case 1
DDx:
Hepatic artery thrombosis
U/S liver & Doppler, CT & arterial phase, Angiogram
Biliary Stenosis, Leak
U/S, ERCP
Infection
CMV --> CMV antigenemia, Liver Bx
recurrent HCV --> Biopsy
Acute Rejection
Biopsy

44. Rejection Activity Index:
infiltrate, phlebitis, ductitis

45. Transplantation - Immunosuppression Risk Factors for Acute Rejection
Increased Risk
ABO incompatibility (preformed anti- A or B antibodies)
presensitized (+ve crossmatch) - ** not with liver
high PRA - ** not with liver
previous immunologic graft loss (chronic rej’n)
underlying autoimmune disease
PSC, Autoimmune CAH
Younger, well nourished patients
Lower risk
malnourished, older patient
critically ill

46. HLA Matching Effect (1995-2001)
100 63 58
16% 50 52 47
Percent Graft Survival (log)
HLA mm n
t1/2
8,196
16.0
1-2
7,835
13.2
3-4
23,776
11.1
5-6
13,173
9.8 10 1 2 3 4 5 6 7 8 9 10
Years Posttransplant
Cecka, Clinical Transplants 2002 (p.10)

47. Transplantation - Immunosuppression Risk Factors for Early Toxicity
Increased Risk
renal failure
Rx: avoid CsA or FK by using antibody therapy * days,
introduce low dose CN-inhibitor with MMF or Azathioprine
preop coma, postop depressed LOC
Rx same as above
CMV -ve recipient of CMV +ve organ
Rx, lower immunosuppression plus antiviral prophylaxis
EBV naïve recipient
surveillance

48. Transplantation - Immunosuppression Risk Factors for Early Toxicity
Options for patients at Increased Risk
in general: it is the nephro- or neuro-toxicity
avoid (or minimize calcineurin (IL2) inhibition
i.e. avoid cyclosporin or tacrolimus
use anti-lymphocyte antibodies
for days
combine with MMF or Aza
introduce low dose CsA or Tac ~ POD 7

49. Transplantation - Immunosuppression
Case 1
52 y.o. male, HCV+ve, Liver transplant
POD 20:
Bili: 13 --> 28, ALP 96 --> 170
AST 35 --> 125, ALT > 140
Bx = Acute Rejection
Grade 5-6 / 9
Treatment?

50. Transplantation - Immunosuppression Treatment of Acute Rejection
Treat Rejection
Increase CNI
If RAI < 4
Corticosteroids
methylprednisilone 500 mg/d * 3
Prevent Recurrence
depends on reason for AcR
if Tac or CsA levels sub-therapeutic
increase Tac or CsA
if Tac or CsA levels adequate
add a third agent: MMF or Rapamycin

51. Transplantation - Immunosuppression Treatment of Acute Rejection
Outcome
normalization of liver biochemistry
+ liver Bx confirmation
For high RAI
Steroid - Resistant Rejection
antilymphocyte anti-body therapy:
Polyclonal anti-lymphocyte antibodies
RATS, ATG, ALS
Monoclonal ALG
OKT3

52. Transplantation - Immunosuppression Treatment of Acute Rejection
Sequelae of an episode of AcR
treatment increases risks of all immunotherapy related complications
viral infections
CMV, EBV
DM, psychosis,
Renal Tx
reduced graft 1/2 life
Also Lung & Heart
“Cumulative graft injury”
Liver
Increase recurrence of Hepatitis C
fewer long term sequelae
? Induce tolerance

53. Transplantation - Immunosuppression
Case 1
52 y.o. male, HCV+ve, Liver transplant
POD 20:
Acute Rejection , Grade 5-6 / 9
Treatment: corticosteroid (2 cycles)
POD 90:
fever (39O), generally unwell
WBC = 2.8, Liver enzymes d 25%
PE: unremarkable
DDX?

54. Transplantation - Immunosuppression
DDx:
Bacterial Infection
CXR, Urine C&S, Blood culture
U/S or CT scan abdomen
Treat on speculation?

55. Transplantation - Immunosuppression
DDx:
Viral Infection
) Cytomegalovirus (CMV)
risk in CMV +ve recipients = 25%
risk in -ve recipients of +ve organ = % (should receive prophylaxis)
CMV syndrome (antigenemia)
CMV disease (Bx confirmation)
liver (Bx), lung (BAL), brain (CT or MRI)
Treatment
reduce immunosuppression
Gancyclovir (IV --> PO)

56. Transplantation - Immunosuppression
DDx:
Viral Infection
) Epstein Barr Virus (EBV)
presents as lymphoproliferative disease (LPD)
lympadenopathy
CT: head, chest, abdomen
Biopsy
graded: LPD --> monoconal B-cell lymphoma
Treatment
reduce (stop) immunosuppression
antiviral therapy (Gancyclovir)
chemotherapy for lymphoma

57. Transplantation - Immunosuppression
DDx:
Fungal Infection
candida, aspergillosis, cryptococcus, mucormycosis
image and culture

58. Transplantation - Immunosuppression
DDx:
Other Infection TB
cat-scratch fever
Herpes simplex

59. Transplantation - Immunosuppression Chronic Rejection
Advanced graft injury
Secondary to repeated episodes of acute rejection and/or persistent low grade immunologic injury
Additive to previous injury
In donor
Preservation/ischemia/reperfusion
Liver: duct loss: “ductopenic rejection”
Target = duct or small arterioles
Lung: bronchiolar loss: “Brochiolitis obliterans”
Cumulative injury
Heart: accelerated atherosclerotic change: “graft vasculopathy”
Kidney: “chronic graft nephropathy”
Probably multifactorial
Including donor injury, preservation injury, postop injury…

60. Transplantation - Immunosuppression TOWARDS TOLERANCE
Partial Tolerance
“adaptation” allows reduction in total immunosuppression during first 3 months
= microchimerism?
Tolerizing Strategies
objective
drug-free, donor-specific hyporesponsiveness
needs:
stem or dendritic cell
induction therapy with tolerizing antibodies
continuous antigen exposure

61. Transplantation - Immunosuppression FUTURE
Multi-drug Regimens
variety of “protocol” therapies
increased patient-specific individualization
New Drugs
less toxicity
or non-overlapping toxicities
increased efficacy
reduced chronic rejection
more “patient-friendly”
for improved long-term compliance