Transplantation Immunosuppression A Case-based Approach

January 20, 2009 Paul D. Greig, MD, FRCS(C) Professor of Surgery University of Toronto 1

Saint Cosmas & Saint Damian perform the first transplant 280 CE

Alexis Carrel (1875-1944) “I have started research into the procedure of vascular anastomoses in order to be able to transplant certain organs…” 1901 Sir Peter Medawar (1915-1987) Recognized that lymphocytes were the “immunocompetent cells” that were responsible for rejection – Nobel prize, 1960

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)

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

Liver Transplant at the University of Toronto

1985 - 2008

180 160 140 120 100 80 60 40 20 0 19 85 19 87 19 89 19 91 19 93 19 95

Year

19 97 19 99 20 01 20 03 20 05 20 07 Children Adult

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 11

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? 12

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? 17

Transplantation - Immunosuppression

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

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: 20

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

• • •

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 – 1 0 agent – ? Optimal monitoring using C 2 (peak level) not C 0 (trough levels)

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

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

• • •

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

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

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

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 10 - 15 mg/kg/d divided BID, orally

OR

– Tacrolimus (PROGRAF) • FK 1 - 1.5 mg/kg/d divided BID, orally – Third agent • • MMF (Cellcept) 2 gm/d divided BID Azathioprine 1-2 mg/kg/d

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?

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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 31

Transplantation - Immunosuppression Risk Factors for Early Toxicity • Increased Risk – renal failure • Rx: avoid CsA or FK by using antibody therapy * 5 - 10 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 32

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 5 - 10 days combine with MMF or Aza introduce low dose CsA or Tac ~ POD 7 33

Transplantation - Immunosuppression Anti-Lymphocyte Antibodies • • • Polyclonal Products: RATS, ATG, ALS – – cocktail of anti-bodies to antigens on activated t-cells Toxicity: 1. Fever 2. Cross-react with platelets (thrombocytopenia) Monoclonal Antibody: OKT3 – – murine antibody to the CD3 receptor Toxicity: 1. 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 34

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

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

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

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 10 - 15 mg/kg/d divided BID, orally

OR

Tacrolimus (PROGRAF) • FK 1 - 1.5 mg/kg/d divided BID, orally Third agent • • • MMF (Cellcept) 2 gm/d divided BID Azathioprine 1-2 mg/kg/d Sirolimus (Rapammune)

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 10 - 15 ng/ml POD 20: – Bili: 13 --> 28, ALP 96 --> 170 – AST 35 --> 125, ALT 40 --> 140 DDx?

39

Transplantation - Immunosuppression

• Case 1 DDx: – Hepatic artery thrombosis • U/S liver & Doppler, CT & arterial phase, Angiogram 40

Transplantation - Immunosuppression

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

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 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 – Acute Rejection • Biopsy 43

• • Rejection Activity Index: infiltrate, phlebitis, ductitis

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 45

HLA Matching Effect (1995-2001)

100 50 63 58 52 47 16% 10 0 HLA mm 0 1-2 3-4 5-6 1 2 n 8,196 7,835 23,776 13,173 t1/2 16.0

13.2

11.1

9.8

3 4 5 6 7

Years Posttransplant

8 9 10 Cecka, Clinical Transplants 2002 (p.10)

Transplantation - Immunosuppression Risk Factors for Early Toxicity • Increased Risk – renal failure • • Rx: avoid CsA or FK by using antibody therapy * 5 - 10 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 47

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 5 - 10 days combine with MMF or Aza introduce low dose CsA or Tac ~ POD 7 48

Transplantation - Immunosuppression

• • • • Case 1 52 y.o. male, HCV+ve, Liver transplant POD 20: – Bili: 13 --> 28, ALP 96 --> 170 – AST 35 --> 125, ALT 40 --> 140 Bx = Acute Rejection – Grade 5-6 / 9 Treatment?

49

Transplantation - Immunosuppression Treatment of Acute Rejection

1 Treat Rejection – Increase CNI • If RAI < 4 – Corticosteroids • methylprednisilone 500 mg/d * 3 2 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 50

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 51

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 52

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 (39 O ), generally unwell WBC = 2.8, Liver enzymes d 25% – PE: unremarkable DDX?

53

Transplantation - Immunosuppression

DDx: 1 Bacterial Infection – CXR, Urine C&S, Blood culture – U/S or CT scan abdomen – Treat on speculation?

54

Transplantation - Immunosuppression

DDx: 2 Viral Infection a ) Cytomegalovirus (CMV) • • risk in CMV +ve recipients = 25% risk in -ve recipients of +ve organ = 50 - 100% (should receive prophylaxis) • • CMV syndrome (antigenemia) CMV disease (Bx confirmation) – liver (Bx), lung (BAL), brain (CT or MRI) – Treatment • • reduce immunosuppression Gancyclovir (IV --> PO) 55

Transplantation - Immunosuppression

DDx: 2 Viral Infection b ) 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 56

Transplantation - Immunosuppression

DDx: 3 Fungal Infection – candida, aspergillosis, cryptococcus, mucormycosis – image and culture 57

Transplantation - Immunosuppression

DDx: 4 Other Infection – TB – cat-scratch fever – Herpes simplex 58

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… 59

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

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