Jeremy Chapman

Westmead Hospital, Sydney

CMV Infection and Allograft Rejection :

Are we missing the point?

The simple Paradigm

CMV Infection

D+ R-

OKT3/ATG

HHV6/7

Chronic Rejection

Acute Rejection

CMV Disease

HLA induction

Adhesion mols

Cytokines

Chronic Something

Evidence that the relationship with CMV may be more

complex• Biology of CMV infection/disease

• Effects of CMV prophylaxis

• Relationships between CMV and rejection

• Effects of Biopsy identified Cellular infiltrate

• Mechanisms of damage

Questions not answers

Biology of CMV

ER Golgi

TAPProteosome

Nucleus

CMV

US2,US11

US6

US3

HLA E

100000

10000

1000

100

CMV disease Asymptomatic infection

Log

vir

al lo

ad (

cop

ies/

ml)

Humar et al Transplantation 1999; 68:1305 -11

Detection of CMV after Liver Transplantation

Control of CMV

SELF ALLO

Why isn’t the

graft lost to CMV?

CMV TetramersC

D8

pos

itiv

e

Tetramer positive

5%

Singhal et al Transplantation 2000; 69: 2251-2259

CMV Tetramers in BMT

•Donor & Recip CMV + CMV CTL = 21% of CD8 T cells

•Matched Unrelated Donors CMV C TL recovery delayed

•CMV CTL by CMV reactivation, by pred

•CMV CTL > 10x 106/l associated with protection from CMV

Cwynarski et al Blood 2001: 97: 1232-40

CMV - HHV6 STUDYOdds of getting Disease

0

5

0 10 20 30 40 50 60 70 80 90 100

ODDS RATIO

CMV + HHV6

HHV6

CMV

D + R -

OKT3/ATG

Detecting CMVHistopathology

Immunohistochemistry

In-situ hybridisation

IHC and ISH detected CMV in 70% of cases with negative histology.(1)

1. Am J Clin Path 1996;166:544-8

2. Hepatology 1997;Jan: 190-4

ISH detected CMV in bile ducts of 10/10 liver transplants with VBDS. (2)

Prevention of CMV disease after Transplantation:

Effects on incidence of rejectionEvidence from clinical trials

R+ (n=408)% D+/R- (n=208)%

VACV Placebo VACV Placebo

CMV disease 90days

0 6* 3 45*

CMV disease 6months

1 6* 16 45*

Acute rejection 6months

30 36 26 52*

HSV 8 34* 9 24*

1Lowance D, N Engl J Med (1999) 340(19):1462-70

VALACICLOVIR

*P<0.01

Lowance et al New Engl J Med 1999; 340: 1462 - 70

Valacyclovir Prophylaxis reduces both CMV and Biopsy confirmed acute rejection

Grattan et al JAMA 1989; 261: 3561 - 66

Transplant Coronary Artery Disease after CMV infection

Valentine et al Circulation 1999; 100: 61-66

Prophylactic Ganciclovir prevents Transplant Coronary Artery Disease

Soghikian et al J Heart and Lung Transplant 1996; 15: 881-7

Ganciclovir prophylaxis reduces incidence of CMV pneumonitis and chronic Obliterative Bronchiolitis

Messages from Protocol Histology

Determinants of long term damage to renal allografts

Nankivell et al Transplantation 2001; 71: 515-523

Westmead Study

• consecutive renal Tx (n = 180)

• study group (function @ 3 mo., n = 163)

• protocol Tx. biopsy (n = 112)

• blinded Banff (95) evaluation

• adequate tissue (n = 102)

analysis

donor biopsy(n = 91)

No biopsy •anticoagulation•hyperacute rejection•PC - dilatation•pediatric kidney•medical•declined/unknown

Westmead CMV data

No CM V DISEASE71

CM V DISEASE6

CM V R POS77

CM V ?1

CM V DISEASE8

CM V D POS16

CM V D NEG11

CM V R NEG27

All105

Acute Rej 45%

5yr GS 91%

Acute Rej 58%

5yr GS 69%

No CMV Prophylaxis

3-month histology

1. Acute changes

• Banff “borderline” changes 49%

• subclinical rejection 29%

HLA mismatch & acute rejection (P < 0.05)

2. Chronic changes

• Banff chronic nephropathy 24%DGF, donor microvascular & age, cold ischemia, vascular rejection (P < 0.05 - 0.01)

Effects of prior acute rejection

CVCTCI

0

0.5

1

1.5

NIL Cellular Vascular

*

*

Mean Banff scores (3 mo)Mean + SEM

DGF excluded

Effects of subclinical rejection on 12 month histology

12 month Banff scores

0

0.5

1

1.5

2

Nil Borderline Subclinical

3 month Banff grade

chronic nephropathy

cv

ci * *

3 mo 12 mo r P

i -> ci 0.36 0.05t -> ct 0.32 0.05v -> cv 0.66 0.001

compartment specific• chronic damage is localized to histological

compartment of 3 month acute injury

Site of chronic 12-month damage

CMV Disease patients

Protocol 3 month histology - acute qualifiers

Patient g i t v outcome

1 0 3 3 0 >10years

2 0 2 2 0 >8years

3 0 2 2 0 Fail 7years non-compliance

4 0 1 1 1 >10years

mean 0 1.1 1.1 .08

CAN: multivariate predictors

Proteinuria

Late rejection

Tubular Injury

CV (grade)

KAT (10 min)

Hypertension

1 10 100ODDS RATIO

95% CI

Late rejection

0

0.05

0.1

0.15

0.2

Cumulative hazard

0 5 10 15

Years after transplantation

Late rejection

No late rejection

***Late rejection

No late rejection

0

0.25

0.5

0.75

1

Survival (%)

0 5 10 15

Year after transplantation

• 45% of graft failures

• non-compliance (r=0.57, P < 0.001)

50

60

70

80

90

100

0 5 10 15

Years after transplantation

Graft survival (%)

** ci 2 >

ci 1

ci 0

Chronic interstitial fibrosis

Chronic vascular changesGraft survival (%)

50

60

70

80

90

100

0 5 10 15

Years after transplantation

* cv 1 >

cv 0

Graft failure: Cox predictors

10.1

interstitial lymph.

Late rejection

Tubular Injury

10 100

CI

CV

Age (year) ODDS RATIO

95% CI

What damages a transplant?

EARLY LATE

donor quality (cv) chronic CSA toxicity

ischemia non-compliance

ATN-DGF late rejection

acute vascular recurrence of GN

rejection proteinuria

subclinical rejection(hypertension)

CMV

Target Organ

Damage

Activation

Immune response

Cytopathic effect

CTL mediated effect

Control of Virus

CTL mediated rejectionT

T

T T

T

TT

T T

Hypothesis:

Host control of CMV infection by T cells is a normal process in latently infected individuals, that co-exists with other allograft pathology such as acute rejection and stable graft acceptance, but may have consequences for the graft.

Failure of Host control mechanisms leads to viral disease, which may also have direct consequences for the graft

Mechanisms of Graft Damage

CMV Cytopathic effect

CTL vs CMV+Allo

Allograft RejectionAm

oun

t of

GR

AF

T D

AM

AG

E

Spectrum of response

Balance Mechanisms

Anti-T cell Immunosuppression

Anti-Viral Agents

Mechanisms of Graft Damage

CMV Cytopathic effect

CTL vs CMV+Allo

Allograft Rejection

ANTI-T CELL THERAPY

Mechanisms of Graft Damage

CMV Cytopathic effect

CTL vs CMV+Allo

Allograft Rejection

ANTI-VIRAL THERAPY

Mechanisms of Graft Damagewhat can you see?

CMV Cytopathic effect

CTL vs CMV+Allo

Cellular Allograft Rejection

Hypothesis:Host control of CMV infection by T cells is a

normal process in infected individuals, that both co-exists and interacts with other allograft pathology such as acute rejection and stable graft acceptance, but may have consequences for the graft.

Failure of Host control mechanisms leads to viral disease, which may also have direct consequences for the graft

Does it matter?

• If CMV infection is controlled by T cells and damages the graft then anti-T cell therapy will increase the damage, while anti CMV therapy will reduce the damage

• When a cellular infiltrate is due to T cells directed at Allo Ag then increased anti T cell therapy will be effective. But when the T cells are directed at CMV/Allo anti T cell therapy will lead to uncontrolled CMV

Graft failure• CAN 75%, recurrent GN 15%, other 10%

Features: CAN Nil P

• late rejection 43% 3% 0.001

• non-compliance 30% 3% 0.001

• proteinuria 86% 24% 0.001

• hypertension 95% 76% NS

• mean Ch. Banff 1.33 0.92 0.05

Lowance et al New Engl J Med 1999; 340: 1462 - 70

Westmead CMV - HHV6 STUDY

CMV &HHV6

CMV HHV6 NONE CMV &HHV

CMV HHV6 NONE

SEVERE 1 0 0 0

MOD/MILD

8 1 3 0

TOTAL 9 1 3 0 0 5 0 4

SEVERE 0 0 0 0

MOD/MILD

2 0 0 0

TOTAL 2 0 0 0 0 0 1 5

OKT3/ATG

NONE

DISEASE

NO DISEASE

IV GANCICLOVIR VERSUS PLACEBO/CONTROL

IN HEART TRANSPLANTATION

R+ (%) D+/R-(% Regimen

n Control Active Control Active

149 46 9* 29 35 Placebo vs IV GCV/10mg/d (d 1–14) – 6 mg/dfor 5 d/wk (d 16–28) 1

56 25 25 71 11* Placebo vs IV GCV 5mg/1xd x 6wk++2wk ifrejection2

*P<0.05; +ATG induction1Merigan TC, N Engl J Med (1992) 326(18):1182–6; 2MacDonald PS, J Heart LungTransplant (1995) 14(1)32–8