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 TAP Proteosome Nucleus CMV US2,US11 US6 US3 HLA E

CMV disease Asymptomatic infection Log viral load (copies/ml) Humar et al Transplantation 1999; 68: Detection of CMV after Liver Transplantation

Control of CMV SELF ALLO Why isn’t the graft lost to CMV?

CMV Tetramers CD8 positive Tetramer positive 5% Singhal et al Transplantation 2000; 69:

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 10 6 /l associated with protection from CMV Cwynarski et al Blood 2001: 97:

CMV - HHV6 STUDY Odds of getting Disease ODDS RATIO CMV + HHV6 HHV6 CMV D + R - OKT3/ATG

Detecting CMV Histopathology Immunohistochemistry In-situ hybridisation IHC and ISH detected CMV in 70% of cases with negative histology.(1) 1. Am J Clin Path 1996;166: Hepatology 1997;Jan: ISH detected CMV in bile ducts of 10/10 liver transplants with VBDS. (2)

Prevention of CMV disease after Transplantation: Effects on incidence of rejection Evidence from clinical trials

VALACICLOVIR *P<0.01

Lowance et al New Engl J Med 1999; 340: Valacyclovir Prophylaxis reduces both CMV and Biopsy confirmed acute rejection

Grattan et al JAMA 1989; 261: Transplant Coronary Artery Disease after CMV infection

Valentine et al Circulation 1999; 100: Prophylactic Ganciclovir prevents Transplant Coronary Artery Disease

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

Westmead Study consecutive renal Tx (n = 180) study group 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 Acute Rej 45% 5yr GS 91% Acute Rej 58% 5yr GS 69% No CMV Prophylaxis

3-month histology 1. Acute changes Banff “borderline” changes49% subclinical rejection29% HLA mismatch & acute rejection (P < 0.05) 2. Chronic changes Banff chronic nephropathy24% DGF, donor microvascular  & age, cold ischemia, vascular rejection (P < )

Effects of prior acute rejection CV CT CI NILCellularVascular * * Mean Banff scores (3 mo) Mean + SEM DGF excluded

Effects of subclinical rejection on 12 month histology 12 month Banff scores NilBorderlineSubclinical 3 month Banff grade chronic nephropathy cv ci * *

3 mo 12 mo r P i->ci t->ct v->cv 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 Patientgitvoutcome 10330>10years 20220>8years 30220Fail 7years non-compliance 40111>10years mean

CAN: multivariate predictors Proteinuria Late rejection Tubular Injury CV (grade) KAT (10 min) Hypertension ODDS RATIO 95% CI

Late rejection 45% of graft failures non-compliance (r=0.57, P < 0.001)

Years after transplantation Graft survival (%) ** ci 2 > ci 1 ci 0 Chronic interstitial fibrosis

Chronic vascular changes Graft survival (%) Years after transplantation * cv 1> cv 0

Graft failure: Cox predictors interstitial lymph. Late rejection Tubular Injury CI CV Age (year) ODDS RATIO 95% CI

What damages a transplant? EARLYLATE donor quality (cv)chronic CSA toxicity ischemianon-compliance ATN-DGFlate rejection acute vascularrecurrence of GN rejectionproteinuria subclinical rejection(hypertension)

CMV Target Organ Damage Activation Immune response Cytopathic effect CTL mediated effect Control of Virus CTL mediated rejection T T T T T T T 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 Rejection Amount of GRAFT DAMAGE 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 Damage what 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:CANNilP late rejection43%3% non-compliance30%3% proteinuria86%24% hypertension95%76%NS mean Ch. Banff

Lowance et al New Engl J Med 1999; 340:

Westmead CMV - HHV6 STUDY OKT3/ATG NONE DISEASENO DISEASE

IV GANCICLOVIR VERSUS PLACEBO/CONTROL IN HEART TRANSPLANTATION