Management of interstitial fibrosis and tubular atrophy in renal

transplantation

K. HARZALLAH

The 12th Congress of the Middle East Society for Organ Transplantation 2010

Novartis Symposium

Lack of improvement in long term Renal Allograft Survival Early ant late acute rejection RR of death-censored graft loss

Meier-Kreische AJT 2004; 4: 378

Good or poor donor kidney: same finality ?

Chapman, JASN 2005

4

Arteriolar hyalinosis

Interstitial fibrosis and tubular atrophy

GBM double contours

ArteriolosclerosisCAN, chronic allograft nephropathy; IFTA, interstitial fibrosis and tubular atrophy; GBM, glomerular basement membrane

CAN / IFTA: a non-specific descriptive entity defined by pathology

Fletcher JT et al. Pediatric Nephrol 2009;24:1465–71

Histologic criteria of Chronic Allograft Nephropathy (CAN)

GradeHistologyInterstitialFibrosis

Tubular Atrophy

IMildci1*6-25 % of

cortical area

ct1Up to 25 % of

cortical tubules

IIModerateci226-50 %

ct226-50 %

IIISevereci3> 50 %

ct3> 50 %

*: 0-5 % fibrosis acceptable

• Hypertension• Proteinuria

– Typically in the non-nephrotic range (300 mg-3 g/24)

• Renal failure– Rise in serum creatinine

(mean rate of decline -10 to -4 ml/min/year).

• Onset:– months to years post

transplantation

Clinical features of CAN

Antigen DependentAcute Rejection

AlloantibodyAllorecognitionViral Infection

Tissue Antigen IndependentInsuffisant renal mass

Graft ischemia/Reperfusion InjuryOlder donor age

CNIs

Infiltration,Inflammatory cells,

lymphocytes, monocytes

Cytokines, Chemokines,

Growth Factors

Proliferation, Inflammatory cells,Fibroblasts, TECs

Extracellular Matrix Deposition

FIBROSIS

Injury

EMT

Mat

rix P

hase

Fibr

ogen

esis

Pha

seIn

itiat

ion

Pha

se

Allo-immunity CNI toxicity

Interstitial fibrosisand

tubular atrophy

De novo DM

Chronic obstruction

Recurrent disease

CAN, chronic allograft nephropathy; IFTA, interstitial fibrosis and tubular atrophy; CNI, calcineurin inhibitor; CMV, cytomegalovirus; I/R, ischaemia / reperfusion; DM, diabetes mellitus

Multiple factors contribute to early CAN / IFTA

Hypertension

Polyoma-virusCMV

Donor factors

I/R-injury

Adapted from Calvin RB. NEJM 2003; 349: 2003

Immunologic associations of Chronic Allograft Nephropathy

Immunologic associations of Chronic Allograft Nephropathy

• Acute Rejection:– Humans:

• Association of graft rejection with decreased graft half-life. (Hariharan, 2000)

• Lymphocytic infiltrates on protocol biopsies associated with developement of CAN (Rush 1999)

• Bw4/Bw6 epitope mismatch ?

– Mechanism:• Antibody production• Ongoing cellular immune response• Reduction in nephron mass due to immune

response/inflammation

« Chronic antibody mediated rejection »

• Morphological evidence of transplant glomerulopathy

• C4d deposition in the glomerulus (paraffin sections) and/or peritubular capillaries.

• Serologic evidence of antidonor AC antiHLA.

• The prevalence of C4d: – 91% of biopsies with transplant

glomerulopathy. – 12 to 61% in cases of chronic rejection with

impaired renal function.– 2 % in the protocols of systematic biopsies.

• The role of non-HLA immunity.

« Chronic antibody mediated rejection »

Viral Infections• CMV infection post-transplantation is associated

with graft failure (1984).• CMV infection is a contributing factor to cardiac

and hepatic arteriosclerosis (Transpl Int 1994)• CMV infection is associated with transplant

glomerulopathy (NEJM 1981, Am J Pathol 1987) • BK virus nephropathy

– Mechanism: generalized immune activation and inflkammation of the vasculature.

Non Immunologic Causes of Chronic Allograft Nephropathy

Non immunologic causes of Chronic Allograft Nephropathy

• Graft ischemia/reperfusion injury– Studies in humans have demonstrated that delayed

graft function leads to shortened graft survival. – Mechanisms:

• Reduced nephron mass• Upregulation of MHC antigens on ischemic renal tubules

may allow for non-professional antigen presentation.• Upregulation of adhesion molecules ICAM 1, VCAM 1, on

ischemic endotthelium and tubular endothelium: E- and P-selectin on endothelial cells: integrins LFA-1, Mac-1 and VLA-4.

• Enhanced expression of proinflammatory cytokines IL1, IL2, IFN, TNF, IL-10.

Age 19

Age 45

+ 11 years

+ 7 years

Melk et al. AJT 5:1375, 2005

Senescence- Associated Biomarkers p16INK4a

Donor Biopsy Graft Biopsy

CNI Toxicity

• Vasoconstriction of preglomerular afferent arterioles and injury of vascular endothelial cells.

• Tubular vacuolation and hyalinization.

• Intimal Fibrosis.

Epithelial-Mesenchymal Transformation (EMT)

• Role in IF/TA and CAN demonstrated in dans l’AT et la FI:– Role of the host (Grimm

et al. NEJM 2001) – May be immune

mediated in man (Roberston et al. JASN 2004)

– In human biopsies with IF/TA (Vongiwawatana et al. AJT 2005)

– Rat model (Djamali et al. AJT 2005)

Donor IF/TA

E-cadherin

Vimentin

S100A4

-SMA

Vonawiwatana AJT 2005

Clinical Management of IFTA

Chronic Allograft NephropathyClinical management

• Assess the causative agent• BP control• Lipid management• Tight blood sugar control if diabetic• Manipulate immunosuppression

Chronic Allograft NephropathyClinical management

• Assess the causative agent• BP controlBP control• Lipid managementLipid management• Tight blood sugar control if diabeticTight blood sugar control if diabetic• Manipulate immunosuppression Manipulate immunosuppression

Allo-immunity CNI toxicity

Interstitial fibrosisand

tubular atrophy

De novo DM

Chronic obstruction

Recurrent disease

CAN, chronic allograft nephropathy; IFTA, interstitial fibrosis and tubular atrophy; CNI, calcineurin inhibitor; CMV, cytomegalovirus; I/R, ischaemia / reperfusion; DM, diabetes mellitus

act against the responsible factors …

Hypertension

Polyoma-virusCMV

Donor factors

I/R-injury

Adapted from Calvin RB. NEJM 2003; 349: 2003

Chronic Allograft NephropathyClinical management

• Assess the causative agentAssess the causative agent• BP control (ACE inhibitors, ARBs)

• Lipid managementLipid management• Tight blood sugar control if diabeticTight blood sugar control if diabetic• Manipulate immunosuppression Manipulate immunosuppression

ACEI/ARBs improve Survival

Lack of impact of RAS blockade on Graft Survival

17 % ACEI 199620 % ACEI 200046 % ACEI 2004

Deleterious effect of HTN on Graft survival

Chronic Allograft NephropathyClinical management

• Assess the causative agentAssess the causative agent• BP controlBP control• Lipid management• Tight blood sugar control if diabeticTight blood sugar control if diabetic• Manipulate immunosuppression Manipulate immunosuppression

Assessment of Fluvastatin in renal transplantation (ALERT) n= 2102

• No impact of fluvastatin 40/80 mg/d on calculated renal function or proteinuria.

• No difference on graft loss.

• Reduction in risk of cardiac death or nonfatal myocardial infarction (MI) by 35 % compared with placebo.

Chronic Allograft NephropathyClinical management

• Assess the causative agentAssess the causative agent• BP controlBP control• Lipid managementLipid management• Tight blood sugar control if diabeticTight blood sugar control if diabetic• Manipulate immunosuppression

CANManagement of immunosuppression

• Treat ant acute inflammation ?• Reduce/remove the CNI• Consider addition of an

antiproliferative immunosuppressant (MMF, Everolimus).

Serum creatinine: falsely reassuring

Chapman, JASN 2005

Role of Subclinical Injury

• Early injury associated with HLA MM.

• Late Injury associated with IS load.

• Associated with CAN in several studies.

• Associated with short graft survivals.

Prevalence of Subclinical Rejection

Time of Bx1-2 w1-2 m 2-3 m 1 y

1a17 %29 %17 % 18 %

Borderline24 %23 %23 %17 %

Nankivell et Chapman AJT 2006

Treating Subclinical Rejection (SCR) ?

• Nankivell and Chapman advocate high dose pulse steroids, but note that of f/u biopsies at 2-3 w have persistent tubulitis.

• Non randomized studies have suggested benefit in serum creatinine in pediatric patients (JASN 2003) and serum creatinine and reduced fibrosis at one year (clin Transpl 2003)

Comparison of patients with frequent Bx (1,2,3,6 and 12

months) and less frequent (6 and 12 months).

Everolimus with CsA minimisation provides similar efficacy when compared with standard CsA

Data from 1 year post-transplant. Efficacy failure = acute rejection, death, graft loss or loss to follow-up

StandardCsA

LowCsA

Efficacy failure (% patients)

p=0.012

Study B156: 12-month efficacy

BPAR(% patients)

Creatinine clearance (mL/min)

StandardCsA

LowCsA

StandardCsA

LowCsA

p=0.007

Nashan B et al. Transplantation 2004;78:1332–40

37

CsA, cyclosporin; BPAR, biopsy-proven acute rejection

28,3

8,6

0

10

20

3017

6,9

0

5

10

15

20

53,560,9

0

20

40

60

80

38

Very low tacrolimus

Everolimus (target C0 3–8 ng/mL)+

tacrolimus (target C0 1.5–3.0 ng/mL)+

steroids

Low tacrolimus

Everolimus (target C0 3–8 ng/mL)+

tacrolimus (target C0 4–7 ng/mL)+

steroids

ASSET (study A2426): investigating the potential of everolimus for minimising tacrolimus

Month 12Month 3Day 1

Everolimus 1.5 mg bid (target C0 3–8 ng/mL)

Steroids

Tacrolimus 0.1 mg/kg/day(target C0 4–7 ng/mL)

IL2RA

TransplantDay 0

1st dose of everolimus<24 hours

IL2RA, interleukin 2 receptor antagonist; bid, twice a day

39

Safety population

ASSET: everolimus facilitates tacrolimus minimisation1

16

14

12

10

8

6

4

2

0Month 3 Month 4 Month 6 Month 9 Month 12

Time

1. Vitko S et al. Presentation at ESOT 2009; 2. Ekberg H et al. N Engl J Med 2007;357:2562–75

Tacrolimus C0 (ng/mL)

Very low tacrolimus (n=109)Low tacrolimus (n=119)

ASSET: tacrolimus C0 levels

Tacrolimus C0 levels were ~50% lower than in the Symphony study at 12 months2

40

Everolimus and very low tacrolimus had clinically meaningful improvement in renal function

1-sided α level 0.025 cGFR, calculated glomerular filtration rate; MDRD, modification of diet in renal disease

∆ = 5.34

908070

6050403020100

p=0.362 p=0.150 p=0.236 p=0.081 p=0.008 p=0.029

3 4 6 9 12Time (months)

Very low tacrolimus (n=92)Low tacrolimus (n=105)

Vitko S et al. Presentation at ESOT 2009

cGFR (MDRD formula)(mL/min/ 1.73m2)

ASSET: cGFR over 12 months

41

De novo Late conversionEarly conversion

Month 1 Month 2–6 >6 months

Time points for initiating PSIs

Time post-transplantation

PSI, proliferation signal inhibitor

42CsA, cyclosporin; Tac, tacrolimus; MMF, mycophenolate mofetil; Aza, azathioprine; CNI, calcineurin inhibitor

Transplantsurgery

6–120 monthsprior to

randomisation

Group 1: Conversion to sirolimus within 24 h of randomisation (n=555)

Group 2: Continuation ofCNI-based regimen (n=275)

CsA / Tac +MMF / Aza +

steroidsfor at least 12 weeks prior to randomisation

2:1 randomisation in groups 1 and 2

0Duration of study(months) 48

Lessons learned from late conversion: the sirolimus renal conversion trial (CONVERT)

Schena F et al. Transplantation 2009;87:233–42

43

CONVERT trial: GFR improves after conversion to PSI only in patients with good renal function

*Values adjusted for baseline by analysis of covariance GFR, glomerular filtration rate; PSI, proliferation signal inhibitor, CNI, calcineurin inhibitor

0

20

40

60

80

100

61.3 61.7 63.4 61.9 63.6 61.164.7

61.2 62.6 59.9

p=0.056 p=0.006 p<0.001 p=0.009

Baseline* Month 6 Month 12 Month 18 Month 24

All patients with baseline >40 mL/min

GFR(mL/min) Sirolimus conversion

CNI continuation

Schena F et al. Transplantation 2009;87:233–42

TRANCEPTA PROSPECTIVE OBSERVATIONAL CLINICAL

STUDY OF PATIENTS SWITCHED TO MMFAT LEAST

6 MONTHS AFTER RENALTRANSPLANTATION

Study Design

1710 patients were included1256 patients had reached follow up for 1 year

Demographics and follow up

And the benefice ? 24 %

48 %

38 %

+ de 50 % des cas ont eu une amélioration de la fonction rénale après le switch

48

CAN / IFTA develops frequently and early after renal transplantation

Nankivell BJ et al. N Engl J Med 2003;349:2326–33

100

75

50

25

00 2 4 6 8 10

Years after transplantation0 (120) 78 (114) 56 (92) 34 (70) 20 (48) 16 (29)No. of

patients

Patients

Grade IGrade IIGrade III

CAN, chronic allograft nephropathy; IFTA, interstitial fibrosis and tubular atrophy

~90% of patients have grade 1 CAN in year 1

“Gold standard used in research protocols”

All renal transplant recipientsPatients at a high risk

Measured GFRProtocol biopsy

Monitor every month during the first year post-transplant, then 3 monthly

Recognise the clinical syndrome

Histology + physiology

Test new non-interventional tests

Ultrasound ± biopsy††

Other causesRecurrent glomerulonephritisRenal artery stenosis Ureteric obstructionBK virus nephropathy

CAN (tubular atrophy + interstitial fibrosis)OR

CAN + CNI nephrotoxicityCAN + transplant vasculopathy

CAN + sub-clinical rejectionCAN + chronic antibody-mediated rejection

(including CTG, DSAb, C4d)

THERAPEUTIC INTERVENTIONTest novel interventional strategies

Absolute serum creatinineChange of serum creatinine (%)Estimated GFRSlope of change of calculated GFRSlope of 1/serum creatinine

Other indications of renal changeProteinurieDeterioration of blood pressure

Measures for early detection of CAN

JM Campistol et alClin Transplant 2009;23:769

High Desnity Array Transcriptional Analysis To Define New Biomarkers

Suspicion of CAN/IFTA by Monitoring• Absolute serum creatinine

–> 1,8 mg/dL (or > 130 mol/L)• Absolute GFR

–< 50 ml/min• Change of serum creatinine

– Irreversible rise of 30% at 6 month post transplant– Increase of 0,3 mg/dL (or 20 mol/L) measured 3 x over 3

months–15-20% rise over one year

• Change of GFR–10% deterioration over 3 months

Summary

• Chronic graft injury is a considerable long term problem for kidney transplant recipients.

• The etiologies are multi-factorial and include both antigen dependent and independent events, culminating in injury and inflammation.

• Early detection appears to be critical issue for this disorder. The role of protocol biopsy ans management of SCR are under study.

• Treatment options are nonspecific and limited.• Various immunosuppressive strategies avoiding or

limiting CNIs, biologics and anti-proliferatives are under study.

Conclusions

• Despite marked improvements in short graft survival and reduction in acute rejection rates, long term graft function remains a critical issue.

• Current immunosuppressive regimens do not adequately address the causes of long-term allograft dysfunction and loss

• CNI-sparing regimens / strategies are urgently required