Experience withAntibody-Mediated Rejection

Millie Samaniego, M.D.Associate Professor of Medicine

University of Wisconsinand

Robert A. Montgomery, M.D., D.Phil.Chief, Division of Transplantation

Director, The Johns Hopkins Comprehensive Transplant CenterThe Johns Hopkins Hospital

•Characteristic histologic features including:1) glomerulitis/capillaritis2) margination of neutrophils in the PTC3) fibrin thrombi4) interstitial hemorrhage5) severe or necrotizing vasculitis

•Diffuse, linear C4d staining in the PTC

•Identification of DSA

Diagnostic Criteria for Acute AMR

Grade 1

Grade 3

AMR Cellular Accommodation

Patterns of Rejection in ABO Incompatible Transplants

Therapeutic Options For The Treatment Of AMR

Antibody Reduction

•Plasmapheresis/IA

•IVIg

B-cell Modulation

•Splenectomy

•Anti-CD20

•Cytoxan

Immunomodulation

•IVIg

•ATG

•IL-2R blockers

•Fk 506, Rapamycin

•MMF/DSG

•CAMPATH?

Antibody Reduction TherapyAntibody Reduction Therapy

•High dose IVIG (1-2 gms/kg)•Mechanism:

•Anti-idiotypic networks probably important •Many putative immunomodulatory pathways identified

•Advantages:•In vitro test for predicting efficacy•Ease of administration?

•Disadvantages:•Non-responders•Different techniques required to follow DSA titers•Less rapid Ab removal, unproven for high-titer DSA•Toxicity & batch-to-batch variability•Unproven for ABOi Tx

•Plasmapheresis/Low Dose IVIg (100 mg/kg)•Mechanism:

•Rapid reduction in anti-HLA or isoagglutinin Ab•Induces donor specific unresponsiveness (HLA) or accommodation (ABOI)

•Advantages:•Predictable kinetics of plasmapheresis•No evidence of “nonresponders”•Able to easily follow DSA levels during/after therapy

•Disadvantages:•DSA may rebound between treatments or if discontinued•Treatment may be prolonged and immunosuppressive•Expensive and resource intensive

Antibody Reduction TherapyAntibody Reduction Therapy

B-Cell ModulationB-Cell Modulation•Anti-CD20

•Mechanism:•Rapid ablation of the peripheral B-cell compartment

•Advantages:•Probably reduces precursor cells responsible for clonal expansion during AMR•May produce more effective antibody reduction when combined with plasmapheresis or IVIG •Well-tolerated, little apparent toxicity •Effect on the immune system is temporary (6-months)

•Disadvantages:•Plasma cells persist in the spleen•May not, on its own, reduce DSA titers during AMR •Immunosuppressive

Days from Transplant

-19 -17 -15 -12 -8 -7 -6 -5 -4 -3 -2 -1 0 +2 +3 +4 +5 +6 +7 +8 +9 +11 +12 +13 +16 +18 +19

64

32 32

16

84

8 84 4 2 4 4

8 8

16

8

16 16 16

2 2 1 1 1

98

85

100

0

20

40

60

80

100

120

0

10

20

30

40

50

60

70

80

90

100

512

128

100100

58

0

Tx

Anti-CD20

DSA titer

PRAPP/ CMVIg

PR

A

DS

A t

iter

Case Study: AMR in (+) Cytotoxic XM withHigh Titer Anti-HLA DSA

Cr 6.5

Cr 1.5

Cr 4.4

Cr 2.1Cr 1.6

CD20=23.7 CD20=0CD19=0

B-cell ModulationB-cell Modulation•Splenectomy

•Mechanism:•Reduces plasma cells, precursor cells, B-cell immune surveillance capabilities

•Advantages:•Can be performed using minimally invasive techniques•May produce more effective antibody reduction when combined with plasmapheresis or IVIG

•Disadvantages:•Life-long risk of sepsis from encapsulated bacteria•Does not appear on its own to reduce DSA titers•Effect on immune system is permanent

0

16

32

64

128

256

-28 -23 -21 -18 -16-15 -14 -12 -10 -6 -4 -3 -2 -1 0 3 5 7 8 10 12 14 17 21 25 27 31 32 34 40 42 45

Day With Respect to Transplant

An

ti-A

Tit

ers

(1:

X)

Seru

m C

reatinin

e(m

g/d

L)

4

3

1

2

The Effect of Splenectomy on Anti-Blood Group Ab

512

Tx

Splenectomy

PP/IVIg

Targets of Strategies for Antibody Removal

Plasma cells

B-cells &Pre B-cells

Clonal Expansion

Plasmapheresis/IVIG

Anti-CD20

Splenectomy

Acute De Novo AMR•Occurs in 4-6% of transplants (80-100% fail)

•Risk factors include: + historic XM,history of sensitizing event(s), high risk donor/recipient combination

•Diagnosis should be made by histology anddemonstration of the appearance of DSA

•Historically suspected only after there is a poor response to anti-lymphocytic agents

•By definition the current XM is negative

PP/CMVIg Treatment Protocolfor Acute De Novo AMR

8642Dx ofAMR

PP/Ig

Steroid bolus-OR-

-thymocyte globulin

PP/Ig PP/Ig PP/Ig PP/Ig

Time Relative to Initiation of Therapy (Days)

Plasmapheresis – single plasma volume exchange

IVIG – 100mg/kg following each PP treatment(CMV hyperimmune globulin)

HeparinD/C FK 506

High Grade:

De Novo AMR: Renal Allograft Function

0

5

10

15

Serum Creatinine (mg/dL)

Nadir Rejection1 Week 1 MonthCurrent

* * *

MedianNadir Cr

(IQR)

MedianCr at AMR

(IQR)

Median1 week Cr

(IQR)

Median1 month Cr

(IQR)

MedianCurrent Cr

(IQR)

3.3(2.2 – 7.1)

6.4(3.2 – 9.3)

4(2.3 – 7.9)

1.9(1.5 – 3.0)

1.5(1.2 – 2.1)

* p<0.001

1994-2003: 22 recipients of deceased or live donor kidney transplants with AMR by Bx or DSAtreated with PP/IVIg

Mean f/u: 5 1/2 years

PP/CMVIg Treatment for De Novo AMR

Kaplan-Meier Estimate of Graft Survival for recipients who developed de novo AMR and were treated with PP/CMVIg therapy

Allograft Survival

10

20

30

40

50

60

70

80

90

100

0 365 730 1095Time (days)

Live donor Deceased donor

p = NS

10

20

30

40

50

60

70

80

90

100

0 365 730 1095Time (days)

Live donor Deceased donor

10

20

30

40

50

60

70

80

90

100

0 365 730 1095Time (days)

Live donor Deceased donor

p = NS

1-Year: 87.5% 85.8%

Live Deceased

3-Year: 87.5% 77.1%

5-Year: Overall 81.1%

Bx and DSA Proven De Novo AMR

LD DD p

n 5 13

Median Days to AMR

(Range)

11

(8-253)

9

(7-50)

0.25

Median Months F/U

(Range)

13.6

(4-76)

11.2

(3-89)

0.77

De Novo Renal Function

03

69

12

15

Se

rum

Cre

atin

ine

(m

g/d

L)

LD DD

Creatinine at Biopsy Creatinine 1 week

Creatinine 1 mo Current Cr

P=NS for comparison between groups at each timepoint

De Novo AMR Allograft Survival

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

Survival (%)

0 6 12 18 24 30 36Time (Months)

Live Deceased

POSITIVE CROSSMATCH ABO INCOMPATIBLE

# OF PATIENTS

1-YEAR GRAFT SURVIVAL3-YEAR GRAFT SURVIVAL

86 28

Rejection and Clinical Outcomes Following(+) XM and ABOi

Previous Txs123

31125

# OF PATIENTS

Previous Txs

AMRCELLULAR REJECTION

3/28 (11%)4/28 (14%)

1-YEAR GRAFT SURVIVAL3-YEAR GRAFT SURVIVAL

89.8%80.9%

AMRCELLULAR REJECTION

SUBCLINICAL AMRSUBCLINICAL CELLULAR

SUBCLINICAL AMRSUBCLINICAL CELLULAR

0/28 (0%)7/28 (25%)

92.9%**92.9%

**1 death WNE 1 Noncompliance

7/86 (8%)*16/86 (19%)

27/86 (31%)26/86 (30%)

123

410

*Bx @ 1, 3, 6, 12 mos

(+) XM vs. De Novo AMR

De Novo Desensitized p

n 18 31

Median Days to AMR

(Range)

10

(7-253)

20

(2-634)

0.16

Median Months F/U

(Range)

12.4

(3-89)

14.1

(0.6-65)

0.76

(+) XM vs. De Novo AMR Outcomes

03

69

12

15

Se

rum

Cre

atin

ine

(m

g/d

L)

PP/CMVIg Desensitized De Novo Rejection

Creatinine at Biopsy Creatinine 1 week

Creatinine 1 mo Current Cr

P=0.002

P=0.01

P=0.04

P=NS between groups at current timepoint

Allograft Survival After AMR (+) XM vs. De Novo

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

Survival (%)

0 6 12 18 24 30 36Time (Months)

(+) XM DeNovo

p=NS

Kaplan-Meier Estimate of Graft Survival (+) CDC XM @ Time of

Tx vs (-) CDC XM

10 20 30 40 50 60 70 80 90

100

% Allograft Survival

0 30 60 90 120 150 180 210 240 270 300 330 360 Time (Days)

+ XM @ Tx - XM @ Tx

+XM @ Tx - XM @ Txp=NS

1 Year Graft Survival

92.3% 87.2%

N= 14 N= 32

Anti-CD20 Rescue ProtocolInclusion Characteristics

•Failure to Respond to Plasmapheresis/CMVIg Therapy

•Study Group•Recipients of Deceased or Live Donor Kidneys

•De novo AMR

•AMR After Desensitization

•Poor or Incomplete Clinical Response

•Persistence of High-Titer DSA

•Persistence of Histologic Evidence of AMR

•Initial Histologic Features That Portend Poor Outcome and/or Graft Loss (Grade 2-3 AMR)

Renal Function Following Anti-CD20 Rescue

Best AMR 2 weeks 1 month Current

1.8(1.4 – 2.1)

4.3(2.5 – 6.5)

3.4(1.9 – 5.4)

2.1(1.6 – 3.3)

1.7(1.1 – 2.6)

0

1

2

3

4

5

6

7

8

9

10

Best Cr AMR Cr

2 week Cr 1 month Cr

Current Cr

Best AMR 2 weeks1 MonthCurrent

p=0.0003

p=0.25

p=0.07

p=0.01

17 recipients undergoing -CD20 rescue therapy for AMR

Kaplan-Meier Estimate of Graft Survival for Anti-CD20

Rescue

25

50

75

100

0 1 2 3 4 5 6 7 8 9 10 11 12

Months Following Anti-CD20 Treatment

%Survival

Splenectomy RescueN 4

Median Days to AMR

(Range)

4

(2-15)

Median Days to Splenectomy Following AMR Dx

(Range)

1

(1-4)

Median SCr at Biopsy Dx

(Range)

3.4

(1.5 – 6.0)

Median SCr 1 week

(Range)

2.1

(0.8 – 5.8)

Median SCr 1 month

(Range)

1.5

(0.7 – 2.3)

Median Current SCr

(Range)

1.3

(1.2 – 2.6)

Allograft Survival 100%

Median Months Followup

(Range)

6.9

(2.2 – 11.7)

Conventional KPD

A B

B A

# of KPD: 6 (12 patients)

Mean PRA: 14

Unconventional KPD

A O

O A

ABOi

(+) XM

ABOi

ABOi

6 mos Cr: 1.2 mg/dl

AMR: 0%

Patient Survival: 100%

Graft Survival: 91.7%

# of KPD: 5 (13 patients)

Mean PRA: 58

6 mos Cr: 1.1 mg/dl

AMR: 0%

Patient Survival: 100%

Graft Survival: 100%

Cellular 23%Cellular 8%

Paired Donation May Reduce the Incidence of AMR

Summary Summary •The diagnosis of AMR can now be made with a high level of certainty

•There are therapeutic interventions for AMR with clinically proven efficacy

•De novo AMR has a good long-term prognosis when treated with PP or IVIg

•Results of PP or IVIg treatment for De novo AMR and AMR in the setting of desensitization are comparable

•A (+) cytotoxic XM at the time of Tx does not predict a worse outcome

•AMR recalcitrant to PP/IVIg is associated with a lower graft survival rate

•Results of emergent splenectomy at the time of severe AMR look promising

•KPD may decrease AMR by lowering immunologic risk

De Novo AMR AMR after (+) XM AMR after ABOi

PP/IVIg

Response Incomplete Response

Observe

Severe AMR

Anti-CD20 Splenectomy Anti-CD20

Algorithm For Approach To AMR

Acknowledgements Acknowledgements

Matt Cooper

Lorraine Racusen

Mark Haas

Karen King

Andrea Zachary

Susie Lefell

Donna Lucas

Julie Graziani

Renato Vega

Chris Sonnenday

Dan Warren

Chris Simpkins

Janet HillerJennie RickardAmie SwardsonJames BurdickEdward KrausHamid RabbRichard UgarteBrigitte ReebMary Jo HolechekDiane LepleyDorry SegevTomasz Kazlowski

Johns Hopkins InKTP

ColumbiaLloyd Ratner

Johns Hopkins InKTP