1. Antibody-Mediated Rejection
Experience with
Antibody-Mediated Rejection
Millie Samaniego, M.D.
Associate Professor of Medicine
University of Wisconsin
and
Robert A. Montgomery, M.D., D.Phil.
Chief, Division of Transplantation
Director, The Johns Hopkins Comprehensive Transplant Center
The Johns Hopkins Hospital

2. Diagnostic Criteria for Acute AMR
Characteristic histologic features including:
1) glomerulitis/capillaritis
2) margination of neutrophils in the PTC
3) fibrin thrombi
4) interstitial hemorrhage
5) severe or necrotizing vasculitis
Diffuse, linear C4d staining in the PTC
Identification of DSA
Grade 1
Grade 3

3. Patterns of Rejection in ABO Incompatible Transplants
AMR
Cellular
Accommodation

4. Therapeutic Options For The Treatment Of AMR
Antibody Reduction
Immunomodulation
Plasmapheresis/IA
IVIg
IVIg
ATG
IL-2R blockers
Fk 506, Rapamycin
MMF/DSG
CAMPATH?
B-cell Modulation
Splenectomy
Anti-CD20
Cytoxan

5. Antibody 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

6. Antibody Reduction Therapy
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

7. B-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

8. Case Study: AMR in (+) Cytotoxic XM with High Titer Anti-HLA DSA
DSA titer
512
Cr 6.5
PP/ CMVIg
PRA
128
100
Cr 4.4
100
100
100
120 98 90
Cr 2.1
Cr 1.5
Cr 1.6 85 80
100 70
DSA titer 80 60
PRA 64 58 50 60
Anti-CD20
CD20=0
CD19=0
CD20=23.7 40 40 32 32 30 Tx 20 20 16 16 16 16 16 8 8 8 8 8 8 10 4 4 4 2 4 4 2 2 1 1 1
-19
-17
-15
-12 -8 -7 -6 -5 -4 -3 -2 -1 +2 +3 +4 +5 +6 +7 +8 +9
+11
+12
+13
+16
+18
+19
Days from Transplant

9. B-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

10. The Effect of Splenectomy on Anti-Blood Group Ab
PP/IVIg
512
256
Splenectomy 4 3
Anti-A Titers (1:X)
Serum Creatinine
(mg/dL)
128 Tx 2 64 1 32 16
-28
-23
-21
-18
-16-15
-14
-12
-10 -6 -4 -3 -2 -1 3 5 7 8 10 12 14 17 21 25 27 31
32 34 40 42 45
Day With Respect to Transplant

11. Targets of Strategies for Antibody Removal
Plasmapheresis/IVIG
Plasma cells
Splenectomy
Clonal Expansion
B-cells &
Pre B-cells
Anti-CD20

12. Acute De Novo AMR Occurs in 4-6% of transplants (80-100% fail)
By definition the current XM is negative
Risk factors include: + historic XM,
history of sensitizing event(s), high risk
donor/recipient combination
Historically suspected only after there is a poor
response to anti-lymphocytic agents
Diagnosis should be made by histology and
demonstration of the appearance of DSA

13. PP/CMVIg Treatment Protocol for Acute De Novo AMR
Plasmapheresis – single plasma volume exchange
Steroid bolus
-OR-
a-thymocyte globulin
IVIG – 100mg/kg following each PP treatment
(CMV hyperimmune globulin)
PP/Ig
PP/Ig
PP/Ig
PP/Ig
PP/Ig
Dx of
AMR 2 4 6 8
Time Relative to Initiation of Therapy
(Days)
Heparin
D/C FK 506
High Grade:

14. De Novo AMR: Renal Allograft Function5 10 15
Serum Creatinine
(mg/dL)
Nadir
Rejection
1 Week
1 Month
Current *
* p<0.001
: 22 recipients
of deceased or live donor
kidney transplants
with AMR by Bx or DSA
treated with PP/IVIg
Mean f/u: 5 1/2 years
Median
Nadir Cr
(IQR)
Cr at AMR
1 week Cr
1 month Cr
Current Cr
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)

15. PP/CMVIg Treatment for De Novo AMR10 20 30 40 50 60 70 80 90
100
365
730
1095
Time (days)
Live donor
Deceased donor
100
100
Allograft Survival 90 90 80 80 70 70
p = NS
Live Deceased 60 60
p = NS 50 50
1-Year: % % 40 40 30 30 20 20
3-Year: % % 10 10
Add rate of failure with protocol necessitating Rituximab therapy (don’t include patients who received it for severe AMR)
365
365
730
730
1095
1095
Time (days)
Time (days)
5-Year: Overall 81.1%
Live donor
Deceased donor
Live donor
Deceased donor
Kaplan-Meier Estimate of Graft Survival for recipients who
developed de novo AMR and were treated with PP/CMVIg therapy

16. Bx and DSA Proven De Novo AMRLD DD p n 5 13
Median Days to AMR
(Range) 11
(8-253) 9
(7-50)
0.25
Median Months F/U
13.6
(4-76)
11.2
(3-89)
0.77

17. De Novo Renal Function 15 12 9
Serum Creatinine (mg/dL) 6 3 LD DD
Creatinine at Biopsy
Creatinine 1 week
Creatinine 1 mo
Current Cr
P=NS for comparison between groups at each timepoint

18. De Novo AMR Allograft Survival
100.00
90.00
80.00
70.00
60.00
Survival
(%)
50.00
40.00
30.00
20.00
10.00
0.00 6 12 18 24 30 36
Time (Months)
Live
Deceased

19. Rejection and Clinical Outcomes Following (+) XM and ABOi
POSITIVE CROSSMATCH
ABO INCOMPATIBLE
# OF PATIENTS 86
# OF PATIENTS 28 1 2 3 31 12 5 1 2 3 4 1
Previous Txs
Previous Txs
AMR
CELLULAR REJECTION
27/86 (31%)
26/86 (30%)
AMR
CELLULAR REJECTION
3/28 (11%)
4/28 (14%)
SUBCLINICAL AMR
SUBCLINICAL CELLULAR
7/86 (8%)*
16/86 (19%)
SUBCLINICAL AMR
SUBCLINICAL CELLULAR
0/28 (0%)
7/28 (25%)
1-YEAR GRAFT SURVIVAL
3-YEAR GRAFT SURVIVAL
89.8%
80.9%
1-YEAR GRAFT SURVIVAL
3-YEAR GRAFT SURVIVAL
92.9%**
92.9%
1, 3, 6, 12 mos
**1 death WNE
1 Noncompliance

20. (+) 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
12.4
(3-89)
14.1
(0.6-65)
0.76

21. (+) XM vs. De Novo AMR Outcomes3 6 9 12 15
Serum Creatinine (mg/dL)
PP/CMVIg Desensitized
De Novo Rejection
Creatinine at Biopsy
Creatinine 1 week
Creatinine 1 mo
Current Cr
P=0.04
P=0.01
P=0.002
P=NS between groups at current timepoint

22. Allograft Survival After AMR (+) XM vs. De Novo
100.00
90.00
80.00
70.00
p=NS
60.00
Survival
(%)
50.00
40.00
30.00
Deaths: incompatible group = 7 (1-year = 81.5%, 3-year = 75.5%) , denovo group = 3 (1-year 94.4%, 3-year 81.9%)
20.00
10.00
0.00 6 12 18 24 30 36
Time (Months)
(+) XM
DeNovo

23. Kaplan-Meier Estimate of Graft Survival (+) CDC XM @ Time of Tx vs (-) CDC XM10 20 30 40 50 60 70 80 90
100 %
Allograft
Survival
120
150
180
210
240
270
300
330
360
Time (Days)
+ Tx - Tx
1 Year
Graft Survival
p=NS
Tx - Tx
N= 14 N= 32
92.3% %

24. Anti-CD20 Rescue Protocol
Inclusion Characteristics
Failure to Respond to Plasmapheresis/CMVIg Therapy
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)
Study Group
Recipients of Deceased or Live Donor Kidneys
De novo AMR
AMR After Desensitization

25. Renal Function Following Anti-CD20 Rescue
p=0.0003
p=0.01 10
p=0.07 9
p=0.25 8 7
17 recipients
undergoing a-CD20
rescue therapy
for AMR 6 5 4 3 2 1
Best
AMR
2 weeks
1 Month
Current
Best Cr
AMR Cr
2 week Cr
1 month Cr
Current Cr
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)

26. Kaplan-Meier Estimate of Graft Survival for Anti-CD20 Rescue
100 75 %
Survival 50 25 1 2 3 4 5 6 7 8 9 10 11 12
Months Following Anti-CD20 Treatment

27. Splenectomy Rescue N 4 Median Days to AMR (Range) (2-15)
Median Days to Splenectomy Following AMR Dx 1
(1-4)
Median SCr at Biopsy Dx
3.4
(1.5 – 6.0)
Median SCr 1 week
2.1
(0.8 – 5.8)
Median SCr 1 month
1.5
(0.7 – 2.3)
Median Current SCr
1.3
(1.2 – 2.6)
Allograft Survival
100%
Median Months Followup
6.9
(2.2 – 11.7)

28. Paired Donation May Reduce the Incidence of AMR
Conventional KPD
Unconventional KPD A B
ABOi A
ABOi O B A
ABOi O
(+) XM A
# of KPD: 6 (12 patients)
# of KPD: 5 (13 patients)
Mean PRA: 14
Mean PRA: 58
6 mos Cr: 1.2 mg/dl
6 mos Cr: 1.1 mg/dl
AMR: 0%
Cellular 8%
AMR: 0%
Cellular 23%
Patient Survival: 100%
Patient Survival: 100%
Graft Survival: 91.7%
Graft Survival: 100%

29. 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

30. Algorithm For Approach To AMR
De Novo AMR
AMR after (+) XM
AMR after ABOi
PP/IVIg
Severe AMR
Response
Incomplete Response
Anti-CD20
Splenectomy
Observe
Anti-CD20

31. Acknowledgements Johns Hopkins InKTP Johns Hopkins InKTP Columbia
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 Hiller
Jennie Rickard
Amie Swardson
James Burdick
Edward Kraus
Hamid Rabb
Richard Ugarte
Brigitte Reeb
Mary Jo Holechek
Diane Lepley
Dorry Segev
Tomasz Kazlowski
Columbia
Lloyd Ratner