Complement in Heart Complement in Heart Allograft BiopsiesAllograft Biopsies

E. Rene RodriguezE. Rene RodriguezW. M. Baldwin, IIIW. M. Baldwin, III

Acute humoral rejection is recognized as aclinical entity in the grafted heart.It remains controversial, however, with ahighly varied incidence between differentcenters and no consensus has yet beenreached on its recognition and diagnosiseither histopathologically orimmunologically.

The 2004 ISHLT meeting reviewed evidence from theimmunopathology and clinical task forces and felt able tosuggest diagnostic criteria in specific circumstances so thatfurther assessment of this entity could be encouraged.

Variables in Heart StudiesVariables in Heart Studies

Patient PopulationPatient PopulationPercent SensitizedPercent Sensitized

•LVAD LVAD •Blood TransfusionsBlood Transfusions•PregnancyPregnancy•Previous transplant Previous transplant

ImmunosuppressionImmunosuppression

Prospective Study of Prospective Study of Cardiac TransplantsCardiac Transplants

• All biopsies from Jan ‘01 to Dec ‘03All biopsies from Jan ‘01 to Dec ‘03

• 665 biopsies from 165 patients 665 biopsies from 165 patients

• 107 males: 58 females107 males: 58 females

• 34 patients followed from time of 34 patients followed from time of transplantationtransplantation

• almost all patients had 0%PRAalmost all patients had 0%PRA

Rodriguez et al AJT 2005 (in press)

ROUTINE DIAGNOSTICPROTOCOL BIOPSIES FROM

CARDIAC TRANSPLANTS

1 mo1 mo 2 mo2 mo 3 mo3 mo 6 mo6 mo 1 yr1 yr

H&E, H&E, IP (CD68)IP (CD68) FITC (IgG, IgM, IgA, C1q, C4d, C3d)FITC (IgG, IgM, IgA, C1q, C4d, C3d)

Number of Patients with Number of Patients with Positive BiopsiesPositive Biopsies

0153045607590

105120135150165

IgG IgM IgA C1q C4d C3d

16(9.6%)

17(10.3%)

C3d+ C3d -

C4d+ 13 (8%)* 3 (2%)

C4d- 4 (2%) 145 (88%)

* One patient 10% PRA

C4d and/or C3d DepositsC4d and/or C3d Deposits

(665 consecutive biopsies from 165 patients)

0

1

2

3

4

5

6

Number of Patients

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Years after Transplantation

Time of Positive Biopsies for C4d and/or C3d

C4d

C3d

C4d & C3d

C4dC4d C3dC3d

C4d + C3dC4d + C3d

n = 3n = 3 n = 4n = 4

n = 13n = 13

Incidence of C4d and C3d depositsIncidence of C4d and C3d deposits

DysfunctionDysfunctionn = 5n = 5

Patients with AMRPatients with AMRISHLT ISHLT gradegrade

C4d + C4d + C3dC3d

CD CD 6868

Dys- Dys- functionfunction

##

graftgraft

Donor Donor Sp. Ab.Sp. Ab.

HLA HLA (I or II)(I or II)

1B + + + 2nd2nd + I + III + II

1A + + + 2nd2nd - -

0 + + + 2nd2nd + II

1B + + + 1st - -

1A + + + 1st + IIII

ANTIBODY ASSOCIATED REJECTION

7 years after transplantation anti-DR7 and DRw53

MacrophagesMacrophages

Response to TherapyResponse to TherapyPlasmapheresis and IVIgPlasmapheresis and IVIg

• Graft function improvedGraft function improved• DSA decreased or eliminatedDSA decreased or eliminated• (C consumption not measured)(C consumption not measured)• C3d deposits cleared firstC3d deposits cleared first• Low levels of antibodies (as Low levels of antibodies (as detected Flow beads) can persist detected Flow beads) can persist beyond C4dbeyond C4d

0

2

4

6

8

10

C4d only C3d only C4d + C3d C4d + C3dAMR

Vasculopathytotal

Association of Cardiac Allograft VasculopathyAssociation of Cardiac Allograft Vasculopathywith C4d C3d and AMRwith C4d C3d and AMR

C4dC4d C3dC3d

C4d + C3dC4d + C3d

n = 3n = 3 n = 4n = 4

n = 13n = 13

Incidence of C4d and C3d depositsIncidence of C4d and C3d deposits

DysfunctionDysfunctionn = 5n = 5

0

1

2

3

4

0

Months after Transplantation

Fluorescence (1 to 4+)

C4dC3dISHLT

1A1B

No antibodiesClass I or II

Second Heart Transplant with Repeat HLA MismatchSecond Heart Transplant with Repeat HLA MismatchStrong C4d, Little C3d, No HLA antibodies, Good FunctionStrong C4d, Little C3d, No HLA antibodies, Good Function

1st heart HLA-A12nd heart HLA-A1

0

12

Baldwin et al 2004 AJT 4:311

C1 C4 C3C2 C5 C6

C7C8C9

C4bpDAF MCP*CR1*

Factor I

Factor HDAF MCP*CR1*

Factor I

CD59

Regulation of Regulation of Complement CascadeComplement Cascade

C1 C4 C3C2 C5 C6

C7C8C9

C4bpDAF MCP*CR1*

Factor I

Factor HDAF MCP*CR1*

Factor I

CD59

C4d C3d

C4d and C3d are ProductsC4d and C3d are ProductsComplement RegulationComplement Regulation

C1 C4 C3C2

Sensitization vs RegulationSensitization vs Regulation

C1 C4 C3C2

C1 C4 C3C2

Sensitization vs RegulationSensitization vs Regulation

C1 C4 C3C2

C1 C4 C3C2

C1 C4 C3C2

C1 C4 C3C2

C1 C4 C3C2 C5 C6

C7C8C9

Sensitization vs RegulationSensitization vs Regulation

EpilogueEpilogue“Acute humoral rejection is recognized …with a highly varied incidence betweendifferent centers…”

EpilogueEpilogue“Acute humoral rejection is recognized …with a highly varied incidence betweendifferent centers…”

…and between different eras in the same center

eg, JHU

Increased patients with >0% PRA

2 patients with episodes of antibody-mediatedrejection in the first weeks after transplantation Required longer treatment with PP & IVIg

SummarySummaryC4d and C3d in Heart TransplantsC4d and C3d in Heart Transplants

• Incidence depends on sensitization• Can occur years after transplantation

• Needs to be correlated with graft function and Donor Specific Antibody (DSA) for a diagnosis of antibody-mediated rejection

• May be correlated with increased graft vasculopathy

Kenji MinamiKenji MinamiKazunuri MurataKazunuri Murata

Clinical studiesClinical studiesE. Rene RodriguezE. Rene Rodriguez

Experimental studiesExperimental studies