evidence of anti-cardiac antibody deposition in end-stage failing myocardium: a potential...
DESCRIPTION
Best International Research Project of CADECI 2012 (Annual Congress of International Interventional Cardiology) oral presentation given by Dr. Christian Assad-Kottner This is a 6 year research project involving 100 patients with heart failure and 40 normal hearts. 70/100 patients with heart failure showed deposition of anticardiac antibodies in the myocardium while 0/40 in the normal hearts. This further supports the theory that the immune system plays a key role in the development and progression of heart failure and could be the target for future therapeutic modalities. The beautiful background Images from the slides were created by Edmond Alexander (http://www.shannonassociates.com/artists.php?artist=edmondalexander#url=artists/alexander/fs/Monoclonal_Antibody_1082911)TRANSCRIPT
Evidence of anti-cardiac antibody deposition in end-stage failing myocardium: A
potential contributor to disease progression
Christian Assad-Kottner, MD1, 2; Andrea M Cordero-Reyes, MD2; Alejandro R Trevino, MD2; Jose H Flores-Arredondo, MD2; Evaristo Fernandez2, MD; Roberto Barrios, MD2; Keith A Youker, PhD2; Guillermo Torre-Amione, MD, PhD2
The University of Texas Medical Branch at Galveston Texas (UTMB)The Methodist DeBakey Heart Center
Herskowitz, A. et al. (1993) Concepts of autoimmunity applied to idiopathic dilated cardiomyopathy. J. Am. Coll. Cardiol. 22, 1385–1388
IntroductionSeveral studies have suggested the possibility that the humoral immune response may play an important roll in the development and progression of heart failure.
Previous studies have focused on demonstrating the presence of antibodies against the myocardium in the serum of patients with cardiomyopathy.
To date, no study has shown the deposition of native anti cardiac antibodies deposited in the patient's failing myocardium
Antibodies
Mitochondria
M7ANT
BCKD-E2
Sarcolemma / Contractile
Proteins
TroponinActin
Myosin
MuscarinicReceptors
B1-AdrenérgicReceptors
Caforio AL, Mahon NJ, Tona F, McKenna WJ. Circulating cardiac autoantibodies in dilated cardiomyopathy and myocarditis: pathogenetic and clinical significance. Eur J Heart Fail. 2002 Aug;4(4):411-7.
Introduction
Introduction
The presence of anticardiac autoantibodies have been studied in the serum of patients with heart failure since 1986.
One of the biggest challenges up to date regarding the presence of anticardiac antibodies has been verifying their specificity since a great number have been shown to be present in similar numbers in healthy individuals.
Schimke I, Muller J, Priem F, et al. Decreased oxidative stress in patients with idiopathic dilated cardiomyopathy one year after immunoglobulin adsorption. J Am Coll Cardiol. 2001;38:178–183.
Several groups have shown that removing anticardiac antibodies in patients with heart failure improve systolic function, diastolic function and NYHA class.
When removing these antibodies particular importance has been placed in the IgG3 subclass.
Introduction
IntroductionHow where the Anticardiac Antibodies removed?
Plasmapheresis
Inmunoadsorption
Felix SB, Staudt A. Immunoadsorption as treatment option in dilated cardiomyopathy. Autoimmunity. 2008 Sep;41(6):484-9.
So… What is so special of IgG3Activates the complemente in the most efficient way
From all the subclasses it is the one that has the most notable cytotoxic activity
Several autoimmune disease have shown to have IgG3 as a predmominant subtype (Rheumatoid Arthritis, Connective Tissue Diseases, Psoriasis)
Introduction
Staudt A, Böhm M,Felix SB. Potential role of autoantibodies belonging to the immunoglobulin G-3 subclass in cardiac dysfunction among patients with dilated cardiomyopathy. Staudt A, Böhm M,Felix SB. Circulation. 2002 Nov 5;106(19):2448-53.
Jahns R, Boivin V, Siegmund C, et al. Autoantibodies activating human B-1-adrenergic receptors are associated with reduced cardiac function in chronic heart failure. Circulation. 1999;99:649–654
Antibodies against the B-1 Adrenoreceptor
60% of patients with idiopathic cardiomyopathy have it<1% of healthy individuals10-13% of patients with ischemic cardiomyopathy
Introduction
MethodsMyocardial samples were obtained from 100 patients with heart failure at the time of transplantation or implantation of a left ventricular assist device.
40 samples from normal hearts were used as control
Samples were then fixed in paraffin following standardized protocols
MethodsThe samples were subsequently analyzed by immunofluorescence techniques in order to identify; 1) Anticardiac antibodies 2) The IgG3 subclass 3) Activated Complement
Antihuman antibodies conjugated with FITC (fluorescein isothiocyanate) or Cy3 (carbocyanine 3) were used to identify native anticardiac antibodies and activated complement.
Samples were then analyzed by a board certified pathologist
Antibodies 1
01
IgA IgD IgE IgG IgM
IgG1 IgG2 IgG4IgA1 IgA2
IgG3
Structure of the Immunoglobulin
Fab
Fc
Structure of the ImmunoglobulinLight Chain
Heavy Chain
Fragment, antigen binding
Fragment crystallizable
region
Domains of the Immunoglobulin
Antibody DomainsV: VariableC: Constant
Fab
Fc
Fragment, antigen binding
Fragment crystallizable
region
Antibodies conjugated with FITC (fluorescein isothiocyanate) and Cy3 (carbocianine 3)
Antihuman anti-FAB antibodyConjugated with
FITC (fluorescein isothiocyanate)
Antihuman antibody conjugated with Cy3 (carbocianine 3)
Myocardium with deposition of Anticardiac antibodies being identified by the antihuman anti-fab FITC antibody
Myocardium with deposition of Anticardiac antibodies being identified by the
antihuman anti-fab FITC antibodies
Anticardiac Antibody
Antihuman anti-fab FITCantibody
Myocardium with no deposition of Anticadiac Antibodies
Now What?
Healthy Myocardium
Heart Failure
Deposition of Anticardiac Autoantibodies in the myocardium identified by the antihuman anti-fab FITC labeled antibodies
Deposition of Anticardiac Autoantibodies in the myocardium identified by the antihuman anti-fab FITC
labeled antibodies
Antibodies
Mitochondria
M7ANT
BCKD-E2
Sarcolemma / Contractile
Proteins
TroponinActin
Myosin
MuscarinicReceptors
B1-AdrenérgicReceptors
Prevalence of Anticardiac IgG antibodies
Samples of healthy
hearts ( 40 pts) without
anticardiac antibody deposition
Patients (71/100 )
with deposition
of anticardiacautoantibo
diesOut of the 71/100
patients with
deposition of
anticardiac antibodies68% was of
the IgG3 subclass
Myocardium of a patient with heart failure and double stain for IgG3 y C3c.
Deposition of FITC labeled antibody directed agains C3c
Deposition of CY3 labeled antibody directed agains IgG3
Overlap of C3C and IgG3 staining
Magnification
• Group A shows a subset of patients who were positive for both IgG3 and for the complement activation marker C3c.
• Group B shows a subset of patients who tested negative for both IgG3and C3c.
• Average Years of disease in patients who tested positive was 11 years to 6 years of those who were negative.
• This suggests that with increasing duration of the disease increases the presence and activation of the immune system
Heart Failure duration (yrs) and activation of the immune system
ConclusionsWe demonstrate for the first time that 70% of patients with heart failure regardless of etiology has deposition of anticardiac autoantibodies
The IgG3 subtype the most commonIt has the largest cell cytotoxic effectActivates complement in the most efficient
It has the potential to cause severe proinflammatory effects.
As disease duration increases so does the presence and activation of the immune system.
Additional studies are needed to understand the role of different classes of antibodies in myocardial dysfunction
These findings support the theory that the immune system plays an important role in the development and progression of cardiac dysfunction and therefore is a reasonable target for future therapeutic modalities.