Documented viral infection...

[JAMESFETT]

I have collected data on 15 PPCM patients who showed evidence of viral infection causing their cardiomyopathy. The testing done included a combination of blood testing showing titer rise in viral antibodies, viral particles in peripheral blood and/or endomyocardial biopsy tissue. Viruses involved are: Parvovirus B19, Coxsackievirus, E-B virus, Human Herpesvirus 6, Cytomegalovirus, and Influenza A and B. These accumulating data support a role for virus infection triggering the cardiomyopathy in at least some mothers with PPCM. Hopefully, our Peripartum Cardiomypathy Network study in North American PPCM patients will add data about the potential role of viral infections.

[Erin]

Wow, that is significant. Dr. Fett, is the evidence mounting against cardiotropic viruses as the probable trigger generally in PPCM? How likely is it that there could be other triggers of PPCM in some patients besides a viral catalyst, or is there any way to know at this time?

Happy Heart Health month to everyone! Wishing you all healing and well-being.

[JAMESFETT]

The evidence is actually rising about the potential role of cardiotropic viruses. In fact, that is still the leading hypothesis, virus as a trigger, evolving into an autoimmune cardiomyopathy. Even the prolactin hypothesis may require a viral trigger; at least it played a role in Hilfiker's original CELL report, investigating experimental animals (mice). Anyway, I think in the end we may see several potential triggers, and of course, the genetic link needs to be pursued. There is also a lot of evidence that an autoimmune or immune system dysfunction kicks in at some time in the process. I expect the PCN North American study to advance knowledge about these issues.

JD

[LovinLife]

wow, so let me get this straight. we would already be predisposed to autoimmune issues, but those would've been triggered by a cardiotropic virus. The virus would "activate" the attack process on the heart? (I know this is all theory right now, but just trying to make sure I have it right)

So if this does turn out to be the case, then we really had to have some crazy issues all align to finally develop PPCM....pregnancy, autoimmune, AND a cardiotropic virus. what else??

[JAMESFETT]

Yes, just as in the laboratory with experimental animals, in which one must have virus + genetic susceptibility = cardiomyopathy and autoimmune cardiomyopathy. When the mice without a genetic predisposition to cardiomyopathy are exposed to the same virus, nothing happens so far as a cardiomyopathy. Experimental autoimmune myocarditis in the laboratory suggests mechanisms that actually do come into play in real-life people situations. Of course that may describe the situation for one form of PPCM; but there can be multiple "triggers." Time will tell. The PCN (Peripartum Cardiomyopathy Network) study of recovery in human PPCM will help.

JD

[Erin]

Dr. Fett, those viruses you listed in the first post (coxsackie, etc.) are all relatively common cold/flu type of viruses that most people get throughout their life, is that right? Or am I mistaken?

[JAMESFETT]

Right. Those are all common viruses, and in most people, cause a rather minor illness in childhood, or no illness at all, just a sub-clinical infection, only detectable if one does serum antibody studies. Later-in-life and/or during pregnancy, first exposure may result in more severe infection due to changes in immune system, other illnesses, or virulence of virus.

JD

[Erin]

Dr. Fett, what will need to happen before we begin to see more medical journal articles produced about the role of cardiotropic viruses as triggers in some PPCM patients?

[JAMESFETT]

I have outlined a plan in my editorial (some of these tests will be done through PCN study, and hopefully, others will pick up on this):

Diagnosis of viral cardiomyopathy by analysis of peripheral blood?
James D Fett
Hospital Albert Schweitzer, Deschapelles, Haiti, mailing address: 2331 Mt. Hood Ct SE, Lacey, WA 98503, USA (E-mail: fett.sprunger@comcast.net)

ABSTRACT: Polymerase chain reaction testing has become an important tool in assessing the role of virus in inflammatory cardiomyopathies, including fulminant myocarditis, lymphocytic myocarditis, peripartum cardiomyopathy, unknown cause or idiopathic dilated cardiomyopathy, and acute myocarditis of suspected viral etiology. While this tool has been traditionally reserved for application to endomyocardial biopsy tissue, there is increasing evidence that it may also be helpful in the study of peripheral blood samples, particularly during the viremic phase when there may also be IgM antibodies present against one or more of the cardiotropic viruses.

Keywords: heart failure, inflammatory cardiomyopathy, peripartum cardiomyopathy, PCR, PPCM, pregnancy, virus
Expert Opin. Ther. Targets (2008) 12(9):1073-1075