Thursday, July 26, 2012

Myeloablative vs Non-Myeloablative

Myeloablative (MB) vs Non-Myeloablative (NMB)?  If you are considering HSCT this is a question you will probably end up contemplating.  There are supporters of both.  Dr Richard Burt from North Western Hospital prefers the NMB protocol whereas others like HSCT recipient George Goss advocate for the MB.

The question is who is right and why?  Personally I believe that there is a room for both.  And here is why.  To start I would just like to add that the theories and points I'm laying out in this post are my own and have not been ratified by any research or medically qualified people.  But it does make sense.  Well to me anyway.

The MB procedure is where the entire bone marrow is attacked by the chemotherapy regime.  This destroys all blood producing cells.  The NMB targets the white cells and does not completely destroy the bone marrow.  The theory being that the fault with the immune system lies in the white cells and destroying them will destroy the immune problem too.  The MB in destroying the bone marrow also destroys the white blood cells and the immune system.

To begin with I'm going to do a short list of the pros and cons of each procedure.

MB Pros

  • Destroying the bone marrow will completely destroy the immune system.  It is much more thorough.
  • It has been successful in treating auto immune diseases.
MB Cons
  • The chemo treatment is much more severe and intense
  • There is an increased risk of complications
  • Recovery is longer

NMB Pros
  • It is less invasive than the MB protocol
  • It has been successful in treating auto immune diseases.
NMB Cons
  • It is not as successful as the MB
I will give you two examples.  First, my favourite subject, Me!  I had the NMB and it worked for me really well and I'm not the only one.  But when you look at diseases such as multiple sclerosis, the selection criteria is much more strict for the North Western NMB protocol.  It is their understanding that once your EDSS score (A score out of 10 to that measures degree of disability) is greater than 6, HSCT is ineffective.

That brings me onto my second example.  Carmel Turner had MS and her EDSS was 7 which would have rendered her ineligible for the North Western trial.  She had the MB HSCT using the BEAM protocol and just like mine worked for me, hers worked for her.

That brings me onto attempting to answer the question of which protocol for you if you are considering HSCT for an autoimmune disease.  Now bear with me here, this is the point where I'm creating my own hypotheses.  I have no scientific data to back these up.  But I believe there are a number of factors that one should consider:
  • Severity of disease.  If your disease is severely debilitating a stronger approach may be considered.
  • Longevity of disease.  The longer you have had a disease the more entrenched it will become in your body and the stronger the treatment may need to be.
  • Type of disease.  I believe that if the disease is predominantly inflammatory in nature then the NMB protocol will work.  If the diseases has progressed beyond an inflammatory stage a stronger regime will probably be required
I would love to see a medical researcher test these hypotheses to see if I'm right and if I'm not, are there any discernible patterns?  Believe me the NMB was bad enough.  You wouldn't want to go through the MB protocol unless you had to.  Well, I hope that this does inspire some educated discussion.  Until next time, stay well:)

3 comments:

  1. Interesting, as usual, Andy! I'm just glad I had my MB SCT done before I got much sicker to have to contemplate this decision!
    Wendy :)

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  2. Andrew, thanks for doing this as I DID wonder, and your explanation is spot-on,
    thank you as adds to the clarity of all this,

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  3. Kudos! Informational and easy to understand. I have enjoyed your blog for some time. Seeing you run again has given me hope that I too can ride myself of cidp.

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