Nigel,
I understand how you feel you're in a holding pattern and can't get on with your life with this hanging over you, and I wish the right choice was clearer. It's wise to gather all the information you can, and opinions from other patients can help, but ultimately the most important voices are your own, your wife's, and the doctors you most trust.
If you could live with low counts without needing treatment of any kind, I'd be inclined to favor waiting a bit longer in case you find a better match. I think that having a young son is another reason to wait a bit longer, but the long-term outcome is more important than the short term, and that against favors treatment over wait-and-watch.
I wouldn't wait just because transplant techniques and success rates improve over time, since that's a slow process. Waiting also runs the risk that your sister could become medically unavailable for one reason or another.
The need for transfusions is the main factor that would lead me to favor a transplant in your situation. It's not a sustainable condition for life and statistically a history of transfusions reduces transplant success rates.
If that's the #1 reason for a transplant, the #1 opposing reason is your lack of a better match. I'd be quite concerned having nothing better than a haplo match, and I think those two factors are what put you in this dilemma. I don't know what the statistics show for haplo transplants, especially for those in your age group, and you can't trust statistics based on data from years past to represent your current chances of success very accurately. However, if it was me I'd ask the treatment center or a national agency to provide me with whatever statistics they have, to give me a better basis for considering or rejecting that choice. We know that a close match from an unrelated donor would be better than a half-match, but how much better?
Is the Australian Organ and Tissue Authority the agency that's been searching for a better match for you? [Correction: It's the
Australian Bone Marrow Donor Registry (ABMDR), as Sandi points out below. Thanks for correcting this!] Do you know for certain that all of the international registries have been searched, not just your national registry? If you don't mind my asking, were your parents from very different backgrounds, and that's the reason for your rare HLA tissue type? Or are your ancestors from a small community? I'm wondering if with enough effort, backing, funding, support, and publicity you could get a number of bone marrow registration drives going among certain geographic, national, or ethnic communities. That's what
Krissy Kobata is doing with her search for a donor among those with the same mixed ethnicity.
You didn't mention trying other drugs. Has your doctor suggested that?