Why so good?

I have had a few people say to me since the last blog: 'that is such good news about the donor, I'm not sure why it is such good news, but I'm so happy for you'. Well this entry is for you, and to understand why it is such good news we have to look at what was planned.

The reason I have just had a stem cell transplant, or self transplant, is because there was no donor available at the time when I needed the procedure doing. The only options presenting were to perform a transplant using stem cells from umbilical cords - a cord blood transplant - or something else even more drastic using my parents stem cells or an unmatched donor transplant. The latter two options were never discussed in length as I believe that would have only been done in very dire circumstances. As for the cord blood transplant this was discussed and the issues with it as an option were quite extensive. To go on I need to explain what I know about tissue typing.

When looking for a donor match, the consultant needs to know both the patient and donor human leukocyte antigens (HLA) or 'tissue type'. My limited understanding of this as explained to me in layman's terms by my consultant is that they attempt to match 5 HLA: A, B, C, Dr and Dq. For an acceptable 'matched unrelated donor' (MUD or mudblood to those in the know), the aim is to match 4 out of 5 antigens. A is generally the easiest to match leaving most patients requiring 3 out of the remaining 4 to match. These are harder to match as they are combined, i.e. a particular B means you will have a certain range of C, and a particular Dr means you will have a certain range of Dq. I do not know how many combinations there are but I assume there are a lot. Why? Well it is my A that is 'odd'. When I was formed some genes jumped around between my mum and dad's combined chromosomes to create a unique A, which was never going to be matched with anyone anywhere, meaning for me to get a donor someone out there had to have the exact combination of B, C, Dr and Dq as me to be a suitable donor. The response of my consultant was that, although we couldn't rule out someone out there being suitable, the chances were so small that we needed to start thinking about the other options. That is why I think there are a lot of combinations and that is why a donor turning up on the list which matches me is such incredible, unlikely news.

For a cord blood transplant as the stem cells are quite immature, there is only a requriement to match 3 out of 5 antigens when tissue typing. However, the first issue with cord blood is that you do not get enough stem cells for an adult out of one cord, therefore you have to mix the cells from a number of cords to get enough. The understanding of the effects of mixing cords is not understood particularly well as not many cord blood transplants have been perfomed in adults, and the number of myeloma patients treated with a cord blood transplant is probably in the region of 0. The next issue is that the stem cells are less likely to graft (do what they are supposed to), or take longer to graft once inside, meaning either extended time in hospital or the transplant not working at all. Again as cord blood transplants in adults are so new, this is something else not particularly well understood. If the transplant worked, I would have the immunity of a baby and there are significant issues with infection post transplant, much greater than those when having a regular donor transplant. However, the bottom line at the time this was being considered and the main reason a cord blood transplant was not performed (thank god now) was that the people who hold the purse strings would not approve a procedure costing in the 10's of thousands which has no research backing up it's efficacy, especially without the standard treatments being tried first - hence the self transplant going ahead. Plus my consultant wasn't happy with the closest matches found in the cord blood registry, my odd tissue type not helping there either. So we would be going into unknown territory, with increased risks  which are little understood (including increased risk of death or some serious disability) and with no way of knowing if it would actually work. Quite a desparate solution.

Hopefully that gives some indication why finding a donor has been such an incredible bit of news. The plan for me has gone from: 'let's see where the self transplant gets us (not considered to get me into remission for long) then think about what type of high risk transplant we should do when we absolutely have to', to: 'let's see if you're in remission then blast this disease properly using a well understood procedure that gives you a 50% chance of a cure'. Yes, it is worth remembering that the allogeneic (allo-gen-AY-ik) or donor transplant has been shown to be 50% effective (feet firmly back on the ground), and does itself hold risks such as graft-versus-host disease and a 25% chance of mortality. But this is the best option, and lowest risk option there is, and certainly the one that if nothing else leads to the longest remission. It is no walk in the park, it will result in me being pretty ill for at least 6 months and potentially up to a year, but compared to what was being considered...well it says something about the decisions being made that when he found out I had a donor my consultant had to be told to calm down.

I also found out yesterday that my platelet levels are now 52 million per litre of blood which means I can have my central line out. Below 50 mill and they won't remove it due to the possibility of bleeding. As the nurse joked: 'we wouldn't want to get this far then have you bleed to death taking that out, ha ha, ha!'. Ha ha indeed.