I wonder if any of you can explain to me in words of one syllable how the regrowth of immunity thing works? I have asked the consultant - twice - and haven't had a sensible answer from him on either occasion! His answer (both times) was that I was only nine months post-transplant and I didn't need to worry about it! That's not whgat I asked him!
So, when I had chemo (two lots) before the transplant, I was neutropenic post-chemo (and thus susceptible to infection) until my neutrophils recovered. Now, post-transplant, I have a full complement of blood cells, but zero immunity to infection still. I am guessing that this is because pre-transplant I still had the acquired immunity of a lifetime, whereas post-transplant, it had all been wiped out.
Dim brain can cope so far!
I had GvHD treated with steroids and Cyclosporine for some weeks, which I know suppresses the immune system. Now I am off both and have been for some time. My CD4 marker is still only at 0.006, which the consultant says is 'non-existant'.
I have 100% chimerism and have had it at that level since a few weeks post transplant. So why haven't I just inherited my donor's immunity to infection to add to my healthy compliment of neutrophils and job done?
So how long does it take (on average - I know we're all different!) to reconstitute the immune system and what is the mechanism for that to happen?
I know they can kick-start it with a DLI, but that's not an option for me because I've already had GvHD. The consultant told me that it would grow back, but I would just need to be patient. That's fine - but it still doesn't help me to understand how it all works and how long it's all likely to take! WHAT needs to 'grow back'?
I asked my daughter (who is a GP) and even she wasn't sure how it worked for transplant patients, though is helpfully just going off to do a course on immunity! She said that you acquire immunity through exposure to pathogens. So why doesn't a donor-acquired immunity + a healthy score of neutrophils = a new immune system able to cope with exposure to infection? What is it we all have to wait for ages to happen?
It's a puzzle!
