Bailie - first of all, thanks. The doctors have suggested to try for cyclosporin once her counts hit the 50s, and if that doesn't work - to do a transplant.
Neil - thank you so much for the detailed and informative reply.
Regarding the risks of repeated ATG, my source is
this study (done in 1998). "The probability of developing a late clonal disorder was 53 +/- 10% after multiple, as compared to 34 +/- 7% after single exposure (P = 0.15)."
My wife is 29, and is healthy overall with the exception of her AA. She's not so young that a transplant is almost a no-brainer, but she's definitely far from the more dangerous ages. That's precisely why we're in this dilemma.
On one hand, you're right. ATG could help her again for a year, two years, or even seven. Or it could not. Or it could cause her tiny PNH clone to take a leap forward and then we'll find ourselves in a bigger problem.
On the other hand, a transplant could cure her. Or not. Or cure her and cause her to suffer from cGVHD that would make her life miserable.
There's just no way to know which road is the right one to take, and that is why we're so torn. It's like there's no right answer.
Which is why I included option #3 - to pray hard, no matter which course we'll eventually take.