[Marlene]

I think it's mainly to see if there are any abnormalities. It's possible they mis-diagnosed the SAA in the first place or they want to see if maybe it's progressed to MDS/AML. But the second, post ATG BMB would have shown that. I guess you can make an argument to do a BMB before retreating to make sure you are still dealing with SAA.

SAA is a diagnosis of exclusion. Well....you don't X, Y or Z. Your counts are low and you have little marrow. Must be SAA. That's my simple view of this disease.

Cellularity alone is not a good indicator of when to treat. There have people with good cellularity but continued with low counts. While others with low cellularity, seem to maintain normal counts.

I think it's a very valid question to ask your doctor why he wants to do another. You are in a watch and wait scenario. Your current options are to continue to wait, retreat with ATG or another immunosuppressant, or a BMT.

My guess is that your doctor thinks he need to move forward with something and needs a BMB to help him figure out your next steps.

But since John did not have ATG, I may be over simplifying things. So hopefully, others with ATG experience can address this also.