Our next target, now that she’s begun to grow cells, is to reach “engraftment”. The official definition of engraftment, from what I understand, is to have an ANC of over 500 for over 3 days.
ANC means Absolute Neutrophil Count, which is a formula for calculating the immune system’s disease fighting capability. An ANC of under 500 is neutropenic, which means the body is at a significantly increased risk of infection.
For Zoe, reaching an ANC of over 500 will mean she has officially engrafted. The next step will be to determine which cells engrafted, her new cells or her old, by doing a chimera test around day +30.
To calculate her ANC we take her Segmented and Banded Neutrophil counts (which we should get on a printout tomorrow) and add them together, then multiply them by her WBC count.
So: (%SEG + %BAND) x WBC = ANC
When that number reaches 500 or above and stays there, we are at our next milestone.
Update: I was a little off on the ANC calculation, corrected that.