Chimerism Test Results Post Stem Cell Transplant
My husband, Mark, 69 years old, was diagnosed with Myelodysplastic Syndromes blood cancer in May 2022 and had an allo SCT in November 2022 at Mayo Clinic Phoenix. Mark has had four chimerism tests done. The first three chimerism tests were at 1 month post SCT, 2 months post SCT, and 3 months post SCT and all results showed “approximately 100% donor DNA and approximately 0% recipient DNA”.
He had a fourth chimerism test on October 31, 2023, and the results are below:
Peripheral blood, chimerism analysis:
CD3-positive T-cells: A low level of recipient chimerism below our established reliable analytical sensitivity (5%) was detected. At least 95% of donor DNA is present.
CD33-positive myeloid cells: The CD33-positive fraction contains approximately 90% donor DNA and approximately 10% recipient DNA.
We had a virtual appointment with his Mayo SCT specialist on November 16 and she is not overly concerned but she does want a bone marrow biopsy done at Mayo Clinic due to the CD33 being 90% donor and 10% recipient and not 100% donor. We are a bit anxious wondering what this test result could mean. Would this result necessarily mean his MDS is coming back and he is relapsing? Or, is this not uncommon to have the percentage fluctuate in the first year? Any insight you can provide would be wonderful.
Thank you! Jamie and Mark Brown