Recommended assessment of chimerism
| Chimerism . | Assessment . | Interval . |
|---|---|---|
| Clinical | STR analysis on bone marrow or sorted peripheral blood cells (myeloid and T cells) | 1, 3, 6, 12, and 24 months |
| Repeat if continued mixed chimerism | ||
| Repeat in the event of return of abnormal hematologic/hemolysis parameters | ||
| Autologous cell engraftment | Percent of edited cells (gene editing) | All GT patients should be tracked for at least 15 y by mandate |
| Vector copy number (average of viral vector per stem cell) | ||
| Hemoglobin analysis for Hb S level | Every 3 months × 1 year | |
| Every 6 months in year 2 | ||
| Yearly × 5 years | ||
| As needed subsequently | ||
| Hemolysis parameters, including hemoglobin, absolute reticulocyte count, lactate dehydrogenase, and indirect bilirubin | Every 3 months × 1 year | |
| Every 6 months in year 2 | ||
| Yearly × 5 years | ||
| As needed subsequently | ||
| Research | Glycophorin A + CD71+ red cell precursor genomic analysis for engraftment128,129 | |
| Functional biomarkers | ||
| Red cell viscosity, RBC elongation index by ektacytometry, and RBC adhesion index | ||
| Specialized cell subtypes, cytokines, and chemokines |
| Chimerism . | Assessment . | Interval . |
|---|---|---|
| Clinical | STR analysis on bone marrow or sorted peripheral blood cells (myeloid and T cells) | 1, 3, 6, 12, and 24 months |
| Repeat if continued mixed chimerism | ||
| Repeat in the event of return of abnormal hematologic/hemolysis parameters | ||
| Autologous cell engraftment | Percent of edited cells (gene editing) | All GT patients should be tracked for at least 15 y by mandate |
| Vector copy number (average of viral vector per stem cell) | ||
| Hemoglobin analysis for Hb S level | Every 3 months × 1 year | |
| Every 6 months in year 2 | ||
| Yearly × 5 years | ||
| As needed subsequently | ||
| Hemolysis parameters, including hemoglobin, absolute reticulocyte count, lactate dehydrogenase, and indirect bilirubin | Every 3 months × 1 year | |
| Every 6 months in year 2 | ||
| Yearly × 5 years | ||
| As needed subsequently | ||
| Research | Glycophorin A + CD71+ red cell precursor genomic analysis for engraftment128,129 | |
| Functional biomarkers | ||
| Red cell viscosity, RBC elongation index by ektacytometry, and RBC adhesion index | ||
| Specialized cell subtypes, cytokines, and chemokines |
Hb S, hemoglobin S; RBC, red blood cell; STR, short tandem repeat.