ELN 2021 MFC-MRD recommendations based on a Delphi poll
| No. . | Multiparameter flow cytometry MRD recommendation . | LoE . | GoR . | LoA (%) . |
|---|---|---|---|---|
| A1 | When available, a diagnostic sample is preferred to: 1. determine if a patient has a diagnostic flow cytometric MRD target, and 2. assess treatment efficacy on potential clearance of the diagnostic LAIP populations. | V | B | 94 |
| A2 | Implementation of a minimum required set of tubes/ fluorochromes combination is a prerequisite for harmonized LAIP/DfN MRD detection, analysis and reporting. | I | A | 94 |
| A3 | We recommend harmonized use of the integrated diagnostic LAIP and DfN strategy for MRD detection that incorporates the core MRD markers CD34, CD117, CD45, CD33, CD13, CD56, CD7, and HLA-DR, to assess all samples. | V | B | 88 |
| A4 | Particular attention should be devoted to evaluating the expression of the identified aberrant immunophenotypes in control samples that include regenerating BM. | V | A | 88 |
| A5 | When immunophenotypic abnormalities in specific samples may reflect transient features of regenerating or “stressed” hematopoiesis, the MRD report should comment on this possibility and note that a repeat sample in 2-4 wk, if clinically indicated, may be informative. | V | C | 94 |
| A6 | Request first-pull BM aspirate for MRD, and process sample within 3 days of storage, undiluted, in ambient conditions. | V | A | 94 |
| A7 | For samples stored at ambient temperature >3 d, the MRD report should make specific note of potentially compromised cell viability. | V | B | 94 |
| A8 | Explore strategies to assess hemodilution that can be incorporated and reported as part of the MRD assay. | V | B | 88 |
| A9 | For clinical decision making, MRD assessment should be performed with a qualified assay, as based on the guidelines for rare events in MFC. | I | A | 76 |
| A10 | To ensure the best quality of relevant events acquisition, use a gating syntax including FSC vs time and doublet exclusion plots. | V | A | 81 |
| A11 | The standard for determining MFC MRD negativity is the acquisition of >500 000 CD45+ cells and ≥100 viable cells in the blast compartment assessed for the best aberrancy(ies) available. | V | B | 76 |
| A12 | LLOD and LLOQ should be calculated to assess MFC-MRD assay performance. | V | B | 93 |
| No. . | Multiparameter flow cytometry MRD recommendation . | LoE . | GoR . | LoA (%) . |
|---|---|---|---|---|
| A1 | When available, a diagnostic sample is preferred to: 1. determine if a patient has a diagnostic flow cytometric MRD target, and 2. assess treatment efficacy on potential clearance of the diagnostic LAIP populations. | V | B | 94 |
| A2 | Implementation of a minimum required set of tubes/ fluorochromes combination is a prerequisite for harmonized LAIP/DfN MRD detection, analysis and reporting. | I | A | 94 |
| A3 | We recommend harmonized use of the integrated diagnostic LAIP and DfN strategy for MRD detection that incorporates the core MRD markers CD34, CD117, CD45, CD33, CD13, CD56, CD7, and HLA-DR, to assess all samples. | V | B | 88 |
| A4 | Particular attention should be devoted to evaluating the expression of the identified aberrant immunophenotypes in control samples that include regenerating BM. | V | A | 88 |
| A5 | When immunophenotypic abnormalities in specific samples may reflect transient features of regenerating or “stressed” hematopoiesis, the MRD report should comment on this possibility and note that a repeat sample in 2-4 wk, if clinically indicated, may be informative. | V | C | 94 |
| A6 | Request first-pull BM aspirate for MRD, and process sample within 3 days of storage, undiluted, in ambient conditions. | V | A | 94 |
| A7 | For samples stored at ambient temperature >3 d, the MRD report should make specific note of potentially compromised cell viability. | V | B | 94 |
| A8 | Explore strategies to assess hemodilution that can be incorporated and reported as part of the MRD assay. | V | B | 88 |
| A9 | For clinical decision making, MRD assessment should be performed with a qualified assay, as based on the guidelines for rare events in MFC. | I | A | 76 |
| A10 | To ensure the best quality of relevant events acquisition, use a gating syntax including FSC vs time and doublet exclusion plots. | V | A | 81 |
| A11 | The standard for determining MFC MRD negativity is the acquisition of >500 000 CD45+ cells and ≥100 viable cells in the blast compartment assessed for the best aberrancy(ies) available. | V | B | 76 |
| A12 | LLOD and LLOQ should be calculated to assess MFC-MRD assay performance. | V | B | 93 |
GoR, grade of recommendation; LLOD, lower limit of detection; LLOQ, lower limit of quantification; LoA, level of agreement; LoE, level of evidence.