Characteristics of high-throughput MRD techniques
| MRD technique . | EuroFlow-based flow cytometry (≥8 colors) . | PCR-based HTS of IG-TR genes . |
|---|---|---|
| Targets | N-dimension (eg, principal component analysis)-based deviations from normal leukocytes (normal differentiation/maturation pathways) using novel software (eg, Infinicyt) | Rearranged IG/TR genes |
| Specific onco-genetic aberrations | ||
| Estimated sensitivity | 10−4-10−5(2.5-5.0 × 106 cells analyzed) | 10−4-10−6(depending on amounts of DNA analyzed) |
| Applicability | BCP-ALL: >95% | >95% of all lymphoid malignancies |
| T-ALL: >90% | ||
| Availability | Multiple laboratories in Europe, South America, Asia, South Africa, and Australia (still limited in United States) | Limited no. of labs; mainly centralized in companies |
| Standardization/ assay verification | Full technical EuroFlow standardization and assay verification | No standardization between laboratories |
| No guidelines for data analysis | ||
| QA rounds | Yearly external technical QA (will be increased to several QA rounds per year) | No external QA rounds yet |
| Clinical validation | Ongoing | Ongoing |
| Advantages | Rapid (within 3-4 h) Highly standardized with possibilities for automated gating (Infinicyt software) Efficient data storage and management with easy data comparison Accurate quantitation Provides information on normal and malignant cells Ready for IVD development | High sensitivity Not dependent on primers for patient-specific junctions Potential for IVD development Provides information on background repertoire of B and T cells Potential to identify oligoclonality and clonal evolution phenomena |
| Disadvantages | Education and training required Many cells needed to reach the required sensitivity, eg, 5.0 × 106, if quantitation down to 10−5 is needed | Super-multiplex PCR, prone to disproportional target amplification Discrimination from normal clonal background Complex bioinformatic pipeline + need for error correction Turnaround time of ∼1 week per sample Prone to contamination problems (if no barcoded primers are used) No clear definition for positivity Limited experience in the field |
| MRD technique . | EuroFlow-based flow cytometry (≥8 colors) . | PCR-based HTS of IG-TR genes . |
|---|---|---|
| Targets | N-dimension (eg, principal component analysis)-based deviations from normal leukocytes (normal differentiation/maturation pathways) using novel software (eg, Infinicyt) | Rearranged IG/TR genes |
| Specific onco-genetic aberrations | ||
| Estimated sensitivity | 10−4-10−5(2.5-5.0 × 106 cells analyzed) | 10−4-10−6(depending on amounts of DNA analyzed) |
| Applicability | BCP-ALL: >95% | >95% of all lymphoid malignancies |
| T-ALL: >90% | ||
| Availability | Multiple laboratories in Europe, South America, Asia, South Africa, and Australia (still limited in United States) | Limited no. of labs; mainly centralized in companies |
| Standardization/ assay verification | Full technical EuroFlow standardization and assay verification | No standardization between laboratories |
| No guidelines for data analysis | ||
| QA rounds | Yearly external technical QA (will be increased to several QA rounds per year) | No external QA rounds yet |
| Clinical validation | Ongoing | Ongoing |
| Advantages | Rapid (within 3-4 h) Highly standardized with possibilities for automated gating (Infinicyt software) Efficient data storage and management with easy data comparison Accurate quantitation Provides information on normal and malignant cells Ready for IVD development | High sensitivity Not dependent on primers for patient-specific junctions Potential for IVD development Provides information on background repertoire of B and T cells Potential to identify oligoclonality and clonal evolution phenomena |
| Disadvantages | Education and training required Many cells needed to reach the required sensitivity, eg, 5.0 × 106, if quantitation down to 10−5 is needed | Super-multiplex PCR, prone to disproportional target amplification Discrimination from normal clonal background Complex bioinformatic pipeline + need for error correction Turnaround time of ∼1 week per sample Prone to contamination problems (if no barcoded primers are used) No clear definition for positivity Limited experience in the field |