Table 5. Definitions for MRD response... | American Society of Hematology

Table 5.

Definitions for MRD response categories and MRD relapse

Response category	Abbreviation	Defining criteria
CR with negative MRD	CR_MRD−	1. Complete morphologic remission and 2. MRD⁻ in all MRD technologies that were used: a. FC-MRD⁻ in BM (if MFC-MRD was used). b. qPCR-MRD⁻ in BM (or in PB after cycle 2 for NPM1- and CBF-MRD) (if qPCR-MRD was used). c. NGS-MRD⁻ in BM (if NGS-MRD was used).
CR with positive MRD	CR_MRD+	1. Complete morphologic remission, and 2. MFC-MRD⁺in PB and/or BM, or 3. NGS-MRD⁺ in PB and/or BM, or 4. qPCR-MRD⁺ in PB and/or BM.
CR with molecular MRD detection at low level	CR-MRD-LL	1. Morphologic CR, and 2. Molecular MRD detectable at low level in PB and/or BM (ie, qPCR for NPM1 <2% or NGS-MRD <0.1%, but above the detection limit of the assay).
MRD relapse	—	1. Conversion of MRD negativity to MRD positivity independent of the MRD technique, or 2. increase in MRD copy numbers ≥1 log₁₀ between any 2 positive samples in patients with CR-MRD-LL who are monitored by qPCR. 3. The result of (1) or (2) should be rapidly confirmed in a second consecutive sample, preferably from the BM.

Response category	Abbreviation	Defining criteria
CR with negative MRD	CR_MRD−	1. Complete morphologic remission and 2. MRD⁻ in all MRD technologies that were used: a. FC-MRD⁻ in BM (if MFC-MRD was used). b. qPCR-MRD⁻ in BM (or in PB after cycle 2 for NPM1- and CBF-MRD) (if qPCR-MRD was used). c. NGS-MRD⁻ in BM (if NGS-MRD was used).
CR with positive MRD	CR_MRD+	1. Complete morphologic remission, and 2. MFC-MRD⁺in PB and/or BM, or 3. NGS-MRD⁺ in PB and/or BM, or 4. qPCR-MRD⁺ in PB and/or BM.
CR with molecular MRD detection at low level	CR-MRD-LL	1. Morphologic CR, and 2. Molecular MRD detectable at low level in PB and/or BM (ie, qPCR for NPM1 <2% or NGS-MRD <0.1%, but above the detection limit of the assay).
MRD relapse	—	1. Conversion of MRD negativity to MRD positivity independent of the MRD technique, or 2. increase in MRD copy numbers ≥1 log₁₀ between any 2 positive samples in patients with CR-MRD-LL who are monitored by qPCR. 3. The result of (1) or (2) should be rapidly confirmed in a second consecutive sample, preferably from the BM.