MS assays for measuring PB MRD
| Assay . | Type . | Platform . | Sensitivity∗ . | Examples of trials in which assay has been used . | Comments . |
|---|---|---|---|---|---|
| Mass-Fix (Mayo Clinic) | Intact light chain | MALDI-TOF | <0.01 g/dL42 | STaMINA56 | Commercially available through Mayo Clinic reference laboratory; has replaced SPEP/IFX in their workflow42,43 |
| Exent (Thermo Fisher, previously known as QIP-MS) | Intact light chain | MALDI-TOF | 0.0015 g/dL46 | GEM2012MENOS65,57,58 GMMG-MM5,59 ATLAS,60 GEM-CESAR,61 and Derman et al62 | Can be automated for high throughput Platform commercially available in Europe; availability in the United States pending |
| LC-MS | Intact light chain | LC-MS | 0.0001 g/dL48 | Can reflex off of Exent-negative samples Not commercially available | |
| EasyM (Rapid Novor) | Clonotypic peptide | LC-MS | 5.8 × 10−5 g/dL53 | MCRN-001,53 MM19, and MM2168 | Commercially available in the United States |
| M-Insight (Sebia) | Clonotypic peptide | LC-MS | 1 × 10−5 g/dL54 | IFM 200969,70 | Commercially available in the United States |
| Assay . | Type . | Platform . | Sensitivity∗ . | Examples of trials in which assay has been used . | Comments . |
|---|---|---|---|---|---|
| Mass-Fix (Mayo Clinic) | Intact light chain | MALDI-TOF | <0.01 g/dL42 | STaMINA56 | Commercially available through Mayo Clinic reference laboratory; has replaced SPEP/IFX in their workflow42,43 |
| Exent (Thermo Fisher, previously known as QIP-MS) | Intact light chain | MALDI-TOF | 0.0015 g/dL46 | GEM2012MENOS65,57,58 GMMG-MM5,59 ATLAS,60 GEM-CESAR,61 and Derman et al62 | Can be automated for high throughput Platform commercially available in Europe; availability in the United States pending |
| LC-MS | Intact light chain | LC-MS | 0.0001 g/dL48 | Can reflex off of Exent-negative samples Not commercially available | |
| EasyM (Rapid Novor) | Clonotypic peptide | LC-MS | 5.8 × 10−5 g/dL53 | MCRN-001,53 MM19, and MM2168 | Commercially available in the United States |
| M-Insight (Sebia) | Clonotypic peptide | LC-MS | 1 × 10−5 g/dL54 | IFM 200969,70 | Commercially available in the United States |
Bottom-up (clonotypic peptide) methods are generally more sensitive than top-down (intact light chain) approaches. To achieve this performance, bottom-up approaches require a baseline sample to determine the monoclonal protein sequence to follow. Top-down approaches (intact light chain) offer improved turnaround time and do not require a baseline sample. Adapted from Yee.71
For comparison, SPEP/IFX has a sensitivity of 0.01 g/dL.