Relapse criteria used to define the type of relapse
| Type of relapse . | Change in paraprotein between maximum response and relapse . | Change in FLC levels between maximum response and relapse . |
|---|---|---|
| PO | ≥5g/L and an increase ≥25% | Urine FLC <200 mg/24 h and iFLC <100 mg/L and dFLC <100 mg/L |
| PLC | ≥5g/L and an increase ≥25% | iFLC must have increased by ≥100 mg/L and the increase must be ≥25% and dFLC ≥100 mg/L and the FLC ratio must be abnormal |
| FLC escape | <5 g/L | iFLC must have increased by ≥100 mg/L and the increase must be ≥25% and dFLC ≥100 mg/L and the FLC ratio must be abnormal |
| Clinical relapse | <5 g/L | iFLC <100 mg/L and dFLC <100 mg/L |
| Type of relapse . | Change in paraprotein between maximum response and relapse . | Change in FLC levels between maximum response and relapse . |
|---|---|---|
| PO | ≥5g/L and an increase ≥25% | Urine FLC <200 mg/24 h and iFLC <100 mg/L and dFLC <100 mg/L |
| PLC | ≥5g/L and an increase ≥25% | iFLC must have increased by ≥100 mg/L and the increase must be ≥25% and dFLC ≥100 mg/L and the FLC ratio must be abnormal |
| FLC escape | <5 g/L | iFLC must have increased by ≥100 mg/L and the increase must be ≥25% and dFLC ≥100 mg/L and the FLC ratio must be abnormal |
| Clinical relapse | <5 g/L | iFLC <100 mg/L and dFLC <100 mg/L |
Modified from Durie et al12 and Rajkumar et al18 with permission.
dFLC, difference between involved and uninvolved serum FLC levels; iFLC, involved serum FLC level.