Consensus guidelines for myeloma minimal residual disease sample staining and data acquisition

Background: Flow cytometric (FC) detection of minimal residual disease (MRD) in multiple myeloma (MM) is prognostic and predictive of response to therapy. Therefore, standardization of FC MM MRD testing is vital to ensure better and uniform assessment of response to therapy and clinical prognostication. The International Clinical Cytometry Society and European Society for Clinical Cell Analysis, recognizing the need for standardized FC approaches, organized a working group to develop consensus guidelines on good clinical practice in FC MM MRD. Consensus guidelines are presented for specimen quality, staining process, reagent combinations, and the data acquisition process, all key factors in achieving high quality FC MM MRD testing. Methods: A group of eight flow cytometrists currently performing FC testing in MM evaluated available literature on FC MM MRD testing. A document presenting best practice was developed and reviewed in successive rounds until consensus was reached. Results/Conclusion: The consensus on best practice for detection of MRD in MM is that CD38, CD138, and CD45 are analyzed in combination with CD19, CD56, CD27, CD81, and CD117. Consensus guidelines on acceptable specimen quality, staining procedures, panel design, and data acquisition were developed.