Myd88l265p detection in igm monoclonal gammopathies: Methodological considerations for routine implementation

Martina Ferrante, Daniela Furlan, Silvia Zibellini, Michela Borriero, Chiara Candido, Nora Sahnane, Silvia Uccella, Elisa Genuardi, Beatrice Alessandria, Benedetta Bianchi, Barbara Mora, Daniele Grimaldi, Irene Defrancesco, Cristina Jiménez, Federica Cavallo, Dario Ferrero, Irene Dogliotti, Michele Merli, Marzia Varettoni, Simone FerreroDaniela Drandi

Research output: Contribution to journalArticlepeer-review

Abstract

In IgM monoclonal gammopathies MYD88L265P is a prognostic and predictive biomarker of therapy response. MYD88L265P detection is mainly performed by allele-specific quantitative PCR (ASqPCR), however recently, droplet digital PCR (ddPCR) has been proved to be suitable for MYD88L265P screening and minimal residual disease monitoring (MRD). This study compared ASqPCR and ddPCR to define the most sensitive method for MYD88L265P detection in bone marrow (BM), peripheral blood (PB) sorted or unsorted CD19+ cells, and in plasma cell-free DNA (cfDNA). Overall, the analysis showed a good concordance rate (74%) between the two methods, especially in BM samples, while discordances (26%) were mostly in favor of ddPCR (ddPCR+ vs. ASqPCR-) and were particularly evident in samples with low mutational burden, such as PB and cfDNA. This study highlights ddPCR as a feasible approach for MYD88L265P detection across different specimen types (including cfDNA). Interestingly, its high sensitivity makes CD19+ selection dispensable. On the other hand, our results showed that MYD88L265P detection on PB samples, especially with ASqPCR, is suboptimal for screening and MRD analysis. Finally, significantly different MYD88L265P mutational levels observed between Waldenström Macroglobulinemia and IgM monoclonal gammopathy of undetermined significance patients suggest the need for further studies in order to identify possible correlations between mutational levels and risk of progression to Waldenström.

Original languageEnglish
Article number779
JournalDiagnostics
Volume11
Issue number5
DOIs
Publication statusPublished - May 2021

Keywords

  • ASqPCR
  • DdPCR
  • IgM-MGUS
  • MYD88
  • WM

ASJC Scopus subject areas

  • Clinical Biochemistry

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