Flow cytometric immunophenotypic alterations of persistent clonal haematopoiesis in remission bone marrows of patients with NPM1-mutated acute myeloid leukaemia

Sanam Loghavi, Courtney D. DiNardo, Ken Furudate, Koichi Takahashi, Tomoyuki Tanaka, Nicholas J. Short, Tapan Kadia, Marina Konopleva, Rashmi Kanagal-Shamanna, Noushin R. Farnoud, Sherry Pierce, Joseph D. Khoury, Jeffrey L. Jorgensen, Keyur P. Patel, Naval Daver, Musa Yilmaz, L. Jeffrey Medeiros, Hagop Kantarjian, Farhad Ravandi, Sa A. Wang

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Clonal haematopoiesis (CH) in patients with acute myeloid leukaemia (AML) may persist beyond attaining complete remission. From a consecutive cohort of 67 patients with nucleophosmin 1-mutated (NPM1mut) AML, we identified 50 who achieved NPM1mut clearance and had parallel multicolour flow cytometry (MFC) and next generation sequencing (NGS). In total, 13 (26%) cleared all mutations, 37 (74%) had persistent CH frequently involving DNA methyltransferase 3α (DNMT3A,70%), tet methylcytosine dioxygenase 2 (TET2, 27%), isocitrate dehydrogenase 2 (IDH2, 19%) and IDH1 (11%). A small number (<1%) of aberrant CD34+ myeloblasts, but immunophenotypically different from original AML blasts [herein referred to as a pre-leukaemic (PL) phenotype], was detected in 17 (49%) patients with CH, but not in any patients with complete clearance of all mutations (P = 0·0037). A PL phenotype was associated with higher mutation burden (P = 0·005). Persistent IDH2 and serine and arginine-rich splicing factor 2 (SRSF2) mutations were exclusively observed in PL+ CH+ cases (P = 0·016). Persistent dysplasia was seen exclusively in cases with a PL+ phenotype (29% vs. none; P = 0·04). The PL+ phenotype did not correlate with age, intensity of induction therapy or relapse-free survival. Post-remission CH in the setting of NPM1mut clearance is common and may result in immunophenotypic changes in myeloid progenitors. It is important to not misinterpret these cells as AML measurable residual disease (MRD).

Original languageEnglish (US)
Pages (from-to)1054-1063
Number of pages10
JournalBritish Journal of Haematology
Volume192
Issue number6
DOIs
StatePublished - Mar 2021
Externally publishedYes

Keywords

  • AML
  • Clonal hematopoiesis
  • MRD
  • NPM1

ASJC Scopus subject areas

  • Hematology

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