中国生物工程杂志

Purpose: The 5th edition of the World Health Organization Classification of Haematolymphoid Tumours defines new diagnostic criteria for chronic myelomonocytic leukemia (CMML) and myelodysplastic neoplasms (MDS). This study aims to explore the clinical and molecular characteristics of CMML and MDS patients belonging to these categories. Method: A thorough review of clinical records of 52 patients with increased peripheral blood absolute monocyte count (AMC) and bone marrow pathological hematopoiesis was performed and their diagnoses were revised according to the new criteria. These patients were compared with 48 non-AMC increased MDS (non MDS-Mo) patients. A retrospective analysis of clinical characteristics and prognostic differences of patients with different diagnoses was conducted. Results: Among 52 patients with increased AMC and pathological hematopoiesis, 35 cases were previously diagnosed with CMML, of which 3 cases (8.6%) were revised to acute myeloid leukemia (AML) due to the presence of NPM1 mutation; 17 cases with increased AMC were previously diagnosed with MDS, of which 4 cases (23.52%) were revised to CMML. There was no difference in clinical characteristics and prognosis between CMML patients with AMC ≥ 1.0 × 10⁹/L (32 cases) and AMC<1.0 ×10⁹/L (4 cases). The MDS with monocytosis group (MDS-Mo) showed a difference in the frequency of driving gene mutations from CMML (AMC<1.0×10⁹/L). Compared to the non MDS-Mo group, the MDS-Mo group showed more TP53 mutations and chromosomal karyotypes of -5/5q -, -7/7q -, with a significantly shorter median survival time (3.85 years vs. 19.43 years). Conclusions: Adhering to the 2022 World Health Organization (WHO) standards can better distinguish between CMML and AML, as well as MDS. MDS-Mo patients have characteristic molecular mutations and genetic characteristics, and their prognosis is worse than that of patients with CMML and non MDS-Mo. Therefore, it is recommended to consider MDS-Mo as an independent subtype of MDS.