Niche Cell Levels Linked to Faster Conversion of MDS to AML

In patients who have myelodysplastic syndromes (MDS), transformation of the disease into acute myeloid leukemia (AML) is influenced by the amount of mesenchymal stem cell (MSC)-like cells present at disease diagnosis. This is according to findings presented at the European Hematology Association 2024 Hybrid Congress.

The study cohort was composed of 29 patients with MDS, which had progressed to secondary AML. The cohort was predominantly male, had a median age of 70 years, and 52% of the patients had been receiving azacitidine as their selected MDS treatment before transformation to AML.

The investigators performed a retrospective search of flow cytometry files from the cohort to obtain phenotypic information on bone marrow MSC-like cells in the patients. For each patient the investigators determined what was the percentage of MSC-like cells present at MDS diagnosis, after MDS conversion to AML, and at an intermediate timepoint.

The information collected on the cohort’s MSC-like cells included CD105 and CD90 surface marker data. Flow cytometry analysis of these data found that more than 60% of the cells in the cohort were enriched for the classical MSC phenotype.

The largest takeaway from the study was that having a high percentage of MSC-like cells at MDS diagnosis carries a significantly earlier conversion of the disease to secondary AML.

Additionally, among the findings were that patients treated with azacitidine, compared with patients who did not receive that therapy, had significantly higher levels of MSC-like cells at the intermediate time point and after MDS conversion to AML (P=.02 for both). The cell levels in these patients were also seen to peak after the end of azacitidine therapy, immediately before AML conversion. However, all patients with high-risk MDS who received azacitidine had long survival rates (P=.09) and a delayed conversion of the disease to AML.

Although these findings in patients with MDS need further confirmation, the investigators said their results “suggest that better phenotypic characterization and monitoring of this population during the course of the disease could help to understand niche cell composition and its implication in the leukemogenesis of MDS.”

Reference

Atance Pasarisas M, Serrano C, Soto C, et al. Impact of niche cells in the progression of MDS to secondary AML. Abstract P1869. Presented at the European Hematology Association 2024 Hybrid Congress; June 13-16, 2024; Madrid, Spain.