Evaluation of mucosal-associated invariant T cell subsets in acute myeloid leukemia

Background
Acute myeloid leukaemia (AML) is a condition distinguished by the clonal enlargement of non-lymphoid hematopoietic progenitor cells. Mucosal-associated invariant T (MAIT) cells, were studied in hematological cancers but their potential role in AML lacks comprehensive studies so far. This study aims to determine the frequencies of various MAIT cell subsets, including MAIT cells secreting interferon-gamma (IFNγ) and granzyme B (GrB), in the peripheral blood (PB) and bone marrow of AML patients compared with the controls.


Methods
This case-control study involved 34 AML patients and 20 control patients. The frequencies of different MAIT cell subsets were evaluated using flow cytometry.


Results
A significant decrease was observed in the frequency of MAIT cells in the PB of AML patients compared with controls (P=0.001 for cluster of differentiation 8+ MAIT cells, and P < 0.001 for double negative MAIT cells). MAIT cells in AML patients exhibited heightened activation, as indicated by increased frequencies of IFNγ- and GrB-producing cells. No differences were found in the frequencies and activation of MAIT cell subsets between PB and bone marrow in AML patients. Additionally, significant differences in MAIT cell subsets were observed based on AML phenotypes and remission status.


Conclusion
Our study reveals a decreased frequency of circulating MAIT cells in AML patients, accompanied by heightened activation characterized by IFNγ, and GrB production, suggesting a potential role of MAIT cells in AML pathophysiology.