Clinical significance of decreased or loss of ABO blood group expression in acute myeloid leukaemia: A single‐centre retrospective study

Abstract Background and Objectives Decreased or loss of ABO blood group antigen expression has been observed in acute myeloid leukaemia (AML) patients. We studied the clinical significance of this group in AML patients. Materials and Methods This was a retrospective, single‐centre cohort study in which the data were retrieved from April 2009 to December 2019. A total of 1592 AML patients with normal ABO blood group antigen (Group I) and 65 patients of decreased or loss of ABO blood group antigen (Group II) group were enrolled. Data were collected at the time of initial admission for pathological diagnosis. To interrogate the underlying mechanism, publicly available The Cancer Genome Atlas AML data were downloaded. Results Group II consisted of 3.9% (65/1657) of AML patients. The 90‐day survival (D90) probability was higher for Group II with a mean survival of 86.4 days compared to 80.6 days for Group I ( p = 0.047). Group II had higher haematocrit (28.6 vs. 27.4%) and lower d ‐dimer, fibrinogen degradation production and C‐reactive protein. Publicly available data revealed that among 11 CpG methylation sites within the ABO gene, 4 sites with elevated methylation level were associated with improved D90 survival probability and demonstrated an inverse correlation with ABO gene expression. Lower expression of the ABO gene showed improved survival trends for D90 ( p = 0.058) and 180‐day survival ( p = 0.072). Conclusion AML with decreased expression or loss of ABO blood group showed better early survival during D90. Transfusion support for this subgroup of AML patients should be meticulously performed considering serum typing.