Prognostic Value of Cross-lineage Expression of the Myeloid-associated Antigens CD13 and CD33 in Adult B-lymphoblastic Leukemia: A Large Real-world Study of 1005 Patients

Background: Cross-lineage expression of the myeloid-associated antigens CD13/CD33 is common in adult B-lymphoblastic leukemia (B-ALL) patients, yet its prognostic value is still controversial.

Methods: We conducted a retrospective study of 1005 de novo adult B-ALL patients from January 2009 to December 2019 in our hospital. Logistic and Cox regression were used to analyze the prognostic value of CD13/CD33 expression in B-ALL. A Cox regression model was established to predict overall survival (OS) for B-ALL patients.

Results: Of the 1005 B-ALL patients, 53.7% (n = 540) aberrantly expressed CD13/CD33 (CD13/CD33 ). Patients in the CD13/CD33 group showed a higher incidence of BCR::ABL1 rearrangement and minimal/measurable residual disease (MRD) positivity but similar complete remission rate, relapse-free survival, mortality, and OS with CD13/CD33 . CD13/CD33 patients had a higher risk of MRD positivity than CD13/CD33 patients. Notably, CD13/CD33 patients who underwent tyrosine kinase inhibitor (TKI) therapy had a better long-term prognosis than those without TKI experience. Sex, group based on CD13/CD33 expression and TKI experience and white blood cell count were variables independently associated with OS. The Cox regression model integrating these three variables showed a moderate performance for OS prediction (C-index: 0.724).

Conclusions: In real-world practice, CD13/CD33 expression can predict the risk of MRD in patients without TKI experience, but has no adverse effect on the prognosis of adult B-ALL patients. Incorporating CD13/CD33 into the standard antibody panels of B-ALL diagnosis and MRD measurements can help predict relapse risk and decisions on therapy options.