Objectives: As a marker of minimal residual disease in B-cell acute lymphoblastic leukemia (B-ALL), CD58 has been reported in B-ALL at diagnosis and short-term follow-ups after standard chemotherapies. However, there are no data available in relapsed/refractory (r/r) patients who have received long-term and multiline therapies, especially chimeric antigen receptor (CAR) T cells; here, we focused on investigating CD58 status in these patients.
Methods: CD58 expression on lymphoblasts was detected by multiparameter flow cytometry. CD58 status was evaluated in patients with r/r B-ALL before CAR-T therapy, and the patients who failed or relapsed after CAR-T.
Results: Among 274 pediatric and adult patients prior to exposure to CAR-T cells (22.3% of them underwent allogeneic hematopoietic cell transplantation, allo-HCT), 228 (83.2%) showed CD58 positivity. Furthermore, among 58 patients who were CD58 positive before CAR-T failed or relapsed after CAR-T (half also received CD22 CAR-T or allo-HCT as a consolidation treatment following CD19 CAR-T), the frequency of CD58 expression was 79.3% (46/58) in all patients and 86.2% (25/29) in patients exposed to CD19 CAR-T cells alone.
Conclusions: CD58 antigen was stably expressed in patients with r/r B-ALL after multiline therapies, including allo-HCT and CAR-T, indicating that it could still be a leukemic marker in heavily treated patients.
Keywords: CAR-T cell therapy; CD58; acute lymphoblastic leukemia; flow cytometry; relapsed/refractory.
© The Author(s) 2025. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.