Open AccessBCR‐ABL1 positive B‐ALL can undergo T‐cell lineage shift to become CD19 negative T‐ALL
Author(s) -
De Bie Jolien,
Demeyer Sofie,
Gielen Olga,
Segers Heidi,
Michaux Lucienne,
Vandenberghe Peter,
Boeckx Nancy,
Uyttebroeck Anne,
Cools Jan
Publication year - 2018
Publication title -
hemasphere
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 11
ISSN - 2572-9241
DOI - 10.1097/hs9.0000000000000042
Subject(s) - cd19 , cancer research , breakpoint cluster region , b cell , myeloid leukemia , myeloid , immunotherapy , haematopoiesis , lineage (genetic) , immunology , stem cell , biology , medicine , antigen , immune system , microbiology and biotechnology , receptor , antibody , genetics , gene
Lineage shifts in acute lymphoblastic leukemia (ALL) are anti-CD19 directed therapy. They presented 2 cases of BCRuncommon and if they occur usually involve a switch from lymphoid to myeloid lineage. Here we report the observation of a Bto T-cell switch in a BCR-ABL1 positive B-ALL that was engrafted in immune deficient NOD.Cg-PrkdcIl2rg/SzJ (NSG) mice. We studied the engraftment of 4 BCR-ABL1 positive B-ALL cases (Table 1), and observed the unexpected appearance of a BCR-ABL1 positive T-ALL for 1 of the 4 cases (XC49). These data indicate that a switch from B-ALL to T-ALL is possible, and that this could be a novel mechanism to develop resistance against anti-CD19 directed therapy in some B-ALL cases. Indeed, with the introduction of CD19-directed immunotherapy for the treatment of B-cell malignancies, clinicians were suddenly confronted with previously unobserved tumor escape mechanisms. More and more patients present themselves at relapse with a downregulation or alteration of the CD19 surface antigen on their malignant cells or with an acquired extramedullary invasion. In a recent study, Nagel et al described an alternative escape route for malignant B-ALL cells after receiving