The prognostic significance of CRLF2 expression at diagnosis in adult Ph-negative B-cell precursor acute lymphoblastic leukemia.

The prognostic significance of cytokine receptor like factor 2 ( CRLF2 ) expression at diagnosis in adult B-cell precursor acute lymphoblastic leukemia (BCP-ALL) needs to be clarified. A total of 357 bone marrow samples collected from consecutive adult cases with Ph-negative BCP-ALL at diagnosis retrospectively detected CRLF2 transcript levels by real-time quantitative PCR. Twenty percent was selected as the cutoff value for CRLF2 to divide patients into CRLF2 _H and CRLF2 _L groups. CRLF2 _H was associated with higher WBC count, P2RY8-CRLF2 fusion and IKZF1 deletions ( IKZF1 del). In both the whole cohort and B-other patients, CRLF2 _H independently predicted lower CR rates after induction. Furthermore, CRLF2 _H/ IKZF1 del(+) patients had significantly lower CR, RFS, and OS rates and tended to have lower RFS and OS rates than others in the whole cohort and B-other patients, respectively. Therefore, coexistence of CRLF2 _H and IKZF1 del at diagnosis predicts poor response and outcome in adult Ph-negative BCP-ALL.