Identification of Cellular Markers for the IKZF1plus Subgroup of B-cell Acute Lymphoblastic Leukemia

Background B-ALL can be classified by the occurrence of several genetic alterations. Recently, a new subgroup – named IKZF1plus – was associated with a worse prognosis in B-ALL. IKZF1plus is defined by the co-occurrence of IKZF1 deletion and CDKN2A, CDKN2B (homozygous), PAX5 or PAR1 deletion, in the absence of ERG alteration. Therefore, we aim to identify cellular markers for the prediction of the IKZF1plus group. Methods and results: We used the TARGET database (WGS, RNA-seq and clinical data) for the analyses. A total of 125 pediatric patients were included and grouped as IKZF1plus (13 %), IKZF1 deletion only (9 %) and IKZF1 wild-type (78 %). There was an enrichment of IKZF1plus cases in the B-other subgroup, which was selected for further analyses. The differential expression analyses performed with DESeq2 was used to compare the three groups. Results showed that four genes had increased expression, while thirteen were downregulated in the IKZF1plus group. CRLF2 had the highest expression when IKZF1plus was compared with the wild-type. Conclusion: We identified potential markers for IKZF1plus. Indeed, CRLF2 expression could be a good candidate marker to identify this subtype.