Wit
h t
he combination of immunop
henotyping and molecular tests, it is still a c
hallenge to identify t
he c
haracteristics of T cell acute lymp
hoblastic leukemia (T-ALL) associated wit
h distinct outcomes. T
his study tests t
he possible correlation of cellular expression of CD135 and CD117 wit
h somatic gene mutations in T-ALL. One
hundred sixty-two samples were tested, including 143 at diagnosis, 15 from T-lymp
hoblastic lymp
homa at relapse, and four relapse samples from sequential follow-up of T-ALL. CD135 and CD117 monoclonal antibodies were included in t
he T-ALL panel of flow cytometry. T
he percentage of cells positivity and t
he median fluorescence intensity were correlated wit
h gene mutational status.
STIL-TAL1,
TLX3,
FLT3 and
IL7R mutations were tested using standard tec
hniques.
STIL-TAL1 was found in 24.8%, TLX3 in 12%, IL7R in 10% and FLT3-ITD in 5% of cases. FLT3 and IL7R mutations were mutually exclusive, as were FLT3-ITD and STIL-TAL1. Associations of CD135high (p < 0.01), CD117intermediate/high (p = 0.02) and FLT3-ITD, CD117low with IL7Rmutated (p < 0.01) and CD135high with TLX3pos were observed.
We conclude that the addition of CD135 and CD117 to the diagnosis can predict molecular aberrations in T-ALL settings, mainly segregating patients with FLT3-ITD, who would benefit from treatment with inhibitors of tyrosine.