POSTER 37
ASSESSMENT OF RESIDUAL CD26+LEUKEMIC STEM CELLS IN TUNISIAN
CHRONIC MYELOID LEUKEMIA PATIENTS IN THE IMATINIB ERA: A
PRELIMINARY STUDY
Fatma Turki1, Nour Louati2, Hela Mnif2, Hassen Kamoun1 and Rim Frikha1
(1)Medical Genetic department, SFAX, Tunisia
(2)Regional transfusion center, SFAX, Tunisia
Background: Chronic myeloid leukemia (CML) is a stem cell (SC) neoplasm characterized by
the BCR/ABL1 oncogene. Recent investigations in chronic myeloid leukemia (CML) have
focused on the identification and characterization of leukemic stem cells (LSCs). Bone marrow
Ph+ CML CD34+/CD38- LSCs were found to specifically co-express CD26 (dipeptidylpeptidase-
IV). CD26 evaluation could be a useful tool to improve the identification of CML LCSs.
The aim of this study was to quantify CD26LSCs and correlate expression to the molecular
response in the imatinib era.
Methods: CD26 expression was evaluated by a standardized multiparametric flow cytometry
analysis in peripheral blood (PB) of a total of 15 CML Tunisian patients. Quantitative
assessment of the BCR-ABL transcript was performed using the Cepheid Xpert BCR-ABL ultra
assay.
Results: The expression of CD26 on CD34+CD38- population was detectable in all PB samples
of both confirmed newly diagnosed CML patients (median= 25.67*109/L; range 3.34-113.52))
and those during treatment ( median=1.72; range 1.24-8.95).
According to the molecular response, CD26+ LSCs was 2.14*109/L (range 1.34-8.95) and
1.54*109/L(range 1.24-3.54), for failed and optimal response; respectively Bcr-ABL ratio ( IS)
was significantly correlated residual CD26 LSCs (p=0.017).
Conclusion : Despite the limit of our study; this is the evidence that "circulating" CML LSCs
persist in the majority of CML patients during TKI treatment. Moreover, CD26 would be an
alternate tool for monitoring MRD. Larger studies evaluating the dynamics of peripheral blood
CD26+ LSCs during TKI treatment are mandatory.
SCIENTIFIC PROGRAMME
SESSION I
OPTIMIZING
CYTOREDUCTION
SESSION II
MANAGEMENT OF CML
WITH TKI
SESSION III
MPN RISK
STRATIFICATION
INCLUDING VASCULAR
EVENTS
DEBATE 1
INTERFERON ALPHA
SHOULD BE FRONT LINE
THERAPY IN ALL ET/PV
PATIENTS
ROUNDTABLE 1
INFECTIONS IN
MYELOPROLIFERATIVE
DISORDERS, INCLUDING
CML
ROUNDTABLE 2
PREGNANCY AND
PARENTING
DEBATE 2
ALLOGENEIC STEM CELL
TRANSPLANTATION
SHOULD BE CONSIDERED
THIRD LINE OPTION IN
CHRONIC PHASE CML
SESSION IV
EVOLVING THERAPIES
IN MYELOFIBROSIS
SESSION V
MANAGEMENT OF
ADVANCED AND UNUSUAL
DISEASE (MPN AND CML)
SESSION VI
TREATMENT FREE
REMISSION IN CML
KEYNOTE LECTURE
SELECTED ABSTRACTS
FOR AN ORAL
PRESENTATION
SELECTED ABSTRACTS
FO R A POSTER
PRESENTATION
DISCLOSURES