Prognostic value of regulatory T cells in newly diagnosed chronic myeloid leukemia patients.
BACKGROUND
Chronic myeloid leukemia (CML) is a clonal disease, characterized by a reciprocal t(9, 22) that results in a chimeric BCR/ABL fusion gene. Regulatory T cells (Tregs) constitute the main cell population that enables cancer cells to evade immune surveillance.


OBJECTIVE
The purpose of our study was to investigate the level of Tregs in newly diagnosed CML patients and to correlate it with the patients' clinical, laboratory and molecular data. We also aimed to assess the effect of treatment using tyrosine kinase inhibitor (TKI) on Treg levels.


METHODS
Tregs were characterized and quantified by flow cytometry in 63 newly diagnosed CML patients and 40 healthy controls. TKI was used in 45 patients with chronic phase CML, and the response to therapy was correlated with baseline Treg levels.


RESULTS
The percentages of Tregs were significantly increased in CML patients compared to the controls. Treg numbers were significantly lower in patients with chronic phase CML versus the accelerated and blast phases, and were significantly lower in patients with complete molecular remission (CMR) compared to those patients without CMR.


CONCLUSIONS
Tregs may play a role in the maintenance of CML. Moreover, the decrease of their levels in patients with CMR suggests that Tregs might have a clinical value in evaluating the effects of therapy.
South Egypt Cancer Institute, Assiut University, EL-Mesak Street, Assiut, Egypt.
Asmaa M
AM
Zahran
Hosny
H
Badrawy
Abeer
A
Ibrahim
D000328:Adult; D015704:CD4 Antigens / Q000097:blood; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000097:blood; D016044:Fusion Proteins, bcr-abl / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000097:blood; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000097:blood* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology
D015704:CD4 Antigens; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D053645:Interleukin-2 Receptor alpha Subunit; D016044:Fusion Proteins, bcr-abl