Aberrant expression of CD133 and CD82 in patients with pediatric acute lymphoblastic leukemia and the clinical significance.

Cluster of differentiation (CD)133 is considered to be a marker of leukemia stem cells (LSCs), which are one of the primary causes of occurrence, drug resistance and relapse of acute lymphoblastic leukemia (ALL). CD82, an adhesion molecule, performs an important role in the interaction between LSCs and their niche. The purpose of the present study was to assess CD133 and CD82 expression in patients with pediatric ALL, and to evaluate the association with the clinical data. Using flow cytometric assessment and reverse transcription-polymerase chain reaction, CD133 and CD82 expression levels were measured in the bone marrow (BM) of 37 patients with newly diagnosed (ND) pediatric ALL [ALL-ND; 30 B-cell-ALL (B-ALL) and 7 T-cell-ALL (T-ALL)], in 22 patients with complete remission pediatric ALL (ALL-CR) and in 16 age-matched children without BM disease. BM plasma CD82 concentrations were measured by ELISA. The CD82 mRNA expression level in the patients with ALL-ND was significantly higher compared with that in the controls. CD82 mRNA expression levels in pediatric patients with B cell-ALL (B-ALL) were higher than those in ALL-CR patients and controls. For T-ALL, CD82 expression in ND patients was higher than in controls. CD133 mRNA expression levels in patients with pediatric B-ALL-ND were higher than that of controls and patients with ALL-CR. The frequency of CD34(+) cells in pediatric ALL was significantly higher than that in controls. Frequencies of CD34(+)CD133(+) or CD34(+)CD82(+) cells in pediatric ALL were higher than those in controls. A positive association was observed between CD133 and CD82 mRNA expression in patients with B-ALL. A significant association was observed between CD133 mRNA expression and the hyperdiploid karyotype. Therefore, it was considered that CD133 and CD82 may serve an important role in the evolution of pediatric ALL. CD133 and CD82 should be considered as potential markers for the prognosis of patients with ALL.