[CXCR4 expression in B-lineage acute lymphocyte leukemia and its significance]

The study was aimed to explore the chemokine receptor CXCR4 expression on the B-lineage acute lymphocyte leukemia (B-ALL) cells of various differentiation stages and its relationship with myeloid antigen expression. Flow cytometry was used to detect the CXCR4 expression by means of double-fluorescence labeling with CD19/SCC gating. The results demonstrated that 92.9% B-ALL patients were positively expressed CXCR4. The CD10, CD34 antigens were differently expressed in differentiation stages of B-ALL. The immunotypes of (1) CD10(-)/CD34(+), (2) CD10(+)/CD34(+), (3) CD10(+)/CD34(-), (4) CD10(-)/CD34(-) presented at various differential stages from premature to mature. The positive rate of CXCR4 were (27.60 +/- 15.25)%, (30.95 +/- 15.50)%, (55.62 +/- 18.37)% and (77.25 +/- 10.86)% from (1) to (4) respectively. The median fluorescence intensity (MFI) of CXCR4 expression were 46.69 +/- 15.06, 47.43 +/- 12.39, 79.28 +/- 24.71 and 132.92 +/- 88.09. CXCR4 expressions were not significantly different between the premature stages of CD10(-)/CD34(+) and CD10(+)/CD34(+) subtypes, but both were lower than the CXCR4 expression in CD10(+)/CD34(-) and CD10(-)/CD34(-) subtypes. The highest incidence of CXCR4 expression was found in CD10(-)/CD34(-) B-ALL. The average level of CXCR4 expression on B-ALL cell with positive myeloid antigen CD13 or/and CD33 (my(+)B-ALL) was (12.56 +/- 3.88)% of positive rate and 39.82 +/- 11.58 of MFI, both of which were less than the positive rate (37.57 +/- 11.59)% and the MFI (50.72 +/- 13.34) on B-ALL cells with negative myeloid antigen expression (mye(-)B-ALL). In conclusion, the CXCR4 expression is associated with differentiation level of B-ALL cells and down-regulated when co-expressed with myeloid antigens.