Detection of Minimal Residual Disease in Acute Myeloid Leukemia by Multi-color Flow Cytometry / 中国实验血液学杂志

OBJECTIVE@#To establish 10-color fluorescent antibody combination panels for the detection of minimal residual disease (MRD) of acute myeloid leukemia (AML) in our laboratory and discuss the value of clinical application.@*METHODS@#According to the antigen expression characteristics of leukemia cells of incipient AML patients, MRD in bone marrow were detected by multiparameter flow cytometry, and the test results were compared with both bone marrow cell morphology and PCR results, then 10-color fluorescent antibody combination panels in our lab for MRD detection was determined.@*RESULTS@#The immunophenotypic characteristics of 392 incipient patients with AML in the First Affiliated Hospital of Zhengzhou University were analyzed, among them 357 (91.07%) cases showed abnormal immunophenotypes, which mainly included cross-lineage expression, cross-stage expression, deficiency of antigen expression or abnormal antigen intensity and other abnormal expression. The 10-color fluorescent antibody combination panels established according to abnormal immunophenotypic characteristics of leukemia cells were applied for detecting MRD in 156 patients with AML, the positive rate (43.6%) was higher than 26.8% of morphology, and the results were highly consistent with PCR detection results (96.49%), moreover, the recurrence rate of MRD positive patients (86.96%) was significantly higher than 5.75% of MRD negative patients. Therefore, this method could truly reflect the load of leukemia cells and prompt change of disease condition.@*CONCLUSION@#Multiparameter flow cytometry can detect various abnormal immunophenotypes of AML. The 10-color fluorescent antibody combination panels in our lab based on the characteristics of antigens expression in leukemia cells can well detect MRD of leukemia cells, so as to predict relapse and provide basis for clinical treatment.

Prognostic Value of CD123 in Acute Myeloid Leukemia Patients with Intermediate Risk in Normal Karyotype / 中国实验血液学杂志

OBJECTIVE@#To investigate the expression of CD123 in patients with acute myeloid leukemia (AML) and its relationship between clinical features, concomitant fusion gene or gene mutation, efficacy and prognosis.@*METHODS@#365 patients with newly diagnosed AML (except M3) treated in the First Affiliated Hospital of Zhengzhou University were enrolled and retrospective analysis, and multi-parameter flow cytometry was performed to detect the expression of CD123 in myeloid leukemia cell population. CD123≥20% was defined as positive. Clinical features, concomitant fusion gene or gene mutation, efficacy and prognosis of CD123@*RESULTS@#The positive rate of CD123 in 365 newly diagnosed AML patients was 38.9%. Compared with the CD123@*CONCLUSION@#CD123 positive indicates that AML patients have higher tumor burden and are more difficult to reach remission. It is an independent risk factor for OS and EFS in patients with normal karyotype and intermediate risk, which is important to evaluate the prognosis of patients with AML without specific prognostic marker.

Expression of CD146 in Adult and Children's Acute B Cell Lymphoblastic Leukemia and Its Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the differences of CD146 expression in adult and children's acute B cell lymphoblastic leukemia(B-ALL), and its relation with clinical features, molecular biological and cytogenctic claracteristics.</p><p><b>METHODS</b>The expression of CD146 in bone marrow samples from adult and children's B-ALL patients were detected by flow cytometry (FCM) and the relation of CD146 abnormal high expression with the patients' clinical features, molecular biological and cytogenetical characteristics, as well as other antigens were analyzed.</p><p><b>RESULTS</b>The abnormal high expression rates of CD146 in adult and children's B-ALL patients were 29.17% and 9.09% respectively, showing that the expression rate of CD146 in adult patients was higher than that in children's patients(P<0.05). In adult B-ALL, CD146 was positively related with CD64 and CD117, while in children's B-ALL CD146 was positively related with CD71 and CD58 (P<0.05). After 1 course of standardized chemotherapy, the complete remission rates in adult and children's B-ALL patients with abnormal high expression of CD146 both were low as compared with adult and children's B-ALL without abnormal high expression of CD146 (P<0.05).</p><p><b>CONCLUSION</b>The expression rate of CD146 in adult B-ALL is higher than that in children's B-ALL. The CD146 positively relates with poor prognostic antigens, the CD146 may be one poor prognosis marker.</p>

Expression of CD25 in Acute Myeloid Leukemia Is An Adverse Prognostic Factor Independent of the Chromosome Karyotype / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the CD25 expression in patients with acute myeloid leukemia (AML) and its significance.</p><p><b>METHODS</b>Clinical data of 168 newly diagnosed AML patients (except APL) were collected. The expression of CD25 in AML patients and its clinical characteristics were retrospectively analyzed.</p><p><b>RESULTS</b>The leukemia cells of 29 out of 168 cases (17.26%) expressed CD25 antigen. Most of CD25 positive AML patients were occurred in patients with unfavourable or normal karyotype, higher WBC and Plt count at diagnosis and higher percentage of blasts in peripheral blood and bone marrow. Compared with CD25(-) AML patients, CD25(+) AML patients had lower CR rate (the CR rate of 1 course of treatment were 49.02% and 16.00%, respectively, P < 0.05, the CR rate of 2 courses of treatment were 74.60% and 46.67%, respectively, P < 0.05), and the OS time of CD25(+) AML patients were obviously shorter (P < 0.05). The OS in CD25(+) AML patients with unfavorable karyotype were not significantly different from that in patients with intermediate karyotype (P < 0.05).</p><p><b>CONCLUSION</b>The CD25(+) AML patients have some typical clinical features, and the expression of CD25 in AML is an risk factor independent of the chromosome karyotype in terms of low complete remission rate and short survival time.</p>

Expression and Clinical Significance of N-cadherin in Bone Marrow Leukemic Cells Derived from Patients with Acute Leukemia / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of N-cadherin in bone marrow leukemic cells derived from acute leukemia patients and its clinical significances.</p><p><b>METHODS</b>A total of 113 patients with acute leukemia were enrolled in this study. Flow cytometry was employed to detect the expression of N-Cadherin in bone marrow leukemic cells from acute leukemia patients and the relationships between the N-cadherin expression and the clinical characteristics of patients with acute leukemia were analyzed.</p><p><b>RESULTS</b>The expression of N-Cadherin in bone marrow leukemic cells deriveted from patients with acute leukemia was variable with 0%-99.7%. For adult AML patients, the positive rate of CD34 in N-cadheringroup was significantly higher than that in N-cadheringroup(67.39% vs 33.33%)(P=0.013), while the differences of total CR rate and rate of CR after 1 cycle of induction treatment were not significant between these 2 groups(P>0.05). As to ALL patients, N-cadheringroup had significant lower WBC count (21.31±7.07 vs 51.10±23.69)(P=0.008) and lower percentage of peripheral blood blast (43.22±5.75% vs 66.45±5.65%)(P=0.015). The CR rate after 1 cycle of induction treatment and rate of overall CR were lower and the relapse rate was higher in N-cadherinALL group than those in N-cadherinALL group, but the differences were not significant (P>0.05). For childhood ALL, the positive rate of CD33 in N-cadheringroup was significantly higher than that in N-cadheringroup(47.62% vs 0%)(P=0.012). The relapse rate was higher in N-cadheringroup than that in N-cadheringroup (30.00% vs 0%)(P=0.115). The median survival time, 3-year overall OS rate and 3-year relapse-free survival rate in N-cadheringroups of adult AML, non-M3 AML, ALL and chidhood ALL paients were superior to N-cadheringroups, but the differences were not significant.</p><p><b>CONCLUSION</b>The expression of N-cadherin in bone marrow leukemic cells relates to some clinical features of patients with acute leukemia and to some extent has inferior effect on survival of patients with acute leukemia.</p>

Expression of Programmed Death Ligand-1 (PD-L1) in Human Acute Leukemia and Its Clinical Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To explore the expression of PD-L1 in acute leukemia patients, and to analyze the relationship of PD-L1 expression with the patients' clinical characteristics and prognosis.</p><p><b>METHODS</b>The expression of PD-L1 in leukemia cells of 75 patients including 59 de novo patients and 16 relapse/refractory patients with acute leukemia was detected by the flow cytometry, the clinical information was collected, and the therapeutic efficacy of de novo patients was analyzed.</p><p><b>RESULTS</b>The PD-L1 was expressed in human acute leukemia cells with total expression rate 32% (24/75), and its expression level in AML-M5 was higher than that in other leukemias [56.3% (9/16) vs 25.4% (15/59)], there was statistical significance (P = 0.019). The PD-L1 possitive rate in relapse/refractory group was higher than that in de novo patient group [(56.3% (9/16) vs 25.4% (15/59)], and there was statistical significance (P = 0.019). In 59 de novo patients, the CR rate of PD-L1 positive group after 1 course of chemotherapy was lower than that in PD-L1 negative group (66.7% vs 71.4%), the CR rate of PD-L1 positive group after 2 courses of chemotherapy was also lower than that in PD-L1 negative group (70% vs 88.6%). The relapse rate and the proportion of refractory patients in PD-L1 possitive group were higher than those in PD-L1 negative group. The expression of PD-L1 did not correlated with the clinical parameters, such as sex, age, extramedullary infiltration, percentage of blast cells in bone marrow, counts of WBC, RBC and platelet, as well as molecular biological features and cytogenetical characteristics.</p><p><b>CONCLUSION</b>PD-L1 is expressed in human acute leukemia cells, and may be involved in the immune escape and primary resistant mechanisms, PD-L1 may be used as an indicator for evaluation of the the patients' prognosis and reocurrence.</p>

Expression of N-Cadherin in Patients with Multiple Myeloma and Its Clinical Significance / 中国实验血液学杂志

<p><b>OBJECTIVE</b>To investigate the expression of N-Cadherin in the patients with multiple myeloma (MM) and to explore its clinical significance.</p><p><b>METHODS</b>A total of 64 patients with multiple myeloma were enrolled in this study. The expression of N-Cadherin in bone marrow CD38⁺/CD138⁺ cells from multiple myeloma patients was detected by flow cytometry. The relationship between N-Cadherin expression and clinical prognostic factors was analyzed.</p><p><b>RESULTS</b>Among 64 cases of MM, the expression of N-Cadherin in 17 patients (26.56%) was high (> 20%), while that in 47 cases (73.44%) was low (< 20%); The differences of N-Cadherin expression in disease staging and classification, known prognostic factors, myeloma cell antigen expression and bone damage between patients with high and low N-Cadherin expression were not statistically different; the difference N-Cadherin expression in genetic abnormalities such as D13S319 deletion, RB1 deletion and IGH gene rearrangement between above-methioned two groups was not significant. The 1q21 amplification rate in the group with high expression of N-Cadherin was enhanced significently; the overall survival (OS) times of patients with abnormally high and low expression levels of N-Cadherin were 26.7 months and 55.5 months respectively, and the difference was statistically significant (P < 0.05).</p><p><b>CONCLUSION</b>The high expression of N-Cadherin in multiple myeloma may be one of the indicator for poor prognosis of MM, which may be related with 1q21 amplification.</p>

Dynamically monitoring minimal residual disease in acute leukemia after complete remission by multiparameter flow cytometry and its relation with prognosis / 中国实验血液学杂志

This study was purposed to investigate the dynamically monitoring minimal residual disease (MRD) by flow cytometry (FCM) in patients with acute leukemia (AL) after complete remission and its relation with prognosis. From October 2010 to May 2012, 58 cases of AL (including 45 cases of AML and 13 cases of ALL) were regularly monitored for MRD in bone marrow by FCM and their bone marrow morphology was observed by light microscopy at the same time which continued to relapse or to follow-up deadline in the Department of Hematology, the First Affiliated Hospital of Zhengzhou University. Through average follow-up for 9 months (3 - 21 months), the average MRD level of patients with CR was got. And the prognostic value of MRD level at different time points in AL patients after CR was analysed and summarized. MRD ≥ 1% was defined as positive, otherwise, as negative. The results showed that the maximum and minimum MRD levels of 45 AML patients were 9.57% and 0.01% respectively, the average was 0.67%; the maximum and minimum MRD levels of 13 cases of ALL patients were 7.9% and 0.0016% respectively, the average was 0.99%. Among 44 cases after induction therapy, the relapse rate of MRD(+) group was 53.3% (8/15), the relapse rate of MRD(-) group was 10.3% (3/29), and the relapse rate of MRD(+) group was higher than that of MRD(-) group (χ(2) = 7.58, P = 0.006). Among 58 cases after the first consolidatory therapy, the relapse rate of MRD(+) group was 62.5% (5/8), the relapse rate of MRD(-) group was 16.0% (8/50), and the relapse rate of MRD(+) group was higher than that of MRD(-) group (χ(2) = 6.11, P = 0.013). It is concluded that MRD detected by FCM has a large range (10(-6) - 10(-2)), which can not be used as a single indicator of complete remission. When MRD ≥ 1% after induction therapy and the first consolidatory therapy, the relapse rate significantly increases, MRD can be used as a sensitive indicator for prognosis.

Correlation of chromosome karyotype with dyshaematopoiesis and reticulin in myelodysplastic syndrome / 中国实验血液学杂志

This study was purposed to explore the correlation of chromosome karyotype with dyshaematopoiesis and reticulin in myelodysplastic syndrome (MDS). The data of 202 MDS patients diagnosed and treated in the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed in term of chromosome karyotype, dyshaematopoiesis and reticulin detection results. The chromosome karyotypes were categorized according to the International Prognostic Scoring System (IPSS). The results showed that there was a positive correlation between chromosome karyotype grading and number of lineages with dyshaematopoiesis (r = 0.443, P < 0.05). The detected rates of multilineage dyshaematopoiesis in patients with good, intermediate and poor chromosome karyotypes were 44.4%, 71.4% and 96.3% respectively. There was a positive correlation between chromosome karyotype grading and reticulin grading (r = 0.451, P < 0.05). The positive rates of reticulin in patients with good grading, intermediate and poor chromosome karyotypes were 36.8%, 64.3% and 92.6% respectively. The detected rate of multilineage dyshaematopoiesis, number of lineages with dyshaematopoiesis, the positive rate of reticulin and reticulin grade in patients with poor karyotypes were higher than those in patients with intermediate or good chromosome karyotypes (separately P < 0.01). The above data in patients with intermediate chromosome karyotypes were higher than those in patients with good chromosome karyotypes (separately P < 0.01). It is concluded that the chromosome karyotype grading positively correlates with the number of lineages with dyshaematopoiesis and reticulin grading. When the chromosome karyotype changed from good to poor, the detected rate of multilineage dyshaematopoiesis, number of lineages with dyshaematopoiesis, positive rate of reticulin and reticulin grading became higher and higher.

Clinical characteristics of CD56(+) patients with acute monocytic leukemia and their prognostic significance / 中国实验血液学杂志

This study was aimed to investigate the clinical features of CD56(+) patients with acute monocytic leukemia (AML-M5) and their prognostic significance. The data of 76 newly-diagnosed patients from our hospital were analyzed retrospectively. Patients were divided into two groups: CD56(+) group (21 patients) and CD56(-) group (55 patients). The clinical features, CR rate, relapse rate, the duration of CR, and survival time of patients between the two groups were compared. The results indicated that the CD56(+) antigen was observed in 21 patients (27.6%), their median age was 51.5 years and with a range 16 - 70 years. Of the 21 CD56(+) patients, the high WBC count was found in 57.1% CD56(+) patients (12/21), but it only in 15% CD56(-) patients (P < 0.05). The extramedullary infiltration was seen in 13 CD56(+) patients, and accounted for 62% (13/21), meanwhile this infiltration was found in 18 CD56(-) patients (18/55) and accounted for 33% (P < 0.05). All cases immunophenotypically highly expressed CD13, CD33, CD64, CD11b, cMPO, CD38, in which only the expression frequency of CD11b was positively related with CD56 (r = 0.59, P < 0.05). The CR rate in CD56(+) group accounted for 60.0%, and had no significant difference in comparison with that in CD56(-) group. In CD56(+) group the relapse rate was 75% (P = 0.042), the mean duration of CR was 5.5 months (95%CI, 3.1 - 8.6, P = 0.002), the median overall survival time was 10.1 months (95%CI, 2.3 - 16.3, P = 0.001). and all these had statistical significance as compared with that in CD56(-) group. It is concluded that CD56(+) AML-M5 patients always complicate with high WBC count and extramedullary infiltration, their CR rate and duration of CR are lower and shorter respectively, their relapse rate and prognosis are high and poor respectively.

Clinical features and survival analysis of patients with CD20 positive adult B-lineage acute lymphoblastic leukemia / 中国实验血液学杂志

The aim of this study was to explore the clinical features and survival of adult patients with CD20 positive B-lineage acute lymphoblastic leukemia (B-ALL). The clinical manifestations, examination results, therapeutic effect and survival rate of 119 adult B-ALL patients diagnosed and treated in our hospital from May 2004 to January 2008 were analyzed retrospectively. The results showed that among 119 cases, CD20 positive B-ALL accounted for 40 cases (33.61%), CD20 negative B-ALL patents accounted for 79 cases (66.39), the percentage of male patients in CD20 positive and negative groups were 72.50% and 50.63%, the leukocyte counts at diagnosis in these two groups were (27.35+/-30.29)x10(9)/L and (0.11+/-81.72)x10(9)/L, respectively, there were significant differences (p<0.05), whereas the distribution of age, infiltration of liver, spleen, lymph nodes and central nervous system, the hemoglobin and platelet levels, the expression of myeloid lineage marker, the incidence of Ph chromosome, the ratio of hyperdiploid and normal karyotype, the complete remission rate within 4 weeks, induction death rate and relapse rate and so on in CD20 positive and negative groups showed no significant differences (p>0.05). The analysis of Kaplan-Meier curve on survival rate demonstrated that the median overall survival time and 3-year overall survival rate of adult B-ALL patients in CD20 positive and negative groups were 11.0 months and 12.0 months, 28% and 20% respectively, there were no statistical differences (p=0.832). It is concluded that the expression of CD20 in adult B-ALL appears to be associated with sex and leukocyte count, but not associated with other clinical features, which indicates no significant influence on the prognosis of patients.

Immunophenotyping characteristics of adult patients with acute lymphoblastic leukemia in different ages / 中国实验血液学杂志

The purpose of this study was to investigate the immunophenotyping characteristics of adult acute lymphoblastic leukemia (ALL) patients in groups of different ages. Immunophenotyping was performed in 260 ALL patients by flow cytometry using a panel of monoclonal antibodies and CD45/SSC gating. The results indicated that (1) all the 82 cases of T-cell acute lymphoblastic leukemia (T-ALL) expressed CD7 (100%) while the positive rate of CD2 remarkably decreased with aging. The positive rate of CD2 in patients aged 14 to 18 years (adolescents) was 91.67%, which is significantly higher than that in cases aged 19 to 35 years (young adults) and > 35 years (older adults) (65.71% and 43.48% respectively, p < 0.05); the positive rate of CD34 and HLA-DR increased with aging, there was significant difference of the HLA-DR expression between the older adults group (39.13%) and the other two groups (4.17% in adolescents and 11.43% in young adults respectively (p < 0.05). Moreover, there were significant differences of the myeloid antigen (MyAg) and CD13 expression between the older adults and younger adults (p < 0.05). (2) As to adult B-cell acute lymphoblastic leukemia (B-ALL), the positive rates of CD19 and HLA-DR in 178 cases were 100%; the positive rate of CD33 in young adults was significant higher than that in adolescents (p < 0.05), the differences of the other marker expressions failed to reach statistical significance in adult B-ALL patients. It is concluded that the immunophenotypes of adult T-ALL are evidently heterogeneous in different ages, and expression with more aberrant phenotypes indicates poor prognostic significance in patients older than 35 years. There is no significant association of immunophenotypes with ages among different age groups of adult B-ALL.

Influence of Iron on Mitochondrion Membrane Potential and Apoptosis of Human Leukemia-60 Cells / 实用儿科临床杂志

Objective To observe the change of mitochondrion membrane potential(??m) in apoptosis induced by an iron chelator(deferoxamine,DFO),and to explore the mechanism of this apoptosis in human leukemia-60(HL-60) cells.Methods HL-60 cells were co-cultivated with various concentration of DFO and FeCl_3 for certain time,resultingin status of intracellular iron deprivation and rich iron.Cell vital force was determinded by the MTT method.The cells were examined by phase contrast microscopy,flow cytometry(FCM) for evidence of apoptosis,and also by FCM for ??m.The transcription of the apoptogene of bax was detected by hybridization in situ.Results The cell growth rate assumed descent tendency.DFO could induce the apoptosis and descent ??m of HL-60 cells(P

Expression and role of beta-catenin in acute leukemia bone marrow cells / 中国实验血液学杂志

The aim of this study was to explore the expression of beta-catenin in acute leukemia bone marrow cells and its role in the development of acute leukemia. The expression of beta-catenin of bone marrow cells was detected by immunocytochemistry and flow cytometry in 20 cases of newly diagnosed acute leukemia. Meanwhile the expression of the proliferating index Ki-67 was detected by immunocytochemistry. The results showed that the expression of beta-catenin and Ki-67 in acute leukemia bone marrow cells was significantly higher than those in control group (P < 0.05). The migration of beta-catenin from cytoplasm to nuclear was observed in acute leukemia bone marrow cells. There was a positive correlation between the expressions of beta-catenin and Ki-67 in all the cases and the Pearson correlation coefficient was 0.845. In conclusion, the expression of beta-catenin was significantly high in acute leukemia bone marrow cells and showed a positive correlation with the cell proliferation. It suggests that beta-catenin may be involved in the development of acute leukemia through promoting the excessive proliferation of cells.

Influence of chemotherapy on expression of TRAIL in primary acute leukemic cells / 中国实验血液学杂志

In order to explore the expression of TRAIL in primary acute leukemic cells and the effect of chemotherapeutic drug on TRAIL expression in acute leukemic cells, the expression of TRAIL was assessed by flow cytometry on day 0, day 1, day 3 and day 5 in 16 patients with acute leukemia received chemotherapy. Meanwhile, the bone marrow mononuclear cells of acute leukemia patients were cultured in vitro with VP-16 and INFalpha-2a. Expression of TRAIL was analyszed by flow cytometry at 24, 48 and 72 hours after treatment. The results showed that the expression of TRAIL in the peripheral blood mononuclear cells was upregulated significantly from day 1 after chemotherapy (P < 0.05). In in vitro culture test, VP-16 upregulated the expression of TRAIL on acute leukemia bone marrow mononuclear cells (P < 0.05). Compared with VP-16 alone, the combination of VP-16 with IFNalpha-2a showed no synergic effects on the expression of TRAIL. It is concluded that the expression of TRAIL increases after chemotherapy in vivo and after treatment with VP-16 and IFN in vitro, which suggests that the apoptosis induced by TRAIL may play an important role in chemotherapy of leukemia.

CXCR4 expression in B-lineage acute lymphocyte leukemia and its significance / 中国实验血液学杂志

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.