急性髓系白血病细胞表面抗原CD11b的表达与其预后的关系

目的:探讨急性髓系白血病(AML)细胞表面抗原表达与预后的关系.方法:回顾性分析90例初治AML患者,流式细胞仪检测骨髓白血病细胞表面抗原的表达情况,按染色体危险分层分为好、中、差3组,x2分析骨髓白血病细胞表面抗原阳性率的差异;Kaplan- Meier生存分析和COX回归分析骨髓白血病细胞表面抗原的阳性率与患者预后...     

Significant association between expression of the CD11b surface molecule and favorable outcome for patients with acute myeloblastic leukemia

The expression of several myeloid and non-lineage associated surface antigens in 70 patients with acute myeloblastic leukemia was investigated in relation to patient and disease characteristics, response to therapy, and prognosis. A leukocyte integrin, CD11b, was the only antigen that showed a significant association with complete remission (CR) duration and survival (P < .025).The mean survival for CD11b+ patients was longer than for CD11b- patients (578 +/- 76 versus 397 +/- 7 days, respectively). CR duration was 897 +/- 84 for CD11b+ patients and 366 +/- 71 for CD11b- patients. Multivariate analysis confirmed the predictive value of CD11b expression for longer survival (relative risk, 3.2; P = .02) and CR duration (relative risk, 3.2; P = .03). CR rate was also significantly higher in CD11b+ patients (77.3%) than in CD11b- patients (46.1%) (P = .01). Survival and remission duration were not influenced by expression of other surface markers including CD13, CD14, CD33, CD34, CD71, CD38, and HLA-DR or by other variables including French-American-British subtype, age, and leukocyte count. Extramedullary disease (EXD) was associated with the presence of both CD13 and CD14 expression (P < .04) but occurred less frequently in CD13+ cases. CD13 expression occurred more frequently in female patients (P = .03). CD38 expression was associated with lower platelet count and an increase in the number of blasts (P < .02).     

High CD33 expression levels in acute myeloid leukemia cells carrying the nucleophosmin (NPM1) mutation

The CD33 antigen is expressed on the blast cells of most cases of acute myeloid leukemia and represents a suitable tumor-associated target antigen for antibody-based therapies. The aim of this study was to investigate the relationship between the CD33 levels quantified by mean fluorescence intensity and antibody binding capacity, and the presence/absence of NPM1 and FLT3 gene mutations in 99 newly diagnosed acute myeloid leukemia cases. The CD33 intensity evaluated as mean fluorescence intensity and antibody binding capacity was significantly higher in the NPM1-mutated acute myeloid leukemia cases compared to the NPM1-unmutated cases (P=0.0001 and P=0.0088, respectively). On the contrary, FLT3 gene mutations did not influence the levels of CD33 expression on the leukemic cells. These results establish a rational basis for the therapeutic use of anti-CD33 antibodies in NPM1-mutated acute myeloid leukemia patients.     

Expression of MAC-1 (CD11b) in acute myeloid leukemia (AML) is associated with an unfavorable prognosis

There is evidence to suggest, that cellular adhesion molecules and receptors could play a role in leukemia, e.g., through altered adhesive qualities of leukemic blasts. We have studied the expression of the beta2-integrin Mac-1 (CD11b) on mononuclear cells in 48 patients with AML at first diagnosis by flow cytometry using a direct fluorescein-conjugated antibody. A case was defined as positive if more than 20% of the cells expressed Mac-1. Within the FAB types, we observed a high expression rate in cases with M5 (100% MAC-1+ cases, 73% MAC-1+ cells), M4 (75% MAC-1+ cases, 48% MAC-1+ cells) and in cases with FAB-M1 with 71% MAC-1+ cases and 29% MAC-1+ cells. Separating our patients' cohort in cytogenetic risk groups, we could detect significant higher proportions of MAC-1+, cases (88% vs. 27%, P = 0.005) and cells (51% vs. 16%, P = 0.015) with poor cytogenetic risk compared to the favorable risk group. For clinical evaluations only patients treated according to the protocols of the German AML Cooperative Group (AML-CG) were included (n = 29, cases with AML-M3 were excluded). More MAC-1+ cases and cells were found in the "non-responders" group (n = 8) compared to the "responders" group (n = 24). We can conclude that AML cases with high MAC-1 expression are characterized by a worse prognosis. Evaluation of MAC-1 expression in AML might therefore contribute clinically important data with respect to develop new therapies that influence the interactions between integrins like MAC-1 on leukemic cells and endothelial or immunoreactive cells.     

Differential expression of CD11b/CD18 (Mo1) and myeloperoxidase genes during myeloid differentiation

During the course of differentiation of early human myeloid cells toward monocytes and granulocytes, cell surface expression of the cell adhesion molecule, CD11b/CD18 (Mo1) increases dramatically and expression of myeloperoxidase (MPO), a bacteriocidal enzyme, decreases markedly. Using the inducible promyelocytic cell line HL-60 as a model, we studied the mRNA expression of these genes. Differentiation of these cells along both a monocytic and a granulocytic pathway demonstrated that the mRNA levels of the two subunits of CD11b/CD18 increased in a pattern temporally and quantitatively similar to the increase in cell surface expression of this heterodimer. In contrast, the expression of MPO mRNA decreased in a temporal and quantitative pattern similar to the known decrease in MPO protein during differentiation, suggesting that regulation of these myeloid-specific proteins may occur at the level of mRNA expression. These findings have important implications with regard to the nature of the block in differentiation in acute nonlymphocytic leukemia and the regulation of myeloid gene expression.     

Analysis of CD34-positive cells in bone marrow from patients with myelodysplastic syndromes and acute myeloid leukemia and in normal individuals: a comparison between FACS analysis and immunohistochemistry

Abstract: In patients with myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML), expression of the hematopoietic stem cell marker CD34 has been associated with a poorer prognosis. CD34 is usually analyzed by flow cytometry (FC), but may also be analyzed using immunohistochemistry (IH). The present study was undertaken to compare these 2 methods. Bone marrow from 16 patients with MDS and 12 with AML and from 12 healthy young volunteers was studied. The expression of CD34 was analyzed with FC on fresh bone marrow cells and with IH on sections of paraffin-embedded bone marrow. The correlation between FC and IH was good both for patients with MDS (p<0.0001) and AML (p<0.01). However, in patients with a high number of CD34-positive cells, the FC method seemed to result in a higher percentage of positive cells compared to the IH method. In normal bone marrow, the ratio between the percentage of CD34-positive cells and the percentage of bone marrow blasts was approximately 0.8. In the whole group of MDS patients, this ratio was 1:1, while in patients with refractory anemia (RA) and ring sideroblastic anemia (RAS) it was 1.6. Patients with MDS differed significantly from patients with de novo AML, who showed a ratio of only 0.23 (p<0.01). We conclude that the FC and IH methods for measuring expression of CD34 are well-correlated in MDS and reasonably well correlated in AML. A stem cell phenotype is more commonly expressed on precursor cells from patients with MDS than from patients with AML.     

FLAG (Fludarabine,Cytarabine, G-CSF) as a second line therapy for acute lymphoblastic leukemia with myeloid antigen expression: in vitro and in vivo effects

Abstract: Thirteen consecutive adult patients with primary refractory (n = 5) or relapsed (n = 8) acute lymphoblastic leukemia (ALL) were treated by an induction schedule (FLAG) consisting of Fludarabine (30 mg/sqm/d) plus high dose Cytarabine (HD-ara-C: 2 g/sqm/d) (d 1–5) and G-CSF (from d 0 to polymorphonuclear recovery). Patients achieving complete remission (CR) were administered a second FLAG course as consolidation and were then submitted to an individualized program of post-remission therapy, depending on the patient's age and performance status. CR was achieved in 8/12 evaluable cases (67%). The median CR duration was 22.5 w. CR attainment was significantly related to the co-expression of lymphoid and myeloid antigens. ALL/My+ patients achieved CR in 6/6 evaluable cases vs. 2/6 for ALL/My^-. In vitro ³H ara-C incorporation into cellular DNA resulted significantly increased by Fludarabine (in 7/9 tested cases) and, furthermore, by the association of Fludarabine-G-CSF in 5 evaluable ALL/My+ cases; in contrast, no effect of G-CSF addition to Fludarabine was observed in 4 ALL/My^–. Myelosuppression was observed in all patients: the median time to neutrophils >0.5 × 10⁹/l was 16.3 d (range 13–22) and 16.2 d (range 9–29) to platelets>20 × 10⁹/l. Nonhematological toxicity was minimal. In conclusion, FLAG is an active and tolerable combination in refractory ALL, particularly in cases with myeloid antigen expression where G-CSF appears to improve efficacy, probably increasing ara-C incorporation into the DNA of leukemic cells.     

Interferon-alpha-induced changes in surface antigens in a hairy-cell leukemia (JOK-1), and a Burkitt's lymphoma cell line (Daudi) during in vitro culture.

In further studying the mechanism of action of IFN-alpha in HCL, we cultured the HCL cell line JOK-1 and the IFN-sensitive Burkitt cell line Daudi with and without IFN-alpha and investigated the changes in density of a number of surface antigens by use of mAb and flow cytometry analyses. During culture with IFN-alpha, reproducible changes were induced in both cell lines, which were qualitatively similar but differed quantitatively with small and transient changes in JOK-1. Significant decreases in surface antigen expression were observed for CD 19, 23, 37, and for IgM on both cell lines. Moreover, decreases were seen for CD 10, 22, 45, and MHC class II on Daudi, and for CD 20, 21, 27, and 40 on JOK-1. By contrast, only a few antigens increased in density, including CD 39, A96/G8 and SC9, on both cell lines, CD 22 on JOK-1, and CD 21 on Daudi. The increase in CD 39, A96/G8 and SC9 was probably directly related to the mechanism of action of IFN-alpha, whereas the other changes were most consistent with an unspecific inhibition of protein synthesis, possibly due to an accumulation of cells in G0, even though a differentiating effect cannot be ruled out. Thus, the unique in vivo effect of IFN-alpha in HCL was not paralleled by a specific direct effect on JOK-1 in vitro. Our findings therefore do not support the theory that IFN's mechanism of action in vivo is a direct effect on HC, but suggest that indirect effects are involved.     

Low L-selectin (CD62L) expression in acute myeloid leukemia correlates with a bad cytogenetic risk

OBJECTIVES: Interactions between hemopoietic cells and the stromal microenvironment or immunoreactive cells are mediated by specific cell surface receptors. The expression of those molecules may alter the adhesive qualities (mobility and homing) as well as immune response behavior of leukemic blasts. L-Selectin (CD62L) is suggested to play a role in the redistribution and homing of hemopoietic progenitor cells to the bone marrow (BM). Down-regulation of L-selectin is responsible for mobilization of blasts from the BM into the circulation and ligation of L-selectin stimulates proliferation of progenitor cells. This could have an influence on the process of leukemia. METHOD: We have studied the expression of L-selectin on mononuclear BM cells of 36 acute myeloid leukemia (AML) patients at first diagnosis by FACS analysis using a directly fluorescein isothiocyanate conjugated antibody (clone DRE G56). RESULTS: On average the patients presented with 88% blasts in the BM. The expression tended to be higher in primary (p) AML compared with secondary (s) AML. L-Selectin was very heterogenously expressed in all FAB groups. Highest expression was found in cases with AML-M4 with four of nine cases presenting with an inv(16) karyotype. Separating our patient cohort in cytogenetic risk groups we could detect a significantly higher expression of L-selectin in cases with a 'good risk' karyotype and a very low expression in cases with a 'bad risk' karyotype (P = 0.037). Comparing patients who achieved remission after double induction therapy (responders) with patients who showed persisting disease (non-responders) we found a higher percentage of L-selectin+ cases or cells in the responder group than in the non-responder group, although the differences were not significant because of only five cases in the 'non-responder' group. Evaluating cut-off points greatest differences in relapse-free survival probabilities were found in patients who presented with > or = 30% L-selectin+ BM cells compared with cases with < 30%: 86% of cases with > or = 30% L-selectin+ cells were still in remission after a mean follow up time of only 8 months compared with only 46% in the group with < 30% L-selectin+ cells. CONCLUSIONS: We can conclude that (i) expression of L-selectin on AML blasts is variable. This reveals the great diversitiy of immunophenotypes in AML and might contribute to identify individual blast phenotypes in order to detect minimal residual disease in remission. (ii) Low L-selectin expression correlates with a bad cytogenetic risk, with a lower probability to achieve remission and with a shorter relapse-free survival time. This might reflect a decreased homing of the blasts to the BM as well as an impaired cytotoxic T-cell reaction against leukemic cells. The expression of L-selectin on leukemic blasts might be influenced by different cytokine therapies (e.g. with interferon alpha) and this might result in an altered hematologic reconstitution after cytotoxic therapies as well as in an altered immunologic recognition of blasts.     

Childhood B-cell acute lymphoblastic leukemia with FAB-L1 morphology and a t(9;11) translocation involving the MLL gene

The t(9;11)(p21–22;q23) translocation is frequently associated with acute monoblastic leukemia but may occasionally be seen in patients with acute lymphoblastic leukemia (ALL). We report a case of childhood ALL associated with t(9;11)(p21–22;q23) as the unique recurring chromosomal abnormality. A 3-month-old girl presented with lymphomatous ALL (renal enlargement), a high leukocyte count and central nervous system (CNS) involvement. Leukemic cell typing revealed a sIg+ B-cell immunophenotype without CD10 and CD34 antigenic expression while the blast cell morphology was of the FAB-L1 type. Splitting of a YAC encompassing the MLL gene was shown by fluorescence in situ hybridization (FISH) studies of the patients metaphase chromosomes. Rearrangement of the MLL gene was confirmed by Southern blot analysis. Despite treatment with an hyperintensive polychemotherapeutic regimen, the patient achieved a complete remission but relapsed 9 months later. These results provide further evidence that the t(9;11) may be observed in ALL, involves the MLL gene and is associated with a poor outcome. Moreover, this observation clearly illustrates that sIg+ B-cell ALL is not necessarily associated with a Burkitt (L3) morphology.     

Prognostic implications of mutations and expression of the Wilms tumor 1 (WT1) gene in adult acute T-lymphoblastic leukemia

Background

The role of the Wilms tumor 1 gene (WT1) in acute leukemias has been underscored by mutations found in acute myeloid leukemia identifying patients with inferior survival. Furthermore, aberrant expression of WT1 in acute myeloid leukemia was associated with an increased risk of relapse. No larger studies have performed a combined approach including WT1 mutation and expression analyses in acute T-lymphoblastic leukemia.

Design and Methods

We analyzed the WT1 mutations and the expression status in a total of 252 consecutive adult patients with newly diagnosed T-lymphoblastic leukemia, who were registered on the GMALL 06/99 and 07/03 protocols and had sufficient material available. The GMALL protocols included intensive chemotherapy as well as stem cell transplantation according to a risk-based model with indication for stem cell transplantation in first complete remission for early and mature T-lymphoblastic leukemia patients; patients with thymic T-lymphoblastic leukemia were allocated to a standard risk group and treated with intensive chemotherapy.

Results

Twenty of the 238 patients analyzed had WT1 mutations (WT1mut) in exon 7. WT1mut cases were characterized by immature features such as an early immunophenotype and higher WT1 expression. In thymic T-lymphoblastic leukemia, WT1mut patients had an inferior relapse-free survival compared to WT1 wild-type patients. T-lymphoblastic leukemia patients with aberrant WT1 expression (high or negative) showed a higher relapse rate and an inferior outcome compared to patients with intermediate WT1 expression. In the standard risk group of thymic T-lymphoblastic leukemia, aberrant WT1 expression was predictive for an inferior relapse-free survival as compared to patients with intermediate expression. In multivariate analysis, WT1 expression was of independent prognostic significance for relapse-free survival.

Conclusions

WT1 mutations were associated with an inferior relapse-free survival in standard risk thymic T-lymphoblastic leukemia patients. Moreover, altered expression associated with inferior outcome also suggests a role of WT1 in T-lymphoblastic leukemia and the potential use of molecularly-based treatment stratification to improve outcome.     

High expression of costimulatory molecules correlates with low relapse-free survival probability in acute myeloid leukemia (AML)

Costimulatory molecules such as lymphocyte function-associated antigen (LFA)-1 (CD11a), LFA-3 (CD58), intercellular adhesion molecule (ICAM)-1 (CD54), neuronal cell adhesion molecule (NCAM) (CD56), B7-1 (CD80), or B7-2 (CD86) are important regulatory elements in healthy immunological cascades, but their role in acute myeloid leukemia (AML) has only been rarely investigated. We studied their expression on mononuclear bone marrow (BM) cells from 105 patients with AML at initial diagnosis and evaluated their prognostic significance. Fluorescence-activated cell sorter (FACS) analyses were performed using antibodies directly conjugated with fluorescein. A BM sample was considered positive if more than 20% of the cells in the blast containing gate expressed the respective marker. The surface expression of CD11a (27 of 29 cases positive with an average of 71% positive blasts; 27⁺/29, 71%), CD54 (23⁺/33, 37%), CD56 (24⁺/93, 20%), CD58 (29⁺/29, 95%), CD80 (13⁺/28, 30%), and CD86 (19⁺/29, 39%) was measured. The expression of these markers in different French-American-British (FAB) classification types (M0–M5) was heterogeneous, except for CD56, which showed a higher proportion of positive cells in monocytic subtypes of AML. In addition, cases with a poor risk karyotype as well as patients succumbing to early death after double induction therapy according to the AML Cooperative Group (CG) protocol were characterized by a high expression of CD56. Relapse-free survival analyses demonstrated that patients with more than 8% CD56⁺ cells in the BM relapsed significantly sooner. CD54 was preferentially expressed in AML M4_eo and in addition in favorable cytogenetic risk groups and in cases that had responded to AML-CG therapy. Only very high proportions (>60%) of CD54⁺ cells were associated with a lower probability for relapse-free survival. CD80 and CD86 expressions were similar in all FAB types. Patients who had responded to AML-CG therapy showed higher CD80 proportions and lower CD86 proportions compared to the nonresponder group. Whereas cases with more than 15% CD80⁺ cells had a significantly lower probability for relapse-free survival, only cases with more than 65% CD86⁺ were characterized by a significantly lower probability for relapse-free survival. Expression profiles of CD11a and CD58 were not associated with specific FAB types or prognostically relevant groups. We can conclude: (1) Expression of costimulatory molecules in AML is very variable. This reflects the great diversity of immunophenotypes in AML. (2) CD56 is mainly expressed in monocytic subtypes of AML. CD56⁺ subtypes of AML seem to be a separate entity with a worse prognosis independent of the karyotype. (3) High expression of some costimulatory molecules correlates with a worse prognosis concerning relapse-free survival times.     

High expression of urokinase plasminogen activator receptor (UPA-R) in acute myeloid leukemia (AML) is associated with worse prognosis

Urokinase-type plasminogen activator receptor (UPA-R; CD87) is a membrane protein responsible for plasmin expression on cells facilitating cellular extravasations and tissue invasions. We studied the expression of the UPA-R on bone marrow (BM) cells of 93 patients with acute myeloid leukemia at first diagnosis and 8 healthy probands as controls by FACS analysis using phycoerythrin (PE)-conjugated antibodies. A case was defined as UPA-R-positive (UPA-R+) if >20% of the gated cells expressed UPA-R. Whereas none of the 8 healthy BM samples was positive for the UPA-R, 32 (34%) of the 93 AML samples were UPA-R+. Expression of UPA-R was heterogeneous in different FAB types, however, with the highest expression rates in monocytic subtypes (FAB M4/M5): 18%/19%/30% of UPA-R+ cases were found in M1/M2 or M3, and 58%/80% of cases with M4 or M5 were UPA-R+. Proportions of UPA-R+ cells varied between 1% and 98% of the mononuclear cell fractions, with the highest proportions in M4/M5 subtypes (on average 27%/40% UPA-R+ cells) and the lowest expression in AML M2 (11% UPA-R+ cells). The density of expressed UPA-R, estimated as mean channel fluorescence activity, was highest in cases with AML M1 (mFI: 124) followed by M4 and M5 (mFI: 78/77) and lowest in AML M2 (mFI: 43). In sAML, higher proportions of UPA-R+ cases (8 of 18; 44%) compared to pAML (24 of 75; 32%) were found as well as higher proportions of UPA-R+ cells (27% vs. 19%). Separating our patients' cohort in cytogenetic risk groups, we could not detect significant differences in the UPA-R expression profiles. For evaluations of the clinical course of AML, only patients treated by the AML-CG protocol (n = 65) were included. In the group of patients who did not respond to AML-CG therapy, significantly higher proportions of UPA-R+ cells (31% vs. 14%, P = 0.0015, t-test) were found. By evaluating a cut-off value for the percentage of positive cells that allows the most significant separation and differentiation between cases with shorter or longer relapse-free survival times, we could show that patients with >26.5% UPA-R-positive cells were characterized by a significantly higher risk for relapse compared to cases with <26.5% positive cells (P = 0.05). In summary, our data show a high expression of the UPA-R in AML, especially in (myelo)monocytoid subtypes. Cases with higher proportions of UPA-R+ cells were characterized by a significant lower remission rate after AML-CG therapy and a higher risk for relapse. Although prospective trials are still lacking, UPA-R is a prognostically relevant factor independent from the karyotype. UPA-R positivity may identify subtypes of AML associated with a more aggressive clinical course. Thus due to lower remission probabilities in UPA-R+ cases, a more intensive induction therapy regimen could be considered.     

Anti-neutrophil cytoplasm antibodies (ANCA) in rheumatoid arthritis: relationship to HLA-DR phenotypes,rheumatoid factor,anti-nuclear antibodies and disease severity

To investigate a possible relationship between the presence of anti-neutrophil cytoplasm antibodies (ANCA), rheumatoid factors (RF), anti-nuclear antibodies (ANA), disease severity and HLA-DR phenotypes, 46 consecutive ANCA⁺ and 48 ANCA^-, clinically well-documented RA patients were studied for RF, ANA and HLA-DR phenotypes. The 46 ANCA⁺ patients showed predominantly an atypical perinuclear staining pattern (89%). ANCA positivity was associated with higher RF titres (P<0.005) and advanced functional Steinbrocker grades III/IV (P<0.015). ANCA⁺ patients were also more often positive for ANA than ANCA^- patients (P<0.008). There was no correlation between ANCA positivity and certain HLA-DR phenotypes although the frequency of DR4⁺ (67% vs 52%) and, in particular, of DR4⁺ blanks (phenotypically homozygous) was increased in ANCA⁺ as compared to ANCA^- patients (20% vs 8%). DR4^-DR1^- RA patients were twice as frequent in the ANCA^- than in the ANCA⁺ group (22.9% vs 8.7%). Correspondingly, the DR4⁺DR1^- phenotype was increased among ANCA⁺ RA patients. Regarding functional Steinbrocker grades, the DR4⁺ phenotypes were slightly but not significantly increased in grades III and IV whereas ANCA positivity was significantly associated with severe functional Steinbrocker grades III/IV (66% ANCA⁺ vs 39% ANCA^-,P<0.015). ANCA positivity identified a population of RA patients with a long-standing and severe clinical course of the disease. There was no correlation between ANCA positivity and certain HLA-DR phenotypes.