Immunophenotyping of acute lymphoblastic leukemia using immunohistochemistry in bone marrow biopsy specimens

Flow cytometry is the preferred method of diagnosing and immunophenotyping acute lymphoblastic leukemia (ALL). However, there are situations in which immunohistochemical staining (IH) of bone marrow trephine biopsy specimens can be used to provide immunophenotypic information. To evaluate the use of IH and to confirm its value in diagnosing and typing of ALL, we studied 50 cases of denovo ALL that were previously classified into pre B, T and B by morphologic, cytochemical and FC methods. Paraffin embedded bone marrow trephine biopsies sections were stained using a panel of antibodies,namely, myeloperoxidase (MPO), terminal deoxynucleotidyl transferase (TdT), CD10, CD20, CD79a, CD3. The cases included 37 pre BALL, 10 T ALL and 3 mature BALL. TdT was the most commonly expressed antibody and was positive in 41 of 50 cases of ALL (82%) and in 95% of pre B ALL cases. CD79a and CD10 were positive in 68% and 65% of pre B ALL cases, respectively. CD79a showed similar positivity in B ALL cases (66%). CD 20 was positive in 66% of mature B ALL cases but less positive in pre B ALL (22%). CD3 was positive in 70% of T ALL cases and negative in other ALL subtypes. All of the cases were negative for MPO. Diagnosis and immunophenotyping of acute lymphoblastic leukemia is possible using immunohistochemical staining of bone marrow trephine biopsies.     

Distribution of the cytoskeletal protein,Nestin, in acute leukemia

Abstract

Nestin is a neuroepithelial stem cell marker that is expressed in some types of tumor cells. Recent reports suggest that Nestin may be closely related to malignant cell proliferation and migration. Acute leukemia (AL) is characterized by a lack of differentiation, which results in uncontrolled proliferation in the bone marrow and accumulation of immature cells. The expression and function of Nestin in AL is unclear. We investigated Nestin immunohistochemical patterns of 87 patients that included 47 cases of acute myeloid leukemia (AML) and 40 cases of acute lymphoblastic leukemia (ALL), and 20 patients in complete remission (CR) from AML or ALL. We also investigated the clinico-pathological features of 87 cases of AL and their CR and overall survival (OS). Nestin was expressed in leukemic blasts and mature granulocytic cells in most cases (39/47) of AML. Conversely, Nestin was expressed in mature granulocytic cells in fewer cases (6/40) of ALL, but not in blasts. Nestin expression appeared in leukemic blasts of AML, but not ALL. Nestin expression in AML blast cells was not associated with CR or OS. We provide evidence that Nestin is expressed in AL and might be a useful immunohistochemical marker for identifying AML and ALL.     

Expression of CD13/aminopeptidase N in precursor B-cell leukemia: role in growth regulation of B cells

Expression of cell surface CD13 in acute B-cell leukemia (ALL-B) is often viewed, as an aberrant expression of a myeloid lineage marker. Here, we attempted to study the stage specific expression of CD13 on ALL-B blasts and understand its role in leukemogenesis as pertaining to stage of B-cell ontogeny. A total of 355 cases of different hematological malignancies were diagnosed by immunophenotyping. Among 68 cases of early B-cell ALL, 22 cases with distinct immunophenotype was identified as immature B-cell ALL. Blasts from these ALL-B patients demonstrated prominent expression of CD10, CD19, CD22, but neither cytoplasmic nor surface IgM receptors. This strongly indicates leukemogenesis at an early stage of B-cell development. We also identified, the existence of a subpopulation of cells with remarkably similar phenotype in non-leukemic marrow from healthy subjects (expressing CD10, CD19, CD22, CD24, Tdt together with the co-expression of CD13). This sub-population of B cells concomitantly expressing CD13 appeared to be a highly proliferating group. By blocking their cell surface CD13 in leukemic blasts with monoclonal antibody we were able to inhibit their proliferation. We hypothesized that neoplastic transformation at this stage may be facilitated by CD13. CD13 may thus be an important target for novel molecular therapy of early stage acute B-cell leukemia.     

急性淋巴细胞白血病CD34+CD38-细胞在NOD/SCID小鼠体内的自我更新与增值能力

目的 探索急性淋巴细胞白血病(ALL)患者CD34+ CD38-细胞移植到NOD/SCID小鼠体内建立白血病的可行性、自我更新与增殖潜能.方法 分选并鉴定ALL患者骨髓CD34+ CD38-细胞及对照CD34- CD38+细胞后,经尾静脉分别注射104个细胞于亚致死剂量射线照射的NOD/SCID小鼠体内,连续监测小鼠状态以及外周血血象改变,对濒死或死亡小鼠进行骨髓检查、肝脾病理学检查.结果 接种从ALL患者分选的CD34+ CD38-细胞到NOD/SCID小鼠体内后4周,小鼠外周血白细胞上升,到8周左右达高峰,约15×109～20× 109/L,原始及幼稚淋巴细胞明显增多.骨髓象显示以原始及幼稚淋巴细胞增生为主,约为40％,且肝脾组织也有白细胞浸润,明显高于接种了对照组CD34- CD38+细胞的NOD/SCID小鼠.结论 ALL患者CD34+CD38-细胞可以成功移植NOD/SCID 小鼠,在小鼠体内增殖形成白血病,说明该群细胞具有自我更新和增殖的潜能,可作为探索白血病起始细胞研究的重要载体.     

Biphenotypic acute leukemia: a case report

We describe an uncommon case of acute leukemia in which leukemic blasts expressed myeloid antigens and cyCD79alpha molecule. In this 49-year old male patient, two distinct blast populations were detected in peripheral blood and bone marrow samples: one of small size resembling lymphoblasts and another with pink cytoplasmic granules resembling myeloblasts. Cytochemical reaction for myeloperoxidase was negative in both cell types. Conventional cytogenetic analysis showed a normal karyotype (46 XY) in all metaphases studied, while gene rearrangement analysis by seminested PCR of the immunoglobulin heavy chain (Ig-H) and T-cell-gamma chain (TCR-gamma) receptor, showed a germline configuration of the TCR and clonal rearrangement of Ig-H chain genes. Multicolour cytofluorimetric analysis showed that bone marrow and peripheral blood blasts expressed CD19, CD79alpha bright, CD22 and terminal deoxynucleotidyl transferase (TdT) as lymphoid markers, CD13, CD117, CD15 as myeloid markers, CD34, HLA-DR as stem cell markers. CD33 myeloid antigen was expressed by 50% of the blastic population. No differences in the immunophenotypic profile were detected in the two blast populations which were identified by morphology. According to EGIL (European Group of Immunological Classification of Leukemias) and WHO (World Health Organization) criteria, a diagnosis of biphenotypic acute leukemia (BAL) was made. The patient was treated with AML induction therapy followed by autologous stem cell transplantation, but relapse free survival was 6 months. The patient died a few weeks later due to unresponsiveness to salvage chemotherapy regimens. We conclude that patients with BAL should have a risk stratification with treatment tailored to their immunophenotype and gene rearrangement profiles.     

A newly established human acute lymphoblastic leukemia cell line with characteristics of the earliest B-cell maturation

A new human acute lymphoblastic leukemia (ALL) cell line, designated HBL-3, was established from the bone marrow of a patient with non-T-ALL. The HBL-3 cell line expressed B4 (CD 19), BA-1 (CD 24) and HLA-DR antigens, but not surface immunoglobulin (SIg) or cytoplasmic immunoglobulin (CIg). The cell line lacked the common acute lymphoblastic leukemia antigen (CALLA) and antigenic markers characteristic of T-cell and myeloid cell lineages. The HBL-3 cells had structural rearrangements of both the homologous chromosome 9s, including a translocation with chromosome 1 which has been reported in a patient with common ALL. The cell line had rearranged immunoglobulin heavy chain genes but retained germ-line kappa light chain genes and germ-line T-cell receptor beta- and gamma-chain genes. The HBL-3 cell line was strongly positive for terminal deoxynucleotidyl transferase (TdT). These findings indicate that the HBL-3 cell line is derived from the earliest B-cell committed to B-cell lineage.     

Acute leukemia in adults: assessment of remission induction with combination chemotherapy by clinical and cell-culture criteria.

Remission induction was assessed by clinical and cell-culture criteria for 65 patients with acute myelogenous leukemia (AML), 11 patients with chronic myelogenous leukemia (CML) in blast crisis and 19 patients with acute lymphoblastic leukemia (ALL). Cyclophosphamide, cytosine arabinoside and vincristine (CAV) therapy resulted in complete remission in 23 of 50 previously untreated patients with AML and in 3 of the 11 patients with CML. Fourteen patients with ALL responded to vincristine-prednisone induction therapy and two to induction therapy with CAV. The median duration of survival of the responding patients was 2.2 years, compared with 4 months for the patients who did not respond to treatment. Granulopoietic colony formation, assessed by assay of colony-forming units dependent on colony-stimulating activity in culture (CFU-C), was abnormal in 37 of 42 bone marrow aspirates from patients with AML before treatement. CFU-C concentration increased when leukocyte-conditioned medium (LCM) was added to the cultures; 13 cultures had normal or elevated CFU-C concentration with LCM. Marrow cells of patients with ALL or CML in blast crisis demonstrated a similar pattern. Serial studies of marrow CFU-C concentration of 31 patients with AML demonstrated a change to a normal pattern with successful remission induction. Results of this study suggest that administration of purified LCM to leukemic patients might increase granulocyte production from potential but unstimulated granulopoietic precursors. This therapy would lessen the probability of death from infection during remission induction.     

A newly established human acute lymphoblastic leukemia cell line with characteristics of the earliest B-cell maturation

A new human acute lymphoblastic leukemia (ALL) cell line, designated HBL-3, was established from the bone marrow of a patient with non-T-ALL. The HBL-3 cell line expressed B4 (CD 19), BA-1 (CD 24) and HLA-DR antigens, but not surface immunoglobulin (SIg) or cytoplasmic immunoglobulin (CIg). The cell line lacked the common acute lymphoblastic leukemia antigen (CALLA) and antigenic markers characteristic of T-cell and myeloid cell lineages. The HBL-3 cells had structural rearrangements of both the homologous chromosome 9s, including a translocation with chromosome 1 which has been reported in a patient with common ALL. The cell line had rearranged immunoglobulin heavy chain genes but retained germ-line κ light chain genes and germ-line T-cell receptorβ- and γ-chain genes. The HBL-3 cell line was strongly positive for terminal deoxynucleotidyl transferase (TdT). These findings indicate that the HBL-3 cell line is derived from the earliest B-cell committed to B-cell lineage.     

恶性血液病患者外周血淋巴细胞亚群变化及其临床意义的研究

目的: 探讨恶性血液病外周血淋巴细胞亚群变化特征及临床意义。方法: 采用流式细胞仪检测64例初诊的血液系统恶性肿瘤患者的外周血淋巴细胞亚群。病种包括急性髓系白血病(acute myeloid leukemia,AML)、急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)、霍奇金淋巴瘤(Hodgkin’s lymphoma,HL)、非霍奇金淋巴瘤(Non-Hodgkinlymphoma,NHL)。分析比较30例正常人的外周血淋巴细胞亚群与实验组的差异,并对64例恶性血液病患者中连续动态监测的21例急性白血病患者外周血淋巴细胞亚群结果变化与预后关系进行分析。结果： 不同成人恶性血液病患者年龄分组淋巴细胞亚群变化无明显差异;恶性血液病患者中CD3 ⁺CD8 ⁺ T淋巴细胞百分比、Treg细胞百分比均增加;CD16 ⁺/CD56 ⁺NK细胞百分比及CD4 ⁺/CD8 ⁺比值均下降;CD3 ⁺T淋巴细胞数量、CD3 ⁺CD4 ⁺淋巴细胞数、CD3 ⁺CD8 ⁺淋巴细胞数量、CD3 ^-CD19 ⁺淋巴细胞数量、CD16 ⁺/CD56 ⁺NK淋巴细胞数量及CD4 ⁺/CD8 ⁺比值均减少;急性白血病及恶性淋巴瘤患者外周血淋巴细胞亚群与正常对照组比较存在一定的差异;急性白血病未缓解组的Treg细胞比例明显高于急性白血病首疗程缓解组及对照组;急性白血病复发组Treg细胞比例明显高于急性白血病持续缓解组以及对照组;对21例急性白血病患者动态监测的淋巴细胞亚群发现,化疗缓解的患者Treg在化疗过程中逐渐下降,至第3~6个疗程逐渐接近正常对照,化疗未缓解的患者Treg细胞在化疗过程中逐渐上升或持续大于10%,明显高于完全缓解组,复发患者Treg在化疗过程中先下降后明显上升。 结论： 恶性血液病患者免疫功能显著低于健康人,且伴随免疫功能紊乱,且不同疾病类型、不同的疾病状态免疫紊乱的程度不一,Treg细胞比例可以用来预测急性白血病患者疗效及复发,可以为患者的临床治疗方案及用药强度提供指导依据。     

Use of colony assays and anti-T cell immunotoxins to elucidate the immunobiologic features of leukemic progenitor cells in T-lineage acute lymphoblastic leukemia

The specific binding of radioiodinated rIL-2 to fresh marrow blasts from T-lineage acute lymphoblastic leukemia (ALL) patients was initially investigated. The estimated number of radioiodinated rIL-2 molecules bound per blast ranged from undetectable to 1948. In colony assays, 72% of 32 cases analyzed showed a significant proliferative response to rIL-2, which depended on PHA-stimulated lymphocyte conditioned medium activation. Colony stimulation indices correlated with the number of radioiodinated rIL-2 molecules bound per blast but not with expression of CD25/Tac Ag on fresh marrow blasts or primary colony blasts. These findings provide evidence that in T-lineage ALL functional IL-2R proteins are expressed on leukemic progenitor blasts which may be distinct from Tac Ag. We used the mAb 35.1, T101, and G3.7 to test for expression of CD2, CD5, and CD7 on fresh marrow blasts from 126 T-lineage ALL patients. CD2, CD5, and CD7 were expressed in 84%, 93%, and 99% of cases, respectively. Furthermore, colony blasts that represent the early progeny of leukemic progenitor blasts were also CD2+CD5+CD7+. Ricin conjugates of 35.1, T101, and G3.7 mAb were used as Ag-specific cytotoxic probes to test for expression of CD2, CD5, and CD7 at the level of T-lineage leukemic progenitor blasts. Each immunotoxin was able to selectively eliminate greater than 99% of leukemic progenitor blasts, providing unique and direct evidence that these cells co-express CD2, CD5, and CD7. Neither mixtures of anti-CD5 and anti-CD7 nor anti-CD2, anti-CD5, and anti-CD7 immunotoxins were more effective against blast progenitor cells than the individual immunotoxins alone, confirming that CD2, CD5, and CD7 are not expressed on non-overlapping progenitor cell subpopulations.     

Detection of minimal residual disease (MRD) after bone marrow transplantation (BMT) by multi-parameter flow cytometry (MPFC)

Multi-parameter flow cytometry (MPFC) was used to detect minimal residual disease (MRD) following bone marrow transplantation (BMT) in 21 patients. Bone marrow (BM) was analyzed pre-transplant and 3–4 months post-BMT while the patients were in clinical and morphological remission. MRD was detected by identifying cells with aberrant antigen expression and/or leukemia-associated phenotype (LAP) using MPFC. Prior to BMT, 8 out of 21 patients exhibited normal antigen expression based on normal BM samples while 13 BM aspirates had abnormal MPFC. Pre-BMT MPFC was abnormal in all 10 patients who were not in complete remission (CR) (>5% blasts in BM) as well as 3 patients acute lymphoblastic leukemia (ALL) who were in CR. In BM from ALL patients, an abnormal uniform B cell population was observed however antigen expression patterns varied greatly between patients. BM from acute myeloblastic leukemia (AML) patients showed an abnormal distribution of CD34+ cells. In addition, a correlation was observed between pre-BMT cytogenetics and MPFC. Only 2 out of 8 (25%) patients with normal MPFC pre-autologous bone marrow transplantation (ABMT) relapsed (AML), while 6 out of 13 (46%) patients with abnormal pre-BMT MPFC relapsed including 2 out of 3 patients who were transplanted in clinical CR. Pre-BMT MPFC may thus be an effective tool for detection of MRD by detection of a pre-transplant MPFC abnormality.     

Granulocytopoiesis in children with acute lymphoblastic leukaemia.

Numbers, proliferative potential, and differentiative capacity of bone marrow granulocyte-macrophage precursor cells were studied in 130 children with acute lymphoblastic leukaemia (ALL), including 77 children in an acute phase of the disease and 53 in remission. Bone marrow samples from 65 children without haematopoietic abnormalities were used as controls. The numbers of clonogenic precursors were found to be below normal in all phases of ALL, particularly during the acute period when the bone marrow was heavily infiltrated with leukaemic cells. It is shown that the decreases in the numbers and proliferative potential of the precursor cells during the acute phases was associated with the effects of leukaemic blast cells, but that in remission the observed reduction in the precursor cell pool was due to the cytostatic effect of therapy. The differentiative capacity of clonogenic granulocyte and macrophage precursors was not altered in children with ALL.     

Acute lymphoblastic leukemia (ALL) antigens detected with antisera to E rosette-froming and non-E rosette-forming ALL blasts.

Based on the presence or absence of erythrocyte receptors(E) a T cell marker, acute lymphocytic leukemia (ALL), can be divided into E+ALL and E-ALL. We studied cell surface antigens on blasts from 12 children with untreated ALL: eight with E-ALL and four with E+ALL. Heterologous antisera were raised against thymus cells, E+ and E-ALL blasts, appropriately absorbed and tested by immunofluorescence and a radiolabeled antibody assay with normal and leukemic lymphoid cells. By both methods, anti-thymus and anti-E+ALL sera reacted with human thymocytes. Specific binding of anti-E+ALL serum to T antigens was indicated by the fact that a single absorption with thymocytes abolished its binding to allogenic thymocytes, and the reactivity of anti-E+ALL serum with thymus, blood and bone marrow lymphocytes was similar to that of anti-thymus serum. After exhaustive absorption with blood leukocytes, anti-E+ALL and E-ALL sera were negative against normal lymphocytes and bone marrow cells from children with ALL in remission. Anti-thymus and anti-E+ALL sera reacted with blasts from patients with E+ALL, but not with E-ALL. In contrast, anti-E+ALL serum reacted with 40 to 96% of blasts from all children with E-ALL, whereas of the four patients with E+ALL, two were negative and two had the lowest percentage of immunofluorescent cells (10 to 22%). These results were confirmed with the radiolabeled antibody assay. Patients with active E-ALL had cells bearing E-ALL antigen(s) in the peripheral blood and bone marrow, but the number of immunofluorescent cells was lower in blood. Cells reactive with anti-E-ALL serum did not react with thymus cells, blood lymphocytes, remission bone marrow cells, Raji cells, PWM and PHA-induced blasts and CLL cells bearing mIg (uk). These data suggest that the antigen detected on E-ALL blasts by anti-E-ALL serum is neither a HLA-related nor a cell differentiation antigen. Thus, by using antiserum to E+ALL blasts, we have confirmed the presence of a T cell-specific antigen(s) on E+ALL cells. This antiserum did not recognize other leukemia-associated antigens common to E+ and E-ALL. We have also demonstrated an antigen(s) which is regularly expressed on E-ALL blasts and is either not detectable or is present in a lower proportion of E+ALL blasts.     

Dynamics of lineage-restricted mixed chimerism following sex-mismatched allogeneic bone marrow transplantation

Scant knowledge is available about the dynamics of lineage-specific mixed chimerism (Ch) following bone marrow transplantation (BMT). This review is focused on findings derived from bone marrow (BM) biopsies in patients with chronic myeloid leukemia (CML) including a sex-mismatched host/donor constellation. Appropriate techniques involved immunophenotyping by monoclonal antibodies to identify the various cell lineages, dual color fluorescence in situ hybridization (FISH) with x- and y-chromosome-specific DNA-probes and a proper detection system for a simultaneous labeling of the bcr/abl locus. A significant degree of Ch with more than 20% host CD34+ progenitors was found in the early and late (up to 200 days after BMT) posttransplant period. However, only 10% of these cells harbored the bcr/abl translocation gene. This result fits well with corresponding molecular biological findings of so-called minimal residual disease. Conversion of Ch evolved during leukemic relapse with 90% host progenitors of which 50% revealed the bcr/abl locus. A Ch of nucleated erythroid percursors (5%) and CD68+ macrophages (8%) was expressed to a significantly lower degree. The slightly increased frequency found in CD61+ megakaryocytes (16%) was probably due to the polyploid state of these cells. Similar to the CD34+ progenitor cells abrupt changes from donor to host type was associated with an insidious transformation into recurrent leukemia. The CD34+ endothelial cells showed a minor degree of Ch, because donor-derived elements ranged from 18% to 25%. Leukemic relapse was characterized by an almost complete conversion of the endothelial cells to a host type. These findings point towards a CD34+ progenitor cell origin of the (leukemic) endothelial cell layer and suggests that their dysfunction may contribute to an expansion of the neoplastic clone.     

Human acute lymphoblastic leukemia (ALL) blasts as accessory cells during T-cell activation: differences between patients in costimulatory capacity affect proliferative responsiveness and cytokine release by activated T cells

The ability of acute lymphoblastic leukemia (ALL) blasts to mediate costimulatory signals during T-lymphocyte activation was investigated in an experimental model in which monoclonal T-cell populations were stimulated with standardized activation signals (anti-CD3 and anti-CD28 monoclonal antibodies; phytohemagglutinin, PHA). Leukemia cells from 12 consecutive ALL patients with high peripheral blood blast counts were studied. Proliferative T-cell responses were detected for a majority of these patients when irradiated leukemia blasts were used as accessory cells during activation. T-cell cytokine release was also observed for most patients when using nonirradiated ALL accessory cells. Low or undetectable cytokine levels were usually observed for CD8+ clones, whereas the CD4+ clones often showed a broad cytokine response with release of interleukin-2 (IL-2), IL-4, IL-10, IL-13 and interferon gamma(IFN-gamma) in the presence of the ALL accessory cells. ALL blasts were also able to function as allostimulatory cells for normal peripheral blood mononuclear responder cells. However, both T-cell proliferation and cytokine release showed a wide variation between ALL patients. The accessory cell function of ALL blasts showed no correlation with the release of immunomodulatory mediators (IL-2, IL-10, IL-15) or the expression of any single adhesion/costimulatory membrane molecule (CD54, CD58, CD80, CD86) by the blasts. We conclude that for a majority of patients, native ALL blasts can mediate costimulatory signals needed for accessory cell-dependent T-cell activation, but differences in costimulatory capacity between ALL patients affects both the proliferative responsiveness and cytokine release by activated T cells.     

Influence of BCR/ABL fusion proteins on the course of Ph leukemias

The hallmark of chronic myeloid leukemia (CML) and a subset of acute lymphoblastic leukemia (ALL) is the presence of the Philadelphia chromosome as a result of the t(9;22) translocation. This gene rearrangement results in the production of a novel oncoprotein, BCR/ABL, a constitutively active tyrosine kinase. There is compelling evidence that the malignant transformation by BCR/ABL is critically dependent on its Abl tyrosine kinase activity. Also the bcr part of the hybrid gene takes part in realization of the malignant phenotype. We supposed that additional mutations accumulate in this region of the BCR/ABL oncogene during the development of the malignant blast crisis in CML patients. In ALL patients having p210 fusion protein the mutations were supposed to be preexisting. Sequencing of PCR product of the BCR/ABL gene (Dbl, PH region) showed that along with single-nucleotide substitutions other mutations, mostly deletions, had occurred. In an ALL patient a deletion of the 5th exon was detected. The size of the deletions varied from 36 to 220 amino acids. For one case of blast crisis of CML changes in the character of actin organization were observed. Taking into account the functional role of these domains in the cell an etiological role of such mutations on the disease phenotype and leukemia progression is plausible.     

The immunophenotypic and cytogenetic characteristics of the blast cells in subvariants of acute myeloid leukemia

The results of study of morpho-cytochemical peculiarities, antigenic profile and peripheric blood and/or bone marrow blast cell karyotype of 21 patients with acute myeloid leukemia are presented. Hemopoietic cell immunophenotyping was carried out with the use of cytofluorometer FACScan and chromosome cytogenetic analysis with the use of analyzer "Metascan". It has been shown that in the AML M1 blast cell plasmatic membrane carries pan-myeloid CD33 and CD13 antigens, the last having high density of expression, and the CD38 antigen, which is a myeloid cell-precursor marker. In these patients tetraploidy, being the testimony of karyotype change, has been ascertained. It has been found out that the AML M2 blasts, except pan-myeloid antigens, express the cell proliferation CD71 marker. Blast cell karyotype peculiarities typical for this leukemia sub-variant have been revealed. In patients with the AML M4 in 3 of 6 cases an anomalous karyotype has been found. It has been also shown that the CD14 antigen, and rather its percentage in blast total population, is the differential-diagnostic criterion for the AML M4 and M5.     

Disruption of Annexin II /p11 Interaction Suppresses Leukemia Cell Binding,Homing and Engraftment,and Sensitizes the Leukemia Cells to Chemotherapy

The bone marrow microenvironment plays an important role in acute lymphoblastic leukemia (ALL) cell proliferation, maintenance, and resistance to chemotherapy. Annexin II (ANX2) is abundantly expressed on bone marrow cells and complexes with p11 to form ANX2/p11-hetero-tetramer (ANX2T). We present evidence that p11 is upregulated in refractory ALL cell lines and patient samples. A small molecule inhibitor that disrupts ANX2/p11 interaction (ANX2T inhibitor), an anti-ANX2 antibody, and knockdown of p11, abrogated ALL cell adhesion to osteoblasts, indicating that ANX2/p11 interaction facilitates binding and retention of ALL cells in the bone marrow. Furthermore, ANX2T inhibitor increased the sensitivity of primary ALL cells co-cultured with osteoblasts to dexamethasone and vincristine induced cell death. Finally, in an orthotopic leukemia xenograft mouse model, the number of ALL cells homing to the bone marrow was reduced by 40–50% in mice injected with anti-ANX2 antibody, anti-p11 antibody or ANX2T inhibitor compared to respective controls. In a long-term engraftment assay, the percentage of ALL cells in mouse blood, bone marrow and spleen was reduced in mice treated with agents that disrupt ANX2/p11 interaction. These data show that disruption of ANX2/p11 interaction results in reduced ALL cell adhesion to osteoblasts, increased ALL cell sensitization to chemotherapy, and suppression of ALL cell homing and engraftment.     

急性髓系白血病免疫表型特征及遗传学特征分析

目的:研究急性髓系白血病免疫表型特征以及遗传学特征。方法:选取2011年1月到2014年5月我院收治的急性髓系白血病患者169例,采用流式细胞术和相关的单克隆抗体来分析所有患者的骨髓免疫表型,采用染G染色体显带技术分析患者的核型,根据淋系抗原(lym Ag)的表达将患者分为lym Ag+组和lym Ag-组。结果:抗原CD13、CD33、CD117以及MPO等髓系抗原最常在急性髓系白血病患者中表达,其中CD117在M3型病例中表达为85.7%(24/28),而CD34、HLA-DR双阴性、较强的自发荧光、CD13、CD33和MPO对M3型的诊断也具有一定的价值;其中47.9%(81/169)的患者伴随着淋系抗原表达,以CD7和CD56为主;60.4%(102/169)的患者伴随着核型异常;而伴随着t(8:21)的M2患者中的CD15、CD19和CD56的表达显著增强,而t(15:17)均发生于M3型患者中;而lym Ag+组患者CD34的阳性患者为77.8%(63/81)显著高于lym Ag-组的47.7%(42/88),两组比较差异具有统计学意义(P0.05)。结论:免疫表型对急性髓系白血病的诊断具有重要的意义,且免疫表型和异常核型存在密切的联系。