Comprehensive flow cytometry phenotype in acute leukemia at diagnosis and at relapse

Li X, Du W, Liu W, Li X, Li H, Huang S‐A. Comprehensive flow cytometry phenotype in acute leukemia at diagnostic and at relapse. APMIS 2010; 118: 353–59. Multiparameter flow cytometry (MFC) plays a vital role in the detection of minimal residual disease (MRD) and diagnosis of relapse in acute leukemia. However, application of a limited panel of antibodies in MFC leads to high rates of false‐negative and false‐positive results. Thirteen patients with acute lymphoblastic leukemia (ALL) and 12 patients with acute myeloid leukemia (AML) were immunophenotyped by MFC at diagnosis and at relapse using a comprehensive panel of monoclonal antibodies (McAbs) to 27 antigens and CD45/SSC gating. In 23 of 25 patients (92.3%), changes in at least one of progenitor‐associated, myeloid and lymphoid antigens between diagnosis and relapse were observed. Antigen changes were observed in 92 of 239 antigens (38.5%) expressed in 25 patients, in 49 of 117 antigens (41.9%) expressed in 13 ALL patients, and in 43 of 122 antigens (35.2%) expressed in 12 AML patients. Phenotypic changes were characterized by the expression of cross‐lineage antigens. The intralineage change was observed in the majority of patients. However, myeloid lineage shift was identified by MFC in two patients with T‐ALL. Multiple panels of three or more McAbs are likely to be required in the monitoring of MRD and diagnosis of relapse in acute leukemia by MFC.     

MLL-CBP fusion transcript in a therapy-related acute myeloid leukemia with the t(11;16)(q23;p13) which developed in an acute lymphoblastic leukemia patient with Fanconi anemia

We describe a boy with Fanconi anemia (FA) who developed acute lymphoblastic leukemia (ALL) (FAB-LI) followed by acute myeloid leukemia (AML) (FAB-M5) at relapse. The patient was diagnosed with early pre-B-cell ALL without preceding aplastic anemia and was treated with ALL-oriented chemotherapy which included doxorubicin (a total dose of 140 mg/m(2) administered), which is a topoisomerase II inhibitor. Complete remission was obtained, but after 38 weeks AML developed. The karyotype of ALL cells at diagnosis showed 46,XY, and that of AML cells at relapse was 46,XY, t(11;16)(q23;p13). An MLL gene rearrangement and MLL-CBP chimeric mRNA were found in AML, but not in ALL. A diagnosis of FA was confirmed by an increased number of chromosomal breaks and rearrangements in peripheral blood lymphocytes cultured with mitogen in the presence of mitomycin C. We conclude that this FA patient developed ALL followed by a therapy-related t(11;16)-AML resulting in an MLL-CBP fusion. Further examination of such patients would shed light on leukemogenesis in FA patients. Genes Chromosomes Cancer 27:264-269, 2000.     

PRAME induces apoptosis and inhibits proliferation of leukemic cells in vitro and in vivo

PRAME is a germinal tissue-specific gene that is expressed at high levels in haematological malignancies, but the physiological functions of PRAME in leukemia cells are unknown. It has reported that PRAME was found to be predominantly expressed in acute leukemias and high PRAME expression is correlated with a favorable prognosis in childhood acute leukemias, which suggested that PRAME could be involved in the regulation of cell death or apoptosis. In the present study, we tested a hypothesis that the PRAME gene plays a role in the regulation of apoptosis and proliferation of leukemia cells. We observed that KG-1 cells transient overexpressing the PRAME gene (when transfected with pcDNA3.1-PRAME plasmid) significantly induces apoptosis and decreases proliferation in vitro, and repression of PRAME expression by a short interfering RNA exhibited a increased proliferation in K562 cells in vitro and increases tumorigenicity of K562 leukemic cells in nude mice. Our results suggest that the leukemias expressing high levels of PRAME has favorable prognosis. PRAME may be as an attractive target for potential immunotherapy for acute leukemic.     

急性髓系白血病PRAME基因转录本的定量研究

目的 探讨黑色素瘤优先表达抗原(preferentially expressed antigen of melanoma,PRAME)基因转录本在急性髓系白血病(acute myeloid leukemia,AML)患者中的表达和临床意义.方法 建立荧光染料EvaGreen实时定量聚合酶链反应(real-time quantitative PCR,RQ-PCR)对56例初诊AML患者和20例对照的骨髓单个核细胞标本中PRAME转录本进行检测,分析其临床相关性.结果 PRAME转录本含量在对照组和AML患者中分别为0～1.46%(中位0.18%)和0～21 618.09%(中位9.79%)(P＜0.01);FAB亚型中M1、M2、M3和M4患者中PRAME转录本含量较对照组明显增高,而M5患者与对照组差异无统计学意义.PRAME转录本含量与染色体预后分组显著负相关(r=-0.438,P=0.001),低危组患者中PRAME转录本含量显著高于中危组和高危组患者.AML-M2患者中t(8;21)易位阳性者PRAME转录本含量(135.06%～21 618.09%,中位2 201.88%)明显高于无t(8;21)易位者(0.14%～1696.30%,中位17.97%)(P=0.002).对1例AML患者不同阶段的标本检测发现诱导缓解后PRAME转录本明显下降,复发时又明显升高.结论 PRAME转录本在AML患者中高表达,是患者预后良好的一个标记,可用于AML患者的随访监测.     

Allogeneic bone marrow transplantation after hyperfractionated total-body irradiation and cyclophosphamide in children with acute leukemia

Ninety-seven children with either acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML) received HLA-identical bone marrow transplants from sibling donors, after preparation with 1320 cGy of hyperfractionated total-body irradiation and high-dose cyclophosphamide. Kaplan-Meier product-limit estimates (means +/- SE) of disease-free survival at five years among patients with ALL in second remission, third remission, and fourth remission or relapse were 64 +/- 9, 42 +/- 14, and 23 +/- 11 percent, respectively, with probabilities of relapse of 13 +/- 7, 25 +/- 13, and 64 +/- 16 percent. Among patients with AML in first remission, second remission, and third remission or relapse, five-year disease-free survival estimates were 66 +/- 10, 75 +/- 15, and 33 +/- 19 percent, with respective relapse probabilities of 0, 13 +/- 12, and 67 +/- 19 percent. The most frequent cause of death in patients in early remission (ALL in second or third remission or AML in first or second remission) was bacterial sepsis, fungal sepsis, or both, most often in the presence of acute or chronic graft-versus-host disease. Among patients with ALL who received transplants while in second remission, the duration of the initial remission had no effect on the probability of relapse after transplantation. The only pretransplantation factor that significantly affected outcome was the disease status at the time of transplantation; patients in early remission had better disease-free survival. We conclude that transplantation after preparation with hyperfractionated total-body irradiation and cyclophosphamide is an effective mode of therapy in children with refractory forms of acute leukemia.     

Leukemia in the central nervous system

The frequency of central nervous system (CNS) leukemia was studied in patients aged 15-59 with acute leukemia, who had received induction treatment in the years 1971-1986. Twelve out of 103 patients with acute lymphoblastic leukemia (ALL) developed CNS leukemia in spite of prophylaxis consisting of intrathecal methotrexate. Ten out of 217 patients with acute myelogenous leukemia (AML) developed CNS leukemia. None had been given preventive treatment. Leukemic blasts with either M4 or M5 morphology appeared to increase the risk of CNS relapse. Treatment was adjusted to the clinical problem of each patient, but always included intrathecal methotrexate. Median survival after a diagnosis of CNS leukemia was 8 and 6 months in ALL and AML respectively, with bone marrow failure due to hematologic relapse as the leading cause of death. CNS leukemia, if properly treated, does probably not shorten survival. An active approach to diagnosis and treatment is therefore mandatory.     

Extramedullary Relapse of Acute Leukemia after Allogeneic Hematopoietic Stem Cell Transplantation: Different Characteristics between Acute Myelogenous Leukemia and Acute Lymphoblastic Leukemia

Extramedullary relapse (EMR) of acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a contributor to post-transplantation mortality and remains poorly understood, especially the different characteristics of EMR in patients with acute myelogenous leukemia (AML) and those with acute lymphoblastic leukemia (ALL). To investigate the incidence, risk factors, and clinical outcomes of EMR for AML and ALL, we performed a retrospective analysis of 362 patients with AL who underwent allo-HSCT at the First affiliated Hospital of Soochow University between January 2001 and March 2012. Compared with patients with AML, those with ALL had a higher incidence of EMR (12.9% versus 4.6%; P = .009). The most common site of EMR was the central nervous system, especially in the ALL group. Multivariate analyses identified the leading risk factors for EMR in the patients with AML as advanced disease status at HSCT, hyperleukocytosis at diagnosis, history of extramedullary leukemia before HSCT, and a total body irradiation–based conditioning regimen, and the top risk factors for EMR in the patients with ALL as hyperleukocytosis at diagnosis, adverse cytogenetics, and transfusion of peripheral blood stem cells. The prognosis for EMR of AL is poor, and treatment options are very limited; however, the estimated 3-year overall survival (OS) was significantly lower in patients with AML compared with those with ALL (0 versus 18.5%; P = .000). The characteristics of post–allo-HSCT EMR differed between the patients with AML and those with ALL, possibly suggesting different pathogenetic mechanisms for EMR of AML and EMR of ALL after allo-HSCT; further investigation is needed.     

Impact of cellular CD71 (transferrin receptor 1) expression in Egyptian acute leukemia: correlation with clinicopathologic features

Cellular transferrin receptor 1 (CD71) has been identified as a proliferation marker. Inferior outcome with higher expression was observed in many solid tumors. This study objected to assess the expression of CD71 in patients with acute leukemia and to address its prognostic significance and relations to clinicopathologic features. The study included 34 acute myeloid leukemia (AML) and 64 acute lymphoblastic leukemia (ALL) newly diagnosed cases from Mansoura Oncology Center. CD71 was analyzed on blast cells by flow cytometry. CD71 expression was significantly elevated in both AML and ALL. Antigen expression apparently increased in T-ALL, while in AML there was a trend toward a gradual increase of antigen expression in relation to maturation evidence of myeloid subtypes. CD71 expression correlated positively with total leukocyte count in ALL cases and negatively with platelet count in AML cases. In ALL, higher CD71 expression was associated with higher relapse rate and was an independent prognostic factor of overall survival (HR 1.8; 95 % CI 1.2–4.1). In conclusion, CD71 is overexpressed in acute leukemia; it predicts adverse clinical outcome in ALL. In addition, CD71 antagonism could be a possible therapeutic target in acute leukemia.     

Loss or downregulation of HLA class I expression at the allelic level in acute leukemia is infrequent but functionally relevant, and can be restored by interferon

Human leukocyte antigen (HLA) class I expression at the allelic level was analyzed in 397 acute myeloid leukemia (AML) and 186 acute lymphoid leukemia (ALL) using a complement-dependent cytotoxicity assay. Impaired recognition possibly due to HLA downregulation was observed in 2% of the patients with AML and ALL in complete remission, and in 8%-15% in the groups with blasts. In 15 instances of diminished cytotoxicity, leukemic cells and control PHA blasts from the same patients were further analyzed using flow cytometry. In 4/6 ALL and 4/9 AML patients HLA downregulation or complete loss (2 patients) of cell surface expression could be confirmed. No genomic abnormalities were observed. In addition, 12 AML and 13 ALL patients were tested during relapse using flow cytometry. In 1/12 AML patients and 1/13 ALL patients allelic downregulation of cell surface expression was found. In two patients tested, downregulation or loss of cell surface expression of HLA class I antigens corresponded with impaired T cell mediated lysis by HLA restricted cytotoxic T lymphocyte.Treatment of the cells with alpha- or gamma-interferon could restore HLA class I expression and T-cell recognition. In conclusion, downregulation of cell surface expression of HLA class I expression at the allelic level in AML and ALL is infrequent but functionally relevant. HLA downregulation was reversible and T-cell recognition could be restored by alpha- or gamma-interferon.     

Intracellular IL-4, IL-10, and IFN-gamma levels of leukemic cells and bone marrow T cells in acute leukemia

The quantitative levels of intracellular cytokines IL-4, IL-10, and IFN-gamma (ie, the number of bound PE-conjugated antibody molecules/cell) of leukemic cells and bone marrow T cells (bmT cells) of acute leukemia patients were analyzed by flow cytometry. One hundred, thirty-one (95 AML, 25 ALL, 11 ABL) patients were studied. The leukemic cell IL-4 level was highest in the monocytic AML group (1735 +/- 1056) and lowest in the dysplastic AML group (960 +/- 545). The IFN-gamma level was highest in the acute promyelocytic leukemia (APL) group (495 +/- 159), and lowest in the ALL group (252 +/- 119). The IL-10 level was not significantly different among the diagnosis groups. In bmT cells, the IL-10 level was highest in the dysplastic AML group (972 +/- 1049) and lowest in the APL group (397 +/- 352). The leukemic cell cytokine levels were lowest and bmT cell cytokine levels were highest in the dysplastic AML group. There were no significant correlations of these cytokine levels with 2-yr survival rate, complete remission (CR) rate, or relapse rate. The cytokine levels of bmT cells at the time of CR became normal and were not different among the diagnosis groups. In summary, leukemic cell and bmT cell cytoplasmic expression profiles of IL-4, IL-10, and IFN-gamma are characteristic for each diagnostic group of acute leukemia patients and the profiles of bmT cells are normal at the time of CR.     

The proportion of abnormal karyotypes in acute leukemia samples related to method of preparation

Bone marrow and peripheral blood were studied from 200 patients with acute leukemia [109 with acute myeloid leukemia (AML), 91 with acute lymphoblastic leukemia (ALL)] who had samples cultured for varying times and who had a mixture of chromosomally abnormal and normal cells. The mean percentage of abnormal metaphase cells increased with culture time. The peak was reached at 48 hours and declined slightly after 72 hours in culture for ALL patients. The mean percentage of abnormal cells increased up to 72 hours in culture for AML patients. In 68 patients (31 AML and 37 ALL), cytogenetic data were available from samples processed with both direct preparations and culture methods. The percentage of abnormal cells increased after culture in 49 patients (23 AML and 26 ALL), while it decreased or remained at the same level in 19 patients. For AML patients, the mean percentage of abnormal cells was significantly different between direct (38%) and cultured preparations (63%), (p less than 0.001). Seven of 9 patients with AML who showed a greater than 50% increase in abnormal cells after culture had either a t(8;21), t(15;17), or abnormalities involving 11q23. The two patients who showed a significant decrease in abnormal cells both had a translocation involving 11q13. Compared with ALL, more AML patients showed greater than 80% abnormal bone marrow metaphase cells at diagnosis or at relapse.     

Plasma soluble interleukin-2 receptor (sIL-2R) levels in patients with acute leukemia

The plasma soluble interleukin-2 receptor (sIL-2R) level was higher in 137 patients with acute leukemia (1,489 +/- 1,798 U/ml, including 98 cases of acute myeloid leukemia (AML), 1,063 +/- 1,414 U/ml, and 39 cases of acute lymphoblastic leukemia (ALL), 2,561 +/- 2,194 U/ml), compared to 49 normal control subjects, 421 +/- 151 U/ml). The ALL patients showed elevated plasma sIL-2R levels more frequently than the AML patients (92.3% vs 44.9%). No patient with either hypoplastic AML or AML with multilineage dysplasia and only 1 of 13 patients with acute promyelocytic leukemia (APL) had an elevated plasma sIL-2R level. All the My+ ALL patients (15 cases) showed elevated plasma sIL-2R levels. Plasma sIL-2R levels were significantly lower after chemotherapy in the ALL patients, but were not significantly lower in the AML patients. IL-2R was expressed on the leukemic cells in 36 (53.7%) of 67 AML and in 9 (21.4%) of 42 ALL cases. None of the AML M3, M4, M5, M6, or M7 subgroups showed IL-2R expression. The My+ ALL patients (42.9%, 6/14) showed IL-2R expression more frequently than the other ALL subgroups (10.7%, 3/28) (p = 0.025). The plasma sIL-2R level was correlated with the proportion of leukemic cells expressing IL-2R in acute leukemia. However, there were many cases, particularly ALL cases, who had elevated plasma sIL-2R levels without IL-2R expression on their leukemic cells. These results suggest that the plasma sIL-2R level is a valuable marker for monitoring ALL after chemotherapy, particularly in My+ ALL cases, and that the T cell immune reaction to leukemia appears to be much higher in ALL patients than in AML patients.     

Unrelated Cord Blood Transplantation for Acute Leukemia Diagnosed in the First Year of Life: Outcomes and Risk Factor Analysis

Infant acute leukemia still has a poor prognosis, and allogeneic hematopoietic stem cell transplantation is indicated in selected patients. Umbilical cord blood (UCB) is an attractive cell source for this population because of the low risk of chronic graft-versus-host disease (GVHD), the strong graft-versus-leukemia effect, and prompt donor availability. This retrospective, registry-based study reported UCB transplantation (UCBT) outcomes in 252 children with acute lymphoblastic leukemia (ALL; n?=?157) or acute myelogenous leukemia (AML; n?=?95) diagnosed before 1 year of age who received a single-unit UCBT after myeloablative conditioning between 1996 and 2012 in European Society for Blood and Marrow Transplantation centers. Median age at UCBT was 1.1 years, and median follow-up was 42 months. Most patients (57%) received a graft with 1 HLA disparity and were transplanted in first complete remission (CR; 55%). Cumulative incidence function (CIF) of day 100 acute GVHD (grades II to IV) was 40%?±?3% and of 4-year chronic GVHD was 13%?±?2%. CIF of 1-year transplant-related mortality was 23%?±?3% and of 4-year relapse was 27%?±?3%. Leukemia-free-survival (LFS) at 4 years was 50%?±?3%; it was 40% and 66% for those transplanted for ALL and AML, respectively (P?=?.001). LFS was better for patients transplanted in first CR, regardless of diagnosis. In multivariate model, diagnosis of ALL (P?=?.001), advanced disease status at UCBT (<.001), age at diagnosis younger than 3 months (P?=?.012), and date of transplant before 2004 were independently associated with worse LFS. UCBT is a suitable option for patients diagnosed with infant acute leukemia who achieve CR. In this cohort, patients with AML had better survival than those with ALL.     

Myeloperoxidase gene expression in acute leukemias

Since myeloperoxidase (MPO) is considered to be a critical marker of differentiating acute myelogenous leukemia (AML) from acute lymphocytic leukemia (ALL), the analysis of MPO gene expression may provide further insight into the leukemia classification and the lineage fidelity of leukemia cells. By Northern blot hybridization using full-length MPO cDNA as a probe, approximately 66% of AML cells (3/4 M1 cases, 2/4 M2 cases, 15/15 M3 cases, 11/15 M4 cases, and 2/12 M5 cases) were found to express MPO mRNAs, whereas none of 18 ALL cases did. MPO mRNA was detectable when AML cells contained at least 10% peroxidase-positive cells. APL (M3) cells expressed high levels of mRNA in accordance with heavy staining for peroxidase.     

HLA-DRw Antigens Associated with Acute Leukemia

In mice, susceptibility to leukemia is closely linked to "Ia" antigens coded by the major histocompatibility complex and is transmitted recessively. To test this hypothesis in man, 89 patients with acute leukemia were typed for the eight known HLA-DRw specificities, representing the human counterpart of the Ia system, and compared with a normal unrelated control population (n=123). Phenotypes showing only one identifiable DRw antigen were significantly increased in patients with acute leukemia. Within such phenotypes, there was a predominant and significant occurrence of DRw antigens 3, 6, and 7, depending on the type of leukemia (AML, ALL in adults, and ALL in children respectively). These findings are most probably due to an excess of homozygotes for these particular DRw antigens, thus suggesting a recessive mode of transmission of susceptibility to leukemia in man.     

Premature chromosome condensation as a predictive indicator of relapse in children and adolescents with acute leukemia: initial observations

Premature chromosome condensation has been used to determine a proliferative potential index (PPI) in a study of children in leukemia remission at varying times during the disease. Values 35% and greater were considered predictive of relapse. Such values preceded relapse with a mean of 5 months in acute lymphoblastic leukemia (ALL) patients who had previously relapsed and in myeloid leukemia patients. ALL patients followed from diagnosis and children off therapy had fluctuating and false predictive PPI values preceding long courses of continued remission. This study suggests that the PPI as a predictive indicator for relapse may be useful for patients with ALL who have previously relapsed and for patients with myeloid leukemias. Future exploration to further evaluate this mechanism of prediction is to be attempted by investigating the ability to obtain similar and more detailed information through the use of peripheral blood rather than bone marrow samples.     

Low incidence of TEL/AML1 fusion and TEL deletion in Korean childhood acute leukemia by extra-signal fluorescence in situ hybridization

TEL/AML1 fusion in acute leukemia results from cryptic translocation of chromosome 12 and 21, the presence of which suggests a favorable prognosis. The incidence of TEL/AML1 fusion in B-lineage ALL is approximately 25%, but the incidence in Korea has not yet been reported. To investigate the incidence of TEL/AML1 fusion and TEL deletion, bone marrow specimens from 77 Korean children with newly diagnosed acute leukemia were analyzed by FISH. We applied extra-signal FISH to discriminate a true TEL/AML1 fusion from a false-positive fusion signal. To determine the cut-off value of the TEL/AML1 fusion signal, 20 normal bone marrow specimens and 28 normal peripheral blood specimens were also analyzed. The frequency of patients with TEL/AML1 fusion was 13.3% (4 cases) among 30 B-lineage ALL and 9.5% among 42 ALL. One TEL/AML1 fusion-positive patient was also found among 4 acute biphenotypic leukemias. TEL/AML1 fusion was not found in any samples from patients with T-lineage ALL or AML. The incidence of TEL deletion was 6.7% (2 cases) among 30 B-lineage ALL and 4.8% among 42 ALL. The incidences of TEL/AML1 fusion and TEL deletion in Korean children with acute leukemia appear to be lower than those in other countries, suggesting a racial difference.