Detection of minimal residual disease in acute leukemia by flow cytometry.

Patients with acute leukemia in clinical remission may still have up to 10(10) residual malignant cells (the upper limit of detection by standard morphologic techniques). Sensitive techniques to detect minimal residual disease (MRD) may allow better estimates of the leukemia burden and help the selection of appropriate therapeutic strategies. Flow cytometry and polymerase chain reaction have emerged as the most promising methods for detecting submicrospopic levels of leukemia. Flowcytometric detection of MRD is based on the identification of immunophenotypic combinations expressed on leukemic cells but not on normal hematopoietic cells. It affords the detection of one leukemic cell among 10,000 normal bone marrow cells, and can be currently applied to at least two thirds of all patients with acute leukemia. Prospective studies in large series of patients have demonstrated a strong correlation between MRD levels during clinical remission and treatment outcome. Therefore, MRD assays can be reliably used to assess early response to treatment and predict relapse. In this review, we discuss methodologic aspects and clinical results of flowcytometric detection of MRD in patients with acute leukemia.     

Fractionated total body irradiation and high dose cyclophosphamide: a preparative regimen for bone marrow transplantation for patients with hematologic malignancies in first complete remission

We treated 73 patients with hematologic malignancies in first complete remission (acute lymphoblastic leukemia = 23 patients; acute non-lymphoblastic leukemia = 25 patients; chronic myelogenous leukemia in first chronic phase = 20 patients, and high grade lymphoma = five patients) with a uniform preparative regimen consisting of fractionated total body irradiation (1,320 cGy) and high dose cyclophosphamide (100 mg/kg), followed by allogeneic bone marrow transplantation. By radiation dosimetry we demonstrated that the calculated doses were delivered accurately and reproducibly. Actuarial survival rates (+/- SEM) in complete remission were as follows: Acute lymphoblastic leukemia = 74 +/- 9%; acute nonlymphoblastic leukemia = 50 +/- 11%; and chronic myelogenous leukemia = 55 +/- 11%. Actuarial relapse rates for these three diagnoses were 19 +/- 9%, 17 +/- 11%, and 0% respectively. Three of the five lymphoma patients are alive in complete remission at 22+, 28+, and 54+ months. Overall probability of survival for the 73 patients was 59 +/- 7%. Interstitial pneumonia, usually associated with cytomegalovirus infection and graft-versus-host disease, and relapse of the underlying malignancy were the major causes of death.     

难治性急性白血病研究现状与进展

难治性急性白血病治疗反应差,诱导缓解率低,复发率高,生存期短,因而是白血病治疗中的难题。本文从难治性急性白血病诊断标准与免疫学、细胞遗传学及分子生物学特征,多药耐药与难治性白血病,难治性急性白血病治疗现状以及治疗展望五大方面阐述了难治性急性白血病研究现状与进展。基础与初步临床研究显示中药配合化疗能够提高难治性急性白血病围化疗期临床缓解率。认为中药在提高难治性白血病临床疗效方面具有潜在临床应用前景和开发的商业价值,值得进行深入研究。     

CFU-gm colony formation of peripheral blood and bone marrow in adult acute leukemia at presentation, during remission, and at relapse

Granulocyte/macrophage colony-forming unit (CFU-gm) formation was studied simultaneously in bone marrow and peripheral blood of 52 previously untreated adult patients with acute non-lymphocytic (ANLL) and 36 with acute lymphoblastic leukemia (ALL). They were followed during induction therapy at monthly intervals while in remission and in 19 ANLL and 22 ALL cases, until relapse. Patients showing a decreased colony number in the marrow but normal or increased colony numbers in the peripheral blood had a high probability of entering remission. Non-responding patients displayed an opposite pattern. The higher the degree of marrow repopulation with granulocytic progenitor cells after induction treatment, the longer remission duration and survival for ANLL patients and the longer survival for ALL patients. CFU-gm formation returned to normal in the early stages of complete remission, but then declined progressively. At ANLL and ALL relapse, colony growth was reduced markedly while cluster formation remained normal. The number of marrow colonies and clusters in ANLL were significantly higher at first and second relapse compared to the growth pattern at first presentation. A similar trend had been observed in ALL, suggesting a selection advantage.     

An analytical biomarker for treatment of patients with recurrent B-ALL after remission induced by infusion of anti-CD19 chimeric antigen receptor T (CAR-T) cells

Anti-CD19 chimeric antigen receptor-modified T (CAR-T-19) cells have emerged as a powerful targeted immunotherapy for B-cell lineage acute lymphoblastic leukemia with a remarkable clinical response in recent trials. Nonetheless, few data are available on the subsequent clinical monitoring and treatment of the patients, especially those with disease recurrence after CAR-T-19 cell infusion. Here, we analyzed three patients who survived after our phase I clinical trial and who were studied by means of biomarkers reflecting persistence of CAR-T-19 cells in vivo and predictive factors directing further treatment. One patient achieved 9-week sustained complete remission and subsequently received an allogeneic hematopoietic stem cell transplant. Another patient who showed relapse after 20 weeks without detectable leukemia in the cerebrospinal fluid after CAR-T-19 cell treatment was able to achieve a morphological remission under the influence of stand-alone low-dose chemotherapeutic agents. The third patient gradually developed extensive extramedullary involvement in tissues with scarce immune- cell infiltration during a long period of hematopoietic remission after CAR-T-19 cell therapy. Long-term and discontinuous increases in serum cytokines (mainly interleukin 6 and C-reactive protein) were identified in two patients (Nos. 1 and 6) even though only a low copy number of CAR molecules could be detected in their peripheral blood. This finding was suggestive of persistent functional activity of CAR-T-19 cells. Combined analyses of laboratory biomarkers with their clinical manifestations before and after salvage treatment showed that the persistent immunosurveillance mediated by CAR-T-19 cells would inevitably potentiate the leukemia-killing effectiveness of subsequent chemotherapy in patients who showed relapse after CAR-T-19-induced remission.     

Poor prognosis of acute lymphoblastic leukemia with translocation (1;19) in childhood: potential interest of allogeneic bone marrow transplantation

We report a new case of childhood acute lymphoblastic leukemia with translocation (1;19). At the time of diagnosis, the only adverse prognosis factor was the existence of this translocation. Under conventional chemotherapy, the girl experienced early marrow relapse (duration of first remission was 2 months). She received allogeneic bone marrow transplantation during the second remission and is alive in continuous complete remission 20 months after transplant. Several earlier reports have suggested that children with the (1;19) have a poor prognosis; If this poor response to conventional therapy is confirmed, an allogeneic bone marrow transplantation should be considered during the first remission.     

Late marrow recurrences in childhood acute lymphoblastic leukaemia.

Thirty children with acute lymphoblastic leukemia had a recurrence in the bone marrow after treatment was stopped electively. A second haematological remission was achieved in 27 (90%), and the median duration of remission was shortest (six months) in those relapsing within six months of stopping treatment. Four of six children relapsing over one year after stopping treatment remained in second haematological remission. Leukaemic infiltration of the central nervous system developed in four patients remaining in marrow remission. It is concluded that conventional chemotherapy is unlikely to be effective in children with acute lymphoblastic leukaemia who relapse soon after stopping treatment, that "reprophylaxis" of the central nervous system probably with long-term intrathecal chemotherapy is essential, and that some patients relapsing after prolonged unmaintained remission may achieve long-term leukaemia-free survival.     

The Management of Acute Leukemia

The therapy of acute leukemia has improved rapidly in the last two decades. Using available therapeutic agents, complete clinical and hematological remission can be achieved regularly in children with acute lymphocytic leukemia. The choice of chemotherapeutic agent, management of complications of hemorrhage and infection, and recognition of prognostic factors are important for the induction of a hematological remission. While patients in complete hematological remission are free of evidence of disease they still have residual leukemic cells, but in our present state of knowledge and with available techniques, we are unable to detect these. For this reason it is important to treat patients while in remission. The importance of dosage schedule for remission maintenance chemotherapy is stressed.In patients studied to date, regardless of the treatment used, the disease has recurred eventually. Available therapeutic agents are highly effective and highly selective, but they still fall short of providing ideal control of the disease. The continuing search for new chemotherapeutic agents is aided by the knowledge gained and techniques developed with current agents.     

Acute myeloid leukemia: treatment of adults under 60 years

Current chemotherapy with advanced supportive care will enable 75-80% of acute myeloid leukemia patients aged 60 years or under to enter complete remission. Several regimens achieve broadly similar results. For patients who enter complete remission, the overall relapse risk is now 45-50%, but this is highly variable and is primarily determined by the biology of the disease. Cytogenetics are strongly influential in response to induction and consolidation with t(15:17), t(8:21) and inv(16) either occurring alone or with additional abnormalities having a relapse risk of about 30% and complex changes, abnormal 3q or abnormalities of chromosomes 5 and 7 resulting in a lower remission rate and a rapid relapse cumulating to 80%. FLT3 mutations occur in 25% of patients and are an independent predictor of relapse and, when combined with cytogenetics, adversely influence the prognosis in each cytogenetic risk group. Recent prospective collaborative group trials have endeavored to evaluate allogeneic and autologous bone marrow transplant against or in addition to consolidation chemotherapy. Suboptimal treatment delivery emerged as a problem. When the results were reported on an intention-to-treat basis, no overall survival advantage was consistently seen for either type of transplant. However, a significant reduction in risk of relapse was usually seen overall and within risk groups. Analysis within risk groups suggests that transplant is not indicated in good risk disease and continues to require evaluation in standard or poor risk patients. It is probable that traditional dose intensification has now reached its limits of tolerability, so new approaches will be required for further progress to be made. Modulation of chemoresistance mechanisms or immunologically directed chemotherapy represent immediate prospects for clinical study.     

Prognostic value of the reaction to steroids in the treatment of acute lymphoblastic leukemia in children]

Relationship between the result of therapy in 48 cases of the acute lymphoblastic leukemia in childhood and character of response to corticosteroids, classified according to BMF group, has been assessed. Follow up period ranged from 13 to 75 months (mean 36 months, median 39 months). In was found, that the probability of survival free from any events, probability of complete remission persistence, and probability of survival after diagnosis have been statistically significantly higher in the group of patients with positive response to corticosteroids in comparison with patients non-responding to these agents. However, there was no significant difference in the number of recurrencies with the involvement of CNS. Authors share the opinion that their results confirm an opinion of Riehm et al. that the response to corticosteroids is of prognostic value in the acute lymphoblastic leukemia in childhood.     

Adoptive transfer of T cells transduced with a chimeric antigen receptor to treat relapsed or refractory acute leukemia: efficacy and feasibility of immunotherapy approaches

Treatment outcomes of acute leukemia(AL) have not improved over the past several decades and relapse rates remain high despite the availability of aggressive therapies. Conventional relapsed leukemia treatment includes second allogeneic hematopoietic stem cell transplantation(allo-HSCT) and donor lymphocyte infusion(DLI), which in most cases mediate, at best, a modest graft-versus-leukemia effect, although their clinical efficacy is still limited. Although allo-HSCT following myeloablative conditioning is a curative treatment option for younger patients with acute myeloid leukemia(AML) in a first complete remission(CR), allo-HSCT as a clinical treatment is usually limited because of treatment-related toxicity. The overall DLI remission rate is only 15%–42% and 2-year overall survival(OS) is approximately 15%–20%, with a high(40%–60%) incidence of DLI-related graft-versus-host disease(GVHD). Therefore, development of new, targeted treatment strategies for relapsed and refractory AL patients is ongoing. Adoptive transfer of T cells with genetically engineered chimeric antigen receptors(CARs) is an encouraging approach for treating hematological malignancies. These T cells are capable of selectively recognizing tumor-associated antigens and may overcome many limitations of conventional therapies, inducing remission in patients with chemotherapy-refractory or relapsed AL. In this review, we aimed to highlight the current understanding of this promising treatment modality, discussing its adverse effects and efficacy.     

预激方案HAG及CAG治疗老年初治急性髓性白血病的对比研究

目的:评价含粒细胞集落刺激因子(granulocyte colony-stimulating-factor,G-CSF)的预激HAG及CAG方案治疗老年初治急性髓性白血病(AML)的疗效及不良反应,并对两个方案的疗效及不良反应进行比较。方法:65例老年初治AML分为HAG预激治疗组及CAG预激方案治疗组,31例患者予以HAG预激方案治疗,34例患者予以预激方案CAG方案治疗,所有患者在第1疗程后间歇14d左右进行第2个疗程。结果:HAG预激方案治疗组的完全缓解率为74.2%,总有效率为83.8%;CAG预激治疗组完全缓解(CR)率为67.6%,总有效率达为82.4%。两治疗组的血液系统不良反应及非血液系统毒性不良反应比较无显著性差异。结论:HAG预激方案化疗强度温和、敏感性好、CR率及有效率高、毒副作用小;与CAG预激治疗比较,HAG预激方案可以取的相似的疗效及较少的不良反应,在老年初治AML患者值得推荐应用。     

Vincristine and Prednisone for the Induction of Remissions in Acute Childhood Leukaemia

A total of 65 children with acute lymphoblastic leukaemia and seven with other types of acute leukaemia received treatment with a combination of vincristine and prednisone. In all 122 courses of treatment were given. Of 22 patients with acute lymphoblastic leukaemia who received this as their first treatment, all achieved complete remission. The complete remission rates were 82% for patients with acute lymphoblastic leukaemia in their first relapse, 63% in the second relapse, and much lower in subsequent relapses and in the patients with other types of acute leukaemia. Alopecia and gastrointestinal and neuromuscular toxicity occurred respectively in 51%, 29%, and 21% of instances, only the last of these side-effects of vincristine being dose-related. Most of the complete remissions were obtained with a total dose of vincristine which carried only a low risk of neurotoxicity.     

Flow cytometric determination of atypical antigen expression in acute leukemia for the study of minimal residual disease.

The aim of this study was to investigate to which extent acute leukemias could be monitored for residual disease by using atypical antigen combinations as leukemia-related markers. Atypical antigenic features were determined by double color flow cytometry and included coexpression of lymphoid and myeloid related antigens, unphysiological coexpression of immature and mature antigens, and lack of an antigen that is normally expressed during maturation. Atypical immunophenotypes were detected in 35 of 68 patients with AML (51.5%) and 15 of 24 patients with ALL (62.5%). When 12 patients with leukemia-associated markers were again analyzed at relapse, the relevant antigen combinations were retained in 11 of them. The sensitivity of this two color flow cytometric assay as determined in dilution experiments was 1 in 10(3) to 10(4) cells. Follow-up studies of bone marrow samples revealed that, after induction chemotherapy cells with leukemia-associated markers were detectable in several patients at a frequency of 0.5 to 4%, but only patients in whom the cells with atypical antigens never disappeared suffered from relapse. In contrast, patients who became negative for the atypical cells remained in complete remission (median remission duration after the first negative bone marrow assessment by flow cytometry 52 weeks, range 20-102). We conclude that atypical antigen combinations, which are present in a meaningful number of acute leukemias, are a valuable means of monitoring acute leukemia patients during follow-up. This flow cytometric approach can complement other strategies to get a more accurate definition of remission in acute leukemia.     

缓解与未缓解髓系白血病干细胞表面抗原CD34＋CD123＋表达差异研究

目的：探索缓解与未缓解急性髓系白血病干细胞表面抗原表达差异,为判定化疗疗效及其预后提供依据。方法：按照急性白血病诊断标准,根据患者入院时骨髓白血病细胞数量多少分成临床缓解与未缓解两组,以流式细胞仪分别检测骨髓中白血病干细胞表面相关抗原表达情况,比较二者之间差异。其中经标准化疗方案治疗结束后,通过复查骨髓象判定疗效并比较化疗前后白血病干细胞表面相关抗原表达变化。结果：与缓解的急性髓系白血病患者骨髓白血病干细胞相关抗原表达值相比,未缓解的患者骨髓白血病干细胞表面相关抗原表达明显升高,差异具有统计学意义（P〈0．05,0．001）;未缓解的患者经标准方案化疗后骨髓虽然已经获得完全缓解,但依然具有白血病干细胞表面抗原高表达,提示这部分患者依然有复发的可能性。结论：急性髓系白血病患者的白血病干细胞相关抗原表达值升高是急性白血病复发难治的根源之一。     

缓解与未缓解髓系白血病干细胞表面抗原CD34~+CD123~+表达差异研究

目的:探索缓解与未缓解急性髓系白血病干细胞表面抗原表达差异,为判定化疗疗效及其预后提供依据。方法:按照急性白血病诊断标准,根据患者入院时骨髓白血病细胞数量多少分成临床缓解与未缓解两组,以流式细胞仪分别检测骨髓中白血病干细胞表面相关抗原表达情况,比较二者之间差异。其中经标准化疗方案治疗结束后,通过复查骨髓象判定疗效并比较化疗前后白血病干细胞表面相关抗原表达变化。结果:与缓解的急性髓系白血病患者骨髓白血病干细胞相关抗原表达值相比,未缓解的患者骨髓白血病干细胞表面相关抗原表达明显升高,差异具有统计学意义(P0.05,0.001);未缓解的患者经标准方案化疗后骨髓虽然已经获得完全缓解,但依然具有白血病干细胞表面抗原高表达,提示这部分患者依然有复发的可能性。结论:急性髓系白血病患者的白血病干细胞相关抗原表达值升高是急性白血病复发难治的根源之一。     

A test with dexamethasone in acute leukemia.

A simple test with dexamethasone (DMS) in acute leukemia (AL) is described. In peripheral blood, blast cell count is determined before 8 mg DMS are given intravenously, and 2, 4 and 6 hours afterwards. The result is expressed as the lowest blast cell count after DMS in percentage of the initial value. This test was performed on 51 adult patients with AL. The results were correlated with the morphological and cytochemical classification. Only patients with clearly classified AL were evaluated. A statistically significant difference in blast cell response between acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML) was observed. In 12 out of 16 cases of ALL, but in only 1 out of 19 cases of AML, the blast cell count decreased to 50 percent or less of the initial value. The results of the test were further correlated with the results of treatment. In 11 out of 12 patients with ALL, who showed a response to DMS, glucocorticoids were included in the treatment regimen. A complete remission was obtained in 7 out of 10 patients who were treated for the first time. In the remaining 4 patients with a poor response to DMS, a complete remission after the first treatment was obtained in only one case. The number of patients examined is to small for final conclusions on the value of this test for a discrimination between glucocorticoid-responsive and non-responsive cases of AL. Nevertheless, these preliminary results indicate that further trials seem to be warranted.     

Remission induction and remission maintenance in adult acute nonlymphocytic leukemia employing a modified cytostatic (COAP) regimen.

Thirty adult patients suffering from acute nonlymphocytic leukemia (ANLL) were treated according to a modified COAP regimen. Vincristine, cyclophosphamide, and prednisone were given by push injection, while cytosine arabinoside was infused over periods of 8 h. Nineteen patients (63%) achieved complete remission. Remission maintenance therapy consisted of 6-mercaptopurine daily and methotrexate twice weekly. Later in the study, COAP consolidation and reinduction was added, which improved the median duration of complete remission from 7 to 24 months. Comparison of the results with the literature shows that the modified COAP regimen is one of the most effective treatment schedules for adult ANLL.     

Stem cell transplantation in pediatric leukemia and myelodysplasia: state of the art and current challenges

The role of stem cell transplantation in the treatment of leukemia and myelodysplasia (MDS) in children has changed over the past decade. In pediatric acute lymphoblastic leukemia (ALL), the overall cure-rate is high with conventional chemotherapy. However, selected patients with a high-risk of relapse are often treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first remission (CR1). Patients with a bone-marrow relapse who attain a second remission frequently receive HSCT. High minimal residual disease (MRD) levels directly prior to HSCT determines the relapse risk. Therefore, MRD positive patients are eligible for more experimental approaches such as intensified or experimental chemotherapy pre-HSCT, as well as immune modulation post-HSCT. In pediatric acute myeloid leukemia (AML) the role of allo-HSCT in CR1 is declining, due to better outcome with modern multi-agent chemotherapy. In relapsed AML patients, allo-HSCT still seems indispensable. Targeted therapy may change the role of HSCT, in particular in chronic myeloid leukemia, where the role of allografting is changing in the imatinib era. In MDS, patients are usually transplanted immediately without prior cytoreduction. New developments in HSCT, such as the role of alternative conditioning regimens, and innovative stem cell sources such as peripheral blood and cord blood, will also be addressed.     

Secondary leukemia after severe aplastic anemia

We describe a patient with acute myeloid leukemia (AML) occurring 5 years after successful treatment of severe aplastic anemia (SAA) with antilymphocyte globulin (ALG). Four years after ALG, SAA had relapsed. A second remission of SAA was achieved, but was followed by transformation of the myelodysplastic syndrome into overt AML. After 2 courses of high-dose cytosine arabinoside and VP-16 complete remission occurred. This case shows that chemotherapy of secondary leukemia after SAA is feasible, and that ex-aplastic bone marrow is capable of complete recovery from chemotherapy-induced aplasia. Morphological anomalies of bone marrow noticed early during remission of SAA might predict a late transformation in leukemia.