Jan J. Cornelissen

Human fetal lymphoid tissue–inducer cells are interleukin 17–producing precursors to RORC + CD127 + natural killer–like cells

The human body contains over 500 individual lymph nodes, yet the biology of their formation is poorly understood. Here we identify human lymphoid tissue–inducer cells (LTi cells) as lineage-negative RORC+ CD127+ cells with the functional ability to interact with mesenchymal cells through lymphotoxin and tumor necrosis factor. Human LTi cells were committed natural killer (NK) cell precursors that produced interleukin 17 (IL-17) and IL-22. In vitro, LTi cells gave rise to RORC+ CD127+ NK cells that retained the ability to produce IL-17 and IL-22. Postnatally, similar populations of LTi cell–like cells and RORC+ CD127+ NK cells were present in tonsils, and both secreted IL-17 and IL-22 but no interferon-γ. Our data indicate that lymph node organogenesis is controlled by an NK cell precursor population with adaptive immune features and demonstrate a previously unappreciated link between the innate and adaptive immune systems.

Autologous peripheral blood stem cell transplantation for acute myeloid leukemia.

We report the results of a prospective, randomized phase 3 trial evaluating autologous peripheral blood stem cell transplantation (ASCT) versus intensive consolidation chemotherapy in newly diagnosed AML patients in complete remission (CR1). Patients with AML (16-60 years) in CR1 after 2 cycles of intensive chemotherapy and not eligible for allogeneic SCT were randomized between intensive chemotherapy with etoposide and mitoxantrone or ASCT ater high-dose cyclophosphamide and busulfan. Of patients randomized (chemotherapy, n = 259; ASCT, n = 258), more than 90% received their assigned treatment. The 2 groups were comparable with regard to prognostic factors. The ASCT group showed a markedly reduced relapse rate (58% vs 70%, P = .02) and better relapse-free survival at 5 years (38% vs 29%, P = .065, hazard ratio = 0.82; 95% confidence interval, 0.66-1.1) with nonrelapse mortality of 4% versus 1% in the chemotherapy arm (P = .02). Overall survival was similar (44% vs 41% at 5 years, P = .86) because of more opportunities for salvage with second-line chemotherapy and stem cell transplantation in patients relapsing on the chemotherapy arm. This large study shows a relapse advantage for ASCT as postremission therapy but similar survival because more relapsing patients on the chemotherapy arm were salvaged with a late transplantation for relapse. This trial is registered at www.trialregister.nl as #NTR230 and #NTR291.

Hematopoietic stem cell transplantation for patients with AML in first complete remission.

Postremission therapy in patients with acute myeloid leukemia (AML) may consist of continuing chemotherapy or transplantation using either autologous or allogeneic stem cells. Patients with favorable subtypes of AML generally receive chemotherapeutic consolidation, although recent studies have also suggested favorable outcome after hematopoietic stem cell transplantation (HSCT). Although allogeneic HSCT (alloHSCT) is considered the preferred type of postremission therapy in poor- and very-poor-risk AML, the place of alloHSCT in intermediate-risk AML is being debated, and autologous HSCT is considered a valuable alternative that may be preferred in patients without minimal residual disease after induction chemotherapy. Here, we review postremission transplantation strategies using either autologous or allogeneic stem cells. Recent developments in the field of alternative donors, including cord blood and haploidentical donors, are highlighted, and we discuss reduced-intensity alloHSCT in older AML recipients who represent the predominant category of patients with AML who have a high risk of relapse in first remission.

Acute myeloid leukaemia

Acute myeloid leukaemia (AML) is a disorder characterized by a clonal proliferation derived from primitive haematopoietic stem cells or progenitor cells. Abnormal differentiation of myeloid cells results in a high level of immature malignant cells and fewer differentiated red blood cells, platelets and white blood cells. The disease occurs at all ages, but predominantly occurs in older people (>60 years of age). AML typically presents with a rapid onset of symptoms that are attributable to bone marrow failure and may be fatal within weeks or months when left untreated. The genomic landscape of AML has been determined and genetic instability is infrequent with a relatively small number of driver mutations. Mutations in genes involved in epigenetic regulation are common and are early events in leukaemogenesis. The subclassification of AML has been dependent on the morphology and cytogenetics of blood and bone marrow cells, but specific mutational analysis is now being incorporated. Improvements in treatment in younger patients over the past 35 years has largely been due to dose escalation and better supportive care. Allogeneic haematopoietic stem cell transplantation may be used to consolidate remission in those patients who are deemed to be at high risk of relapse. A plethora of new agents — including those targeted at specific biochemical pathways and immunotherapeutic approaches — are now in trial based on improved understanding of disease pathophysiology. These advances provide good grounds for optimism, although mortality remains high especially in older patients.

Cost analysis of HLA-identical sibling and voluntary unrelated allogeneic bone marrow and peripheral blood stem cell transplantation in adults with acute myelocytic leukaemia or acute lymphoblastic leukaemia

Allogeneic stem cell transplantation (SCT) is one of the most expensive medical procedures. However, only a few studies to date have addressed the costs of HLA-identical sibling transplantation and only one study has reported costs of unrelated transplantation. No recent cost analysis with a proper follow-up period and donor identification expenses is available on related or voluntary matched unrelated donor (MUD) SCT for adult AML or ALL. Therefore, we calculated direct medical (hospital) costs based on 97 adults who underwent HLA-identical sibling bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT), and patients who received a graft from a MUD between 1994 and 1999. The average costs per transplanted patient were [euro ] 98 334 (BMT), [euro ]151 754 (MUD), and [euro ]98 977 (PBSCT), including donor identification expenses, 2 years follow-up and costs of patients who were not transplanted after they had been planned to receive an allograft. The majority of these costs was generated during the hospitalisation for graft infusion. For MUD transplants, nearly one-third of these costs was spent on the search for a suitable donor. For patients who were alive after 2 years, cumulative expenses were calculated to be [euro ]103 509 (BMT), [euro ]173 587 (MUD), and [euro ]105 906 (PBSCT).

Allogeneic Stem Cell Transplantation in Acute Myeloid Leukemia in First or Subsequent Remission: Weighing Prognostic Markers Predicting Relapse and Risk Factors for Non-relapse Mortality

Allogeneic hematopoietic stem cell transplantation (alloSCT) has been established as a powerful treatment modality in acute myeloid leukemia (AML) in first or subsequent remission. Although alloSCT effectively prevents relapse, non-relapse mortality (NRM) associated with the procedure may counterbalance that beneficial effect. As a result, alloSCT generally is restricted to patients with a relatively high risk of relapse and a relatively low risk for NRM. Here, we review recent studies that evaluated specific risk factors that, on the one hand, identified categories of AML patients with a higher risk of relapse and, on the other hand, identified patients with an increased risk for NRM. We discuss how these recent developments may affect our decision-making about whether and when to proceed to alloSCT.

Rapid complete cytogenetic remission after upfront dasatinib monotherapy in a patient with a NUP214-ABL1-positive T-cell acute lymphoblastic leukemia

Rapid complete cytogenetic remission after upfront dasatinib monotherapy in a patient with a NUP214-ABL1-positive T-cell acute lymphoblastic leukemia

Impact of ATG-containing reduced-intensity conditioning after single- or double-unit allogeneic cord blood transplantation.

We analyzed 661 adult patients who underwent single-unit (n = 226) or double-unit (n = 435) unrelated cord blood transplantation (UCBT) following a reduced-intensity conditioning (RIC) consisting of low-dose total body irradiation (TBI), cyclophosphamide, and fludarabine (Cy/Flu/TBI200). Eighty-two patients received rabbit antithymocyte globulin (ATG) as part of the conditioning regimen (ATG group), whereas 579 did not (non-ATG group). Median age at UCBT was 54 years, and diagnoses were acute leukemias (51%), myelodysplastic syndrome/myeloproliferative neoplasm (19%), and lymphoproliferative diseases (30%). Forty-four percent of patients were transplanted with advanced disease. All patients received ≥4 antigens HLA-matched UCBT. Median number of collected total nucleated cells was 4.4 × 10(7)/kg. In the ATG group, on 64 evaluable patients, ATG was discontinued 1 (n = 27), 2 (n = 20), or > 2 days before the graft infusion (n = 17). In multivariate analyses, the use of ATG was associated with decreased incidence of acute graft-versus-host disease (hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.17-0.55; P < .0001), higher incidence of nonrelapse mortality (HR, 1.68; 95% CI, 1.16-2.43; P = .0009), and decreased overall survival (HR, 1.69; 95% CI, 1.19-2.415; P = .003). Collectively, our results suggest that the use of ATG could be detrimental, especially if given too close to graft infusion in adults undergoing UCBT following Cy/Flu/TBI200 regimen.

Post-remission treatment with allogeneic stem cell transplantation in patients aged 60 years and older with acute myeloid leukaemia: a time-dependent analysis

BACKGROUNDnAcute myeloid leukaemia mainly affects elderly people, with a median age at diagnosis of around 70 years. Although about 50-60% of patients enter first complete remission upon intensive induction chemotherapy, relapse remains high and overall outcomes are disappointing. Therefore, effective post-remission therapy is urgently needed. Although often no post-remission therapy is given to elderly patients, it might include chemotherapy or allogeneic haemopoietic stem cell transplantation (HSCT) following reduced-intensity conditioning. We aimed to assess the comparative value of allogeneic HSCT with other approaches, including no post-remission therapy, in patients with acute myeloid leukaemia aged 60 years and older.nnnMETHODSnFor this time-dependent analysis, we used the results from four successive prospective HOVON-SAKK acute myeloid leukaemia trials. Between May 3, 2001, and Feb 5, 2010, a total of 1155 patients aged 60 years and older were entered into these trials, of whom 640 obtained a first complete remission after induction chemotherapy and were included in the analysis. Post-remission therapy consisted of allogeneic HSCT following reduced-intensity conditioning (n=97), gemtuzumab ozogamicin (n=110), chemotherapy (n=44), autologous HSCT (n=23), or no further treatment (n=366). Reduced-intensity conditioning regimens consisted of fludarabine combined with 2 Gy of total body irradiation (n=71), fludarabine with busulfan (n=10), or other regimens (n=16). A time-dependent analysis was done, in which allogeneic HSCT was compared with other types of post-remission therapy. The primary endpoint of the study was 5-year overall survival for all treatment groups, analysed by a time-dependent analysis.nnnFINDINGSn5-year overall survival was 35% (95% CI 25-44) for patients who received an allogeneic HSCT, 21% (17-26) for those who received no additional post-remission therapy, and 26% (19-33) for patients who received either additional chemotherapy or autologous HSCT. Overall survival at 5 years was strongly affected by the European LeukemiaNET acute myeloid leukaemia risk score, with patients in the favourable risk group (n=65) having better 5-year overall survival (56% [95% CI 43-67]) than those with intermediate-risk (n=131; 23% [19-27]) or adverse-risk (n=444; 13% [8-20]) acute myeloid leukaemia. Multivariable analysis with allogeneic HSCT as a time-dependent variable showed that allogeneic HSCT was associated with better 5-year overall survival (HR 0·71 [95% CI 0·53-0·95], p=0·017) compared with non-allogeneic HSCT post-remission therapies or no post-remission therapy, especially in patients with intermediate-risk (0·82 [0·58-1·15]) or adverse-risk (0.39 [0·21-0·73]) acute myeloid leukaemia.nnnINTERPRETATIONnCollectively, the results from these four trials suggest that allogeneic HSCT might be the preferred treatment approach in patients 60 years of age and older with intermediate-risk and adverse-risk acute myeloid leukaemia in first complete remission, but the comparative value should ideally be shown in a prospective randomised study.nnnFUNDINGnNone.

Imatinib discontinuation in chronic phase myeloid leukaemia patients in sustained complete molecular response: A randomised trial of the Dutch-Belgian Cooperative Trial for Haemato-Oncology (HOVON)

BACKGROUNDnTyrosine kinase inhibitors treatment in responding chronic myeloid leukaemia (CML) patients is generally continued indefinitely. In this randomised phase II trial, we investigated whether CML patients in molecular response(4.5) (MR(4.5), quantitative reverse-transcription polymerase chain reaction (RQ-PCR)) after previous combination therapy with imatinib and cytarabine may discontinue imatinib treatment safely.nnnPATIENTS AND METHODSnThirty-three patients from the HOVON 51 study with an MR(4.5) for at least 2 years who were still on imatinib treatment were randomised between continuation of imatinib (arm A, n=18) or discontinuation of imatinib (arm B, n=15).nnnRESULTSnAfter a median follow up of 36 months since randomisation, 3 patients (17%) in arm A and 10 patients (67%) in arm B had a molecular relapse. All 3 relapsing patients in arm A had also stopped imatinib after randomisation. All but one relapsing patient relapsed within 7 months after discontinuation of imatinib. The molecular relapse rate at 12 and 24 months after randomisation was 0% and 6% (arm A) and 53% and 67% (arm B) respectively. As-treated analysis revealed 56% and 61% relapses at 1 and 2 years since cessation in patients who discontinued imatinib, in contrast to 0% of patients who continued imatinib. All evaluable patients remained sensitive to imatinib after reinitiation and regained a molecular response.nnnCONCLUSIONnOur data suggest that discontinuation of imatinib is safe in patients with durable MR(4.5).