High multiplex analysis of the immune microenvironment in bone marrow trephine samples using GeoMX™ digital spatial profiling.

Background: To date, studies into the bone marrow (BM) immune microenvironment have been limited due to reliance on the analysis of BM aspirates in which the microenvironmental context is lost. GeoMX™ digital spatial profiling (DSP) is a new technique developed for the analysis of formalin-fixed paraffin-embedded tissue samples which allows high multiplex analysis of protein expression in multiple user-defined regions within a tissue section. We examined the applicability of this technique to the analysis of protein expression in diagnostic BM trephine samples. Materials and methods: Archival BM trephines were obtained from patient groups (normal, myelodysplasia and aplastic anaemia). Regions of interest in each section were identified by dual CD3+/CD45+ immunohistochemistry staining to identify immune infiltrates, and DSP was applied. Results: Due to variability in cell number within regions of interest and differing cellular composition of the BM trephines, raw protein expression counts were normalised by internal controls and nuclei count to determine the expression level of each protein within each region of interest. In heat map analysis using Spearman's rank correlation, aplastic anaemia samples clustered away from both normal and myelodysplasia samples, demonstrating significant differences in their BM immunology. Conclusions: GeoMX™ DSP is an innovative new technique that, for the first time, allows the analysis of archival BM trephines at an unprecedented level of detail. It will allow investigations in large cohorts of patients with haematological malignancies to identify new biomarkers, new mechanisms of disease pathogenesis and new drug targets.

Chimeric antigen receptor T cells form nonclassical and potent immune synapses driving rapid cytotoxicity.

Chimeric antigen receptor T (CAR-T) cells are effective serial killers with a faster off-rate from dying tumor cells than CAR-T cells binding target cells through their T cell receptor (TCR). Here we explored the functional consequences of CAR-mediated signaling using a dual-specific CAR-T cell, where the same cell was triggered via TCR (tcrCTL) or CAR (carCTL). The carCTL immune synapse lacked distinct LFA-1 adhesion rings and was less reliant on LFA to form stable conjugates with target cells. carCTL receptors associated with the synapse were found to be disrupted and formed a convoluted multifocal pattern of Lck microclusters. Both proximal and distal receptor signaling pathways were induced more rapidly and subsequently decreased more rapidly in carCTL than in tcrCTL. The functional consequence of this rapid signaling in carCTL cells included faster lytic granule recruitment to the immune synapse, correlating with faster detachment of the CTL from the target cell. This study provides a mechanism for how CAR-T cells can debulk large tumor burden quickly and may contribute to further refinement of CAR design for enhancing the quality of signaling and programming of the T cell.

Nephrotic syndrome as a complication of chronic graft-versus-host disease after allogeneic haemopoietic stem cell transplantation.

Nephrotic syndrome (NS) is a rare complication following allogeneic haemopoietic stem cell transplantation (allo-HSCT), with limited current understanding of its pathogenesis. Here, we describe four cases of NS following allo-HSCT diagnosed at our institutions to identify key clinical and pathological features. In addition, a PubMed search was performed to identify existing reports that were pooled together with our cases for analysis. NS occurred as a late complication following allo-HSCT, with median onset 19.5 months after transplant (range: 3.9-84 months). The most common histopathology observed was membranous nephropathy; however, cases of minimal change disease have also been reported. There is a high incidence of prior extra-renal graft-versus-host disease (GvHD), with all four of our cases and 82% of published cases having prior GvHD. Glucocorticosteroids are the most common treatment, with variable degrees of response. Responses to immunosuppression with calcineurin inhibitors and rituximab have been described in steroid-refractory cases.

The impact of HLA class I and EBV latency-II antigen-specific CD8(+) T cells on the pathogenesis of EBV(+) Hodgkin lymphoma.

In 40% of cases of classical Hodgkin lymphoma (cHL), Epstein-Barr virus (EBV) latency-II antigens [EBV nuclear antigen 1 (EBNA1)/latent membrane protein (LMP)1/LMP2A] are present (EBV(+) cHL) in the malignant cells and antigen presentation is intact. Previous studies have shown consistently that HLA-A*02 is protective in EBV(+) cHL, yet its role in disease pathogenesis is unknown. To explore the basis for this observation, gene expression was assessed in 33 cHL nodes. Interestingly, CD8 and LMP2A expression were correlated strongly and, for a given LMP2A level, CD8 was elevated markedly in HLA-A*02(-) versus HLA-A*02(+) EBV(+) cHL patients, suggesting that LMP2A-specific CD8(+) T cell anti-tumoral immunity may be relatively ineffective in HLA-A*02(-) EBV(+) cHL. To ascertain the impact of HLA class I on EBV latency antigen-specific immunodominance, we used a stepwise functional T cell approach. In newly diagnosed EBV(+) cHL, the magnitude of ex-vivo LMP1/2A-specific CD8(+) T cell responses was elevated in HLA-A*02(+) patients. Furthermore, in a controlled in-vitro assay, LMP2A-specific CD8(+) T cells from healthy HLA-A*02 heterozygotes expanded to a greater extent with HLA-A*02-restricted compared to non-HLA-A*02-restricted cell lines. In an extensive analysis of HLA class I-restricted immunity, immunodominant EBNA3A/3B/3C-specific CD8(+) T cell responses were stimulated by numerous HLA class I molecules, whereas the subdominant LMP1/2A-specific responses were confined largely to HLA-A*02. Our results demonstrate that HLA-A*02 mediates a modest, but none the less stronger, EBV-specific CD8(+) T cell response than non-HLA-A*02 alleles, an effect confined to EBV latency-II antigens. Thus, the protective effect of HLA-A*02 against EBV(+) cHL is not a surrogate association, but reflects the impact of HLA class I on EBV latency-II antigen-specific CD8(+) T cell hierarchies.

Allogeneic hematopoietic cell transplant for AML: no impact of pre-transplant extramedullary disease on outcome.

The impact of extramedullary disease (EMD) in AML on the outcomes of allogeneic hematopoietic cell transplantation (alloHCT) is unknown. Using data from the Center for International Blood and Marrow Transplant Research, we compared the outcomes of patients who had EMD of AML at any time before transplant, with a cohort of AML patients without EMD. We reviewed data from 9797 AML patients including 814 with EMD from 310 reporting centers and 44 different countries, who underwent alloHCT between and 1995 and 2010. The primary outcome was overall survival (OS) after alloHCT. Secondary outcomes included leukemia-free survival (LFS), relapse rate and treatment-related mortality (TRM). In a multivariate analysis, the presence of EMD did not affect either OS (hazard ratio 1.00, 95% confidence interval (CI) 0.91-1.09), LFS (0.98, 0.89-1.09), TRM (relative risk 0.92, 95% CI 0.80-1.16, P=0.23) or relapse (relative risk=1.03, 95% CI, 0.92-1.16; P=0.62). Furthermore, the outcome of patients with EMD was not influenced by the location, timing of EMD, or intensity of conditioning regimen. The presence of EMD in AML does not affect transplant outcomes and should not be viewed as an independent adverse prognostic feature.

CD3bright signals on γδ T cells identify IL-17A-producing Vγ6Vδ1+ T cells.

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has an important role at mucosal sites in a wide range of immune responses including infection, allergy and auto-immunity. γδ T cells are recognized as IL-17 producers, but based on the level of CD3 expression, we now define the remarkable ability of a CD3(bright) γδ T-cell subset with an effector memory phenotype to rapidly produce IL-17A, but not interferon-γ. CD3(bright) γδ T cells uniformly express the canonical germline encoded Vγ6/Vδ1(+) T-cell receptor. They are widely distributed with a preferential representation in the lungs and skin are negatively impacted in the absence of retinoic acid receptor-related orphan receptor gammat expression or endogenous flora. This population responded rapidly to various stimuli in a mechanism involving IL-23 and NOD-like receptor family, pyrin domain containing 3 (NLRP3)-inflammasome-dependent IL-1ß. Finally, we demonstrated that IL-17-producing CD3(bright) γδ T cells responded promptly and strongly to pneumococcal infection and during skin inflammation. Here, we propose a new way to specifically analyze IL-17-producing Vγ6/Vδ1(+) T cells based on the level of CD3 signals. Using this gating strategy, our data reinforce the crucial role of this γδ T-cell subset in respiratory and skin disorders.

A multicentre retrospective comparison of central nervous system prophylaxis strategies among patients with high-risk diffuse large B-cell lymphoma.

BACKGROUND: Central nervous system (CNS) relapse in diffuse large B-cell lymphoma (DLBCL) is a devastating complication; the optimal prophylactic strategy remains unclear. METHODS: We performed a multicentre, retrospective analysis of patients with DLBCL with high risk for CNS relapse as defined by two or more of: multiple extranodal sites, elevated serum LDH and B symptoms or involvement of specific high-risk anatomical sites. We compared three different strategies of CNS-directed therapy: intrathecal (IT) methotrexate (MTX) with (R)-CHOP 'group 1'; R-CHOP with IT MTX and two cycles of high-dose intravenous (IV) MTX 'group 2'; dose-intensive systemic antimetabolite-containing chemotherapy (Hyper-CVAD or CODOXM/IVAC) with IT/IV MTX 'group 3'. RESULTS: Overall, 217 patients were identified (49, 125 and 43 in groups 1-3, respectively). With median follow-up of 3.4 (range 0.2-18.6) years, 23 CNS relapses occurred (12, 10 and 1 in groups 1-3 respectively). The 3-year actuarial rates (95% CI) of CNS relapse were 18.4% (9.5-33.1%), 6.9% (3.5-13.4%) and 2.3% (0.4-15.4%) in groups 1-3, respectively (P=0.009). CONCLUSIONS: The addition of high-dose IV MTX and/or cytarabine was associated with lower incidence of CNS relapse compared with IT chemotherapy alone. However, these data are limited by their retrospective nature and warrant confirmation in prospective randomised studies.

Plerixafor plus pegfilgrastim is a safe, effective mobilization regimen for poor or adequate mobilizers of hematopoietic stem and progenitor cells: a phase I clinical trial.

The safety, kinetics and efficacy of plerixafor+pegfilgrastim for hematopoietic stem and progenitor cell (HSPC) mobilization are poorly understood. We treated 12 study patients (SP; lymphoma n=10 or myeloma n=2) with pegfilgrastim (6 mg SC stat D1) and plerixafor (0.24 mg/kg SC nocte from D3). Six SP were 'predicted poor-mobilizers' and six were 'predicted adequate-mobilizers'. Peripheral blood (PB) CD34(+) monitoring commenced on D3. Apheresis commenced on D4. Comparison was with 22 historical controls (HC; lymphoma n=18, myeloma n=4; poor mobilizers n=4), mobilized with pegfilgrastim alone. Eight (67%) SP had PB CD34(+) count ⩽5 × 10(6)/L D3 post pegfilgrastim; all SP surpassed this threshold the morning after plerixafor. In SP, PBCD34(+) counts peaked D4 6/12 (50%), remaining ⩾5 × 10(6)/L for 4 days in 8/12 (67%). All SP successfully yielded target cell numbers (⩾2 × 10(6)/kg) within four aphereses. After maximum four aphereses, median total CD34+ yield was higher in SP than HC; 8.0 (range 2.4-12.9) vs 4.8 (0.4-14.0) × 10(6)/kg (P=0.04). Seven of twelve (58%) SP achieved target yield after one apheresis. Flow cytometry revealed no tumor cells in PB or apheresis product of SP. Plerixafor+pegfilgrastim was well tolerated with bone pain (n=2), diarrhoea (n=2) and facial paraesthesiae (n=3). Plerixafor+pegfilgrastim is a simple, safe and effective HSPC mobilization regimen in myeloma and lymphoma, in both poor and good mobilizers, and is superior to pegfilgrastim alone.

Limited role for surveillance PET-CT scanning in patients with diffuse large B-cell lymphoma in complete metabolic remission following primary therapy.

BACKGROUND: The usefulness of positron emission tomography with computed tomography (PET-CT) in the surveillance of patients with diffuse large B-cell lymphoma (DLBCL) in complete metabolic remission after primary therapy is not well studied. METHODS: We performed a retrospective review of our database between 2002 and 2009 for patients with de novo DLBCL who underwent surveillance PET-CT after achieving complete metabolic response (CMR) following primary therapy. RESULTS: Four-hundred and fifty scans were performed in 116 patients, with a median follow-up of 53 (range 8-133) months from completion of therapy. Thirteen patients (11%) relapsed: seven were suspected clinically and six were subclinical (all within first 18 months). The positive predictive value in patients with international prognostic index (IPI) <3 was 56% compared with 80% in patients with IPI ≥3. Including indeterminate scans, PET-CT retained high sensitivity 95% and specificity 97% for relapse. CONCLUSION: Positron emission tomography with computed tomography is not useful in patients for the majority of patients with diffuse large B-cell lymphoma in CMR after primary therapy, with the possible exception of patients with baseline IPI ≥3 in the 18 months following completion of primary therapy. This issue could be addressed by a prospective clinical trial.

Central nervous system involvement in mantle cell lymphoma: clinical features, prognostic factors and outcomes from the European Mantle Cell Lymphoma Network.

BACKGROUND: Central nervous system (CNS) involvement in mantle cell lymphoma (MCL) is uncommon, and the manifestations and natural history are not well described. PATIENTS AND METHODS: We present the data on 57 patients with MCL who developed CNS involvement, from a database of 1396 consecutively treated patients at 14 institutions. RESULTS: The crude incidence of CNS involvement was 4.1%, with 0.9% having CNS involvement at diagnosis. Blastoid histology, B-symptoms, elevated lactate dehydrogenase, Eastern Cooperative Group performance status ≥2 and a high Mantle Cell Lymphoma International Prognostic Index score were enriched in the cohort with CNS involvement, and the presence of ≥1 of these features defined a high-risk subset (an actuarial risk of CNS involvement 15% at 5 years) in a single-institution subset. The median time to CNS relapse was 15.2 months, and the median survival from time of CNS diagnosis was 3.7 months. The white blood cell count at diagnosis <10.9 × 109/l, treatment of CNS involvement with high-dose anti-metabolites, consolidation with stem cell transplant and achievement of complete response were all associated with improved survival. CONCLUSIONS: In MCL, CNS involvement is uncommon, although some features may predict risk. Once manifest outlook is poor; however, some patients who receive intensive therapy survive longer than 12 months.

Pegfilgrastim compared with filgrastim for cytokine-alone mobilization of autologous haematopoietic stem and progenitor cells.

Haematopoietic stem and progenitor cells (HSPC) mobilization, using cytokine-alone, is a well-tolerated regimen with predictable mobilization kinetics. Single-dose pegfilgrastim mobilizes HSPC efficiently; however, there is surprisingly little comparative data on its use without chemotherapy for HSPC mobilization. Pegfilgrastim-alone and filgrastim-alone mobilization regimens were compared in 52 patients with haematological malignancy. Pegfilgrastim 12 mg (n=20) or 6 mg (n=2) was administered Day 1 (D1) in 22 patients (lymphoma n=17; myeloma n=5). Thirty historical controls (lymphoma n=18; myeloma n=12) received filgrastim 10 mcg/kg daily from D1. Peripheral blood (PB) CD34(+) counts reached threshold (5 × 10(6)/L) and apheresis commenced on D4(4-5) and D4(4-6). Median PB CD34(+) cell count on D1 of apheresis was similar (26.0 × 10(6)/L (2.5-125.0 × 10(6)/L) and 16.2 × 10(6)/L (2.6-50.7 × 10(6)/L); P=0.06), for pegfilgrastim and filgrastim groups, respectively. Target yield (2 × 10(6) per kg CD34(+) cells) was collected in 20/22 (91%) pegfilgrastim patients and 24/30 (80%) in the filgrastim group (P=0.44), in a similar median number of aphereses (3(1-4) versus 3(2-6), respectively; P=0.85). A higher proportion of pegfilgrastim patients tended to yield 4 × 10(6) per kg CD34(+) cells; 16/22 (73%) versus 14/30 (47%) filgrastim patients (P=0.09). One pegfilgrastim patient developed hyperleukocytosis that resolved without incident. Pegfilgrastim-alone is a simple, well-tolerated, and attractive option for outpatient-based HSPC mobilization with similar mobilization kinetics and efficacy to regular filgrastim.

Use of antibacterial prophylaxis for patients with neutropenia. Australian Consensus Guidelines 2011 Steering Committee.

The use of oral prophylactic antibiotics in patients with neutropenia is controversial and not recommended by this group because of a lack of evidence showing a reduction in mortality and concerns that such practice promotes antimicrobial resistance. Recent evidence has demonstrated non-significant but consistent, improvement in all-cause mortality when fluoroquinolones (FQs) are used as primary prophylaxis. However, the consensus was that this evidence was not strong enough to recommend prophylaxis. The evidence base for FQ prophylaxis is presented alongside current consensus opinion to guide the appropriate and judicious use of these agents. Due consideration is given to patient risk, as it pertains to specific patient populations, as well as the net effect on selective pressure from antibiotics if FQ prophylaxis is routinely used in a target population. The potential costs and consequences of emerging FQ resistance, particularly among Escherichia coli, Clostridium difficile and Gram-positive organisms, are considered. As FQ prophylaxis has been advocated in some chemotherapy protocols, specific regard is given to whether FQ prophylaxis should be used to support these regimens. The group also provides recommendations for monitoring and surveillance of emerging resistance in those centres that have adopted FQ prophylaxis.

Ex vivo culture of chimeric antigen receptor T cells generates functional CD8+ T cells with effector and central memory-like phenotype.

The anti-tumor efficacy of adoptively transferred T cells requires their in vivo persistence and memory polarization. It is unknown if human chimeric antigen receptor (CAR)-expressing T cells can also undergo memory polarization. We examined the functional status of CAR CD8(+) T cells, re-directed to Lewis Y antigen (LeY-T), throughout a period of ex vivo expansion. Immediately before culture CD8(+) T cells comprised a mixture of phenotypes including naive (CD45RA(+)/CCR7(+)/CD27(+)/CD28(+)/perforin-), central memory (CM, CD45RA(-)/CCR7(lo)/CD27(+)/CD28(+)/perforin(lo)), effector memory (EM, CD45RA(-)/CCR7(-)/CD27(+)/CD28(+)/perforin(mod)) and effector (Eff, CD45RA(+)/CCR7(-)/CD27(-)/CD28(-)/perforin(hi)) cells. After transduction and expansion culture of peripheral blood mononuclear cells from normal donors or multiple myeloma patients, CD8(+) LeY-T cells polarized to EM- and CM-like phenotype. CD8(+) LeY-T cells differed from starting CD8(+) CM and EM T cells in that CD27, but not CD28, was downregulated. In addition, CD8(+) LeY-T cells expressed high levels of perforin, similar to starting CD8(+) Eff. CD8(+) LeY-T cells also showed hallmarks of both memory and Eff function, underwent homeostatic proliferation in response to interleukin (IL)-15, and showed interferon (IFN)-γ production and cytotoxicity in response to Le-Y antigen on OVCAR-3 (human ovarian adenocarcinoma) cells. This study confirms CD8(+) LeY-T cells have a CM- and EM-like phenotype and heterogeneous function consistent with potential to persist in vivo after adoptive transfer.

Gene-modified T cells as immunotherapy for multiple myeloma and acute myeloid leukemia expressing the Lewis Y antigen.

We have evaluated the carbohydrate antigen Lewis(Y) (Le(Y)) as a potential target for T-cell immunotherapy of hematological neoplasias. Analysis of 81 primary bone marrow samples revealed moderate Le(Y) expression on plasma cells of myeloma patients and myeloblasts of patients with acute myeloid leukemia (AML) (52 and 46% of cases, respectively). We developed a retroviral vector construct encoding a chimeric T-cell receptor that recognizes the Le(Y) antigen in a major histocompatibility complex-independent manner and delivers co-stimulatory signals to achieve T-cell activation. We have shown efficient transduction of peripheral blood-derived T cells with this construct, resulting in antigen-restricted interferon-gamma secretion and cell lysis of Le(Y)-expressing tumor cells. In vivo activity of gene-modified T cells was demonstrated in the delayed growth of myeloma xenografts in NOD/SCID mice, which prolonged survival. Therefore, targeting Le(Y)-positive malignant cells with T cells expressing a chimeric receptor recognizing Le(Y) was effective both in vitro and in a myeloma mouse model. Consequently, we plan to use T cells manufactured under Good Manufacturing Practice conditions in a phase I immunotherapy study for patients with Le(Y)-positive myeloma or AML.

Etoposide induces more severe mucositis than CY when added to TBI as conditioning in allograft recipients receiving CsA and MTX.

Fractionated TBI and etoposide (FTBI-VP16) conditioning is effective therapy for patients receiving allogeneic stem cell transplants for ALL. One of the major dose-limiting toxicities with this regimen is mucositis although its effect on patients and hospital resources is not well described. To determine the severity of mucositis (WHO grade 3-4) experienced and assess resource utilisation, we compared the non-haematological toxicities of 38 patients receiving FTBI-VP16 with 104 patients receiving CY and TBI (CYTBI). FTBI-VP16 patients were more likely to develop severe mucositis (odds ratio (OR) 6.0 (95% confidence interval (CI) 1.36, 54.42), P<0.01) and its duration was longer (11.5 vs 8 days, P<0.01). Resource utilisation was considerably higher especially in the use and duration of i.v. narcotics and parenteral nutrition, nursing care requirements and plt-transfusion support. Patients receiving FTBI-VP16 conditioning are ideal candidates for new therapies to prevent or reduce the severity of mucositis.

Diagnostic and therapeutic approach to persistent or recurrent fevers of unknown origin in adult stem cell transplantation and haematological malignancy.

Persistent or recurrent fevers of unknown origin (PFUO) in neutropenic patients on broad-spectrum antibiotics have traditionally been treated with empirical antifungal therapy (EAFT). The lack of survival benefit seen with the use of amphotericin B deoxycholate (AmB-D) as EAFT has been attributed to its toxicities. More recently, newer, less toxic and more expensive antifungal agents such as the lipid formulations of AmB, the newer azoles (fluconazole, itraconazole and voriconazole) and caspofungin have been analysed in a number of EAFT trials. Compared with AmB-D the newer agents have superior safety but are of equivalent efficacy. This lack of survival advantage is related to the fact that the trigger for commencement of EAFT is late and non-specific. Thus, alternative approaches are required. New sensitive serological and molecular tests for the detection of Aspergillus antigens and genomic DNA have been developed and evaluated in accuracy studies. These tests have been incorporated into management strategies (i.e. pre-emptive strategies) to direct antifungal therapy. The pre-emptive approach has been shown to be safe and feasible but its impact on clinically important patient outcomes such as survival is less clear. Other advances include the introduction of effective, non-toxic mould-active antifungal prophylaxis and patient risk-group stratification. In this paper we provide new evidence-based algorithms for the diagnosis and treatment of PFUO in adult patients undergoing stem cell transplantation and chemotherapy for haematological malignancy which incorporate these newer diagnostic tests and are directed by the risk category of the patient and type of antifungal prophylaxis the patient is receiving.

Cyclosporin, methotrexate and prednisolone for graft-versus-host disease prophylaxis in allogeneic peripheral blood progenitor cell transplants.

The utility of GVHD prophylaxis with cyclosporin, MTX and prednisolone (CSA/MTX/Pred) in allogeneic PBPC transplants is not well described although there are published data using this combination after bone marrow transplants. The effectiveness of this regimen on the prevention of GVHD was assessed in 107 consecutive sibling and less-than-ideal donor transplant recipients over a 5-year period and compared to that observed in 65 patients receiving standard CSA and short-course MTX without prednisolone. Oral prednisolone was commenced on day +14 at 0.5 mg/kg per day, increased to 1 mg/kg per day on day +21 to day +34 then gradually tapered and ceased by day +100. The cumulative incidence of acute GVHD (grades II-IV) to day 100 in those receiving prednisolone prophylaxis was lower (52 versus 76%, P<0.01). The onset of symptomatic GVHD requiring systemic treatment was delayed from a median of 41 days post transplant to 92 days. When assessment of the cumulative incidence of symptomatic GVHD continued to day +180 incidence became similar (74 versus 78%), there was no difference between the two groups in rates of relapse, transplant-related mortality, infections or chronic GVHD. We conclude that the addition of prednisolone to CSA/MTX delays the onset of early acute GVHD in PBPC recipients but has no impact on the overall incidence of GVHD.

DC research in Australia.

Australian researchers have contributed significantly to the understanding of DC biology and clinical application over the past 25 years. Active DC research programs are in place in all major centers, pursuing the key questions of DC phylogeny, physiology and clinical applicability. Pre-clinical and clinical research include the pathophysiology of DC in malignancy, autoimmunity, chronic viral infection, chronic renal failure and transplantation medicine. In addition, Australian laboratories have uncovered some of the subtle complexities of DC subsets, often utilizing novel investigational tools discovered in their laboratories. Above all, Australian DC research has benefited from the existence of a potent culture of active collaboration, which has led to key interactions between cellular immunologists, clinician scientists and clinical researchers. These collaborations have led to the emergence of DC research programs that extend from in vitro and animal models of DC biology through each step of clinical translation and into active clinical trials.

The hyper-CVAD-rituximab chemotherapy programme followed by high-dose busulfan, melphalan and autologous stem cell transplantation produces excellent event-free survival in patients with previously untreated mantle cell lymphoma.

The hyper-CVAD + rituximab (R) programme consists of fractionated cyclophosphamide, vincristine, doxorubicin and dexamethasone + R alternating with high-dose methotrexate + cytarabine (HD MTX/ARA-C) + R. This regimen, when used as initial therapy for patients under 65 years of age with previously untreated mantle cell lymphoma (MCL), results in remission rates of > 85% with a median event-free survival (EFS) of > 50 months, but with a pattern of continuous relapse out to 60 months. We performed a study of hyper-CVAD + R, followed by consolidative peripheral blood progenitor cells autograft [autologous stem cell transplant (AuSCT)] with high-dose busulfan and melphalan (Bu/Mel) conditioning, in patients with responsive disease. Thirteen patients with a median age of 54 (range = 33-61) were treated. Complete remission (CR) was achieved in 12 patients (92%) after hyper-CVAD + R and 12 completed AuSCT after Bu/Mel conditioning. One patient died during the autograft and another declined AuSCT after achieving a CR with hyper-CVAD + R. With a median follow-up from diagnosis of 36 months (range = 16-53 months), the observed 36 months overall survival and EFS are both 92% for the whole cohort. These data confirm the excellent CR rates achieved by the use of hyper-CVAD + R in patients with MCL and suggest that consolidation with Bu/Mel and AuSCT may improve durable disease control when compared to published outcomes of hyper-CVAD + R alone.