Ian M. Franklin

Prospective outcome data on 267 unselected adult patients with Philadelphia chromosome–positive acute lymphoblastic leukemia confirms superiority of allogeneic transplantation over chemotherapy in the pre-imatinib era: results from the International ALL Trial MRC UKALLXII/ECOG2993

Prospective data on the value of allogeneic hematopoietic stem cell transplantation (alloHSCT) in Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) are limited. The UKALLXII/ECOG 2993 study evaluated the outcome of assigning alloHSCT with a sibling (sib) or matched unrelated donor (MUD) to patients younger than 55 years of age achieving complete remission (CR). The CR rate of 267 patients, median age 40, was 82%. Twenty-eight percent of patients proceeded to alloHSCT in first CR. Age older than 55 years or a pre-HSCT event were the most common reasons for failure to progress to alloHSCT. At 5 years, overall survival (OS) was 44% after sib alloHSCT, 36% after MUD alloHSCT, and 19% after chemotherapy. After adjustment for sex, age, and white blood count and excluding chemotherapy-treated patients who relapsed or died before the median time to alloHSCT, only relapse-free survival remained significantly superior in the alloHSCT group (odds ratio 0.31, 95% confidence interval 0.16-0.61). An intention-to-treat analysis, using the availability or not of a matched sibling donor, showed 5-year OS to be nonsignificantly better at 34% with a donor versus 25% with no donor. This prospective trial in adult Ph(+) ALL indicates a modest but significant benefit to alloHSCT. This trial has been registered with clinicaltrials.gov under identifier NCT00002514 and as ISRCTN77346223.

Three distinct subgroups of hypodiploidy in acute lymphoblastic leukaemia

This study of children and adults with acute lymphoblastic leukaemia (ALL) is the largest series of patients with hypodiploidy (<46 chromosomes) yet reported. The incidence of 5% was independent of age. Patients were subdivided by the number of chromosomes; near‐haploidy (23–29 chromosomes), low hypodiploidy (33–39 chromosomes) and high hypodiploidy (42–45 chromosomes). The near‐haploid and low hypodiploid groups were characterized by their chromosomal gains and a doubled hyperdiploid population. Structural abnormalities were more frequent in the low hypodiploid group. Near‐haploidy was restricted to children of median age 7 years (range 2–15) whereas low hypodiploidy occurred in an older group of median age 15 years (range 9–54). Patients with 42–45 chromosomes were characterized by complex karyotypes involving chromosomes 7, 9 and 12. The features shared by the few patients with 42–44 chromosomes and the large number with 45 justified their inclusion in the same group. Survival analysis showed a poor outcome for the near‐haploid and low hypodiploid groups compared to those with 42–45 chromosomes. Thus cytogenetics, or at least a clear definition of the modal chromosome number, is essential at diagnosis in order to stratify patients with hypodiploidy into the appropriate risk group for treatment.

Transforming growth factor beta from multiple myeloma cells inhibits proliferation and IL-2 responsiveness in T lymphocytes.

Multiple myeloma (MM) is a cancer of plasma cells, characterized by profound suppression of host immune responses. Here we show that MM cell lines significantly suppress the proliferation, blasting, response to interleukin‐2 (IL‐2), and expression of CD25 by concanavalin A (Con A)‐activated or allostimulated peripheral blood T lymphocytes. T cells arrest in the G1 stage of the cell cycle, and do not enter the IL‐2 autocrine growth pathway. T cell inhibition was mediated by a soluble factor. MM cell lines did not produce IL‐10 but did produce large amounts of transforming growth factor β1 (TGF‐β1). T cells were assessed for their ability to respond to IL‐2 when co‐cultured with MM cells in the presence or absence of the TGF‐β inhibitor, TGF‐β latency‐associated peptide (LAP). MM cells suppressed IL‐2 responses but this inhibition was completely reversed by TGF‐β LAP. A CD25−, IL‐2‐dependent blast cell line was not inhibited by MM cells or rhTGF‐β, confirming the specificity of the inhibition mechanism for the IL‐2 autocrine growth pathway. We conclude that MM cells suppress T cells in their entry into the autocrine IL‐2/CD25 pathway and in response to IL‐2, and that TGF‐β has a significant role to play. J. Leukoc. Biol. 66: 981–988; 1999.

TEL-AML1 fusion in acute lymphoblastic leukaemia of adults

A number of fusion genes have been identified by study of acquired chromosomal translocations. Their detailed characterization has provided insights into mechanisms of leukaemogenesis and has enabled the development of molecular methods to assist in the diagnosis and monitoring of residual disease after treatment. The TEL‐AML1 fusion gene is associated with a cryptic t(12;21)(p12;q22) translocation, and is the commonest known genetic abnormality in childhood B‐cell precursor acute lymphoblastic leukaemia (ALL), occurring in about 25% of cases. We have used RT‐PCR, followed by Southern blotting and direct sequencing, to establish the incidence of TEL‐AML1 rearrangement in 131 adults with acute leukaemia (101 with ALL and 30 with chronic myeloid leukaemia in blastic crisis). Three patients were positive for TEL‐AML1 transcripts. All three had common‐ALL. All other patients were negative for TEL‐AML1. We conclude that the TEL‐AML1 fusion gene is found in adult ALL, though less commonly than in children.

Expression of adhesion molecules LFA-3 and N-CAM on normal and malignant human plasma cells.

Normal and malignant plasma cells were investigated for the expression of seven cellular adhesion molecules by immunofluorescence microscopy. The antigens investigated were CD2 and its ligand, LFA‐3 (CD58), LFA‐1α (CD11a) and LFA‐1β (CD18) and their ligand ICAM‐1 (CD54), H‐CAM (lymphocyte homing receptor; CD44) and N‐CAM (CD56). Marrow from 18 patients with myeloma, two with plasma cell leukaemia (PCL), four with monoclonal gammopathy of uncertain significance (MGUS) and 10 normal allogeneic bone marrow donors was studied. All plasma cells from normals and multiple myeloma patients were negative for CD2, CD11a and CD18. All normal and myeloma marrow plasma cells were positive for ICAM‐1. 16/18 myeloma cases tested, and all other samples (normal, MGUS and PCL), contained plasma cells positive for H‐CAM. Only one normal, but 12/16 myelomas tested were positive for N‐CAM (P<0.02). One of four MGUS cases was moderately positive and one other weakly positive for N‐CAM. Both PCLs were N‐CAM negative. 12/18 myelomas were positive for LFA‐3, but only two normals (P<0.05). All MGUS cases were negative for LFA‐3, as was one PCL, the other being weakly positive. Three cases were negative for both adhesion molecules, three cases expressed only N‐CAM or LFA‐3 and 10 cases expressed both. LFA‐3 and N‐CAM are expressed significantly in myeloma rather than normal plasma cells. Cases of MGUS may express N‐CAM but not, in this small series, LFA‐3. Plasma cells in the peripheral blood (PCL) and plasma cell lines express little or no LFA‐3 or N‐CAM.

Characterization of a new IgGλ myeloma plasma cell line (EJM) : a further tool in the investigation of the biology of multiple myeloma

Summary. A new IgGλ myeloma plasma cell line known as EJM was established from a peritoneal effusion from a patient with extramedullary myeloma. The EJM cells have a plasmablastic morphology with abundant rough endoplasmic reticulum and grow in liquid culture with a doubling time of 72 h and a labelling index of 36%. In addition to cytoplasmic IgGλ, the cells are positive for CD9, 20, 32, 38, 44, 54, 71, 78, MHC Class II DR. DP and DQ. Studies on the control of the cell line proliferation by cytokines have demonstrated stimulation with interleukin 6. In contrast interferon alpha produces marked inhibition of proliferation in doses of > 100 units/ml. The culture conditions and the importance of accessory cells and cytokines in supporting myeloma plasma cell growth in vitro are discussed.

Immature monocytes from G-CSF-mobilized peripheral blood stem cell collections carry surface-bound IL-10 and have the potential to modulate alloreactivity

Production of the anti‐inflammatory cytokine IL‐10 by monocytes has been implicated as a probable negative regulator of graft‐versus‐host disease (GvHD) in patients undergoing allogeneic stem cell transplants (SCT). Monocytes from G‐CSF‐mobilized peripheral blood stem cell (gmPBSC) collections have been reported to produce more IL‐10 than unmobilized monocytes in response to proinflammatory factors such as LPS. Why this should occur is unclear. In this study, monocyte phenotype and IL‐10 localization and release were investigated in PB mononuclear cells (MNC) from 27 healthy donors mobilized for allogeneic SCT and from 13 patients with hematological malignancies mobilized for autologous SCT. All isolates contained elevated total percentages of monocytes in comparison with unmobilized PB, a high proportion of which displayed an immature phenotype. Stimulation of gmPB MNC with an inflammatory stimulus [fixed Staphylococcus aureus cells (SAC)] induced rapid up‐regulation of CD14, indicating conversion to mature status. Localization studies indicated that IL‐10 was predominantly present, bound on the surface of CD64+/CD14low/neg immature monocytes. Inflammatory stimuli (LPS, polyinosinic:polycytidylic acid, or SAC) induced release of variable quantities of IL‐10 from the cell surface. MNC, separated into surface IL‐10‐positive or ‐negative fractions, differed in their ability to stimulate alloreactivity in MLR, and IL‐10+ MNC induced significantly lower levels of proliferation than IL‐10− MNC. Thus, the subset of immature monocytes carrying surface‐bound IL‐10 in gmPB has the potential to modulate alloreactivity and GvHD after allogeneic SCT through cell‐to‐cell contact and released IL‐10.

Long-term follow-up of HCV-infected hematopoietic SCT patients and effects of antiviral therapy

This prospective study was initiated in 1993 with the aim to study late effects and responses to antiviral therapy in a cohort of hepatitis C virus (HCV)-infected patients. A total of 195 patients were included from 12 centers. In all, 134 patients had undergone allogeneic and 61 autologous hematopoietic SCT (HSCT). The median follow-up from HSCT is currently 16.8 years and the maximum 27.2 years. Overall 33 of 195 patients have died of which 6 died from liver complications. The survival probability was 81.6% and the cumulative incidence for death in liver complications was 6.1% at 20 years after HSCT. The cumulative incidence of severe liver complications (death from liver failure, cirrhosis and liver transplantation) was 11.7% at 20 years after HSCT. In all, 85 patients have been treated with IFN; 42 in combination with ribavirin. The sustained response rate was 40%. The rates of severe side effects were comparable to other patient populations and no patient developed significant exacerbations of GVHD. Patients receiving antiviral therapy had a trend toward a decreased risk of severe liver complications (odds ratio=0.33; P=0.058). HCV infection is associated with morbidity and mortality in long-term survivors after HSCT. Antiviral therapy can be given safely and might reduce the risk for severe complications.

A randomized study (WOS MM1) comparing the oral regime Z-Dex (idarubicin and dexamethasone) with vincristine, adriamycin and dexamethasone as induction therapy for newly diagnosed patients with multiple myeloma

Whilst infusional vincristine, adriamycin and dexamethasone (VAD) is an effective treatment for patients with multiple myeloma (MM), administration may be complicated by line‐associated infections and thromboses. The oral regime, Z‐Dex (idarubicin and dexamethasone) has been shown to be efficacious in MM. We conducted a randomized study comparing Z‐Dex with VAD as induction therapy in newly diagnosed MM patients. A total of 106 patients (median age, 56 years; range: 37–73; Durie‐Salmon stage II/III) were randomized to receive four to six cycles of Z‐Dex or VAD. Central line complications were reported in 38 patients on 57 cycles, primarily because of infection. Neutropenia (all grades) was more common in the Z‐Dex arm (P = 0·009) although grade III/IV neutropenia was not significantly different between the treatment groups (P = 0·06). Infections (all grades) were more commonly seen in the VAD arm (P = 0·001) although grade III/IV infections were not significantly different between the two groups (P = 0·081). The responses to therapy (complete/partial response) in evaluable patients were: VAD 74% vs. Z‐Dex 58%, with an estimated difference in response of 16% (95% CI −2–33, P = 0·075). VAD recipients (15%) suffered early treatment‐related mortality compared with 12% of Z‐Dex recipients. Overall, 45 patients have died: disease progression (Z‐Dex n = 13, VAD n = 10), regimen‐related toxicity (Z‐Dex n = 2, VAD n = 2), infection (Z‐Dex n = 0, VAD n = 3), other causes (Z‐Dex n = 7, VAD n = 2), unknown (Z‐Dex n = 3, VAD n = 2). This study demonstrated that Z‐Dex might be a suitable oral alternative to VAD for treating newly diagnosed MM patients, although definitive evidence for equivalence is not provided.

Very late antigen (VLA) expression by normal and neoplastic human plasma cells; including an assessment of antibodies submitted to the Vth International Workshop on Leucocyte Differentiation Antigens using human myeloma cell lines

The biology of normal plasma cells and the pathophysiology of human multiple myeloma remain poorly understood. Functional assays are scarce and at present cell phenotyping is providing the most information about how human plasma cells may behave. Three different types of human plasma cells: normal, fresh neoplastic myeloma cells and plasma cell lines, have been studied for their reactivity with antibodies to the beta-1 integrins (Very Late Antigens; VLAs), including a panel obtained from the Vth International Workshop on Leucocyte Differentiation Antigens. Most plasma cell targets express VLA-4 (CD49d positive) and the common beta chain recognized by CD29. CD49e (VLA-5) was occasionally positive. Other VLAs were not usually expressed. These data suggest the wide use by plasma cells of VLA-4, possibly as a ligand with fibronectin and high endothelial venules (HEV). Of other adhesion structures expressed by plasma cells, only CD44 is seen as frequently, and this is also a HEV ligand.