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Background: Allogenic blood and marrow transplant (allo-BMT) is an arduous treatment used increasingly for many life-threatening conditions. Recognition of the profound impacts of the long term and late effects is ever-growing, as is the healthcare workload (treatment burden) of survivorship., Purpose: To quantify the treatment burden of long-term survival following allo-BMT, regarding the range of health services, therapies and investigations accessed by survivors., Methods: A large, multi-centre cross-sectional survey of adult allo-BMT survivors transplanted between 2000 and 2012 in Sydney, Australia. Participants completed six validated instruments and one purposed designed for the study, the Sydney Post BMT Study (SPBS), answering questions relating to medication use, medical treatments, referrals, assessments and frequency of hospital/clinic attendance., Results: Of the 441 allo-BMT survivors, over a quarter who were more than 2 years post BMT attended the hospital clinic at least monthly, and 26.7% required a number of regular medical procedures (e.g. venesection, extracorpororeal photopheresis). Specialist medical and allied health referral was very common, and compliance with internationally recommended long-term follow-up (LTFU) care was suboptimal and decreased as time from BMT increased., Conclusion: Respondents reported a large medication (conventional and complementary), screening, assessment and health care burden., Implications for Cancer Survivors: Treatment burden contributes significantly to the 'workload' of survivorship and can have a severe and negative impact on BMT survivors, carers and the healthcare system-making it difficult to comply with optimal care. Clinicians must be primed with skills to identify survivors who are overburdened by the health care required for survival and develop strategies to help ease the burden., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The optimum conditions for storage and transport of freshly harvested HPC in the liquid state are uncertain. It is not specified in commonly applied standards for stem cell transplantation. We used a viable CD34 assay to determine the optimum temperature for maintaining progenitor cell viability in freshly harvested BM and PBSC. Our aim was to identify standardized conditions for storage and transport of marrow or peripheral blood products that would optimize CD34 recovery, leading to better transplant outcomes., Methods: Samples were aseptically removed from 46 fresh HPC harvests (34 PBSC and 12 BM) and stored at refrigerated temperature (2-8 degrees C), room temperature (18-24 degrees C) and 37 degrees C for up to 72 h. Samples were analyzed for viable CD34+ cells/microL at 0, 24, 48 and 72 h., Results: The mean viable CD34+ yield prior to storage was 7.7 x 10(6)/kg (range 0.7-30.3). The mean loss of viable CD34+ cells in HPC products at refrigerated temperature was 9.4%, 19.4% and 28% at 24, 48 and 72 h, respectively. In contrast, the mean loss of viable CD34+ cells at room temperature was 21.9%, 30.7% and 43.3% at 24, 48 and 72 h, respectively. No viable CD34+ cells remained after storage at 37 degrees C for 24 h. Only PBSC products and not BM showed temperature-related loss of CD34 viability. Greater loss of viable CD34+ cells was observed for allogeneic PBSC compared with autologous PBSC., Discussion: These results demonstrate that the optimum temperature for maintaining the viability of CD34+ cells, during overnight storage and transport of freshly harvested HPC, is 2-8 degrees C. These findings will allow the development of standard guidelines for HPC storage and transport.

Acute lymphoblastic leukemia (ALL) blasts undergo migration into layers of bone marrow fibroblasts (BMF) in vitro, utilizing the beta1 integrins VLA-4 and VL-5 as adhesion molecules. However, it has been unclear as to whether this is a selective process mediated by specific chemoattractant molecules, or simply a reflection of the highly motile nature of early B cell precursors. We further characterized this process using a transwell culture system, in which the two chambers were separated by an 8 microm diameter microporous membrane, through which leukemic cells could move. When a BMF layer was grown on the upper surface of the membrane there was an 84.1% reduction in transmigration of the human pre-B ALL cell line NALM-6 into the lower chamber, compared to control membrane with no BMF layer. Localization of leukemic cells under the BMF layer was confirmed ultrastructurally, suggesting the possibility that the migration of leukemic cells was directed by a chemotactic agent secreted by BMF. The involvement of the chemokine stromal cell-derived factor-1 (SDF-1) in this process was next investigated. BMF were shown to express m-RNA for SDF-1. Addition of SDF-1 at 100 ng/ml into the lower chamber increased transmigration of NALM-6 across the membrane by 2.2-fold, and also induced a 1.4- to 6.1-fold increase in movement of NALM-6 through a BMF layer into the lower chamber. The receptor for SDF-1, CXCR4, was demonstrated by flow cytometry on all 10 cases of precursor-B ALL analyzed, as well as on NALM-6, KM-3 and REH lines. An inhibitory antibody to CXCR4 was able to block the migration of NALM-6 cells into BMF monolayers grown on plastic by 51%, and in nine cases of ALL by 8-40%, as well as partially inhibit transmigration of leukemic cells through BMF layers along an SDF-1 concentration gradient. These results confirm that precursor-B ALL cells selectively localize within bone marrow stroma in vitro, and that this process is partially due to the stromal chemokine SDF-1 binding to its receptor CXCR4 on leukemic cells. SDF-1 may be important in influencing the localization of precursor-B ALL cells in marrow microenvironmental inches which regulate their survival and proliferation.

The role of CD44 in the adhesion of haemopoietic cells to bone marrow stromal layers has not been clearly defined in humans, although its importance in the murine system has been well documented. We have demonstrated that the CD44 antibody, NIH44-1, enhances the adhesion of haemopoietic cells to bone marrow stroma. Normal human CD34+ haemopoietic progenitors and blasts from patients with acute myeloblastic, but not lymphoblastic, leukaemia responded to NIH44-1. All CD44 antibodies tested which bound the same epitope as NIH44-1 also augmented haemopoietic cell adhesion to bone marrow adherent layers; however, antibodies which bound to other CD44 epitopes showed mixed responses. Augmented adhesion was independent of cell metabolism, suggesting that antibody binding resulted in direct activation of the CD44 molecule. However, hyaluronic acid was not the ligand for induced adhesion, nor could we show a role for other CD44 ligands including fibronectin, laminin, collagen or chondroitin sulphate proteoglycan. Similarly, none of the 22 CD44 antibodies tested inhibited the stimulatory effect of the NIH44-1. Expression of CD44 was not sufficient to determine NIH44-1 responsiveness since cell lines and leukaemic cells which failed to respond to NIH44-1 expressed high levels of CD44. Neither CD44 isoforms nor glycosylation patterns could be identified as predictive of response. CD44 antibodies enhanced binding of normal and leukaemic haemopoietic progenitors to bone marrow fibroblasts via an unidentified stromal ligand.

Human acute myeloid leukemia (AML) cells adhere to bone marrow fibroblasts (BMF) and extracellular matrix proteins including fibronectin. Adhesion is increased when fibroblast monolayers are exposed to tumor necrosis factor-alpha (TNF) alone and in combination with interferon-gamma (IFN) or interleukin-4 (IL-4). The combination of TNF and IFN caused enhanced AML cell adhesion to treated BMFs, from a mean of 25.0 +/- 4.1% to 36.3 +/- 5.4% (p = 0.0007). Enhanced binding was partially a result of upregulated vascular cell adhesion molecule-1 expression on BMFs. Intercellular adhesion molecule-1 was also upregulated, but did not appear to play a role in the increased binding to cytokine-stimulated BMFs. In contrast to observed adhesion to resting BMFs, AML cells binding to TNF/IFN-stimulated BMFs rely more heavily on the VLA-4 alpha chain (CD49d). In some cases, alpha4 integrin chain antibody was more effective than beta1 antibody in blocking binding, suggesting that a non-beta1 alpha4 integrin, possibly alpha4 beta7, on AML cells may act as a stromal ligand. The addition of alpha4 antibody to beta1 and beta2 antibodies significantly increased the inhibition of AML cells to stimulated BMFs. The myeloid cytokines granulocyte colony stimulating factor, granulocyte-monocyte colony stimulating factor, interleukin-3 and stem cell factor enhanced the adhesion of AML blast cells to BMFs in some cases. The phorbol ester PMA, however, consistently upregulated AML cell-binding to BMFs, the increase being mediated entirely via beta1 and beta2 integrins without altering AML cell integrin expression. Binding of AML cells to marrow stroma can be enhanced by influences on leukemic cell or stroma. Enhanced binding under these conditions occurs via different pathways, illustrating the heterogeneity of mechanisms underlying leukemic cell retention within the bone marrow stroma.

The ultrastructural changes in leukaemic cells on initial contact with, and during migration into, layers of bone marrow stroma in vitro were examined in a variety of types of acute leukaemia and leukaemic cell lines. Bone marrow fibroblasts (BMF) were grown on polycarbonate microporous membranes, and acute leukaemia cells added to cultures and allowed to adhere to BMF for variable periods of time before fixation. Acute lymphoblastic leukaemia (ALL) blasts showed rapid development of surface membrane microvilli on contact with BMF layers. ALL blasts, and the pre-B ALL cell line NALM-6, showed evidence of movement in to the BMF layer within 15-30 min, with intrusion of extended cytoplasic processes into gaps between BMF cytoplasm. ALL cells were frequently seen within the layers of fibroblasts after 30 min incubation, and had pronounced morphological changes, with pseudopodia and attenuated and elongated microvilli interdigitating with the surface of fibroblasts or with strands of extracellular matrix material. Changes were also noted in the surface membrane of BMF adjacent to ALL cells, with invagination of the cytoplasmic membrane and formation of micropits. In contrast to the migratory behaviour of pre-B ALL cells, migration was not observed with acute myeloid leukaemia cells or other leukaemic cell lines. These cells showed membrane activation, with variable degrees of microvillous formation, and in some cases insertion of pseudopodia into BMF layers, but migration was not observed. Ultrastructural immunogold labelling was carried out to determine the localization of leukaemic adhesion molecules and their ligands on BMF. This demonstrated that beta 1 integrins were largely localized to the contact surfaces of both ALL blasts and fibroblasts, with VCAM-1 expressed only on the surface of BMF. These observations confirm the specificity of migratory behaviour for pre-B leukaemic cells, and indicate that a complex pattern of surface and intracellular events mediate this process, including the expression of beta 1 integrins and VCAM-1 at the sites of insertion of leukaemic cells between fibroblast margins.

In this study we have demonstrated that natural killer (NK) cells adhere to elements of the bone marrow stroma (BMS) including fibroblasts, fibronectin and laminin but not to collagen type I, vitronectin and hyaluronic acid. NK cells bind to fibronectin and laminin using the beta 1 integrins VLA-4 and VLA-5, and VLA-6 respectively. The mechanism of adhesion to bone marrow fibroblasts is more complicated with beta 1 and beta 2 integrins being partially responsible but the majority of adhesion remaining unexplained. IL-2 stimulation of NK cells resulted in an increase in the expression of adhesion molecules involved in binding of NK cells to bone marrow fibroblasts (BMF) and extracellular matrix (ECM) proteins including the beta 1 chain CD29, alpha chains of VLA-4 and 5, beta 2 chain CD18 and alpha L chain CD11a. A marked increase in expression of beta 7 was also observed. There was a significant increase in the adhesion of NK cells to fibronectin in response to IL-2 treatment. NK cells also bound more strongly to BMF following IL-2 treatment although the development of cytotoxicity appeared to interfere with the adhesion assay. NK cells competitively inhibit the binding of AML blasts but not ALL blasts to BMF. Mechanisms underlying the inhibition of leukemic growth by NK and LAK cells may include direct and cytokine mediated cytotoxicity and perturbation of the interaction of leukemic blasts with the bone marrow stroma which is essential for blast cell survival.

Acute myeloid leukemia (AML) cells respond to exogenous stimulation from myeloid growth factors that may be secreted by cells of the bone marrow (BM) stroma and retained by glycosaminoglycans in the extracellular matrix. We have analyzed the capacity of malignant cells from patients with AML to maintain close proximity to sites of growth factor production and retention by binding to BM stromal elements, including fibroblasts and extracellular matrix proteins. Leukemic cells from all cases of AML adhered to BM fibroblast (BMF) monolayers (mean +/- standard error [SE] percentage binding, 30.9% +/- 2.5%; n = 23) and to fibronectin and laminin (mean +/- SE percentage binding, 28.0% +/- 4.1% [n = 11] and 21.5% +/- 2.3% [n = 8], respectively). Binding to bovine and human collagen type 1, vitronectin, hyaluronic acid, and albumin was minimal. Analysis of binding mechanisms indicated that very late antigen-4 (VLA-4) and VLA-5 were responsible for AML cell binding to fibronectin. Binding to laminin could be inhibited by antibody to the alpha chain of VLA-6. In contrast, AML cell adhesion to BMF monolayers was not impaired by blocking antibodies to either beta 1 or beta 2 integrins used alone, although the combination of anti-CD11/CD18 and anti-VLA-4 inhibited binding in more than 50% of cases. When anti-VLA-5 was added in these cases, mean +/- SE inhibition of binding of 45.5% +/- 9.1% (P < .001) was observed. Binding of AML cells to extracellular matrix proteins fibronectin and laminin is predominantly beta 1-integrin-dependent, but AML cell adhesion to BMF relies on the simultaneous involvement of beta 1 and beta 2 integrins as well as other currently unrecognized ligands.

Administration of interleukin 2 (IL2) to patients with minimal residual malignant disease following myeloablative chemo-radiotherapy may augment immune reconstitution and reduce the risk of relapse by increasing cytotoxic effector function and cytokine dependent killing directed at residual malignant cells. The ability of IL2 generated activated killer cells to inhibit haemopoietic progenitor cells and to release gamma-interferon (gamma IFN) and tumour necrosis factor (TNF) may, however, retard haemopoietic recovery, as both TNF and gamma IFN inhibit normal myelopoiesis in vitro. To determine the effect of IL2 infusion on myeloid regeneration in vivo, we have examined haemopoietic recovery in patients receiving this cytokine following autologous marrow transplantation or ablative chemotherapy. We find that IL2 infusion accelerates neutrophil recovery and that granulocyte-macrophage colony stimulating factor (GMCSF) and IL3 mRNA become detectable in circulating mononuclear cells. Induction of TNF by IL2 may also contribute to subsequent acceleration of myelopoiesis by initiation of GM-CSF mRNA synthesis in patient marrow fibroblasts. These results show that IL2 infusion may facilitate myeloid recovery when administered during the period of haemopoietic regeneration following ablative chemoradiotherapy.

Two hundred and ten adult CMV seropositive patients undergoing myeloablative conditioning (MAC) [n=127] or reduced intensity conditioning (RIC) [n=83] transplants (HCT) were serially monitored for CMV reactivation and disease, using a qualitative polymerase chain reaction (PCR) followed by quantitation with pp65 antigen or quantitative PCR. CMV reactivation occurred in 53 RIC (63.9%) and 61 MAC (48%; P=0.03) transplants at a median of 47 days (range: 24–1977). Risk factors identified included acute GVHD (P=0.001), RIC regimen (P=0.03), unrelated donor (P=0.02), use of anti-thymocyte globulin/alemtuzumb (P=0.02) and use of bone marrow in MAC transplants (P=0.011). On multivariate analysis, RIC transplants and acute GVHD remained independent predictors. Treatment with antiviral drugs resulted in CMV negativity rates of 86.8% in MAC and 88.6% in RIC transplants. CMV disease occurred in 10.8% of RIC and 4.7% of MAC transplants (P=0.15). At a median follow-up of 26 months (range: 3–88), 48.1% of RIC and 50.3% of MAC transplants are alive. The higher incidence of CMV reactivation among RIC transplants suggests the need for novel prophylactic or pre-emptive strategies in this high-risk group of patients. [ABSTRACT FROM AUTHOR]

Despite the importance of bone marrow stromal cells in hemopoiesis, the profile of surface molecule expression is relatively poorly understood. Mice were immunized with cultured human bone marrow stromal cells in order to raise monoclonal antibodies to novel cell surface molecules, which might be involved in interactions with hemopoietic cells. Three antibodies, WM85, CC9 and EB4 were produced, and were found to identify a 100-110 kDa antigen on bone marrow fibroblasts. Molecular cloning revealed the molecule to be MUC18 (CD146), a member of the immunoglobulin superfamily, previously described as a marker of metastatic melanoma. In addition to the expected expression on melanoma cell lines and endothelial cells, a number of human leukemic cell lines were found to express MUC18, including all six T leukemia lines tested, one of five B lineage lines and one of four myeloid lines. Analysis of bone marrow samples from patients revealed positivity in 20% of B lineage ALL (n = 20), one of three T-ALL, 15% of AML (n = 13) and 43% of various B lymphoproliferative disorders (n = 7). No apparent reactivity was observed with mononuclear cells from normal peripheral blood or bone marrow, including candidate hemopoietic stem cells characterized by their expression of the CD34 antigen. However, positive selection of bone marrow mononuclear cells labeled with MUC18 antibody revealed a rare subpopulation (<1%) containing more than 90% of the stromal precursors identified in fibroblast colony-forming assays. The structure and tissue distribution of MUC18 suggest a functional role in regulation of hemopoiesis. [ABSTRACT FROM AUTHOR]