A review of autologous hematopoietic cell transplantation

Comparison of Inpatient Outcomes Between HIV Positive and Negative Hospitalizations for Autologous Stem Cell Transplant Treatment among Lymphoid Malignancies

BACKGROUND

Comorbidity burden is higher among people living with HIV (PLWH). In addition, they experience adverse effects associated with antiretrovirals. In this study we looked for differences in adverse hospital outcomes between those with and without HIV among hospitalizations for autologous stem cell transplantations (ASCTs) for lymphoid malignancies.

MATERIALS AND METHODS

The current study was a retrospective analysis using the National Inpatient Sample (NIS) database, for the years 2005 to 2014. Adult hospitalizations ≥18 years of age, for ASCTs were included for the analysis, and were stratified into those with and without HIV. The primary outcome variables were in-hospital mortality, prolonged length of stay, and adverse dispositions.

RESULTS

We included a total of 117,686 ASCT hospitalizations, of which, 468 (0.4%) were HIV positive. Among HIV-positive hospitalizations, there were 251 (53.4%), non-Hodgkin lymphoma, 128 (27.4%), Hodgkin lymphoma, and 89 (19.2%) multiple myeloma cases. Only half of the PLWH among Black population received ASCT, compared to Whites (26.8% vs. 54.8%). Regression analyses showed that the odds of in-hospital mortality (OR, 0.77; 95% CI, 0.13-4.44), prolonged length of stay (OR, 1.18; 95% CI, 0.67-2.11), and dispositions other than home (OR, 1.26; 95% CI, 0.61-2.59) did not differ significantly between 2 groups.

DISCUSSION

We found that adverse hospital outcomes did not differ between those with and without HIV among hospitalized autologous stem cell transplant recipients. However, the rates of ASCT were substantially lower among Black PLWH. New interventions and approaches should be developed to improve ASCT rates among HIV positive racial minorities.

Impact of Frailty on Hospital Outcomes Among Patients with Lymphoid Malignancies Receiving Autologous Hematopoietic Stem Cell Transplantation in the United States

BACKGROUND

Frailty could affect outcomes of autologous hematopoietic stem cell transplantation (aHSCT). This study sought to examine the effects of frailty on hospital outcomes among patients with non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), and multiple myeloma (MM) who received aHSCT.

MATERIALS AND METHODS

This study was a retrospective analysis of Nationwide Inpatient Sample database, 2005 to 2014. Outcome variables were in-hospital mortality, prolonged length of stay and hospitalization cost. Frail patients were defined using the Johns Hopkins Adjusted Clinical Groups frailty-defining diagnosis indicator.

RESULTS

There were 20,573 NHL, 8,974 HL, and 40,750 MM patients. Among them, 5.5% NHL, 3.8% HL, and 4.8% MM patients were frail. Among patients with NHL, there were significant associations between frailty and in-hospital mortality (Odds Ratio [OR], 4.04, 95% CI: 2.11-7.76), and prolonged length of stay (OR, 2.32, 95% CI: 1.56-3.46). Similarly, among HL, there were significant associations between frailty and in-hospital mortality (OR, 1.82, 95% CI: 1.43-2.76), and prolonged length of stay (OR, 1.55, 95% CI: 1.34-2.84). Likewise, for MM, there were significant associations between frailty and in-hospital mortality (OR, 4.28, 95% CI: 2.16-8.48), and prolonged length of stay (OR, 3.00, 95% CI: 2.00-4.51). These associations remained significant after stratifying by age and comorbidities. Significant differences were observed in hospitalization cost between frail and non-frail patients.

CONCLUSION

Among patients with lymphoid malignancies undergoing HSCT, frailty was associated with greater in-hospital mortality, longer length of stay, and higher hospitalization costs. Comprehensive health status assessments for identifying and managing frail patients in this population could improve patient outcomes.

The impact of pulmonary function in patients undergoing autologous stem cell transplantation

High-dose chemotherapy, followed by autologous hematopoietic stem cell transplantation (auto-HSCT), is an established therapy for patients with hematological malignancies. The age of patients undergoing auto-HSCT and, therefore, the comorbidities, has increased over the last decades. However, the assessment of organ dysfunction prior to auto-HSCT has not been well studied. Therefore, we retrospectively analyzed the association of clinical factors and lung and cardiac function with outcome and complications after conditioning with BEAM (BCNU/carmustine, etoposide, cytarabine, melphalan) or high-dose melphalan in patients undergoing auto-HSCT. This study included 629 patients treated at our institution between 2007 and 2017; 334 and 295 were conditioned with BEAM or high-dose melphalan, respectively. The median follow-up was 52 months (range, 0.2-152) and 50 months (range, 0.5-149), respectively. In the multivariate analysis, we identified that progressive disease, CO-diffusion capacity corrected for hemoglobin (DLCOcSB) ≤ 60% of predicted, Karnofsky Performance Status (KPS) ≤ 80%, Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) score ≥ 4, and age > 70 years were associated with decreased overall survival (OS) in patients treated with BEAM. Similarly, DLCOcSB ≤ 60% of predicted, HCT-CI score ≥ 4, and age > 60 years were identified in patients treated with high-dose melphalan. Abnormalities in DLCOcSB ≤ 60% of predicted were associated with chemotherapy with lung-toxic substances, mediastinal radiotherapy, KPS ≤ 80%, current/previous smoking, and treatment in the intensive care unit. More often, patients with DLCOcSB ≤ 60% of predicted experienced nonrelapse mortality, including pulmonary causes of death. In summary, we identified DLCOcSB ≤ 60% of predicted as an independent risk factor for decreased OS in patients conditioned with BEAM or high-dose melphalan prior to auto-HSCT.

Application of stem cell transplantation in autoimmune diseases

PURPOSE OF REVIEW

Autologous hematopoietic stem cell transplantation (HSCT) is a promising therapeutic modality for severe autoimmune diseases. In this review, we will outline the immunological mechanisms and the clinical evidence and experiences for therapeutic HSCT in autoimmune diseases, with particular focus on systemic sclerosis and multiple sclerosis.

RECENT FINDINGS

Approximately 3000 patients with autoimmune diseases worldwide have been treated with HSCT. HSCT in systemic sclerosis has been shown in three randomized controlled trials to be associated with significant long-term event-free survival despite some transplant-related mortality in the first year. A recent controlled trial in multiple sclerosis has also show benefit with transplant.

SUMMARY

The aim of HSCT is to 'reset' one's immune system into a naïve and self-tolerant state through immune depletion and regulation. HSCT requires careful patient selection, close collaboration between physicians and expertise of transplant team to ensure optimal outcome.

Providing both autologous and allogeneic hematopoietic stem cell transplants (HSCT) may have a stronger impact on the outcome of autologous HSCT in adult patients than activity levels or implementation of JACIE at Belgian transplant centres

While performance since the introduction of the JACIE quality management system has been shown to be improved for allogeneic hematopoietic stem cell transplants (HSCT), impact on autologous-HSCT remains unclear in Europe. Our study on 2697 autologous-HSCT performed in adults in 17 Belgian centres (2007-2013) aims at comparing the adjusted 1 and 3-yr survival between the different centres & investigating the impact of 3 centre-related factors on performance (time between JACIE accreditation achievement by the centre and the considered transplant, centre activity volume and type of HSCT performed by centres: exclusively autologous vs both autologous & allogeneic). We showed a relatively homogeneous performance between Belgian centres before national completeness of JACIE implementation. The 3 centre-related factors had a significant impact on the 1-yr survival, while activity volume and type of HSCT impacted the 3-yr survival of autologous-HSCT patients in univariable analyses. Only activity volume (impact on 1-yr survival only) and type of HSCT (impact on 1 and 3-yr survivals) remained significant in multivariable analysis. This is explained by the strong relationship between these 3 variables. An extended transplantation experience, i.e., performing both auto & allo-HSCT, appears to be a newly informative quality indicator potentially conveying a multitude of underlying complex factors.

Mobilization of hematopoietic progenitors from normal donors using the combination of granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor results in fewer plasmacytoid dendritic cells in the graft and enhanced donor T cell engraftment with Th1 polarization: results from a randomized clinical trial

Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) both mobilize CD34(+) stem cells into the blood when administered before apheresis but have distinct effects on dendritic cell (DC) differentiation. We previously demonstrated that the combination of GM+G-CSF results in fewer plasmacytoid DCs (pDCs) when used to mobilize peripheral blood stem cells for autologous transplantation. To test the hypothesis that the content of pDCs in an allograft can be modulated with the cytokines used for mobilization, we randomized the human leukocyte antigen-matched sibling donors of 50 patients with hematological malignancies to a mobilization regimen of either GM+G-CSF (n = 25) or G-CSF alone (n = 25). Primary and secondary endpoints included the cellular constituents of the mobilized grafts, the kinetics of posttransplantation immune reconstitution, and clinical outcomes of the transplantation recipients. Grafts from donors receiving GM+G-CSF contained equivalent numbers of CD34(+) cells with fewer pDCs and T cells, with a higher fraction of Th1-polarized donor T cells than G-CSF mobilized grafts. Immune recovery was enhanced among recipients of GM+G-CSF. Survival was not significantly different between transplantation recipients in the two arms. The use of GM+G-CSF modulates immune function and recovery after allogeneic transplantation and should be explored in larger studies powered to evaluate clinical outcomes.

Second hematopoietic SCT for lymphoma patients who relapse after autotransplantation: another autograft or switch to allograft?

Although autologous hematopoietic SCT (auto-HSCT) is the only potentially curative treatment for lymphoma that has relapsed after conventional chemotherapy, the prognosis of patients with disease recurrence after auto-HSCT is poor. Some highly selected patients can benefit from second transplants. One-third with late recurrence after initial auto-HSCT may attain a prolonged remission after second auto-HSCT. Non-myeloablative or reduced-intensity conditioning (RIC) allogeneic hematopoietic SCT (allo-HSCT) has been used successfully after auto-HSCT failures, especially in subjects who have an HLA-compatible donor, chemosensitive disease and good performance status. Patients with chemosenstive disease recurrence who have completed at least 1 year after their first auto-HSCT should be considered for a second auto-HSCT. Patients who have chemoresistant disease are best served by participation in a well-designed clinical trial examining novel antitumor agents.

Peripheral blood stem cell mobilization: new regimens, new cells, where do we stand

PURPOSE OF REVIEW

Granulocyte colony-stimulating factor-mobilized peripheral blood stem cells are widely used to reconstitute hematopoiesis; however, preclinical and clinical studies show that improvements to this mobilization can be achieved. We discuss the development of new mobilizing regimens and evaluation of new findings on mobilized stem cell populations that may improve the utility and convenience of peripheral blood stem cell transplant.

RECENT FINDINGS

Chemokines and their receptors regulate leukocyte trafficking, and altering chemokine signaling pathways mobilizes stem cells. In recent trials, combination use of the chemokine (C-X-C motif) receptor 4 antagonist AMD3100 and granulocyte colony-stimulating factor mobilized more CD34 cells in fewer days than granulocyte colony-stimulating factor alone and allowed more patients to proceed to autotransplant. In preclinical studies the chemokine GRObeta synergizes with granulocyte colony-stimulating factor and when used alone or with granulocyte colony-stimulating factor mobilizes more primitive hematopoietic stem cells with less apoptosis, higher integrin activation, lower CD26 expression and enhanced marrow homing compared with granulocyte colony-stimulating factor. Hematopoietic stem cells mobilized by GRObeta or AMD3100 demonstrate superior engraftment and contribution to chimerism in primary and secondary transplant studies in mice, and peripheral blood stem cells mobilized by AMD3100 and granulocyte colony-stimulating factor in patients demonstrate enhanced engraftment capabilities in immunodeficient mice.

SUMMARY

Alternate regimens differentially mobilize stem cell populations with unique intrinsic properties with the potential to expand the utility of hematopoietic transplantation. Continued mechanistic evaluation will be critical to our understanding of mechanisms of mobilization and their use in regenerative medicine.

Chemokine-mobilized adult stem cells; defining a better hematopoietic graft

Stem cell research is currently focused on totipotent stem cells and their therapeutic potential, however adult stem cells, while restricted to differentiation within their tissue or origin, also have therapeutic utility. Transplantation with bone marrow hematopoietic stem cells (HSC) has been used for curative therapy for decades. More recently, alternative sources of HSC, particularly those induced to exit marrow or mobilize to peripheral blood by G-CSF, have become the most widely used hematopoietic graft and show significant superiority to marrow HSC. The chemokine/chemokine receptor axis also mobilizes HSC that occurs more rapidly than with G-CSF. In mice, the HSC and progenitor cells (HPC) mobilized by the CXCR2 receptor agonist GRObeta can be harvested within minutes of administration and show significantly lower levels of apoptosis, enhanced homing to marrow, expression of more activated integrin receptors and superior repopulation kinetics and more competitive engraftment than the equivalent cells mobilized by G-CSF. These characteristics suggest that chemokine axis-mobilized HSC represent a population of adult stem cells distinct from those mobilized by G-CSF, with superior therapeutic potential. It remains to be determined if the chemokine mobilization axis can be harnessed to mobilize other populations of unique adult stem cells with clinical utility.

Stem cell based therapies to treat muscular dystrophy

Muscular dystrophies comprise a heterogeneous group of neuromuscular disorders, characterized by progressive muscle wasting, for which no satisfactory treatment exists. Multiple stem cell populations, both of adult or embryonic origin, display myogenic potential and have been assayed for their ability to correct the dystrophic phenotype. To date, many of these described methods have failed, underlying the need to identify the mechanisms controlling myogenic potential, homing of donor populations to the musculature, and avoidance of the immune response. Recent results focus on the fresh isolation of satellite cells and the use of multiple growth factors to promote mesangioblast migration, both of which promote muscle regeneration. Throughout this chapter, various stem cell based therapies will be introduced and evaluated based on their potential to treat muscular dystrophy in an effective and efficient manner.

Peripheral blood stem cell mobilization: the CXCR2 ligand GRObeta rapidly mobilizes hematopoietic stem cells with enhanced engraftment properties

Chemokines direct the movement of leukocytes, including hematopoietic stem and progenitor cells, and can mobilize hematopoietic cells from marrow to peripheral blood where they can be used for transplantation. In this review, we will discuss the stem cell mobilizing activities and mechanisms of action of GRObeta, a CXC chemokine ligand for the CXCR2 receptor. GRObeta rapidly mobilizes short- and long-term repopulating cells in mice and/or monkeys and synergistically enhances mobilization responses when combined with the widely used clinical mobilizer, granulocyte colony-stimulating factor (G-CSF). The hematopoietic graft mobilized by GRObeta contains significantly more CD34(neg), Sca-1+, c-kit+, lineage(neg) (SKL) cells than the graft mobilized by G-CSF. In mice, stem cells mobilized by GRObeta demonstrate a competitive advantage upon long-term repopulation analysis and restore neutrophil and platelet counts significantly faster than cells mobilized by G-CSF. Even greater advantage in repopulation and restoration of hematopoiesis are observed with stem cells mobilized by the combination of GRObeta and G-CSF. GRObeta-mobilized SKL cells demonstrate enhanced adherence to vascular cell adhesion molecule-1 and VCAM(pos) endothelial cells and home more efficiently to bone marrow in vivo. The marrow homing ability of GRObeta-mobilized cells is less dependent on the CXCR4/SDF-1 axis than cells mobilized by G-CSF. The mechanism of mobilization by GRObeta requires active matrix metalloproteinase-9 (MMP-9), which results from release of pro-MMP-9 from peripheral blood, and marrow neutrophils, which alters the stoichiometry between pro-MMP-9 and its inhibitor tissue inhibitor of metalloproteinase-1, resulting in MMP-9 activation. The efficacy and rapid action of GRObeta and lack of proinflammatory activity make it an attractive agent to supplement mobilization by G-CSF. In addition, GRObeta may also have clinical mobilizing efficacy on its own, reducing the overall time and costs associated with peripheral blood stem cell transplantation.

Pilot study of allogeneic G-CSF-stimulated bone marrow transplantation: harvest, engraftment, and graft-versus-host disease

Peripheral blood progenitor cell (PBPC) harvests mobilized by granulocyte colony-stimulating factor (G-CSF) contain more CD34+ cells and provide more rapid engraftment than do bone marrow (BM) harvests. However, some reports have suggested a higher risk of chronic graft-versus-host disease (GVHD), possibly because such PBPC harvests contain approximately 10 times more T lymphocytes than do BM harvests. Some groups are attempting to combine the faster engraftment of PBPCs with the lower incidence of GVHD observed after BM transplantation by using G-CSF-primed BM conventionally harvested from iliac crests for allogenic BM transplantation. We report the results of a pilot study of 38 allogeneic transplants using G-CSF-stimulated BM from related donors, with a focus on the harvest composition, engraftment, and incidence of acute and chronic GVHDs.

Factors associated with outcomes in allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning after failed myeloablative hematopoietic cell transplantation

PURPOSE

Several studies have investigated the feasibility of allogeneic hematopoietic cell transplantations (HCTs) after reduced-intensity conditioning in patients who experienced relapse after myeloablative HCT. Although most studies showed relatively low nonrelapse mortality (NRM) rates and encouraging short-term results, it has yet to be defined which patients would benefit most from these approaches.

PATIENTS AND METHODS

We analyzed data from 147 patients with hematologic malignancies who experienced treatment failure with conventional autologous (n = 135), allogeneic (n = 10), or syngeneic (n = 2) HCT and were treated with HLA-matched related (n = 62) or unrelated (n = 85) grafts after conditioning with 2 Gy of total-body irradiation with or without fludarabine.

RESULTS

Three-year probabilities of NRM, relapse, and overall survival were 32%, 48%, and 27%, respectively, for related recipients, and 28%, 44%, and 44%, respectively, for unrelated recipients. The best outcomes were observed in patients with non-Hodgkin's lymphoma, whereas patients with multiple myeloma and Hodgkin's disease had worse outcomes as a result of high incidences of relapse and progression. Being in partial remission (PR) or complete remission (CR) at HCT (P = .002) and developing chronic graft-versus-host disease (GVHD; P = .03) resulted in lower risks of relapse and progression. Factors associated with better overall survival were PR or CR (P = .01) and lack of comorbidity (P = .03) at HCT and absence of acute GVHD after HCT (P = .06).

CONCLUSION

Encouraging outcomes were seen with allogeneic HCT after nonmyeloablative conditioning in selected patients who had experienced relapse after a high-dose HCT, particularly in patients with non-Hodgkin's lymphoma. Results with unrelated grafts were comparable with results with related grafts.

Infections after CD34-selected or unmanipulated autologous hematopoietic stem cell transplantation

Immune reconstitution may be delayed after CD34-selected compared with unmanipulated autologous peripheral blood stem cell transplantation (PBSCT), resulting in a theoretically increased risk of infections. In a case-control matched study we compared the incidence of infection in 25 recipients of CD34-selected PBSC (CD34 group) and 75 recipients of unmanipulated PBSC (PBSC group) transplants. The population included 52 males and 48 females suffering from non-Hodgkin's lymphoma (n = 32), Hodgkin's disease (n = 8), multiple myeloma (n = 40) or breast cancer (n = 20). Neutrophil engraftment was comparable in the two groups. The actuarial incidence of infection was similar in the two groups (56% vs. 49% at day 30, and 70% vs. 64% at 1 yr respectively). The proportion of patients with 1, 2 or 3 infections, the number of infectious event per patient (1.32 vs. 1.04; NS), the number of infections before day 15 or 30, between days 31 and 100 or after day 100, the risk of varicella-zoster virus or cytomegalovirus infection or disease, or the use of antibiotic or antifungal therapy, were not increased in the CD34 compared with the PBSC group. The main agents responsible for infection were bacteria, particularly gram-positive cocci, in both groups. Bacteremia accounted for 33% of all infectious events in the CD34 group vs. 16% in the PBSC group (P < 0.05). Fungal infections were rare. In conclusion, our results do not support the notion that CD34-selection of the graft is associated with an increased rate of infection after autologous PBSC transplantation. The role of extended infection prophylaxis should be evaluated.

Matrix metalloproteinase-9 and cell kinetics during the collection of peripheral blood stem cells by leukapheresis

The plasma levels of matrix metalloproteinase-9 (MMP-9) were determined during 41 collections of peripheral blood stem cells (PBSC) by standard volume (two blood volumes) leukaphereses (SVL) in 29 donors (7 allogeneic and 22 autologous) mobilized with the granulocyte-colony stimulating factor (G-CSF). The association between MMP-9 levels and cell counts in donor's blood was explored. During the processing of the first blood volume (BV), MMP-9 levels declined on average by 31% and persisted at the same level during the processing of the second BV. During the collection, a slight decline of white blood cells (WBC), polymorphonuclear neutrophils (PMN) and platelets (PLT) in donor's blood was accompanied by a significant drop of CD34+ cells by 37% after 1 BV and by 44% after 2 BV had been processed (p=0.001). The drop of MMP-9 plasma levels showed a loose correlation with the decrease of WBC (r=0.68, p=0.002) and PMN counts (r=0.67, p=0.001). We conclude that the levels of MMP-9 that have been elevated by the mobilization of donors with G-CSF, decrease during the collection of PBSC by 4h SVL. The observed decrease was indirectly related to the drop of WBC and PMN counts, suggesting that certain other factors have an influence on MMP-9 kinetics during PBSC collection.

Amifostine and autologous hematopoietic stem cell support of escalating-dose melphalan: A phase I study

This study was conducted to define a new maximum tolerated dose and the dose-limiting toxicity (DLT) of melphalan and autologous hematopoietic stem cell transplantation (AHSCT) when used with the cytoprotective agent amifostine. Fifty-eight patients with various types of malignancy who were ineligible for higher-priority AHSCT protocols were entered on a phase I study of escalating doses of melphalan beginning at 220 mg/m(2) and advancing by 20 mg/m(2) increments in planned cohorts of 4 to 8 patients until severe regimen-related toxicity (RRT) was encountered. In all patients, amifostine 740 mg/m(2) was given on 2 occasions before the first melphalan dose (ie, 24 hours before and again 15 minutes before). AHSCT was given 24 hours after the first melphalan dose. Melphalan was given in doses up to and including 300 mg/m(2). Hematologic depression was profound, although it was rapidly and equally reversible at all melphalan doses. Although mucosal RRT was substantial, it was not the DLT, and some patients given the highest melphalan doses (ie, 300 mg/m(2)) did not develop mucosal RRT. The DLT was not clearly defined. Cardiac toxicity in the form of atrial fibrillation occurred in 3 of 36 patients treated with melphalan doses >/=280 mg/m(2) and was deemed fatal in 1 patient given melphalan 300 mg/m(2). (Another patient with a known cardiomyopathy was given melphalan 220 mg/m(2) and died as a result of heart failure but did not have atrial fibrillation.) Another patient given melphalan 300 mg/m(2) died of hepatic necrosis. The maximum tolerated dose of melphalan in this setting was thus considered to be 280 mg/m(2), and 27 patients were given this dose without severe RRT. Moreover, 38 patients were evaluable for delayed toxicity related to RRT; none was noted. Tumor responses have been noted at all melphalan doses and in all diagnostic groups, and 21 patients are alive at median day +1121 (range, day +136 to day +1923), including 16 without evidence of disease progression at median day +1075 (range, day +509 to day +1638). Amifostine and AHSCT permit the safe use of melphalan 280 mg/m(2), an apparent increase over the dose of melphalan that can be safely administered with AHSCT but without amifostine. Further studies are needed not only to confirm these findings, but also to define the antitumor efficacy of this regimen. Finally, it may be possible to evaluate additional methods of further dose escalation of melphalan in this setting.

Neutrophil-derived MMP-9 mediates synergistic mobilization of hematopoietic stem and progenitor cells by the combination of G-CSF and the chemokines GRObeta/CXCL2 and GRObetaT/CXCL2delta4

Mobilized peripheral blood stem cells (PBSCs) are widely used for transplantation, but mechanisms mediating their release from marrow are poorly understood. We previously demonstrated that the chemokines GRObeta/CXCL2 and GRObetaT/CXCL2Delta4 rapidly mobilize PBSC equivalent to granulocyte colony-stimulating factor (G-CSF) and are synergistic with G-CSF. We now show that mobilization by GRObeta/GRObetaT and G-CSF, alone or in combination, requires polymorphonuclear neutrophil (PMN)-derived proteases. Mobilization induced by GRObeta/GRObetaT is associated with elevated levels of plasma and marrow matrix metalloproteinase 9 (MMP-9) and mobilization and MMP-9 are absent in neutrophil-depleted mice. G-CSF mobilization correlates with elevated neutrophil elastase (NE), cathepsin G (CG), and MMP-9 levels within marrow and is partially blocked by either anti-MMP-9 or the NE inhibitor MeOSuc-Ala-Ala-Pro-Val-CMK. Mobilization and protease accumulation are absent in neutrophil-depleted mice. Synergistic PBSC mobilization observed when G-CSF and GRObeta/GRObetaT are combined correlates with a synergistic rise in the level of plasma MMP-9, reduction in marrow NE, CG, and MMP-9 levels, and a coincident increase in peripheral blood PMNs but decrease in marrow PMNs compared to G-CSF. Synergistic mobilization is completely blocked by anti-MMP-9 but not MeOSuc-Ala-Ala-Pro-Val-CMK and absent in MMP-9-deficient or PMN-depleted mice. Our results indicate that PMNs are a common target for G-CSF and GRObeta/GRObetaT-mediated PBSC mobilization and, importantly, that synergistic mobilization by G-CSF plus GRObeta/GRObetaT is mediated by PMN-derived plasma MMP-9.

Adoptive transfer of costimulated T cells induces lymphocytosis in patients with relapsed/refractory non-Hodgkin lymphoma following CD34+-selected hematopoietic cell transplantation

We explored the feasibility and toxicity of administering escalating doses of anti-CD3/CD28 ex vivo costimulated T cells as a therapeutic adjunct for patients with relapsed, refractory, or chemotherapy-resistant, aggressive non-Hodgkin lymphoma (NHL) following high-dose chemotherapy and CD34+-selected hematopoietic cell transplantation (HCT). Sixteen patients had infusions on day 14 after HCT of autologous T cells that had been stimulated using beads coated with anti-CD3 and anti-CD28 monoclonal antibodies. At baseline, the subjects had severe quantitative and functional T-cell impairments. The culture procedure partially reversed impaired cytokine responsiveness in T cells in vitro and in vivo. Transient dose-dependent infusion toxicities were observed. There was a rapid reconstitution of lymphocytes; however, there were persistent defects in CD4 T cells. Most interestingly, 5 patients had a delayed lymphocytosis between day 30 and day 120 after HCT. Maximal clinical responses included 5 patients with a complete response (CR), 7 patients with a partial response (PR), and 4 patients with stable disease. At a median follow-up of 33 months (range, 26-60 months), 5 patients are alive with stable or relapsed disease and 3 patients remain in CR. In conclusion, this phase 1 trial demonstrates that adoptive transfer of autologous costimulated T cells (1) is feasible in heavily pretreated patients with advanced NHL, (2) is associated with a rapid recovery of lymphocyte counts, (3) reverses cytokine activation deficits in vitro, and (4) is associated with delayed lymphocytosis in a subset of patients.

Peripheral blood stem cell mobilization. A role for CXC chemokines

Chemokines induce rapid hematopoietic stem and progenitor cell mobilization and synergize with hematopoietic cytokines in mobilizing stem and progenitor cells. These proteins alone and in combination offer new paradigms for autologous and allogeneic peripheral blood stem cell transplantation (PBSCT). The mechanisms responsible for hematopoietic stem cell (HSC) mobilization either with growth factors or chemokines are largely unknown, but a better understanding of these mechanisms will permit the development of novel, more rapid and efficacious regimens. Studies presented herein indicate that the CXCR2 chemokine receptor that interacts with selective chemokine ligands, particularly GRObeta/CXCL2 and GRObeta-T, may be the dominant receptor mediating hematopoietic cell mobilization, and that polymorphonuclear neutrophils may be the primary CXCR2 expressing target cell for stem and progenitor cell mobilization.

Alloreactive killer cells: hindrance and help for haematopoietic transplants

Haematopoietic-cell transplantation is a treatment for leukaemia and lymphoma. To reduce the incidence of graft-versus-host disease (GVHD) caused by transplanted T cells, donors and recipients are HLA matched. For patients for whom a matched donor is not available, one option is transplantation from an HLA-mismatched relative who shares one HLA haplotype. This procedure is distinguished by the use of a stronger conditioning regimen for the patient and of a T-cell-depleted graft containing numerous stem cells. After transplantation, natural killer cells are prevalent, and they can include alloreactive cells that kill tumour cells and prevent GVHD. The alloreactions seem to be determined by the mismatched HLA class I ligands and their killer-cell immunoglobulin-like receptors.

Nonmyeloablative allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the most effective treatment for selected hematological malignancies. Its curative potential is largely mediated by an immune-mediated destruction of malignant cells by donor lymphocytes termed graft-versus-leukemia (GVL) effect. However, because of its toxicity, conventional allogeneic HSCT is restricted to younger and fitter patients. These observations led several groups to set up new (less toxic) transplant protocols (nonmyeloablative stem cell transplantation or NMSCT) based on a two-step approach: first, the use of immunosuppressive (but nonmyeloablative) preparative regimens providing sufficient immunosuppression to achieve engraftment of allogeneic hematopoietic stem cells and, in a second step, destruction of malignant cells by the GVL effect. Preliminary results showed that NMSCT were feasible with a relatively low transplant-related mortality (TRM), even in patients older than 65 years. In addition, strong antitumor responses were observed in several hematological malignancies as well as in some patients with renal cell carcinoma. After discussing the mechanisms and efficacy of the GVL effect as well as the rationale for NMSCT strategies, this article reviews the first results of ongoing clinical trials. Innovative modalities that may permit amplification of the GVL effect while minimizing the risk of GVHD are discussed. Because the benefits of NMSCT over alternative forms of treatment remain to be demonstrated, this strategy should be restricted to patients included in clinical trials.

Topotecan-filgrastim combination is an effective regimen for mobilizing peripheral blood stem cells

We compared the efficacy, toxicity, and cost of topotecan-filgrastim and filgrastim alone for mobilizing peripheral blood stem cells (PBSCs) in 24 consecutive pediatric patients with newly diagnosed medulloblastoma. PBSCs were mobilized with an upfront window of topotecan-filgrastim for 11 high-risk patients (residual tumor > or =1.5 cm2 after resection; metastases limited to neuraxis) and with filgrastim alone for 13 average-risk patients. All patients subsequently underwent craniospinal irradiation and four courses of high-dose chemotherapy with stem cell rescue. Target yields of CD34+ cells (> or =8 x 10(6)/kg) were obtained with only one apheresis procedure for each of the 11 patients treated with topotecan-filgrastim, but with a mean of 2.3 apheresis procedures for only six (46%) of the 13 patients treated with filgrastim alone (P = 0.0059). The median peak and median total yield of CD34+ cells were six-fold higher for the topotecan-filgrastim group (328/microl and 21.5 x 10(6)/kg, respectively) than for the filgrastim group (54/microl and 3.7 x 10(6)/kg, respectively). Mean times to neutrophil and platelet engraftment were similar. Myelosuppression was the only grade 4 toxicity associated with topotecan-filgrastim mobilization and lasted a median of 5 days. Compared with filgrastim mobilization, topotecan-filgrastim mobilization resulted in a mean cost saving of $3966 per patient. Topotecan-filgrastim is an efficacious, minimally toxic, and cost-saving combination for PBSC mobilization.

High-dose therapy in lymphomas: a review of the current status of allogeneic and autologous stem cell transplantation in Hodgkin's disease and non-Hodgkin's lymphoma

Autologous stem cell transplantation has proven to be beneficial in selected patients with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL). In patients with HD, transplantation appears to increase event-free survival in patients who fail to enter complete remission with initial therapy. When a patient relapses after a complete remission, transplantation is probably the best option and particularly so if the remission lasted less than 1 year. Transplantation as part of primary therapy for very high-risk patients may be beneficial, but is not standard therapy at this time. For patients with diffuse large-cell NHL, transplantation can be considered standard therapy for relapsed patients if they have chemotherapy-sensitive disease. The use of transplantation for high-risk patients in complete remission is promising, but definite recommendations cannot be made at this time. For follicular lymphomas, selected patients seem to benefit and studies are ongoing. Finally, the use of allogeneic stem cell transplantation can be useful in a select group of younger patients.