Effects of CD3McAb and rhIL-2 activated bone marrow on the killing and purging of leukemia cells.

We investigated the roles of CD3McAb and rhIL-2 activated bone marrow in the killing and purging of leukemia cells. Cytotoxicity of activated bone marrow was detected with MTT assay. CFU-GM level in activated bone marrow and the destruction of leukemia cells were measured using the semi-solid cell culture. Immune activation markers in activated bone marrow were detected by indirect immunofluorescence assay. Bone marrow activated by CD3McAb and rhIL-2 displayed significantly upregulated the killing and purging abilities on the leukemia cell line K562 and HL-60. Such effects were superior to that of bone marrow activated by rhIL-2 or CD3McAb alone (P < 0.05, P < 0.01). Activation by rhIL-2 and (or) CD3McAb exerted no obvious influence on CFU-GM level in bone marrow. Compared with bone marrow activated by rhIL-2 or CD3McAb alone, the synergistic effect of both CD3McAb+ and hIL-2 caused significant increase of CD3(+), CD8(+), CD19(+), CD25(+), CD38(+), and CD56(+) levels. Our study indicates that CD3McAb enhanced the killing and purging effects of rhIL-2 activated bone marrow on leukemia cells.

Influence of ex vivo purging with CliniMACS CD34(+) selection on outcome after autologous stem cell transplantation in non-Hodgkin lymphoma.

The major limitation of autologous stem cell transplantation (auto-SCT) in non-Hodgkin lymphoma (NHL) is relapse. Although autologous graft contamination may be a potential cause, prior purging of the autograft remains controversial. Therefore, we retrospectively analysed 56 consecutive patients with NHL receiving auto-SCT at complete (n = 41) or partial remission (n = 15). Among them, 24 patients underwent autograft manipulation with positive selection of CD34(+) cells using a CliniMACS device (purged group). Twenty-five patients had received ≥2 previous chemotherapy regimens before auto-SCT. After a median follow-up of 41·4 months, transplant-related mortality was observed only in unpurged group (n = 2; 3·6%). The 3-year overall survival (91·7% vs. 56·1%, P = 0·009) and progression-free survival (78·7% vs. 53·1%, P = 0·034) favoured CD34(+) purification. While neutrophil recovery was similar, platelet recovery was delayed in the purged group. Cytomegalovirus reactivation was predominantly observed in the purged group, although no other clinically unmanageable infectious complications occurred. Although this study has the inevitable limitations of heterogeneity in previous treatment and NHL subtypes, and a small number of patients analysed, the high survival rate in the purged group may suggest the need for prospective randomized trials to determine the role of CD34(+) purification in auto-SCT for NHL.

Reovirus as a successful ex vivo purging modality for multiple myeloma.

Autologous stem cell rescue (ASCT) following high-dose myeloablative chemotherapy is considered to be a therapeutic option for many multiple myeloma (MM) patients; however relapse post ASCT presents a major challenge. The oncolytic potential of reovirus has been previously demonstrated and is currently undergoing phase I monotherapy clinical trials for MM and phase II/III clinical trials for solid tumors. Here we tested the hypothesis that reovirus can successfully purge MM in a murine model that partially recapitulates human MM. RPMI 8226, MM1S, H929 and U266 human myeloma cell lines were exposed to reovirus and oncolysis was assessed. Apheresis product admixed with MM cells was purged with live reovirus (LV) or dead virus (DV) and purging efficacy was monitored via flow cytometry, reverse transcribed-PCR (RT-PCR) and disease relapse in non obese diabetic/severe combined immune deficient (NOD/SCID) mice. Significant LV purging was seen with MM1S, H929 and U266 and the complete ex vivo purging achieved with RPMI 8226 was confirmed by flow cytometry, RT-PCR and absence of disease relapse in vivo. Mice that received LV-purged autografts exhibited 100% survival in comparison to mice that received DV-purged controls. Reovirus's unique ability to kill MM while sparing hematopoietic stem cells places it as an attractive purging agent for MM during ASCT.

Rituximab purging and/or maintenance in patients undergoing autologous transplantation for relapsed follicular lymphoma: a prospective randomized trial from the lymphoma working party of the European group for blood and marrow transplantation.

PURPOSE: The objective of this randomized trial was to assess the efficacy and safety of rituximab as in vivo purging before transplantation and as maintenance treatment immediately after high-dose chemotherapy and autologous stem-cell transplantation (HDC-ASCT) in patients with relapsed follicular lymphoma (FL). PATIENTS AND METHODS: Patients with relapsed FL who achieved either complete or very good partial remission with salvage chemotherapy were randomly assigned using a factorial design to rituximab purging (P+; 375 mg/m(2) once per week for 4 weeks) or observation (NP) before HDC-ASCT and to maintenance rituximab (M+; 375 mg/m(2) once every 2 months for four infusions) or observation (NM). RESULTS: From October 1999 to April 2006, 280 patients were enrolled. The median age was 51 years (range, 26 to 70 years), and baseline characteristics were well balanced between groups. On average, patients were 44 months (range, 3 to 464 months) from diagnosis, with 79% having received two lines and 15% three lines of prior therapy. Median follow-up was 8.3 years. In contrast to purging, 10-year progression-free survival (PFS) was 48% for P+ and 42% for NP groups (hazard ratio [HR], 0.80; 95% CI, 0.58 to 1.11; P = .18); maintenance had a significant effect on PFS (10-year PFS, 54% for M+ and 37% for NM; HR, 0.66; 95% CI, 0.47 to 0.91; P = .012). Overall survival (OS) was not improved by either rituximab purging or maintenance. CONCLUSION: Rituximab maintenance after HDC-ASCT is safe and significantly prolongs PFS but not OS in patients undergoing transplantation for relapsed FL. Pretransplantation rituximab in vivo purging, even in rituximab-naive patients, failed to improve PFS or OS.

[Leukemia SH-1 cells purged by ZnPcH(1)-based photodynamic therapy].

The objective of this study was to investigate the effect of a novel Zinc phthalocyanine (ZnPcH(1)) based photodynamic therapy (PDT) on acute monocytic leukemia cell lines SHI-1 and its mechanism, so as to provide theory basis for bone marrow purging in vitro for patients with leukemia. The killing effect of ZnPcH(1)-PDT on SHI-1 cells were assessed by MTT method; the SHI-1 cell death patterns were analyzed by AO/EB fluorescence staining, TdT-mediated dUTP nick end labeling (TUNEL), DNA ploidy analysis, and Annexin V-FITC/PI double staining.Cell mixture was established by integrating SHI-1 cells with normal bone marrow MNC (by 1:100-1:10 000). Purging effect of ZnPcH(1)-PDT against SHI-1 mixed into normal MNC was assessed by analyzing the expression of fusion gene MLL/AF6 mRNA using nested RT-PCR. The results showed that ZnPcH(1)-PDT could effectively inhibit SHI-1 cell proliferation in dose-dependent manner, and ZnPcH(1)-PDT could induce cell apoptosis in time-dependent manner. 0.5 µmol/L ZnPcH(1)-PDT could completely photoinactivated kill SHI-1 cells in the simulated remission bone marrow. It concluded that ZnPcH(1)-PDT may be a effective and convenient promising purging technique for leukemia.

Ex vivo graft purging and expansion of autologous blood progenitor cell products from patients with multiple myeloma.

Autologous peripheral blood progenitor cell (PBPC) transplantation is the treatment of choice for selected myeloma patients. However, tumor cells contaminating the apheresis product are a potential source of relapse. Here we report a sequential purging strategy targeting mature and immature clonogenic myeloma cell populations in the autograft. Thawed PBPC products of myeloma patients were treated with rituximab to kill CD138(-)20(+) B cells (highly clonogenic immature cells), and bortezomib to target CD138(+) cells (normal and differentiated myeloma plasma cells), followed by coculture with allogeneic mesenchymal stem cells (MSC) from normal donors. After 7 days of coculture, nonadherent cells were removed and cultured in the absence of MSC for an additional 7 days. Then, efficacy of purging (removal of CD138(-)20(+) and CD138(+) cells) was assessed by flow cytometry and PCR. We used our ex vivo purging strategy to treat frozen aphereses from 16 patients. CD138(+) and CD138(-)20(+)(19(+)) cells present in the initial products were depleted more than 3 and 4 logs, respectively based on 10(6) flow-acquisition events, and to levels below the limit of detection by PCR. In contrast, total nucleated cell (TNC), CD34(+) cell, and colony-forming cell numbers were increased by approximately 12 to 20, 8-, and 23-fold, respectively. Overall, ex vivo treatment of apheresis products with rituximab, bortezomib, and coculture with normal donor MSC depleted mature and immature myeloma cells from clinical aphereses while expanding the normal hematopoietic progenitor cell compartment.

High dose chemotherapy with autologous stem cell support for patients with histologically transformed B-cell non-Hodgkin lymphomas. A Norwegian multi centre phase II study.

We present a prospective phase II study of patients with relapse after chemotherapy showing transformation of follicular lymphoma to diffuse large B-cell lymphoma, performed before rituximab was included in standard treatment. Patients in complete (CR) or partial remission (PR) after salvage chemotherapy were eligible for high-dose chemotherapy with autologous stem cell support (HDT). Forty-seven patients from five Norwegian centres were included, of whom 30 (63%) received HDT. Eighteen (60%) achieved CR, seven (23%) PR and five (10%) had progressive disease following HDT. Median follow-up for the surviving patients was 75 months; median progression-free (PFS) and overall survival (OS) were 26 and 47 months, respectively. Median OS for all patients was 43 months, compared to only 10 months for patients not eligible for HDT. Patients receiving CD34(+) enriched/B-cell depleted grafts had inferior PFS and a trend for inferior OS compared to patients receiving non-purged grafts (Log Rank 0·025 and 0·151, respectively). In conclusion, two thirds of patients with transformation of follicular lymphoma were eligible for HDT. The majority of patients achieved CR and a considerable number had prolonged OS. The use of in vitro purged grafts did not result in a survival benefit compared to that of non-purged grafts.

Hexaminolevulinate-mediated photodynamic purging of marrow grafts with murine breast carcinoma.

Photodynamic therapy (PDT) with porphyrin precursors is an established therapy for certain tumors. This study aimed to explore the use of hexaminolevulinate (HAL), a porphyrin precursor, for photodynamic purging of BM grafts contaminated with cells of the 4T1 breast carcinoma cell line. The optimal PDT dose was not effective in eradicating 4T1 cells when the tumor cells were mixed with murine marrow cells in vitro. However, the number of pulmonary metastases was reduced, and the survival of experimental animals was prolonged substantially when they were subjected to TBI followed by transplantation of syngeneic BM containing metastasized 4T1 cells that had been treated ex vivo by HAL-PDT. Despite the failure of in vitro experiments, HAL-based photodynamic purging could be a useful modality for treating animals bearing an experimental breast carcinoma.

Cardiovascular changes after PMMA vertebroplasty in sheep: the effect of bone marrow removal using pulsed jet-lavage.

Clinically, the displacement of intravertebral fat into the circulation during vertebroplasty is reported to lead to problems in elderly patients and can represent a serious complication, especially when multiple levels have to be treated. An in vitro study has shown the feasibility of removing intravertebral fat by pulsed jet-lavage prior to vertebroplasty, potentially reducing the embolization of bone marrow fat from the vertebral bodies and alleviating the cardiovascular changes elicited by pulmonary fat embolism. In this in vivo study, percutaneous vertebroplasty using polymethylmethacrylate (PMMA) was performed in three lumbar vertebrae of 11 sheep. In six sheep (lavage group), pulsed jet-lavage was performed prior to injection of PMMA compared to the control group of five sheep receiving only PMMA vertebroplasty. Invasive recording of blood pressures was performed continuously until 60 min after the last injection. Cardiac output and arterial blood gas parameters were measured at selected time points. Post mortem, the injected cement volume was measured using CT and lung biopsies were processed for assessment of intravascular fat. Pulsed jet-lavage was feasible in the in vivo setting. In the control group, the injection of PMMA resulted in pulmonary fat embolism and a sudden and significant increase in mean pulmonary arterial pressure. Pulsed jet-lavage prevented any cardiovascular changes and significantly reduced the severity of bone marrow fat embolization. Even though significantly more cement had been injected into the lavaged vertebral bodies, significantly fewer intravascular fat emboli were identified in the lung tissue. Pulsed jet-lavage prevented the cardiovascular complications after PMMA vertebroplasty in sheep and alleviated the severity of pulmonary fat embolism.

Hexaminolevulinate-mediated photodynamic purging of leukemia cells from BM.

Photodynamic therapy (PDT) with porphyrin precursors has been established for tumor treatment. This study aimed at examining applicability of hexaminolevulinate (HAL) for photodynamic purging of leukemic cells from BM grafts and evaluating the clinical relevance of in vitro models. The PDT dose resulting in no colony formation by leukemic cells in vitro, in pure form or in a mixture with BM cells, was insufficient for complete killing of the leukemic cells ex vivo and for the treatment of the leukemia-bearing animals in vivo. The efficacy of HAL-PDT in cell lines in vitro should be verified in clinically relevant in vivo models.

Incidence and reasons for late failure after allogeneic haematopoietic cell transplantation following BuCy2 in acute myeloid leukaemia.

The long-term follow-up is presented for 317 patients with acute myeloid leukaemia who underwent human leucocyte antigen-identical sibling marrow transplants between 1984 and 1995 following preparation with busulfan 16 mg/kg and cyclophosphamide 120 mg/kg. Among the 142 (45%) who were alive and leukaemia-free 3 years following transplantation, the leukaemia-free survival at 15 years was 72.8%. The cumulative incidence of late (>3 years beyond transplant) non-relapse mortality at 15 years was 12.9% and of late relapse was 16.5%. None of the variables considered (including age, disease stage, and graft-versus-host disease) were predictive of late failure.

[Stem cell therapy in multiple sclerosis: a clinical update]. / Stammzelltherapie bei multipler Sklerose: Eine Bilanz aus klinischer Sicht.

Promising results in an animal model of multiple sclerosis (MS; experimental autoimmune encephalomyelitis, EAE) have shown that immunosuppression followed by allogeneic bone marrow transplantation has the potential to significantly ameliorate the spontaneous course of the disease. Since 1995, emerging data on autologous hematopoietic stem cell transplantation (AHSCT) has supported a benefit also in patients with multiple sclerosis. To date, results on approximately 500 cases have been consecutively reported by the European Group for Blood and Marrow Transplantation (EBMT). These reports have not only proved a favourable outcome for many patients but also provided the rationale for the currently ongoing controlled trials on AHSCT in MS. At present, results from the ASTIMS study in particular, a multicenter active-controlled phase II study, are awaited. However, a number of critical issues remain unresolved. Furthermore, with upcoming new treatment compounds that to some extent act via lymphoablative properties, it remains essential to better select those patients who might profit most from stem cell therapy based on a justifiable benefit-to-risk ratio. Although transplant related mortality has dropped to 1%, mortality combined with concerns about long-term safety remain critical issues in a primarily non-life-threatening disease like MS.

Fibrinolysis-independent role of plasmin and its activators in the haematopoietic recovery after myeloablation.

Proteinases have been implicated in the mobilization of haematopoietic progenitor cells (HPCs) from the bone marrow (BM). Here, we report the involvement of the plasminogen (Plg) system in the haematopoietic recovery following chemotherapy. By using gene-deficient mice, we found that plasmin and its activators tPA and uPA play a role in the haematopoietic recovery upon delivery of the cytotoxic agent 5-fluoro-uracil (5-FU). The impaired haematopoietic recovery of Plg-deficient (Plg(-/-)) mice after 5-FU was not rescued by depletion of fibrinogen, indicating that it was not due to defective fibrinolysis. Instead, loss of Plg impaired breakdown of fibronectin, VCAM-1 and laminin-BM matrix proteins involved in adhesion of HPCs to their BM microenvironment and in transendothelial migration of HPCs. These findings provide novel insights in how plasmin regulates haematopoietic recovery upon cytotoxic myeloablation.

Favourable long-term outcome after matched sibling transplantation for Fanconi-anemia (FA) and in vivo T-cell depletion.

Hematopoietic stem cell transplantation is the only permanent treatment for the hematological manifestations in Fanconi anemia (FA). As FA patients have a dramatically increased intrinsic propensity to develop malignancies later in life and the genotoxic stress afflicted during conditioning advances the manifestation age especially of squamous cell carcinomas, choosing an optimally suited treatment regimen appears critical for long-term, tumor-free survival after stem cell transplantation. Here, we report our experiences in 6 consecutive FA patients transplanted with HLA-matched sibling donors where we combined an established pre-transplantation treatment consisting of thoraco-abdominal irradiation (TAI), cyclophosphamide (CYC) and cyclosporine A graft-versus-host prophylaxis with antibody-mediated IN VIVO T-cell depletion strategies after infusion of the graft. This approach has ensured sustained engraftment with long-term survival and an excellent post transplant performance status without any evidence of secondary malignancies in all six patients after a median follow-up of more than 10 years.

Immunochemotherapy with in vivo purging and autotransplant induces long clinical and molecular remission in advanced relapsed and refractory follicular lymphoma.

BACKGROUND: To evaluate the clinical outcome of patients with relapsed or refractory follicular lymphoma treated with immunochemotherapy, in vivo purging and high-dose therapy with autotransplant. PATIENTS AND METHODS: Sixty-four patients were enrolled in the trial. Primary end point was progression-free survival (PFS). Secondary end points were the in vivo purging effect on stem-cell harvest and the impact of molecular response on the outcome. RESULTS: At enrollment, 59% of patients were PCR+ for bcl-2 rearrangement in bone marrow (PCR-informative). After the immunochemotherapy, before mobilization, 97% obtained complete response or partial response and 87% of patients informative for bcl-2 were molecularly negative. Sixty-one patients proceeded to in vivo purging and peripheral blood stem cell (PBSC) mobilization with rituximab and high-dose AraC. The median number of CD34+ cells collected was 16.6 x 10(6)/kg. Of 33 PCR-informative patients, the harvests resulted in PCR- in all. Fifty-eight patients received high-dose therapy and autotransplant of in vivo purged PBSC. After a median follow-up of 3.5 years, 41 patients are in complete remission. Five-year PFS is 59%. CONCLUSION: This study demonstrates that patients with advanced relapsed or refractory follicular lymphoma treated with immunochemotherapy, in vivo purging and autotransplant may obtain long-lasting PFS. In bcl-2-positive patients, in vivo purging allows the harvest of lymphoma-free PBSC. Absence of the bcl-2 rearrangement after autotransplant is associated with persistent clinical remission.