Factors associated with second-line triplet therapy in routine care in relapsed/refractory multiple myeloma

WHAT IS KNOWN AND OBJECTIVE

Second-line therapy (SLT) trials in relapsed/refractory multiple myeloma (RRMM) report superior outcomes with triplet combinations. We sought to determine factors associated with triplet SLT in routine practice.

METHODS

A retrospective cohort with claims for MM between 01/01/2008 and 03/31/2015 was grouped by 1-2 ("doublet") or 3+ ("triplet") agent therapy. Charlson comorbidity index (CCI) and disability status; CRAB symptoms (hypercalcaemia, renal/bone disease, anaemia); and relapse risk were determined.

RESULTS

Among 623 patients, the triplet group (n=146 [23%]) was younger (65.2 vs 69.8 years) and more likely to have high-risk relapse (67% vs 50%), CRAB symptoms (94.5% vs 81.1%), triplet first-line treatment (75% vs 51%) and frontline stem cell transplant (38% vs 20%) (P<0.001 for all). In multivariate analyses, CRAB symptoms (OR: 3.22, 95% CI: 1.47, 7.10), high-risk relapse (OR: 1.71, 95% CI: 1.12, 2.62) and prior triplet therapy (OR: 2.16, 95% CI: 1.38, 3.40), but neither CCI nor disability, were associated with triplet SLT. A trend towards triplets among younger patients (<65 vs >75 years, OR: 1.73, 95% CI: 0.99, 3.04) was observed.

WHAT IS NEW AND CONCLUSION

The majority of patients did not receive triplet regimens. Treatment selection with triplet therapy for RRMM should carefully consider comorbidities and patient-specific characteristics.

Single-dose fosaprepitant for the prevention of chemotherapy-induced nausea and vomiting associated with moderately emetogenic chemotherapy: results of a randomized, double-blind phase III trial

BACKGROUND

To establish the role of antiemetic therapy with neurokinin-1 (NK1) receptor antagonists (RAs) in nonanthracycline and cyclophosphamide (AC)-based moderately emetogenic chemotherapy (MEC) regimens, this study evaluated single-dose intravenous (i.v.) fosaprepitant for the prevention of chemotherapy-induced nausea and vomiting (CINV) associated with non-AC MEC.

PATIENTS AND METHODS

In this international, phase III, double-blind trial, adult cancer subjects scheduled to receive ≥1 non-AC MEC on day 1 were randomized to a regimen comprising single-dose i.v. fosaprepitant 150 mg or placebo along with ondansetron and dexamethasone on day 1; control regimen recipients received ondansetron on days 2 and 3. Primary end points were the proportion of subjects achieving a complete response (CR; no vomiting and no use of rescue medication) in the delayed phase (25-120 h after MEC initiation) and safety. Secondary end points included CR in the overall and acute phases (0-120 and 0-24 h after MEC initiation, respectively) and no vomiting in the overall phase. Nausea and the Functional Living Index-Emesis were assessed as exploratory end points.

RESULTS

The fosaprepitant regimen improved CR significantly in the delayed (78.9% versus 68.5%; P < 0.001) and overall (77.1% versus 66.9%; P < 0.001) phases, but not in the acute phase (93.2% versus 91.0%; P = 0.184), versus control. In the overall phase, the proportion of subjects with no vomiting (82.7% versus 72.9%; P < 0.001) and no significant nausea (83.2% versus 77.9%; P = 0.030) was also significantly improved with the fosaprepitant regimen. The fosaprepitant regimen was generally well tolerated.

CONCLUSION

Single-dose fosaprepitant added to a 5-HT3 RA and dexamethasone was well tolerated and demonstrated superior control of CINV (primary end point achieved) associated with non-AC MEC. This is the first study to evaluate NK1 RA therapy as an i.v. formulation in a well-defined non-AC MEC population.

CLINICALTRIALSGOV

NCT01594749 (https://clinicaltrials.gov/ct2/show/NCT01594749).

Bortezomib, dexamethasone, cyclophosphamide and lenalidomide combination for newly diagnosed multiple myeloma: phase 1 results from the multicenter EVOLUTION study

This phase 1 study (Clinicaltrials.gov: NCT00507442) was conducted to determine the maximum tolerated dose (MTD) of cyclophosphamide in combination with bortezomib, dexamethasone and lenalidomide (VDCR) and to assess the safety and efficacy of this combination in untreated multiple myeloma patients. Cohorts of three to six patients received a cyclophosphamide dosage of 100, 200, 300, 400 or 500 mg/m(2) (on days 1 and 8) plus bortezomib 1.3 mg/m(2) (on days 1, 4, 8 and 11), dexamethasone 40 mg (on days 1, 8 and 15) and lenalidomide 15 mg (on days 1-14), for eight 21-day induction cycles, followed by four 42-day maintenance cycles (bortezomib 1.3 mg/m(2), on days 1, 8, 15 and 22). The MTD was the cyclophosphamide dose below which more than one of six patients experienced a dose-limiting toxicity (DLT). Twenty-five patients were treated. Two DLTs were seen, of grade 4 febrile neutropenia (cyclophosphamide 400 mg/m(2)) and grade 4 herpes zoster despite anti-viral prophylaxis (cyclophosphamide 500 mg/m(2)). No cumulative hematological toxicity or thromboembolic episodes were reported. The overall response rate was 96%, including 20% stringent complete response (CR), 40% CR/near-complete response and 68% >or=very good partial response. VDCR is well tolerated and highly active in this population. No MTD was reached; the recommended phase 2 cyclophosphamide dose in VDCR is 500 mg/m(2), which was the highest dose tested.

Are comorbidities present in non-Hodgkin's lymphoma (NHL) patients (pts) enrolled in recent clinical trials different from those observed in previous clinical trials?

e19540

Introduction: Co-morbidities are often more prevalent in community practice than in clinical studies due to an increased mortality risk (Kuderer 2006; Noga 2007). As NHL treatments have changed and NHL rates in the US have increased 81% from 1973 to 1997 (Garber 2001), pt characteristics of NHL practice-changing studies may have changed to reflect the general NHL population. Here we summarize major co-morbid conditions present in pts from 4 key NHL trials published from 1976 to 2007. Methods: Intermediate/high-grade NHLs are sensitive to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP; McKelvey 1974; Fisher 1993), especially when combined with rituximab (RCHOP; Coiffier 2002). Entry criteria and demographics were tabulated from 4 interventional NHL trials published from 1976 to 2007: McKelvey 1976, a randomized study of 420 pts comparing CHOP and HOP; Fisher 1993, a phase 3, randomized study of 899 pts comparing CHOP, m-BACOD, ProMACE-CytaBOM, and MACOP-B; Coiffier 2002, a randomized study of 399 pts comparing CHOP with RCHOP; Noga 2007, an open-label study that included 325 NHL pts in community practice. Results: More recent NHL trials enrolled older pts compared with earlier trials ( Table ). Further, in the community-practice study by Noga et al (2007), nearly 1/3 of treated pts had at least 1 major co-morbidity. Such co-morbidities may have been formally or informally excluded in earlier clinical trials. Conclusions: More recent clinical trials tend to enroll older pts compared with earlier trials and tend to include pts with the major co-morbidities often seen in the general NHL population. Physicians may be more aware that cancer pts often have a significant prevalence of co-morbid conditions and that supportive care may allow these pts to benefit from study treatment. Clinical practice may also be changing to allow more elderly pts with co-morbidities to receive aggressive chemotherapy.

[Table: see text]

[Table: see text]

A phase IV, open-label trial using bortezomib for retreatment of patients (pts) with multiple myeloma (MM) following an initial response to bortezomib

17539

Background: Bortezomib (VELCADE; Vc) has substantial single agent activity in heavily pretreated patients. Response rates have been shown to improve when used in combination with other agents. Since some pts experience long durations of response with treatment-free periods, this open-label, single-arm study was designed to determine the utility of retreatment with Vc alone or in combination with dexamethasone, thalidomide or liposomal doxorubicin. Methods: Pts who previously responded to Vc alone or in combination are eligible for this study. Up to 78 pts will receive Vc alone or in combination at the finishing dose of their initial Vc treatment (0.7, 1.0, or 1.3 mg/m2) as a bolus, intravenous injection on days 1, 4, 8, and 11 of a 21-day treatment cycle. Responses are assessed by the investigators and also calculated from percentage reduction in serum or urine M-protein. Results: To date, 15 pts have been treated and 12 are evaluable for response (having received at least 2 cycles of therapy). 8/12 patients had dexamethasone added to their regimen. The population is representative of pts with relapsed and refractory MM: mean age, 68 years; 4 males, 8 females; median of 5 prior lines of therapy; and 67% IgG MM. Median treatment-free period between the end of first Vc treatment and the start of retreatment: 11.1 months (range 5–21 months). Investigator-assessed responses show that 50% of pts have achieved a PR or CR. Only 1 pt had progressive disease. One pt has developed new peripheral neuropathy, while pre-existing neuropathy has worsened in 4 pts. No Vc-related serious adverse events have been reported. Conclusions: Preliminary results show that retreatment with Vc alone or in combination has encouraging activity with manageable toxicity even in pts who are heavily pretreated. These data suggest that repeated use after a treatment break may achieve prolonged disease control. This is the first report of Vc retreatment for MM.

[Table: see text]

High incidence of graft failure in children receiving CD34+ augmented elutriated allografts for nonmalignant diseases

T-cell depletion of the marrow graft using counterflow centrifugal elutriation reduces the risk of graft-versus-host disease (GVHD). However, because of high rates of graft failure and relapse, elutriation alone has not improved survival. We have carried out a phase II clinical trial in 54 pediatric patients to determine if CD34+ selection to rescue pluripotent stem cells from the small lymphocyte fraction improves engraftment. The processed grafts contained a mean of 5.5 x 10(7) cells/kg IBW, 4.7 x 10(6) CD34+ cells/kg IBW, and 6.3 x 10(5) CD3+cells/kg IBW. Patients achieved an ANC >500 at a median of 16 days and platelet count >20 000 at a median of 28 days. The incidence of clinically significant GVHD was 19%. In total, 10 patients enrolled in this study experienced graft failure, with eight of the 14 patients transplanted for nonmalignant indications failing to engraft stably. Graft failure was statistically significantly associated with nonmalignant diagnosis (P<0.001), but was not associated with CMV seropositivity, donor gender, or cell counts of the allograft. We conclude that although time to engraftment is similar to that seen with unmanipulated grafts, graft failure remains a significant problem in patients with hereditary, nonmalignant diseases. Future efforts will seek to preserve the benefits of elutriation with CD34+ selection by increasing immune ablation of the preparative regimen and/or increasing posttransplant immune suppression.

Allogeneic bone marrow transplantation in patients with sensitive low-grade lymphoma or mantle cell lymphoma

PURPOSE

To report survival outcomes of allogeneic BMT in patients with low-grade lymphoma or mantle cell lymphoma (MCL).

PATIENTS AND METHODS

Thirty-five patients with low-grade lymphoma (48%), chronic lymphocytic leukemia (26%), or MCL (26%) underwent myeloablative allogeneic BMT from HLA-identical siblings at the Johns Hopkins Oncology Center. Patients had a median age of 46 years, a median of 2 prior treatments, and 31% were in complete remission at the time of transplantation. The preparative regimen was cyclophosphamide/total body irradiation for most patients. All grafts were T-cell depleted by counter flow centrifugal elutriation with CD34+ augmentation.

RESULTS

The incidence of acute GVHD grade >2 was 6% and of grades 1 to 2 was 37%. The incidence of chronic GVHD was 6%. The median follow-up time was 25 months. The rate of event-free survival (EFS) was 50% (95% confidence interval [CI], 33%-66%). Only 1 patient relapsed. The transplantation-related mortality (TRM) was 46% for all patients. The TRM was 86% for patients with resistant disease and 14% for patients with sensitive disease and <2 prior treatments; rates of EFS were 0% (95% CI, 0%-0%) and 79% (95% CI, 47%-93%), respectively.

CONCLUSION

These data show that, with T-cell depletion, the TRM and relapse rates are modest for patients with sensitive disease and <2 prior treatment courses. Thus, if there is a role for allogeneic BMT in the management of patients with these tumors, it is early in the course of the disease.

Using point-of-care CD34 enumeration to optimize PBSC collection conditions

BACKGROUND

A PBSC graft containing 4-5 x 10(6) CD34(+) cells/kg is considered optimal in terms of durable engraftment. Tracking CD34 kinetics via point-of-care testing during PBSC mobilization could determine which (and when) patients will yield an optimal product. We evaluated whether microvolume fluorimetry (MVF) would be useful in optimizing PBSC mobilization/harvest and if it will shorten our standard 6 h collection.

METHODS

Absolute CD34 values were obtained using the IMAGN 2000 and STELLer CD34 assay (50 microL sample volume). Peripheral blood (PB) CD34 values from 30 patients undergoing PBSC mobilization were used to generate a PB CD34-based algorithm that would predict collection day/duration of apheresis. The algorithm was then used prospectively to collect PBSC products on 50 hematologic malignancy (HM) patients.

RESULTS

Using the algorithm, patients were assigned to either a 6 (11-20 CD34/microL), 4 (21-49 CD34/microL) or 2 (> or = 50 CD34/microL) h collection. Patients with a CD34 value < or = 10/microL were re-tested. All patients (n = 43) predicted to mobilize reached the optimal CD34 (4-5 x 10(6)/kg) value with 1.0 apheresis procedure; seven patients had < or = 10/microL (nonmobilizers). The majority (75%) had apheresis charges decreased by 33-66%; 47% only required a 2 h procedure and 28% required 4 h. All patients demonstrated rapid trilineage engraftment.

DISCUSSION

Absolute PB CD34 measurement using MVF offers a rapid and reliable approach to obtaining optimal PBSC products with minimal technical expertise. Although not a replacement for conventional flow cytometry, it meets the requirements for a point-of-care procedure.

CD34 selection using three immunoselection devices: comparison of T-cell depleted allografts

BACKGROUND

T-cell depletion of allografts markedly reduces the incidence of GvHD following BMT. The approach taken at our Center has utilized the physical separation method of counterflow centrifugal elutriation (CCE), augmented by recovery of stem cells from lymphocyte-rich fractions by immunoaffinity selection of CD34(+) stem cells. We wanted to compare the performance characteristics of three commercially available selection devices, as well as the clinical outcomes of patients who received allografts engineered by the different devices.

METHODS

BM allografts were prepared for patients undergoing BMT for hematologic malignancies. BM cells were separated into lymphocyte-rich and lymphocyte-depleted fractions using CCE, followed by recovery of CD34(+) cells from the lymphocyte-rich fraction using one of three immunoselection devices [CellPro CEPRATE, Nexell Isolex 300i (software version 2.5) and AmCell CliniMACS]. Allografts consisted of the lymphocyte-depleted fraction plus the CD34-selected fraction.

RESULTS

Yields of CD34(+) cells were comparable for the three devices. However, there were significant differences in purity (CEPRATE < Isolex 300i < CliniMACS) and time from start of fractionation to infusion (CEPRATE < CliniMACS < Isolex 300i). More technical problems were encountered with the Isolex 300i device. Allograft compositions were comparable. Transplant outcomes (engraftment and incidence of GvHD) also were comparable.

DISCUSSION

Qualitatively and quantitatively, allografts prepared with the CEPRATE, Isolex 300i (v 2.5) and CliniMACS devices should be considered comparable for use in this setting and probably also for direct T-cell depletion of BM.

Long-term results of blood and marrow transplantation for Hodgkin's lymphoma

PURPOSE

To evaluate the long-term outcome after allogeneic (allo) and autologous (auto) blood or marrow transplantation (BMT) in patients with relapsed or refractory Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

We analyzed the outcome of 157 consecutive patients with relapsed or refractory HL, who underwent BMT between March 1985 and April 1998. Patients <or= age 55 with HLA-matched siblings were prioritized toward allo BMT. The median age was 28 years (range, 13 to 52 years) for the 53 allo patients and 30.5 years (range, 11 to 62 years) for the 104 auto patients.

RESULTS

The median follow-up after BMT for surviving patients was 5.1 years (range, 1 to 13.8 years). For the entire group, the probabilities of event-free survival (EFS) and relapse at 10 years were 26% (95% confidence interval [CI], 18% to 33%) and 58% (95% CI, 48% to 69%), respectively. According to multivariate analysis, disease status before BMT (sensitive relapse if responding to conventional-dose therapy or resistant disease if not) (hazard ratio [HR] = 0.39, P < .0001) and date of BMT (HR = 0.93, P = .004) were independent predictors of EFS, whereas only disease status (HR = 0.35, P < .0001) influenced relapse. There was a trend for probability of relapse in sensitive patients to be less after allo BMT at 34% (range, 8% to 59%) versus 51% (range, 36% to 67%) for the auto patients (HR = 0.51, P = .17). There was a continuing risk of relapse or secondary acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS) for 12 years after auto BMT, whereas there were no cases of secondary AML/MDS or relapses beyond 3 years after allo BMT.

CONCLUSION

There seems to be a clinical graft-versus-HL effect associated with allo BMT. Allo BMT for HL also seems to have a lower risk of secondary AML/MDS than auto BMT. Thus, allo BMT warrants continued study in HL.

NCCN: Multiple myeloma

Although multiple myeloma is sensitive to both chemotherapy and RT, it remains incurable at present. However, treatment algorithms based on published data, as well as clinical experience, can be developed to optimize therapy. This includes not only therapy for the underlying disease but also supportive therapy to enhance quality of life. Because myeloma is incurable, these guidelines prominently identify the clinical settings appropriate for treatment of patients on clinical research protocols.

Autologous graft-versus-host disease induction in advanced breast cancer: role of peripheral blood progenitor cells

The purpose of the present study was to investigate the impact of the use of peripheral blood progenitor cells (PBPCs) on the induction of autologous graft-versus-host disease (GVHD) in patients with advanced breast cancer. 14 women with stage IIIB and 36 women with stage IV breast cancer received cyclosporine (CsA) 2.5 mg kg-1 i.v. daily, d 0-28, and interferon-gamma (IFNg) 0.025 mg/m2 s.c. qod, d7-28, following PBPC-T +/- bone marrow transplantation (BMT). Preceding high-dose chemotherapy consisted of cyclophosphamide 6 g/m2 and thiotepa 800 mg/m2. Histologically proven > or = grade II cutaneous GVHD was induced in18/50 (36%) of patients and was independent of the source of haematopoietic support. In vitro studies showed that post-transplant, 76% of patients had developed auto-cytotoxicity against their own pre-transplant PHA-lymphoblasts. A significant correlation between the occurrence of GVHD > or = grade II and cytolysis was observed in the NK cell-line K562 and the T47D breast cancer cell-line. With a median follow-up of 2(1/2) years, the overall survival (OS) is 58%, the disease-free survival (DFS) 26%, both independent of the development of GVHD and similar to what has been observed in other studies on high-dose chemotherapy in advanced breast cancer. It therefore remains unclear whether the induction of autologous GVHD with the occurrence of auto-cytotoxic lymphocytes can result in an anti-tumour effect in this group of patients.

Engineering hematopoietic grafts using elutriation and positive cell selection to reduce GVHD

A systematic approach to hematopoietic graft manipulation has minimized several of the variables inherent to allogeneic BMT. Through this approach, we have been able to significantly impact on morbidity and quality of life following allogeneic transplantation. Acute and chronic GVHD, blood product and antibiotic usage, in patient hospitalization, acuity, costs and survival (especially in patients older than 40) have been improved. The HLA barrier still presents a formidable obstacle to achieving a more widespread use of this therapy. The complications encountered in HLA matched/TCD grafts occur with even greater magnitude in the HLA-mismatched or unrelated donor setting. Several centers are now engaged in studies using TCD grafts that are augmented with high doses of CD34+ cells to ensure engraftment while reducing the incidence of GVHD (50-53). Mobilized allogeneic PBSC appear to be an excellent source of stem cells for BMT (5,6). The earlier reports showed decreased rates of GVHD, despite having T cell burdens 10 times higher than those found in unmanipulated bone marrow. However, several of these centers now report an unacceptably high incidence of chronic GVHD (along with its attendant morbidity) following allogeneic PBSC transplantation (54-55). Initial results of TCD in these PBSC grafts using CD34+ selection are disappointing in that recipients developed unexpectedly high incidences of both acute and chronic GVHD (56). No doubt, significant differences exist between marrow and PBSC ancillary cell populations. For example, two laboratories now report the presence of natural suppressor cells in these allogeneic PBSC products in both mice (57) and humans (58). Thus, the same, step-wise approach would be expected to improve graft performance when using PBSC, cord blood, fetal tissue, xenografts or genetically engineered products as a stem cell source. Indeed, there are new reports of improved clinical outcome (especially in the incidence of GVHD) in the PMRD setting using both CD34+ selected (59) and sequential CD34+/CD2+ selected (60) PBSC grafts. It is hoped that future graft engineering approaches will be as successful as previous studies and will extend this form of therapy to an even larger patient population.

Graft engineering

Improvements in supportive care, antimicrobials, immunosuppressant therapy, and health care delivery have shifted the emphasis in hematopoietic stem cell transplantation toward raising cure rates and improving the quality of life in the years that follow transplantation. Many large centers have significantly reduced the morbidity of allogeneic transplantation by effecting a decrease in acute and chronic graft-versus-host disease. Extension of this modality through the use of unrelated donors, peripheral blood stem cell products, and HLA-mismatched family members has again introduced significant posttransplantation complications. Conversely, the posttransplantation morbidity of autologous transplantation is minimal, but the chances of remaining in long-term remission are still inferior to those afforded by allogeneic hematopoietic stem cell transplantation. One approach developed to reduce these long-term complications is referred to as "graft engineering." Through the use of successive clinical protocols, hematopoietic grafts and host immune properties can be manipulated in a stepwise fashion using several outcome parameters to judge efficacy. This report details one center's experiences with graft engineering over 12 consecutive years of clinical trials and speculates on future approaches that may supplant transplantation in the new millennium.

Human megakaryocytes and platelets contain the estrogen receptor beta and androgen receptor (AR): testosterone regulates AR expression

Gender differences in vascular thromboses are well known, and there is evidence that platelets may be involved in these differences and that sex hormones affect platelet function. We characterized the expression of the estrogen receptor alpha (ER alpha), estrogen receptor beta (ER beta), progesterone receptor (PR), and androgen receptor (AR) in the megakaryocyte lineage. Megakaryocytes generated ex vivo from normal human CD34(+) stem cells contained RNA for ER beta and AR, which increased with cell differentiation. Platelets and human erythroleukemia (HEL) cells also contained ER beta and AR transcripts. No ER alpha or PR messenger RNA or protein was detected in the megakaryocyte lineage. Immunofluorescence microscopy showed that ER beta protein was present in glycoprotein (GP) IIb(+) megakaryocytes and the HEL megakaryocytic cell line in a predominantly cytoplasmic location. AR showed a cytoplasmic and nuclear distribution in GPIIb(+) and GPIIb(-) cells derived from CD34(+) cells and in HEL cells. Western immunoblotting confirmed the presence of ER beta and AR in platelets. Megakaryocyte and HEL AR expression was up-regulated by 1, 5, and 10 nmol/L testosterone, but down-regulated by 100 nmol/L testosterone. These findings indicate a regulated ability of megakaryocytes to respond to testosterone and suggest a potential mechanism through which sex hormones may mediate gender differences in platelet function and thrombotic diseases.

Human herpesvirus 8 (KSHV) contamination of peripheral blood and autograft products from multiple myeloma patients

Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), has recently been identified within the bone marrow dendritic cells of multiple myeloma (MM) patients. This virus contains homologues to human cytokines such as IL-6 that could potentially stimulate myeloma cell growth and contribute to disease pathogenesis. Since mobilization chemotherapy may increase circulating dendritic cell numbers, we searched for HHV-8 in peripheral blood mononuclear cells (PBMCs) before and after mobilization chemotherapy given to MM patients. Furthermore, we determined if autograft purging using the CEPRATE SC device would reduce the percentage of HHV-8 infected stem cell products. Only two of the 39 PBMC samples collected prior to mobilization chemotherapy contained PCR detectable virus, yet nine of 37 PBMCs collected on the first day of leukapheresis had detectable HHV-8 (P = 0.016). HHV-8 was more frequently identified in autograft products before vs after Ceprate SC selection (40% vs 15%, P = 0.016). Although the role HHV-8 plays in myeloma pathogenesis remains unclear, these results imply that mobilization chemotherapy increases the numbers of circulating HHV-8-infected dendritic cells within the peripheral blood. In addition, CD34 selection of autograft products in MM patients may reduce the reintroduction of virally infected cells following high-dose chemotherapy. Bone Marrow Transplantation (2000) 25, 153-160.

Ex vivo cultured megakaryocytes express functional glycoprotein IIb-IIIa receptors and are capable of adenovirus-mediated transgene expression

Investigation of the molecular basis of megakaryocyte (MK) and platelet biology has been limited by an inadequate source of genetically manipulable cells exhibiting physiologic MK and platelet functions. We hypothesized that ex vivo cultured MKs would exhibit agonist inducible glycoprotein (GP) IIb-IIIa activation characteristic of blood platelets and that these cultured MKs would be capable of transgene expression. Microscopic and flow cytometric analyses confirmed that human hematopoietic stem cells cultured in the presence of pegylated recombinant human MK growth and development factor (PEG-rHuMGDF) differentiated into morphologic and phenotypic MKs over 2 weeks. Cultured MKs expressed functional GPIIb-IIIa receptors as assessed by agonist inducible soluble fibrinogen and PAC1 binding. The specificity and kinetics of fibrinogen binding to MK GPIIb-IIIa receptors were similar to those described for blood platelets. The reversibility and internalization of ligands bound to MK GPIIb-IIIa also shared similarities with those observed in platelets. Cultured MKs were transduced with an adenoviral vector encoding green fluorescence protein (GFP) or beta-galactosidase (beta-gal). Efficiency of gene transfer increased with increasing multiplicities of infection and incubation time, with 45% of MKs expressing GFP 72 hours after viral infection. Transduced MKs remained capable of agonist induced GPIIb-IIIa activation. Thus, ex vivo cultured MKs (1) express agonist responsive GPIIb-IIIa receptors, (2) are capable of expressing transgenes, and (3) may prove useful for investigation of the molecular basis of MK differentiation and GPIIb-IIIa function.

Philadelphia chromosome-negative engraftment after autologous transplantation with granulocyte-macrophage colony-stimulating factor for chronic myeloid leukemia

Autologous bone marrow transplantation (BMT) has not been curative in chronic myeloid leukemia (CML), because of the inability to purge CML from the autograft and the absence of the allogeneic T cell-mediated antileukemic activity. However, recent advances demonstrate that normal progenitors can be selected from CML marrows by a variety of techniques, including isolation by their small size. Furthermore, we found that myeloid growth factors have a potent antileukemic effect against CML progenitors in vitro by inducing their terminal differentiation. Based on these data, we initiated a trial of autologous BMT in patients with high-risk CML. Autografts were processed in an attempt to enrich for normal progenitors, first by isolating small cells by counterflow centrifugal elutriation and then incubating them in granulocyte-macrophage colony-stimulating factor (GM-CSF) for 72 hours. After a conditioning regimen of busulfan and cyclophosphamide, all patients received GM-CSF daily for 2 months. The median age of the 13 patients in the trial was 45 years (range 17-56 years). The median duration of disease before BMT was 24 months (range 13-72 months). Eight patients were in chronic phase (CP), and five were in accelerated phase (AP). All patients failed to achieve a cytogenetic response to interferon-alpha and were 100% Philadelphia chromosome (Ph)+ before BMT. There were three transplant-related deaths, all AP patients. All of the remaining 10 patients engrafted with some degree of Ph- hematopoiesis; despite high-risk features, nine patients engrafted 100% Ph-. All patients relapsed cytogenetically at a median of 6 months (range 4-22 months). These results demonstrate that autologous BMT can consistently induce complete Ph- engraftment in CP patients. GM-CSF appears to produce a clinical antileukemic effect against CML after autologous BMT.

Effectiveness of rotor off fraction in allogeneic murine bone marrow transplantation with complete disparity of major histocompatibility

Counterflow centrifugal elutriation (CCE) has been a highly efficient physical method for separating T cells from bone marrow (BM) without impairing cell function and yield. To investigate the usefulness of CCE, the hematopoietic potential as well as the level of T cell contamination in rotor-off (R/O) fraction of BM was studied using a murine bone marrow transplantation (BMT) model [C3H/He (H-2k)-->BALB/C (H-2d)]. The total recovery of cells after CCE procedure was 71.4%. Morphologically, R/O fraction contained abundant mononuclear cells and a few lymphocytes. The numbers of colony forming unit for granulocyte/monocyte (CFU-GM), Sca-1+ cells, and T cells were compared among four fractions of CCE (fractions at flow rate of 17, 25, 28 mL/min, and R/O fraction). The number of CFU-GM per 10(5) nucleated cells in each fraction were significantly higher in R/O fraction (331.3 +/- 34.4) compared to unfractionated marrow (UM) (21.1 +/- 1.3) and fraction of 17 mL/min (FR 17) (23.7 +/- 2.2 ) (chi2 = 0.0044). Neither fraction of 25 mL/min (FR 25) nor fraction of 28 mL/min (FR 28) contained CFU-GM colonies. The concentration of Sca-1+ cells in R/O fraction was significantly higher (1.96-fold) than UM (p < 0.05), and 80.0 +/- 10.1% of Sca-1+ cells in UM were recovered in R/O fraction; 88.1% of Thy-1.2+ T cells were eliminated in R/O fraction (p < 0.05). Mice receiving UM after lethal irradiation (875cGy) suffered from severe graft-versus-host disease (GVHD) and all five died within 7 days after BMT procedure (Group A). Of interest, mice receiving mixture of R/O fraction with lymphocyte-rich fraction (FR 25 plus FR 28) to equalize T cell number as UM, developed severe GVHD and four out of five died (probability of survival; 20%) (Group B). Mice receiving R/O fraction had mild GVHD and four out of five survived for at least 90 days (probability of survival; 80%) (Group C). In group C, probability of survival (p = 0.0006) was higher, and severity of GVHD (p = 0.0043) and progression rate of GVHD (p = 0.02) was lower. In conclusion, the elutriated R/O fraction cells of BM have the advantages of stable engraftment and tolerable GVHD in murine allogeneic BMT with complete major histocompatibility disparity. This could be directly applicable to patients with high risk of GVHD and graft failure in upcoming clinical trials.

Collection of peripheral blood progenitor cells (PBPC) based on a rising WBC and platelet count significantly increases the number of CD34+ cells

The kinetics of mobilization and optimal timing of peripheral blood progenitor cell (PBPC) collection were evaluated in 190 patients with multiple myeloma undergoing stem cell harvest after mobilization with cyclophosphamide, prednisone and G-CSF. There was a strong correlation between the WBC count and the number of CD34+ cells circulating in peripheral blood (r = 0.875). Initiating leukapheresis based on rising WBC and platelet counts rather than on a fixed day increased the mean number of CD34+ cells 115% (9.7 to 20.9 x 10(6) CD34+ cells/kg; P = 0.010) for the total of all leukaphereses and 59% for the total of all CD34-selected products (5.1 to 8.1 x 10(6) CD34+ cells/kg; P = 0.011). Although the yield and purity of the CD34-selected product were not significantly affected (P > or = 0.071), the percentage of patients with concentrations of CD34+ cells in the initial leukapheresis of > 1% increased from 47% to 70% (P = 0.004). The mean purity of the selected product was related to the starting percentage: 48.9% if < 1% and 81.5% if > or = 1% (P < 0.001). Collection of stem cells based on rising WBC and platelet counts significantly increased the number of CD34+ cells in leukaphereses and CD34-selected products in comparison with collection on a fixed day.

Acute bleeding after allogeneic bone marrow transplantation: association with graft versus host disease and effect on survival

BACKGROUND

Hemorrhagic complications are frequently implicated clinically for the high morbidity and mortality of acute graft versus host disease (GVHD), however, only few reports characterize the incidence and timing of bleeding in relation to GVHD, and essentially no study has quantified the effect of bleeding on survival of allogeneic patients with GVHD. This study examines the association of bleeding with acute GVHD and the effect of both complications on survival.

METHODS

A total of 463 allogeneic patients transplanted at the Johns Hopkins Hospital, were included in the study. Bleeding evaluation was based on daily scores of intensity and blood transfusions. All bleeding sites were recorded. GVHD staging was defined by the extent of rash, serum bilirubin, diarrhea, and confirmatory histology.

RESULTS

The incidence of GVHD was 27.4%, bleeding occurred in 40.2%. The incidence of bleeding was higher in patients with GVHD as compared with non-GVHD, and correlated with GVHD severity. The higher bleeding incidence in GVHD was due to gastrointestinal hemorrhage, hemorrhagic cystitis, and pulmonary hemorrhage. While the majority of bleeding (51/75) in non-GVHD patients initiated within 30 days after bone marrow transplantation (BMT), only 32.3% (21/65) of the bleeding in the GVHD group initiated within 30 days, and the risk for bleeding continued until day 100. Bleeding was a late event compared to GVHD, however, most bleeding episodes were associated with active GVHD. Both GVHD and bleeding were individually associated with reduced survival, with profound additive adverse effect: median survival in 221 nonbleeding non-GVHD was >83.2 months, GVHD nonbleeding (39 patients) had median of 10.6 months, bleeding non-GVHD (99 patients) had median of 4.3 months, and median survival of the GVHD bleeding group (85 patients) was 3.2 months.

CONCLUSIONS

Our results support an association of bleeding with acute GVHD, suggesting that GVHD is a risk factor for bleeding after BMT. The occurrence of bleeding clearly identified poor outcome subgroup within GVHD, suggesting further evaluation for clinical application of bleeding in the assessment of GVHD severity.

Frequent detection of tumor cells in hematopoietic grafts in neuroblastoma and Ewing's sarcoma

Many poor-risk neuroblastomas and tumours of the Ewing's sarcoma family (ET) recur despite autologous transplants. Recurrence may be due to tumor cells contained in the BM harvests or PBSC harvests. The objectives of this prospective study were to: (1) determine the incidence and degree of tumor cell contamination in paired BM and PBSC harvests; and (2) determine the efficacy of tumor cell purging by immunomagnetic CD34+ cell selection. 198 samples from 11 consecutive patients with neuroblastoma or Ewing's sarcoma were analyzed. We assayed tumor contamination by RT-PCR assay for PGP 9.5, plus immunohistochemistry for neuroblastoma-specific antigens (the latter in neuroblastoma only). None of these patients had tumor cells detected in their BM by clinical histology immediately before BM or PBSC harvests. However, 82% of PBSC and 89% of backup BM harvests were contaminated with tumor by RT-PCR and/or immunocytochemistry assays. Unselected PBSC and BM harvests contained similar quantities of tumor cells (median, approximately 200000 cells). Cyclophosphamide plus G-CSF mobilization did not affect the incidence or level of contamination in PBSC harvests, as compared to blood obtained before mobilization. Immunomagnetic CD34+ cell selection depleted tumor cells by a median of 3.0 logs for PBSC, and 2.6 logs for BM harvests.

CD34+ stem cell augmentation of elutriated allogeneic bone marrow grafts: results of a phase II clinical trial of engraftment and graft-versus-host disease prophylaxis in high-risk hematologic malignancies

Although T cell depletion of allografts used in BMT has reduced GVHD, it has been associated with inferior engraftment and an increased risk of relapse. We have found that T cell depletion by counterflow centrifugal elutriation (CCE) also results in depletion of CD34+ stem cells. In order to determine if the discarded CD34+ cells would improve engraftment, we undertook a phase II trial of allogeneic BMT in which 110 patients (median age 43) with a variety of hematologic malignancies received CD34+ stem cell augmented, elutriated marrow grafts. The T cell-depleted grafts were tightly controlled and contained a mean of 4.3 x 10(7) mononuclear cells/kg, 3.3 x 10(6) CD34+ cells/kg, 1.5 x 10(5) CFU-GM/kg and 5.5 x 10(5) CD3+ T cells/kg. Median time to engraftment of granulocytes (>500/microl) was 16 days and of platelets (>50000/microl) was 25 days, comparable to that seen with unmanipulated marrow. No mixed hematopoietic chimerism was observed that was not associated with disease relapse. The four patients (3.6%) who failed to engraft were all at high risk because of prior donor transfusions or underlying marrow disorders. The incidence of GVHD was dependent on the duration of cyclosporin A (CsA) immunosuppression. In patients who received CsA for > or = 80 days, the incidence of clinically significant acute GVHD (>stage 1) and extensive, chronic GVHD was 5% and 11%, respectively. Peritransplant (< or = 100 day post-BMT) mortality for this group of patients was 15%. Event-free survival in selected subsets of patients compared favorably to previous studies in which patients received unmanipulated marrow allografts.

Manipulating the Immunologic Characteristics of Both Graft and Host to Improve Transplant Outcome

BACKGROUND: Several critical outcomes of allogeneic stem cell transplantation for hematologic malignancies such as engraftment, incidence of graft-vs-host disease (GVHD) and disease-free survival depend on a balance between residual host and infused donor T cells and on chemosensitivity of the underlying disorder. Manipulating cell compartments of the allograft does affect long-term outcome. METHODS: The authors review investigations on the effect of blood and marrow graft components, treatment regimens, and immunologic interventions on eventual transplant outcome, an approach termed "graft engineering." Results: Major advances in graft engineering over the last decade are presented as a series of related developments or levels that derive from the goals of reducing GVHD and minimal residual disease. CONCLUSIONS: Morbidity and mortality of GVHD have decreased markedly by methods of T-cell depletion but at the expense of recurrent disease. Cellular therapy and immunotherapy show promise in potentially eradicating residual disease posttransplant.

Chemotherapy does not nullify the ability of donor lymphocyte infusions to mediate graft-versus-host reactions

Two patients with multiple myeloma in relapse after allogeneic BMT received donor lymphocyte infusions (DLI) but later required chemotherapy for treatment of myeloma-related complications. In both patients, recovery from chemotherapy-induced aplasia was accompanied by manifestations of graft-versus-host reactions. The first patient developed grade II acute GVHD and a complete remission which has lasted >22 months. The second patient developed grade III acute GVHD but died with co-existing GVHD and extensive extramedullary myeloma. These results demonstrate that chemotherapy does not nullify the ability of donor lymphocytes to mediate graft-versus-host reactions.

CD34 augmentation improves allogeneic T cell-depleted bone marrow engraftment

T cell depletion (TCD) performed by elutriation has decreased the incidence of acute and chronic graft-versus-host disease (GvHD) following bone marrow transplantation (BMT). However, as with all forms of TCD, patients may experience graft failure (10%), delayed engraftment, and mixed chimerism. Because 66%-75% of the CD34+ cells coseparate with the small lymphocytes, which are removed by elutriation, we designed a phase I trial in HLA-identical siblings to determine if the readdition of these previously lost small CD34+ cells would improve elutriation's engraftment kinetics. CD34+ cells were isolated from the small cell fraction of 10 consecutive donor grafts and infused into the recipients along with the TCD graft. The positively selected product had a mean T cell content of 1.2 x 10(5)/kg and was 80% CD34+, doubling the CD34+ content of the graft. All patients engrafted promptly with a median time to 500 neutrophils/mm3, untransfused 50,000 platelets/mm3, and discharge from the hospital of 19 (range 10-25), 24 (14-52), and 24 (18-29) days, respectively. Acute GvHD occurred in 2 patients, and no patient had chronic GvHD. Augmenting stem cell dose may be an efficient and safe alternative for overcoming TCD-associated delayed engraftment and graft failure, rather than increasing immunosuppression.

Engraftment following in utero bone marrow transplantation for globoid cell leukodystrophy

To date, in utero bone marrow transplantation (BMT) has had limited success, largely because of poor donor engraftment. The poor engraftment is probably the result of performing the procedure late in gestation after significant fetal immunocompetence has developed and/or transplanting insufficient numbers of donor hematopoietic stem cells for competing successfully with ongoing fetal hematopoiesis. To overcome these problems, we performed in utero BMT on a fetus with globoid cell leukodystrophy during the first trimester of gestation using selected paternal bone marrow stem (CD34+) cells. CD34 selection allowed a substantially greater number of stem cells to be transplanted. Although the fetus died 7 weeks after the procedure (during the 20th week of gestation), full donor engraftment was established. Moreover, the cause of death appeared to be overwhelming donor engraftment and leukostasis with paternal myeloid cells infiltrating most tissues. The ability of in utero BMT to produce this degree of engraftment provides great promise for the use of this approach in the treatment of a variety of inherited disorders that can be diagnosed prenatally.

Similar breast cancer cell contamination of single-day peripheral-blood progenitor-cell collections obtained after priming with hematopoietic growth factor alone or after cyclophosphamide followed by growth factor

PURPOSE

To evaluate tumor-cell contamination of peripheral-blood progenitor-cell (PBPC) collections obtained after priming with granulocyte colony-stimulating factor (G-CSF).

PATIENTS AND METHODS

Immunocytochemical (ICC) and tumor clonogenic (TCA) assays were used to analyze tumor-cell contamination of pretreatment peripheral-blood (PB) and bone marrow (BM) samples, and of PBPC collection samples obtained after priming with G-CSF 5 micrograms/kg/d for 5 or 7 days in 38 women with advanced breast cancer undergoing high-dose chemotherapy (HDC). Results were compared with 37 historical control patients who underwent PBPC mobilization with cyclophosphamide (4 g/m2) followed by granulocyte-macrophage colony-stimulating factor (GM-CSF) 5 micrograms/kg/d for 14 days.

RESULTS

Before PBPC priming with G-CSF, only one of 37 (3%) PB and four of 36 (11%) BM samples had tumor cells detected by ICC. Tumor-cell contamination of PBPC collections obtained after 5 or 7 days of G-CSF priming was observed in only three of 38 patients (8%). All patients with tumor cells detected in the PBPC collection had stage IV disease. Cells with in vitro clonogenic potential were detected only in the pretreatment BM sample in one patient, and another two patients had ICC- and TCA-positive PBPC samples despite tumor-negative PB and BM before priming. These results are similar to those previously reported for PBPC primed with cyclophosphamide and GM-CSF.

CONCLUSION

In patients with advanced breast cancer responsive to cytotoxic chemotherapy, tumor-cell contamination is not increased in PBPC collected after 5 or 7 days priming with G-CSF and appears similar to that seen when PBPC are primed with cyclophosphamide followed by GM-CSF.

Cell cycle-specific behavior of erythropoietin

The murine erythropoietin-dependent erythroleukemia cell line, HCD-57, was employed to study the cell cycle-specific behavior of erythropoietin. Cell cycle duration for HCD-57 cells was approximately 12 hours and was uninfluenced by erythropoietin. Populations of HCD-57 cells synchronized in G1 by centrifugal elutriation were able to pass through one complete cell cycle in the absence of erythropoietin but, thereafter, arrested in G1 as identified by propidium iodide staining and flow cytometry. Analysis of cell cycle behavior using the metachromic dye acridine orange, however, revealed that HCD-57 cells pass through a G0 cell cycle phase and, like serum-deprived 3T3 cells, actually arrest in G0 when deprived of erythropoietin. Expression of the cell cycle regulatory protein p34cdc2 was invariant throughout the cell cycle in HCD-57 cells. p34cdc2 was constitutively phosphorylated in G0 cells, and this effect was not modified by erythropoietin. Erythropoietin receptor distribution was log normal in HCD-57 cells in each phase of the cell cycle. The affinity of these surface receptors for erythropoietin was essentially invariant throughout the cell cycle, but receptor expression was upregulated in G2M cells as compared with cells in G1 or S phase. Taken together, these data indicate that erythropoietin has an important role in the G0-G1 to S phase transition but, based on receptor expression, is involved in other phases of the cell cycle as well.

Predictive factors for peripheral-blood progenitor-cell collections using a single large-volume leukapheresis after cyclophosphamide and granulocyte-macrophage colony-stimulating factor mobilization

PURPOSE

(1) To study the ability of mobilized peripheral-blood progenitor cells (PBPC) collected in a single large-volume leukapheresis performed on a predetermined date to accelerate engraftment after high-dose cyclophosphamide and thiotepa; (2) to establish the minimum dose of PBPC associated with early engraftment; and (3) to identify parameters predictive of collection of large numbers of PBPC.

PATIENTS AND METHODS

Twenty-three patients with breast cancer received cyclophosphamide (4 g/m2) and granulocyte-macrophage colony-stimulating factor ([GM-CSF] 5 micrograms/kg/d x 15 days) for PBPC mobilization. A single leukapheresis was performed 15 days after cyclophosphamide administration. Then, patients received high-dose cyclophosphamide and thiotepa followed by reinfusion of PBPC and 4-hydroperoxycyclophosphamide (4HC)-purged bone marrow. PBPC concentration was measured in serial peripheral-blood samples and in the leukapheresis product. Correlation analysis between PBPC dose and engraftment and between leukapheresis yield and patient characteristics was attempted.

RESULTS

A single leukapheresis processed a median 36 L (range, 24 to 46) blood and collected 5 x 10(6) CD34+ cells/kg (< 0.3 to 24) and 6.2 x 10(5) colony-forming units granulocyte-macrophage (CFU-GM)/kg (< 0.001 to 29). All sixteen patients (70%) reinfused with > or = 2.9 x 10(6) CD34+ cells/kg reached a level of greater than 1,000 leukocytes/microL by day 13 and greater than 50,000 platelets/microL by day 15. All of these patients had a percentage of peripheral-blood CD34+ cells > or = 0.5%, and all but one, a level of greater than 100,000 platelets/microL, on the day of leukapheresis. The bone marrow CD34+ cell percentage at study entry predicted the number of CD34+ cells collected after PBPC mobilization (R2 = .42, P = .002). All patients with > or = 2.5% bone marrow CD34+ cells experienced early engraftment.

CONCLUSION

Reinfusion of PBPC collected in a single leukapheresis accelerates engraftment in the majority of patients. Pretreatment bone marrow CD34+ cell content determines PBPC mobilization capacity and may help select hematopoietic rescue strategies.

Absence of breast cancer cells in a single-day peripheral blood progenitor cell collection after priming with cyclophosphamide and granulocyte-macrophage colony-stimulating factor

The effect of priming on occult tumor cell involvement of peripheral blood (PB) and PB progenitor cell (PBPC) collections is poorly characterized. Using sensitive immunocytochemistry (ICC) and tumor clonogenic assays (TCA) specific for epithelial-derived tumor cells, hematopoietic specimens were analyzed for PBPC and occult tumor cell involvement in 28 patients with chemotherapy-sensitive stage IIIB or IV breast cancer. Before PBPC priming, tumor was detected by ICC in PB of 1 of 23 (4%) patients and in bone marrow (BM) harvests of 4 of 27 (15%) patients. Fifteen days after cyclophosphamide and granulocyte-macrophage colony-stimulating factor (GM-CSF) priming, 2 of 28 (7%) patients had ICC-positive PBPC collections. The median amplification of CD34+ PBPC during this time was over 19-fold (range, < 1 to 199). One patient had pretreatment tumor involvement of both PB and BM. One patient grew tumor colonies in TCA; the PB and BM were ICC- and TCA-positive, but the PBPC collection was ICC-positive and TCA-negative. After cytoreduction with conventional-dose chemotherapy, patients with advanced breast cancer and histologically negative BM biopsy specimens have rare tumor cell involvement of PB and BM. Despite effective PBPC priming with cyclophosphamide and GM-CSF, clonogenic breast cancer cells were not found in the PBPC collection performed on day 15.

Large-volume leukapheresis using regional citrate anticoagulation to collect peripheral blood progenitor cells

The use of peripheral blood progenitor cells (PBPC) for hematopoietic rescue after high-dose chemotherapy is limited by the number of leukaphereses required to collect an adequate number of hematopoietic progenitors. To optimize the collection of PBPC, we evaluated a single large-volume leukapheresis protocol with citrate anticoagulation. A group of 23 patients received cyclophosphamide (4 g/m2) and GM-CSF (5 micrograms/kg/day for 15 days) as PBPC mobilization, with a single outpatient 6 h leukapheresis performed on the COBE Spectra 15 days later. Citrate (0.190 mmol/ml) was infused at 1.2 ml/L of blood/minute with a whole blood to citrate ratio between 17:1 and 25:1. Calcium chloride (50 mM) was administered at a citrate to calcium molar ratio between 10:1 and 5:1 to prevent hypocalcemia. A median 36.6 L (range 24.4-46.4) blood was processed using 338 mM citrate (269-473) and 50 mM calcium (25-75). A median 5 x 10(6) CD34+ cells/kg (< 0.3-24) and 6.2 x 10(5) CFU-GM/kg (< 0.001-29) were collected, representing 5.6 and 5.9 more PBPC, respectively, than were in circulation at the initiation of leukapheresis. We conclude that a 6 h large-volume leukapheresis following cyclophosphamide and GM-CSF mobilization is safe, can recruit hematopoietic progenitors into the circulatory compartment, and allows the collection of high numbers of PBPC in a single procedure.

Bone marrow micrometastases in chemotherapy-responsive advanced breast cancer: effect of ex vivo purging with 4-hydroperoxycyclophosphamide

Tumor contamination of hematopoietic stem cell grafts may influence the outcome of breast cancer patients treated with high-dose chemotherapy. The goals of this study were: (a) to evaluate the prevalence of tumor contamination of bone marrow (BM) harvests in patients responding to systemic chemotherapy; (b) to evaluate reduction of BM tumor contamination by ex vivo purging with 4-hydroperoxycyclophosphamide (4HC); and (c) to compare the tumor contamination of peripheral blood progenitor cell collections and BM in advanced-stage breast cancer patients designated for peripheral blood progenitor cell infusion. We evaluated pre- and post-4HC purge BM specimens from 20 patients for tumor contamination using immunocytochemistry and for in vitro growth potential of tumor cells using a tumor cell clonogenic assay. Pre-4HC purge BM specimens from 15 of 20 (75%) patients were immunocytochemistry and tumor cell clonogenic assay negative. The remaining 5 BM specimens were immunocytochemistry positive, but only 3 of 5 specimens were tumor cell clonogenic assay positive. In vitro tumor colony growth was not observed in any post-4HC purge BM specimens. We also evaluated nine patients with bone or BM metastases from the start of induction chemotherapy. We found less tumor involvement of peripheral blood progenitor cell collections than of simultaneously obtained bone marrow aspirates. We conclude that bone marrow micrometastases occur with low frequency in women with chemotherapy-sensitive breast cancer and that ex vivo purging with 4HC may render tumor cells nonviable.

Administration of human recombinant granulocyte colony-stimulating factor (filgrastim) accelerates granulocyte recovery following high-dose chemotherapy and autologous marrow transplantation with 4-hydroperoxycyclophosphamide-purged marrow in women with metastatic breast cancer

Stem cell contamination by tumor is common in many diseases for which autologous bone marrow transplantation is used. In in vitro models chemotherapeutic purging reduces contamination and may have an impact on clinical outcome. Purging, however, delays engraftment. Little is known about the ability of granulocyte colony-stimulating factor (G-CSF) to accelerate myelopoiesis after purged autologous bone marrow transplantation. We treated 22 women with metastatic breast cancer with high-dose cyclophosphamide and thiotepa and, following the infusion of 4-hydroperoxycyclophosphamide-purged marrow, administered G-CSF, 16 micrograms/kg daily, from day 0 to engraftment. Results were compared with a control population of 24 women with breast cancer who received identical chemotherapy and purged marrow but not growth factor. Neutrophil recovery was accelerated in the G-CSF-treated population. An absolute neutrophil count of 500 was reached in 19 days compared with 29 for the historic controls. The median number of days febrile was reduced (8 versus 5.5) as were the number of days of hospitalization from marrow infusion (33 versus 25). There was no difference in the number of days on antibiotics or time to last platelet transfusion. G-CSF was administered without any notable toxicity. G-CSF accelerates myelopoiesis following the infusion of 4-hydroperoxycyclophosphamide-purged autologous marrow and shortens hospitalization.

Lymphocyte depletion in bone marrow transplantation: will modulation of graft-versus-host disease prove to be superior to prevention?

Despite its detrimental effects, graft-versus-host disease (GVHD) has antileukemic properties as evidenced by a lower relapse rate in patients who develop GVHD following allogenic bone marrow transplantation. Meaningful long-term survival may be achieved if this latter property can be retained at the same time that the deleterious immune sequelae of acute and chronic GVHD are diminished. This is the focus of several recent graft engineering protocols. Various bone marrow components (lymphocytes, hematopoietic stem cells, and committed progenitor cells) can now be isolated and then used to reformulate the marrow graft. Combined with host immunosuppression or cytokine augmentation, it now may be possible to modulate GVHD such that its beneficial properties are enhanced without incurring its life-threatening side effects.

Comparison of progenitor cell concentration techniques: continuous flow separation versus density-gradient isolation

Bone marrow harvests were processed using two techniques; 20 mononuclear cell concentrations (MNC) were prepared on the COBE Spectra and compared to 10 light-density cell fractions isolated using the COBE 2991. Both procedures recovered essentially the same percentage of nucleated cells (22 versus 21%) and gave progenitor cell recoveries of 132 and 100% of the CFU-GM and 101 and 104% of the CD34+ cells in the MNC and light-density products, respectively. The advantage of the Spectra MNC concentrate is that it was prepared with reagents approved for injection by the Food and Drug Administration. However, the average hematocrit on the MNC concentrate was 4%, while it was unmeasurable in the light-density cell fractions. This difference is significant only when bone marrows require purging with 4-hydroperoxycyclophosphamide or erythrocytes otherwise interfere with processing. The Spectra procedure recovered a larger percentage of MNC cells and had less contamination with mature granulocytes than did the density-gradient technique. When erythrocytes do not affect the bone marrow processing protocol, a Spectra MNC concentrate is a safe substitute for a light-density cell preparation.

Characterization of YB2/0 cell line by counterflow centrifugation elutriation

The non-secreting rat myeloma cell line YB2/0 could be separated into different cell fractions by counterflow centrifugal elutriation. The obtained fractions are analyzed by morphology studies, morphometrics, clonogenic assays and flow cytometry. The methodology is extensively described. A separation of different cell fractions according to cell cycle stages was achieved. This implies further application possibilities for clinical use like the in vitro fractionation of autologous bone marrow prior to transplantation in patients with multiple myeloma.

Autologous graft-versus-host disease: a novel approach for antitumor immunotherapy

Autologous bone marrow transplantation (BMT) is a therapeutic option for the treatment of lymphohematopoietic malignancies and solid tumors. Despite the intensive cytoreductive therapy, however, the rates of tumor recurrence after autologous BMT remain unacceptably high. Current studies suggest that the administration of cyclosporine (CsA) disrupts the reconstitution of self-tolerance following autologous BMT leading to the induction of an autoimmune graft-versus-host disease (GVHD). Studies in a rat tumor model and preliminary clinical trials suggest that this autoimmune or autologous GVHD provides a significant antitumor effect. Moreover, the antitumor effect of autologous GVHD can be enhanced by administration of gamma-interferon, which upregulates the antigen recognized by the autoreactive effector cells of autologous GVHD. These studies indicate that the induction of an autoimmune GVHD after autologous BMT may be a promising immunotherapeutic approach for treatment of certain neoplastic diseases.

Interferon-γ Potentiates the Antitumor Effect of Cyclosporine-Induced Autoimmunity

Graft-versus-host-disease (GVHD), which results after allogeneic bone marrow transplantation (BMT), is associated with reduced leukemic relapse. This may be mediated by an immunologic attack with subsequent destruction of residual tumor cells. On the other hand, GVHD does not normally occur after autologous BMT (ABMT), which has an inherently high relapse rate. However, an autoimmune syndrome (AIS) similar to GVHD can be induced after autologous/syngeneic BMT by administration of cyclosporine-A (CsA), resulting in the production of major histocompatibility complex (MHC) class II or Ia autoreactive cytolytic effector cells. Since many hematopoietic malignancies express variable levels of class II molecules, we hypothesized that the adjuvant use of interferon-gamma (IFN-gamma) with CsA-induced autoimmunity after autologous/syngeneic BMT may upregulate class II antigens on residual tumor cells and make them more susceptible to attack by the Ia-reactive cells of CsA-induced AIS. The present studies demonstrated that the CsA-induced autoimmune syndrome mediated an anti-tumor effect, although this effect was dependent on challenge with a minimal number of tumor cells. Further studies clearly demonstrated that the antitumor effect could be markedly enhanced by administration of IFN-gamma which increased the susceptibility of the tumor to recognition and lysis by the CsA induced autoimmune effector cells. The induction of MHC class II-restricted AIS similar to GVHD by administration of CsA together with the ability to manipulate the surface phenotype of residual tumor cells may lead to decreased relapse rates in the ABMT setting.

Graft Engineering: The Evolution of Hematopoietic Transplantation

In vivo therapeutic manipulation as well as ex vivo grafting are important strategies for bone marrow manipulation and transplantation. This review article discusses the early techniques for marrow processing and manipulation as a background for discussing later graft engineering protocols, as well as preclinical and experimental protocols designed to modify transplantation biology at the multidisciplinary level. The direction of future trials in graft transplantation is also discussed.

Recovery of the simian immunodeficiency virus (SIV) and depression of colony formation in in vitro infected progenitor cell-enriched rhesus bone marrow (BM)

Rhesus progenitor-enriched BM was exposed overnight to SIV and cultured in a limiting dilution assay where the potential for progenitor interaction with lymphocytes or macrophages was low. Virus was consistently isolated late in culture, detection being aided by coculture with CEM174 lymphoblasts. Although infected cells had reduced clonogenic activity, colonies were indistinguishable from those derived from uninfected BM with respect to proliferative potential, morphology, and longevity in culture. Primate immunodeficiency viruses, therefore, may infect immature BM populations, directly affecting hematopoietic activity.

Isolation of cell cycle fractions by counterflow centrifugal elutriation

Counterflow centrifugal elutriation (CCE) has been used to fractionate cell populations on the basis of sedimentation properties, with minimal perturbation of metabolic function. Therefore, it is an ideal method for the isolation of cell cycle phase specific populations. We present modifications of the standard Beckman centrifugal elutriation system which permit standardization of the elutriation procedure and eliminate inter-run variability. We provide elutriation parameters for the cell cycle fractionation of a variety of cultured cell lines and suggest ways to improve the quality of the cell separations. In addition, we describe protocols for the fractionation of up to 3.50 X 10(8) cells in the small (JE-6B) Beckman elutriation system. This represents a four- to eight-fold increase in cell numbers over current cell fractionation procedures. Cell cycle populations containing greater than 95% G1, greater than 80% S, and greater than 70% G2/M were consistently obtained using these protocols. Finally, we analyzed phase-enriched fractions from several cultured cell lines for the cell cycle regulation of the enzyme thymidine kinase. The data confirm previous findings that CCE is an excellent means of obtaining physiologically unperturbed cell cycle phase specific fractions.