Allogeneic hematopoietic cell transplantation after failed autologous transplant for lymphoma using TLI and anti-thymocyte globulin conditioning.

We describe 47 patients with lymphoma and failed prior autologous hematopoietic cell transplantation (HCT) who received TLI-ATG (anti-thymocyte globulin) conditioning followed by allogeneic HCT. Thirty-two patients had non-Hodgkin lymphoma (NHL; diffuse large B-cell lymphoma (n=19), T-cell NHL (n=6), mantle cell lymphoma (n=4) or other B-cell subtypes (n=3)), and 15 had Hodgkin lymphoma. The median follow-up was 4.9 (range, 2.1-11.9) years. The cumulative incidence of grade II-IV acute GvHD at day +100 was 12%, and the cumulative incidence of extensive chronic GvHD at 1 year was 36%. The 3-year cumulative incidences of overall survival (OS), PFS and non-relapse mortality (NRM) were 81%, 44% and 7%, respectively. Fifteen patients died (relapse, n=10; NRM, n=5). Among the 25 patients with relapse after allogeneic HCT, 11 (44%) achieved durable (>1 year) CRs following donor lymphocyte infusion or chemoradiotherapy. The majority of surviving patients (75%; n=24) were able to discontinue all immunosuppression. For patients with relapsed lymphoma after autologous HCT, allogeneic HCT using TLI-ATG conditioning is a well-tolerated, predominantly outpatient therapy with low NRM (7% at 3 years), a low incidence of GvHD, durable disease control and excellent OS (81% at 3 years).

Tandem chemo-mobilization followed by high-dose melphalan and carmustine with single autologous hematopoietic cell transplantation for multiple myeloma.

Single autologous hematopoietic cell transplant (AHCT) with high-dose melphalan prolongs survival in patients with multiple myeloma but is not curative. We conducted a study of intensive single AHCT using tandem chemo-mobilization with CY and etoposide followed by high-dose conditioning with melphalan 200 mg/m(2) plus carmustine 15 mg/kg. One hundred and eighteen patients in first consolidation (CON1) and 58 patients in relapse (REL) were transplanted using this intensified approach. Disease response improved from 32% very good PR (VGPR)+CR pre-mobilization to 76% VGPR+CR post transplant in CON1. With a median follow-up of 4.7 years, the median EFS was 2.8 years, and the median OS was 5.1 years in CON1. OS from time of transplant was significantly shorter for REL (3.4 years) compared with CON1 (5.1 years; P=0.02). However, OS from time of diagnosis was similar in REL (6.1 years) and CON1 (6.0 years; P=0.80). The 100-day non-relapse mortality in the CON1 and REL groups was 0% and 7%, respectively. In summary, intensified single AHCT with tandem chemo-mobilization and augmented high-dose therapy is feasible in multiple myeloma and leads to high-quality response rates.

Long-term follow-up of patients with diffuse large B-cell non-Hodgkin's lymphoma receiving purged autografts after induction failure.

Patients with diffuse large B-cell lymphoma (DLBCL) who do not achieve a complete response to front-line combination chemotherapy are often offered high-dose therapy and autologous hematopoietic cell transplantation (AHCT). However, the efficacy of this therapy in this patient population has been addressed in only a few published reports. We retrospectively analyzed the outcomes of patients with a diagnosis of de novo DLBCL who underwent AHCT at our center between 1988 and 2002, and identified 43 consecutive patients who had not achieved a CR before AHCT, although most showed at least a partial response (PR) to either induction or subsequent salvage chemotherapy. A total of 15 patients received a conditioning regimen that included high-dose chemotherapy with fractionated TBI (FTBI), whereas 28 patients received high-dose chemotherapy only. All autografts were treated ex vivo with MoAbs and complement in an effort to remove any residual malignant B cells. A total of 33 (77%) patients achieved a CR after AHCT. With a median follow-up of 7.3 years, the 5-year OS was 69% and EFS was 59%. Four patients died from non-relapse mortality. By univariate analyses, the following characteristics did not significantly impact OS: disease stage at diagnosis, age-adjusted IPI (International Prognostic Index) score, age > or =40 years, earlier radiotherapy and the use of FTBI in the conditioning regimen. These results confirm the long-term efficacy of AHCT for patients with DLBCL after induction failure.

Advancing animal models of neoplasia through in vivo bioluminescence imaging.

Malignant disease is the final manifestation of complex molecular and cellular events leading to uncontrolled cellular proliferation and eventually tissue destruction and metastases. While the in vitro examination of cultured tumour cells permits the molecular dissection of early pathways in tumorigenesis on cellular and subcellular levels, only interrogation of these processes within the complexity of organ systems of the living animal can reveal the full range of pathophysiological changes that occur in neoplastic disease. Such analyses require technologies that facilitate the study of biological processes in vivo, and several approaches have been developed over the last few years. These strategies, in the nascent field of in vivo molecular and cellular imaging, combine molecular biology with imaging modalities as a means to real-time acquisition of functional information about disease processes in living systems. In this review, we will summarise recent developments in in vivo bioluminescence imaging (BLI) and discuss the potential of this imaging strategy for the future of cancer research.

Hodgkin disease-derived cell lines expressing ubiquitous mitochondrial creatine kinase show growth inhibition by cyclocreatine treatment independent of apoptosis.

Ubiquitous mitochondrial creatine kinase (uMtCK), a key enzyme in energy metabolism, was identified by differential display PCR to be specifically overexpressed in L1236, the first cell line of definite Hodgkin origin. RT-PCR confirmed overexpression of uMtCK in the L1236 cell line and the absence of cytosolic B-CK, which is co-expressed with MtCK physiologically. Cyclocreatine (cCr), whose phosphorylated form is a very poor substrate for CK, inhibited proliferation of the L1236 cell line nearly entirely. This inhibition by cCr was partially reversed by competition with creatine, which by itself had no effect on proliferation of the L1236 cell line. Although these results support a role of CK activity in the inhibitory action of cCr, it remains open whether the cCr effect is due to its inhibition of CK-linked energy metabolism or if alternative mechanisms have to be considered. Because the anti-proliferative effect of cCr was not due to induction of apoptosis, in contrast to most other anticancer agents, treatment with the creatine analogue cCr may represent an advantageous therapeutic approach for cells resistant to programmed cell death.

Bioluminescence imaging of lymphocyte trafficking in vivo.

Lymphocytes are highly mobile cells that travel throughout the body in response to a tremendous variety of stimuli. Revealing lymphocyte trafficking patterns in vivo is necessary for a complete understanding of immune function, as well as cell-cell and cell-tissue interactions in immune development and in response to insult. Although the location of cell populations in various tissues at any given point in time may be revealed by techniques such as flow cytometry and immunofluorescence, these methods are not readily amenable to the assessment of dynamic cell migration patterns in vivo. In the past 5 years, technologies for imaging molecular and cellular changes in living animals have advanced to a point where it is possible to reveal the migratory paths of these vitally important cells. Here, we review one advancement in cellular imaging, in vivo bioluminescence imaging, which addresses the problem of lymphocyte tracking. This imaging strategy has the potential to elucidate the temporal patterns of immune responses and the spatial distribution of lymphocytes within the body.

CD31 mismatching affects marrow transplantation outcome.

Graft-versus-host disease (GVHD) complicating allogeneic bone marrow transplantation (BMT) is often attributed to mismatched minor histocompatibility antigens (mHags), which are poorly defined in humans. CD31 is a candidate human mHag relevant to acute GVHD, but reports disagree about its level of significance, the role of HLA restriction, and the relative importance of different polymorphic codons within the molecule. We therefore examined in greater detail the impact of CD31-matching on BMT outcome in a prospective study from a single institution. Samples of recipient and donor DNA were collected pretransplantation for all patients receiving unmanipulated bone marrow from an HLA-identical sibling over a 45-month period at our institution. CD31 DNA typing of alleles at the 3 polymorphic codons 125 (L or V), 563 (N or S), and 670 (R or G) was performed for 118 patient-donor pairs plus 2 additional pairs who had codon 125 typing only. Donor-recipient CD31 nonidentity was tested for correlation with BMT clinical outcome measures of severe acute GVHD, chronic GVHD, relapse, and survival. Gene frequencies of approximately 0.5 for each allele at all 3 codons were comparable to previous reports. Because complete association was seen for 563N with 670G and for 563S with 670R, nonidentity for those codons was analyzed as a single genetic marker designated codon 563/670. Donor-recipient CD31 nonidentity was a significant risk factor for overall survival, both at codon 563/670 (hazard ratio [hr] = 2.58, P = .005) and at codon 125 (hr = 1.07, P = .036). Similar results held for disease-free survival. Nonidentity at codon 563/670 was also a significant risk factor (odds ratio [OR] = 11.15, P = .011) for severe (grades III, IV) versus no (grade 0) acute GVHD. Nonidentity at codon 125 posed less but still significant risk (OR = 9.30, P = .030). When the comparison group without severe acute GVHD was expanded to include grade I as well as grade 0 patients, the risk from CD31 nonidentity increased for both codon 563/670 (OR = 12.31, P = .010) and codon 125 (OR = 11.24, P = .011). CD31 nonidentity remained a significant independent risk factor for survival and for severe acute GVHD when tested in multivariate analysis with the covariates of adulthood, recipient-donor sex difference, ethnic group, disease, pretransplantation risk category, HLA-A2 type, B44-like types, and GVHD prophylactic regimen. CD31 nonidentity showed a trend but failed to achieve statistical significance as a risk factor for relapse and for chronic GVHD. In conclusion, donor-recipient CD31 nonidentity is a significant risk factor for survival and for severe acute GVHD in HLA-identical sibling BMT. The stronger associations with codon 563/670 suggest that polymorphism may be more important than the linked polymorphism at codon 125.

Rapid engraftment after allogeneic transplantation of density-enriched peripheral blood CD34+ cells in patients with advanced hematologic malignancies.

BACKGROUND: Acute graft versus host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Preclinical studies have suggested that a T-cell subset with a CD4-/CD8- double-negative (DN) T-cell phenotype is capable of suppressing GVHD. Double-negative T cells can be mobilized into the peripheral blood with granulocyte colony-stimulating factor (G-CSF) and enriched by density centrifugation. The current study was performed to study the feasibility and safety of applying a density gradient separation technique for enrichment of CD34+ and DN T cells, while depleting CD4+ and CD8+ single-positive (SP) T cells from peripheral blood progenitor cells (PBPCs) for the purpose of allogeneic transplantation. METHODS: Twenty-five patients with advanced hematologic malignancies were treated with a myeloablative preparative regimen consisting of fractionated total body irradiation, etoposide, and cyclophosphamide. Human leukocyte antigen identical donors were mobilized with G-CSF PBPC collected by apheresis. The apheresis product was applied to a single-step density gradient, and the low-density cell population was collected. The low-density cell population was infused as the sole source of allogeneic cells after myeloablative therapy. Graft versus host disease prophylaxis consisted of cyclosporine with or without prednisone. RESULTS: CD34 cell recovery was efficient with a median 72% yield, providing for a median CD34+ cell dose of 6.5 x 10(6)/kg (range,1.0- 13.9 x 10(6)/kg). CD3+CD4+ or CD3+CD8+ SP T cells were depleted by a median of 94.4% (range, 58.8- 99.2%), and the ratio of CD34+:SP T cells increased 10-fold. Double-negative T cells were depleted by 92% (range, 18.8- 99.4%), thus the ratio of DN:SP T cells increased less than 2-fold in 71% of apheresis samples tested. Hematopoietic engraftment was rapid, and there was no occurrence of graft failure in examinable patients. Median time to absolute neutrophil count greater than 0.5 x 10(9)/L and platelet count greater than 20 x 10(9)/L was 10.5 and 12 days, respectively. The incidence of Grade 2-4 acute GVHD was 26% (95% confidence interval [CI], 6-45%), although not all patients were examinable due to an unexpectedly high nonrecurrence mortality that at Day 180 was 62% (95% CI, 40-83%). CONCLUSIONS: These data suggest that T-cell subset manipulation via density gradient separation is a safe procedure and allowed rapid hematopoietic recovery. Selective enrichment of a donor DN T-cell subset was observed in only a few and was not associated with a reduced incidence of GVHD. However, the low-density selected cells still resulted in GVHD, and there was a high treatment-related mortality.

High-dose therapy and autologous hematopoietic-cell transplantation for follicular lymphoma beyond first remission: the Stanford University experience.

A retrospective analysis was performed to investigate the outcome of high-dose therapy (HDT) and autologous hematopoietic cell transplantation in patients with follicular lymphomas beyond first remission. Ninety-two patients with primary induction failure or relapsed follicular low-grade lymphoma (FLGL), follicular large cell lymphoma (FLCL), and transformed follicular lymphoma (TFL) were treated with myeloablative therapy consisting of etoposide (60 mg/kg), cyclophosphamide (100 mg/kg), and either carmustine (BCNU;15 mg/kg) or fractionated total body irradiation (FTBI; 1200 cGy) followed by transplantation of purged autologous bone marrow or peripheral blood hematopoietic cells. For the 49 patients with relapsed FLGL, the median age was 49 years and the median interval from diagnosis to HDT was 30 months. The 4-year estimate of overall survival (OS) was 60% (95% confidence interval [CI], 45%-75%) and of disease-free survival (DFS) was 44% (95% CI, 29%-59%). Treatment with the FTBI-containing HDT regimen was associated with significantly longer DFS (P = .04) and OS (P = .04) in our multivariate analysis. OS was also significantly longer among those treated with 3 or fewer chemotherapy regimens. For the 26 FLCL patients, the median age was 51 years and in 31% the indication for HDT was primary induction failure. For FLCL patients, the 4-year estimate of OS was 58% (95% CI, 37%-79%) and of DFS was 51% (95% CI, 30%-72%). Among the 17 patients with TFL, 13 (76%) transformed at first relapse, and only 6 patients (35%) achieved complete remission with salvage therapy prior to HDT. For TFL patients, the 4-year estimate of OS was 50% (95% CI, 24%-76%) and of DFS 49% (95% CI, 20%-78%). There were 3 occurrences of myelodysplasia (1 after treatment with TBI, 2 after BCNU treatment), yielding an estimated incidence of 7% (95% CI, 0%-16%) at 56 months. This analysis shows that relapsed FLGL patients treated with 3 or fewer different chemotherapy regimens show inferior survival. The HDT regimen containing FTBI appears to be superior to the BCNU-based regimen for relapsed FLGL, although longer follow-up is needed to evaluate late effects. Lastly, patients with TFL or induction failure and relapsed FLCL can achieve survival outcome comparable to those observed with the indolent follicular lymphomas.

Expansion of cytotoxic CD3+ CD56+ cells from peripheral blood progenitor cells of patients undergoing autologous hematopoietic cell transplantation.

Immunotherapy may potentially improve the outcome of autologous hematopoietic cell transplantation (HCT). Poor effector cell proliferation and marginal antitumor activity limit attempts to use immunotherapy. We have characterized the ex vivo expansion, up to 1000-fold, of CD3+ CD56+ lymphocytes from the peripheral blood lymphocytes (PBL) of healthy donors. Expanded cells termed cytokine-induced killer (CIK) cells induce non-major histocompatibility complex-restricted lysis of tumor cells and demonstrate cytolytic activity superior to lymphokine-activated killer cells without the requirement of interleukin (IL)-2 treatment in vivo. To determine whether cytolytic cells could be expanded from patient material, we evaluated samples of peripheral blood progenitor cells (PBPCs) from 25 patients undergoing autologous HCT. The PBPCs were expanded by priming with interferon-gamma followed by anti-CD3 monoclonal antibody and IL-2 the next day. Fluorescence-activated cell sorting analysis was performed on days 0, 15, 21, and 28 of cell culture. The median T-cell content rose from 15.3% (range, 1.1% to 89.7%) on day 0 to 97.2% (range, 83.6% to 99.5%) by day 15. By day 21, T cells expanded 21.8-fold (range, 1.7- to 420.0-fold) and CD3+ CD56+ cells expanded 44.8-fold (range, 5.1- to 747.0-fold). CIK cells were used as effector cells against B-cell lymphoma targets (OCI-Ly8) with a median of 24% (range, 3% to 67%) and 42% (range, 6% to 96%) specific lysis of target cells on days 21 and 28, respectively. CIK cells derived from PBL of 2 additional patients with acute myelogenous leukemia demonstrated 39% and 78% specific lysis of OCI-Ly8 and 26% and 58% specific lysis of autologous leukemic blasts at an effector:target ratio of 40:1. CIK cells may be expanded from granulocyte colony-stimulating factor-mobilized PBPCs of patients undergoing autologous HCT. CIK cells may provide a potent tool for use in posttransplantation adoptive immunotherapy.

Expansion of cytolytic CD8(+) natural killer T cells with limited capacity for graft-versus-host disease induction due to interferon gamma production.

T cells with natural killer cell phenotype and function (NKT cells) have been described in both human and murine tissues. In this study, culture conditions were developed that resulted in the expansion of CD8(+) NKT cells from bone marrow, thymus, and spleen by the timed addition of interferon-gamma (IFN-gamma), interleukin 2 (IL-2), and anti-CD3 monoclonal antibody. After 14 to 21 days in culture, dramatic expansion of CD3(+), CD8(+), alphabetaT-cell receptor(+) T cells resulted with approximately 20% to 50% of the cells also expressing the NK markers NK1.1 and DX5. The CD8(+) NKT cells demonstrated lytic activity against several tumor target cells with more than 90% lysis by day 14 to day 21 of culture. Cytotoxicity was observed against both syngeneic and allogeneic tumor cell targets with the greatest lytic activity by the cells expressing either NK1.1 or DX5. The expanded CD8(+) NKT cells produce T(H)1-type cytokines with high levels of IFN-gamma and tumor necrosis factor alpha. Expansion of the CD8(+) NKT cells was independent of CD1d. Ly49 molecules were expressed on only a minority of cells. A single injection of expanded CD8(+) NKT cells was capable of protecting syngeneic animals from an otherwise lethal dose of Bcl1 leukemia cells. Expanded CD8(+) NKT cells produced far less graft-versus-host disease (GVHD) than splenocytes across major histocompatibility barriers, even when 10 times the number of CD8(+) NKT cells as compared to splenocytes were injected. This reduction in GVHD was related to IFN-gamma production since cells expanded from IFN-gamma knock-out animals caused acute lethal GVHD, whereas cells expanded from animals defective in fas ligand, fas, IL-2, and perforin did not. These data indicate that CD8(+) NKT cells expanded in this fashion could be useful for preserving graft-versus-leukemia activity without causing GVHD.

Survivin expression correlates with apoptosis resistance after lymphocyte activation and is found preferentially in memory T cells.

The prevention of apoptosis may be critical for immunological function. Survivin is a recently cloned member of the inhibitor of apoptosis protein family. We analyzed survivin expression before and after lymphocyte activation in isolated cell populations. Prior to activation, survivin was undetectable. After activation with IL-2 and OKT-3, CD3(+) cells expressed survivin. Next, we correlated survivin expression with Fas, FasL and the amount of apoptosis over time in culture. After activation, survivin was readily detected by day 2 and decreased thereafter. Prior to activation (day 0), Fas was present on 60% of the cells and on 100% by days 2-6. Peak FasL mRNA expression was at day 2. During peak survivin expression (days 2-4) the apoptotic fraction was low, but when survivin expression decreased the apoptotic fraction increased rapidly. Finally, we found that CD45RO(+) memory T cells showed a higher expression of survivin than did CD45RA(+) naive T cells after activation. These results suggest that survivin may contribute to T-cell survival early in T-cell responses as well as in memory immune responses.

CD58/LFA-3 and IL-12 provided by activated monocytes are critical in the in vitro expansion of CD56+ T cells.

A small proportion of human CD3+ T lymphocytes are known to co-express CD56, an antigen usually restricted in its expression to natural killer (NK) cells. Whereas the in vivo function of CD3+ CD56+ T cells remains unknown, we and others have previously shown that both in vitro and in vivo, these cells can mediate a significantly greater degree of MHC-unrestricted cytotoxicitv against a variety of human tumor cells when compared to either CD3+ CD56- T cells or lymphokine activated killer (LAK) cells. While the mechanismns regulating the in vivo expansion of CD56+ T cells are not known, here we demonstrate the importance of CD2-mediated IL-12-dependent signals in the in vitro expansion of CD56+ T cells. Specifically, we show that activated monocytes provide a contact dependent factor (CD58/LFA-3) and a soluble factor (IL-12), both critical for the in vitro expansion of CD56+ T cells. The biological and therapeutic implications of these findings are discussed.

High-dose therapy and autologous bone marrow transplantation for follicular lymphoma in first complete or partial remission: results of a phase II clinical trial.

Advanced stage follicular small cleaved and mixed cell lymphoma is characterized by relapse from remission and survival ranging from 6 to 12 years. Because young patients have the greatest compromise in longevity, the efficacy and toxicity of high-dose radiochemotherapy and bone marrow transplantation after conventional chemotherapy was evaluated in a prospective phase II clinical trial. Thirty-seven patients in a minimal disease state after conventional chemotherapy received fractionated total body irradiation and high-dose etoposide and cyclophosphamide, followed by purged autologous bone marrow. A reference sample of 188 patients of similar age, stage, and histology managed at this institution before 1988 was identified for comparison of patient characteristics and outcomes. Compared with reference patients, transplant recipients had a higher tumor burden at diagnosis. With a median follow-up of 6.5 years, the estimated 10-year survival after transplantation was 86%. There was a single lymphoma death yielding a 10-year disease-specific survival of 97%. There were 2 early transplant-related deaths and 2 late acute leukemia deaths. Ten patients relapsed, one with microscopic disease only. High tumor burden at diagnosis and incomplete response to chemotherapy adversely influenced survival in the reference but not in the transplanted patients. The estimated risk of death of 14% and relapse of 30% at 10 years in our transplanted follicular lymphoma patients, the majority of whom had high tumor burdens, compares favorably with our observations in appropriately matched reference patients.

Engineering hematopoietic grafts: purified allogeneic hematopoietic stem cells plus expanded CD8+ NK-T cells in the treatment of lymphoma.

A major benefit of allogeneic hematopoietic cell transplantation (HCT) in the treatment of malignancies is the graft-versus-tumor (GVT) effect conferred by lymphocytes contained within the graft. However, lymphocytes can also induce the potentially lethal complication of graft-versus-host disease (GVHD). We have previously reported a method of generating large numbers of ex vivo activated and expanded T cells with antitumor activity after culture with interferon-y, cross-linking antibodies to CD3, and interleukin-2. Murine splenocytes expanded under these conditions are a heterogeneous population of which approximately 20% to 60% of cells express natural killer (NK)-cell markers (NK1.1 and DX5) and display major histocompatibility complex (MHC)-unrestricted antitumor activity. Here we demonstrate the in vivo antitumor activity of this population of expanded CD8+ NK-T cells when transplanted across MHC barriers into tumor-bearing hosts. In cotransfer studies with purified allogeneic hematopoietic stem cells, expanded CD8+ NK-T cells confer GVT activity with minimal to no GVHD. In vitro studies show that, although expanded NK-T cells lyse normal allogeneic bone marrow cells, they preferentially mediate cytolysis against tumor targets. These cells persist in the peripheral circulation of host animals for at least 3 weeks posttransfer. GVT activity is dependent on perforin, but not on Fas-ligand. We conclude that expanded CD8+ NK-T cells may serve as a valuable adjuvant population for allogeneic HCT because they mediate GVT effects with minimal GVHD.

Efficacy and toxicity of a CCNU-containing high-dose chemotherapy regimen followed by autologous hematopoietic cell transplantation in relapsed or refractory Hodgkin's disease.

High-dose CBV (cyclophosphamide, carmustine, and etoposide) in combination with autologous HCT achieves survival rates of approximately 50% at 5 years in recurrent or refractory Hodgkin's disease (HD). However, carmustine (BCNU) dose-dependent pulmonary toxicity occurs in 20% to 30% of patients. A decreased incidence of interstitial pneumonitis as well as a possible benefit in efficacy has been reported with lomustine (CCNU) compared to BCNU in the standard dose setting. In a dose-escalation study, we substituted CCNU for BCNU in the CBV regimen for 16 patients with HD (n = 12) or non-Hodgkin's lymphoma (n = 4). Based on the promising results, an additional 47 consecutive patients with HD were treated with the following regimen: CCNU (15 mg/kg) orally on day -6, etoposide (60 mg/kg) intravenously on day -4, and cyclophosphamide (100 mg/kg) intravenously on day -2. Peripheral blood progenitor cells and/or bone marrow were infused on day 0. With a median follow-up for the surviving patients of 3.2 years (range, 0.8-9.9 years), the 3-year overall survival rate was 57% (CI, +/-15%), event-free survival was 52% (CI, +/-14%), and freedom from progression was 68% (CI, +/-14%). There were 21 deaths, 10 due to HD. Six patients died due to respiratory failure. Interstitial pneumonitis occurred in 63% of patients and could not be correlated with prior chest radiotherapy. This regimen demonstrated survival rates similar to those of historical studies that used the CBV regimen. However, the incidence of interstitial pneumonitis was in excess of expected.

CD2-mediated IL-12-dependent signals render human gamma delta-T cells resistant to mitogen-induced apoptosis, permitting the large-scale ex vivo expansion of functionally distinct lymphocytes: implications for the development of adoptive immunotherapy strategies.

The ability of human gamma delta-T cells to mediate a number of in vitro functions, including innate antitumor and antiviral activity, suggests these cells can be exploited in selected examples of adoptive immunotherapy. To date, however, studies to examine such issues on a clinical scale have not been possible, owing in large measure to the difficulty of obtaining sufficient numbers of viable human gamma delta-T cells given their relative infrequency in readily available tissues. Standard methods used to expand human T cells often use a combination of mitogens, such as anti-T-cell receptor antibody OKT3 and interleukin (IL)-2. These stimuli, though promoting the expansion of alpha beta-T cells, usually do not promote the efficient expansion of gamma delta-T cells. CD2-mediated, IL-12-dependent signals that result in the selective expansion of human gamma delta-T cells from cultures of mitogen-stimulated human peripheral blood mononuclear cells are identified. It is first established that human gamma delta-T cells are exquisitely sensitive to apoptosis induced by T-cell mitogens OKT3 and IL-2. Next it is shown that the CD2-mediated IL-12-dependent signals, which lead to the expansion of gamma delta-T cells, do so by selectively protecting subsets of human gamma delta-T cells from mitogen-induced apoptosis. Finally, it is demonstrated that apoptosis-resistant gamma delta-T cells are capable of mediating significant antitumor cytotoxicity against a panel of human-derived tumor cell lines in vitro. Both the biologic and the practical implications of induced resistance to apoptosis in gamma delta-T cells are considered and discussed because these findings may play a role in the development of new forms of adoptive cellular immunotherapy. (Blood. 2000;96:3827-3837)

Toxicity of high-dose sequential chemotherapy and purged autologous hematopoietic cell transplantation precludes its use in refractory/recurrent non-Hodgkin's lymphoma.

We conducted a pilot study in 20 patients with high-risk or recurrent/refractory non-Hodgkin's lymphoma (NHL) using high-dose sequential chemotherapy (HDSC) and autologous hematopoietic cell transplantation (AHCT). After cytoreduction with standard salvage therapy, HDSC/AHCT was administered in 4 phases at 2- to 4-week intervals. Phase 1 consisted of cyclophosphamide 7 g/m2 followed by granulocyte colony-stimulating factor (G-CSF) at 10 microg/kg per day and leukapheresis upon recovery from white blood cell nadir. The hematopoietic cell product was enriched by Percoll gradient separation and purged with a B-cell or T-cell monoclonal antibody panel and complement. Phase 2 consisted of methotrexate 8 g/m2 with leucovorin rescue and vincristine 1.4 mg/m2. Phase 3 was etoposide 2 g/m2 with G-CSF 5 microg/kg per day. In phase 4, the preparative regimen of mitoxantrone 60 mg/m2 and melphalan 180 mg/m2 was administered followed by AHCT. The NHL histologies were diffuse large cell, follicular/diffuse mixed, small noncleaved cell, T-cell-rich B-cell, lymphoblastic, and peripheral T cell. The remission status was first partial remission (PR1; n = 1) or beyond first complete remission (post-CR1; n = 19). Of the 20 patients enrolled, 11 proceeded through all 4 phases. Nine were removed from the study after the first or second phase because of progressive disease (n = 5), poor hematopoietic cell mobilization (n = 1), excessive toxicity (n = 2), and chronic active hepatitis C (n = 1). Treatment-related toxicities in the remaining 11 transplant recipients were cardiomyopathy, hemorrhagic cystitis, persistent cytopenias, acute renal failure, abnormal liver function test results, and infectious complications. There were no treatment-related deaths. Eight of the 11 transplant recipients were alive, 6 without disease, at a median follow-up of 2.7 years. The estimated median 2-year event-free survival was 55%, and overall survival was 70%. We conclude that HDSC/AHCT in refractory/recurrent NHL is associated with considerable acute and chronic toxicities. Given the toxicity profile, efficacy data were not sufficiently promising to warrant further study.