M. de Lima

Management of lymphoma recurrence after allogeneic transplantation : the relevance of graft-versus-lymphoma effect

Donor lymphocyte infusions, by virtue of a graft-versus-tumor effect, have been shown to induce remissions in leukemia that recurs after allogeneic bone marrow transplantation. Similar effects have been postulated to contribute to the decreased recurrence rate observed after allogeneic transplantation in non-Hodgkin’s lymphoma. This lower recurrence rate may be due to a variety of other mechanisms. We aimed to evaluate the role of graft-versus-lymphoma effects in patients in whom lymphomas recur after allogeneic transplantation. At the time of recurrence, immunosuppressive therapy was withheld. Patients with non-responding disease received an infusion of donor lymphocytes. Patients were observed for response and graft-versus-host disease. Disease in four of nine patients responded to withdrawal of immunosuppressive therapy. A minor response was observed in one of three recipients of donor lymphocyte infusions. Responses were observed among two patients with follicular lymphoma, one with large cell lymphoma and one with lymphoblastic lymphoma. A minor response was observed in a patient with prolymphocytic leukemia/lymphoma. We conclude that withdrawal of immunosuppressive therapy and donor lymphocyte infusion can induce durable remissions in patients with recurrent lymphoma after allogeneic transplantation.

Transplantation of ex vivo expanded cord blood cells using the copper chelator tetraethylenepentamine: a phase I/II clinical trial.

The copper chelator tetraethylenepentamine (TEPA; StemEx) was shown to attenuate the differentiation of ex vivo cultured hematopoietic cells resulting in preferential expansion of early progenitors. A phase I/II trial was performed to test the feasibility and safety of transplantation of CD133+ cord blood (CB) hematopoietic progenitors cultured in media containing stem cell factor, FLT-3 ligand, interleukin-6, thrombopoietin and TEPA. Ten patients with advanced hematological malignancies were transplanted with a CB unit originally frozen in two fractions. The smaller fraction was cultured ex vivo for 21 days and transplanted 24 h after infusion of the larger unmanipulated fraction. All but two units contained <2 × 107 total nucleated cells (TNCs) per kilogram pre-expansion. All donor–recipient pairs were mismatched for one or two HLA loci. Nine patients were beyond first remission; median age and weight were 21 years and 68.5 kg. The average TNCs fold expansion was 219 (range, 2–620). Mean increase of CD34+ cell count was 6 (over the CD34+ cell content in the entire unit). Despite the low TNCs per kilogram infused (median=1.8 × 107/kg), nine patients engrafted. Median time to neutrophil and platelet engraftment was 30 (range, 16–46) and 48 (range, 35–105) days. There were no cases of grades 3–4 acute graft-versus-host disease (GVHD) and 100-day survival was 90%. This strategy is feasible.

Superior ex vivo cord blood expansion following co-culture with bone marrow-derived mesenchymal stem cells

One factor limiting the therapeutic efficacy of cord blood (CB) hematopoietic progenitor cell (HPC) transplantation is the low cell dose of the graft. This is associated with an increased incidence of delayed or failed engraftment. Cell dose can be increased and the efficacy of CB transplantation potentially improved, by ex vivo CB expansion before transplantation. Two ex vivo CB expansion techniques were compared: (1) CD133+ selection followed by ex vivo liquid culture and (2) co-culture of unmanipulated CB with bone-marrow-derived mesenchymal stem cells (MSCs). Ex vivo culture was performed in medium supplemented with granulocyte colony-stimulating factor, stem cell factor and either thrombopoietin or megakaryocyte growth and differentiation factor. Expansion was followed by measuring total nucleated cell (TNC), CD133+ and CD34+ cell, colony-forming unit and cobblestone area-forming cell output. When compared to liquid culture, CB-MSC co-culture (i) required less cell manipulation resulting in less initial HPC loss and (ii) markedly improved TNC and HPC output. CB-MSC co-culture therefore holds promise for improving engraftment kinetics in CB transplant recipients.

Impact of High-Dose Chemotherapy on Peripheral T-Cell Lymphomas

PURPOSE To evaluate the outcome of high-dose chemotherapy (HDCT) and autologous or allogeneic hematopoietic transplantation in patients with peripheral T-cell lymphoma (PTCL) who experienced disease recurrence after prior conventional chemotherapy. PATIENTS AND METHODS We performed a retrospective analysis of 36 PTCL patients from the University of Texas M.D. Anderson Cancer Center treated between 1989 and 1998 with HDCT and autologous or allogeneic hematopoietic transplantation. RESULTS A total of 36 patients were studied (29 received autologous transplantation, and seven received allogeneic transplantation). The overall survival rate at 3 years was 36% (95% confidence interval [CI], 23% to 59%), and the progression-free survival (PFS) rate was 28% (95% CI, 16% to 49%). The pretransplant serum lactate dehydrogenase level was the most important prognostic factor for both survival and PFS rates (P < .001). A Pretransplant International Prognostic Index score of < or = 1 indicated a superior survival rate (P = .036) but not an improved PFS rate. A median follow-up of 43 months (range, 13 to 126 months) showed 13 patients (36%) were still alive with no evidence of disease. CONCLUSION Our results are comparable to the published data on HDCT in B-cell non-Hodgkins lymphoma (NHL) patients despite the fact that patients with PTCL are known to have a worse outcome compared with B-cell NHL patients. Considering the dismal outcome of conventional chemotherapy in PTCL patients, these data suggest the hypothesis that the poor prognostic implication of T-cell phenotyping in NHL might be overcome by frontline HDCT and transplantation.

Sirolimus in combination with tacrolimus and corticosteroids for the treatment of resistant chronic graft-versus-host disease.

Chronic graft‐versus‐host disease (cGVHD) remains a major cause of morbidity and mortality in haematopoietic transplant recipients. Sirolimus is a macrocyclic triene antibiotic with immunosuppressive, antifungal and antitumour properties, that has activity in the prevention and treatment of acute GVHD. We conducted a phase II trial of sirolimus combined with tacrolimus and methylprednisolone in patients with steroid‐resistant cGVHD. Thirty‐five patients who developed GVHD after day 100 post‐transplant were studied. Six patients had a complete response and 16 a partial response with an overall response rate of 63%. Major adverse events related to the combination of tacrolimus and sirolimus were hyperlipidaemia, renal dysfunction and cytopenias. Four patients had thrombotic microangiopathy (TMA) and 27 (77%) had infectious complications. The median survival for the whole group was 15 months. A significantly better outcome was observed in patients with a platelet count ≥100 × 109/l, as well as in those with true chronic manifestations of GVHD compared to those with acute GVHD beyond day 100. Controlled trials comparing this approach with alternative strategies to determine which can best achieve the goal of GVHD‐free survival are warranted.

Reduced-intensity allogeneic stem cell transplantation in relapsed and refractory Hodgkin's disease: low transplant-related mortality and impact of intensity of conditioning regimen

Summary:A total of 40 patients with relapsed/refractory Hodgkins disease (HD) underwent reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) from an HLA-identical sibling (n=20) or a matched unrelated donor (n=20). The median age was 31 years (range 18–58). Disease status at allo-SCT was refractory relapse (n=14) or sensitive relapse (n=26). The conditioning regimens were fludarabine-cyclophosphamide±antithymocyte globulin (n=14), a less intensive regimen, and fludarabine-melphalan (FM) (n=26), a more intensive one. The two groups had similar prognostic factors. The median time to neutrophil recovery (ie absolute neutrophil count ⩾500/μl) was 12 days (range 10–24). The median time to platelet recovery (ie platelet count ⩾20 000/μl) was 17 days (range 7–132). Day 100 and cumulative (18-month) transplant-related mortalities (TRMs) were 5 and 22%. Twenty-four patients (60%) are alive (14 in complete remission or complete remission, unconfirmed/uncertain) with a median follow-up of 13 months (4–78). In all, 16 patients expired (TRM n=8, disease progression n=8). FM patients had better overall survival (73 vs 39% at 18 months; P=0.03), and a trend towards better progression-free survival (37 vs 21% at 18 months; P=0.2). RIC allo-SCT is feasible in relapsed/refractory HD patients with a low TRM. The intensity of the preparative regimen affects survival.

Ex vivo expansion of cord blood

A marked increase in the utilization of umbilical cord blood (UCB) transplantation has been observed in recent years; however, the use of UCB as a hematopoietic stem cell (HSC) source is limited primarily by the number of progenitor cells contained in the graft. Graft failure, delayed engraftment and profound delay in immune reconstitution lead to significant morbidity and mortality in adults. The lack of cells available for post transplant therapies, such as donor lymphocyte infusions, has also been considered to be a disadvantage of UCB. To improve outcomes and extend applicability of UCB transplantation, one potential solution is ex vivo expansion of UCB. Investigators have used several methods, including liquid suspension culture with various cytokines and expansion factors, co-culture with stromal elements and continuous perfusion systems. Techniques combining ex vivo expanded and unmanipulated UCB are being explored to optimize the initial engraftment kinetics as well as the long-term durability. The optimal expansion conditions are still not known; however, recent studies suggest that expanded UCB is safe. It is hoped that by ex vivo expansion of UCB, a resulting decrease in the morbidity and mortality of UCB transplantation will be observed, and that the availability of additional cells may allow adoptive immunotherapy or gene transfer therapies in the UCB setting.

Risk factors associated with late cytomegalovirus reactivation after allogeneic stem cell transplantation for hematological malignancies.

We analyzed the clinical factors associated with late cytomegalovirus (CMV) reactivation in a group of 269 consecutive recipients of allogeneic stem cell transplant (SCT) for hematological malignancies. Eighty-four subjects (31%) experienced late CMV reactivation, including 64 with prior early reactivation and 20 with isolated late reactivation. Multivariate analyses were conducted in patients with early CMV reactivation to identify factors associated with late recurrence. Important risk factors included lymphoid diagnosis, occurrence of graft-versus-host disease (GVHD), greater number of episodes of early reactivation, persistent day 100 lymphopenia and the use of a CMV-seronegative donor graft. We combined these risk factors in a predictive model to identify those at relatively low, intermediate and high risk. The low-risk group (15% cumulative incidence, CI) encompassed patients without early CMV reactivation, and subjects transplanted for a myeloid malignancy from a matched-related (MR) donor without subsequent acute GVHD. The high-risk patients (73% CI) met all of the following criteria: (1) received an MR graft but developed GVHD, or received a non-MR graft irrespective of GVHD; (2) had more than two episodes of early reactivation; and (3) received a CMV-seronegative graft and/or remained persistently lymphopenic at day 100 after SCT. The remaining patients had an intermediate incidence of 32%.

Prophylactic donor lymphocyte infusions after moderately ablative chemotherapy and stem cell transplantation for hematological malignancies: high remission rate among poor prognosis patients at the expense of graft-versus-host disease

We investigated the use of ‘prophylactic’ donor lymphocyte infusions (DLI) containing 1 × 107 CD3+ cells, given at 30, 60 and 90 days post-allogeneic blood and marrow transplantation (BMT), following conditioning with fludarabine 30 mg/m2/4 days and melphalan 70 mg/m2/2 days. GVHD prophylaxis consisted of cyclosporin A (CsA) 2 mg/kg daily with early tapering by day 60. Our goals were the rapid achievement of chimerism and disease control, providing an immunological platform for DLIs to treat refractory patients with hematological malignancies. Twelve heavily pre-treated patients with life expectancy less than 6 months were studied; none were in remission. Diagnoses were AML (n = 4), MDS (n = 1), ALL (n = 3), CML (n = 3) and multiple myeloma (n = 1). Response rate was 75%. Three patients are alive at a median of 450 days (range, 450–540). Two patients are in remission of CML in blast crisis and AML for more than 14 months. Median survival is 116 days (range, 25–648). Six patients received 12 DLIs; three patients developed acute GVHD after the first infusion and were excluded from further DLIs, but no GVHD occurred among patients receiving subsequent DLIs. One patient with CML in blast crisis went into CR after the first DLI. The overall incidence of acute GVHD was 70%. Primary causes of death were infections (n = 3), acute GVHD (n = 3), chronic GVHD (n = 1) and disease relapse (n = 2). We observed high response and chimerism rates at the expense of an excessive incidence of GVHD. DLI given at day +30 post BMT caused GVHD in 50% of the patients, and its role in this setting remains unclear. Bone Marrow Transplantation (2001) 27, 73–78.

Feasibility of allo-SCT after hypomethylating therapy with decitabine for myelodysplastic syndrome

Decitabine is a hypomethylating agent with activity in myelodysplastic syndrome (MDS). It is largely unknown whether treatment with this drug before allo-SCT will increase the toxicity of the preparative regimen or otherwise affect the results of the transplant. We report the outcome of 17 patients with MDS with a median age of 55.5 years (range, 36–66 years) who underwent an allo-SCT (12 siblings, 5 unrelated) after prior therapy with decitabine. Preparative regimens consisted of fludarabine in combination with BU (n=8) or melphalan (n=9). The source of stem cells was marrow in four patients and peripheral blood (PB) in 13 patients. Thirteen patients were in CR within 100 days of transplant. With a median follow-up of 12 months (range, 3–35 months), 11 patients are alive; eight in CR and three with progressive disease. Prior therapy with hypomethylating agents did not increase toxicity and may improve the outcome of allogeneic transplant in MDS and should be evaluated in a prospective trial.