Lactose drives Enterococcus expansion to promote graft-versus-host disease.

Disruption of intestinal microbial communities appears to underlie many human illnesses, but the mechanisms that promote this dysbiosis and its adverse consequences are poorly understood. In patients who received allogeneic hematopoietic cell transplantation (allo-HCT), we describe a high incidence of enterococcal expansion, which was associated with graft-versus-host disease (GVHD) and mortality. We found that Enterococcus also expands in the mouse gastrointestinal tract after allo-HCT and exacerbates disease severity in gnotobiotic models. Enterococcus growth is dependent on the disaccharide lactose, and dietary lactose depletion attenuates Enterococcus outgrowth and reduces the severity of GVHD in mice. Allo-HCT patients carrying lactose-nonabsorber genotypes showed compromised clearance of postantibiotic Enterococcus domination. We report lactose as a common nutrient that drives expansion of a commensal bacterium that exacerbates an intestinal and systemic inflammatory disease.

High-dose BCNU/Melphalan conditioning regimen before autologous stem cell transplantation in newly diagnosed multiple myeloma.

Single-agent high-dose melphalan (HDM, 200 mg/m2) has been the most commonly used conditioning regimen prior to autologous stem cell transplant, since its introduction in 1992. We used a more aggressive alkylator-based conditioning regimen in an attempt to overcome early relapse and combat drug resistance. We present a retrospective comparison and long-term follow-up of newly diagnosed patients with multiple myeloma (MM) treated with induction followed by either high-dose carmustine (BCNU) and HDM, or HDM alone, both followed by autologous stem cell transplant (ASCT). Between 1997 and 2002, 104 patients were treated with BCNU/HDM; from 2001 to 2008, 103 patients were treated with HDM alone. Median follow-up of survivors was 78 and 68 months for the BCNU/HDM and HDM groups, respectively. The median PFS was significantly increased with the BCNU/HDM regimen (40.4 vs 20.5 months, P<0.001). Median overall survival was increased with the BCNU/HDM regimen when compared with HDM alone (88.4 vs 67.2 months, P=0.07), but the difference was not statistically significant. Transplant-related mortality was similar in both groups (2.9% with BCNU and HDM vs 3.9% with HDM alone). Our findings suggest that the BCNU/HDM preparative regimen should be investigated further and potentially compared in a prospective randomized manner with HDM alone.

Outcomes and costs of autologous stem cell mobilization with chemotherapy plus G-CSF vs G-CSF alone.

Chemotherapy plus G-CSF (C+G) and G-CSF alone are two of the most common methods used to mobilize CD34(+) cells for autologous hematopoietic SCT (AHSCT). In order to compare and determine the real-world outcomes and costs of these strategies, we performed a retrospective study of 226 consecutive patients at 11 medical centers (64 lymphoma, 162 multiple myeloma), of whom 55% of lymphoma patients and 66% of myeloma patients received C+G. Patients with C+G yielded more CD34(+) cells/day than those with G-CSF alone (lymphoma: average 5.51 × 10(6) cells/kg on day 1 vs 2.92 × 10(6) cells/kg, P=0.0231; myeloma: 4.16 × 10(6) vs 3.69 × 10(6) cells/kg, P<0.00001) and required fewer days of apheresis (lymphoma: average 2.11 vs 2.96 days, P=0.012; myeloma: 2.02 vs 2.83 days, P=0.0015), although nearly all patients ultimately reached the goal of 2 × 10(6) cells/kg. With the exception of higher rates of febrile neutropenia in myeloma patients with C+G (17% vs 2%, P<0.05), toxicities and other outcomes were similar. Mobilization with C+G cost significantly more (lymphoma: median $10,300 vs $7300, P<0.0001; myeloma: $8800 vs $5600, P<0.0001), although re-mobilization adds $6700 for drugs alone. Our results suggest that although both C+G and G-CSF alone are effective mobilization strategies, C+G may be more cost-effective for patients at high risk of insufficient mobilization.

Pre-engraftment syndrome after myeloablative dual umbilical cord blood transplantation: risk factors and response to treatment.

High fevers and/or rashes prior to neutrophil engraftment are frequently observed after umbilical cord blood (UCB) transplantation, and the condition is referred to as pre-engraftment syndrome (PES). Few studies have evaluated the risk factors for and treatment response to PES. Therefore, we retrospectively characterized PES in 57 consecutive engrafted patients (≥ 12 years old) who received myeloablative dual UCB transplantation. All patients received TBI (≥ 13.2 Gy)-based myeloablative conditioning. Tacrolimus (n=35) or CYA (n=22) combined with mycophenolate mofetil was used as GVHD prophylaxis. PES was defined as the presence of non-infectious fever (≥ 38.5 °C) and/or rash prior to or on the day of neutrophil engraftment. The incidence (95% confidence interval) of PES was 77% (66-88%). The incidence of PES was significantly higher in patients who received CYA as a GVHD prophylaxis than those who received tacrolimus (P<0.001), and this association was confirmed in the multivariate analysis. The occurrence of PES did not impact OS or tumor relapse, although it may have increased non-relapse mortality (P=0.071). The incidence of acute GHVD or treatment-related mortality was not influenced by the choice to use corticosteroids to treat PES. This study suggests that use of CYA for GVHD prophylaxis increases the risk of PES following dual UCB transplantation.

Lenalidomide before and after Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma.

Although multiple myeloma remains incurable outside of allogeneic hematopoietic stem cell transplantation, novel agents made available only in the last few decades have nonetheless tremendously improved the landscape of myeloma treatment. Lenalidomide, of the immunomodulatory class of drugs, is one of those novel agents. In the non-transplant and relapsed/refractory settings, lenalidomide clearly benefits patients in terms of virtually all meaningful outcomes including overall survival. Data supporting the usage of lenalidomide as part of treatment approaches incorporating high-dose chemotherapy with autologous stem cell support (ASCT) are less mature as pertains to such long-term outcomes and toxicity, and lenalidomide is not currently approved by regulatory agencies for use in the context of ASCT in either the United States or Europe. That said, relatively preliminary efficacy data describing lenalidomide as a component of ASCT-based treatment approaches to MM are indeed promising, and consequently lenalidomide's role in ASCT-based treatment strategies is growing. In this review we summarize existing data that pertains to lenalidomide in the specific context of ASCT, and we share our thoughts on how our own group applies these data to approach this complex issue clinically.

Preemptive dosing of plerixafor given to poor stem cell mobilizers on day 5 of G-CSF administration.

Plerixafor, given on day 4 of G-CSF treatment is more effective than G-CSF alone in mobilizing hematopoietic progenitor cells. We tested a strategy of preemptive plerixafor use following assessment of the peak mobilization response to 5 days of G-CSF. Patients were eligible for plerixafor if, on day 5 of G-CSF, there were <7 circulating CD34+ cells/µL or if <1.3 × 10(6) CD34+ cells/kg were collected on the first day of apheresis. Plerixafor (0.24 mg/kg s.c.) was given on day 5 of G-CSF followed by apheresis on day 6. This was repeated for up to two additional doses of plerixafor. The primary end point of the study was the percentage of patients who collected at least 2 × 10(6) CD34+ cells/kg. Twenty candidates for auto-SCT enrolled on the trial. The circulating CD34+ cell level increased a median of 3.1 fold (range 1-8 fold) after the first dose of plerixafor and a median of 1.2 fold (range 0.3-6.5 fold) after the second dose of plerixafor. In all, 15 out of 20 (75%) patients achieved the primary end point. In conclusion, the decision to administer plerixafor can be delayed until after the peak mobilization response to G-CSF has been fully assessed.

Outcomes of a 1-day nonmyeloablative salvage regimen for patients with primary graft failure after allogeneic hematopoietic cell transplantation.

Primary graft failure after allogeneic hematopoietic cell transplantation is a life-threatening complication. A shortened conditioning regimen may reduce the risk of infection and increase the chance of survival. Here, we report the outcome of 11 patients with hematologic diseases (median age, 44; range, 25-67 years, seven males) who received a 1-day reduced-intensity preparative regimen given as a re-transplantation for primary graft failure. The salvage regimen consisted of fludarabine, cyclophosphamide, alemtuzumab and TBI, all administered 1 day before re-transplantation. All patients received T-cell replete PBSCs from the same or a different haploidentical donor (n=10) or from the same matched sibling donor (n=1). Neutrophil counts promptly increased to >500/µL for 10 of the 11 patients at a median of 13 days. Of these, none developed grade III/IV acute GVHD. At present, 8 of the 11 patients are alive with a median follow-up of 11.2 months from re-transplantation and 5 of the 8 are in remission. In conclusion, this series suggests that our 1-day preparative regimen is feasible, leads to successful engraftment in a high proportion of patients, and is appropriate for patients requiring immediate re-transplantation after primary graft failure following reduced-intensity transplantation.

Differential impact of inhibitory and activating Killer Ig-Like Receptors (KIR) on high-risk patients with myeloid and lymphoid malignancies undergoing reduced intensity transplantation from haploidentical related donors.

The impact of activating KIR (aKIR) and inhibitory KIR (iKIR) on OS, relapse-related mortality (RRM) and acute GVHD (aGVHD) was prospectively studied in 84 adults with high-risk hematologic malignancies receiving reduced intensity conditioning (RIC) T-cell depleted hematopoietic SCT (HSCT) from haploidentical related donors. In this clinical model, freedom from RRM is dependent on GVL effect. Patients were divided into myeloid (n=49) and lymphoid (n=35) malignancy groups. KIR-ligand and ligand-ligand models were studied in both GVH and rejection directions and statistically correlated with outcome measures. In the myeloid group, OS was higher (P=0.009) and RRM was lower (P=0.036) in patients missing HLA-C group2 ligand to donor iKIR. OS was higher if patients had >1 missing ligand (P=0.018). In lymphoid malignancy, missing ligand to donor KIR had no impact on OS or RRM. However, OS was better with donor aKIR 2DS2 (P=0.028). There was a trend towards shorter OS in recipient with KIR 2DS1, 2DS5 and 3DS1, although sample sizes were too small to provide inferential statistics. Findings in lymphoid malignancy patients should be further studied. These results suggest that the absence of appropriate HLA ligands in the recipient to donor iKIR may induce GVL without aGVHD in myeloid malignancy patients undergoing TCD-RIC transplants.

Novel mechanism of rapamycin in GVHD: increase in interstitial regulatory T cells.

Rapamycin (RAPA) is an immunosuppressive drug that prevents and treats graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplant (HCT). One possible mechanism for its efficacy is induction of tolerance, through increased number or enhanced survival of regulatory T cells. In our experiments, B10.D2 BM and splenocytes were injected into lethally irradiated BALB/cJ recipients. The mice received i.p. injections of either RAPA or vehicle control on days 1-28. There was a significant survival advantage in RAPA-treated mice. Evaluation of the skin biopsies showed a dense cellular infiltrate in RAPA-treated mice. Further characterization of these cells revealed a higher percentage of regulatory T cells characterized by FoxP3-positive cells in high-dose RAPA-treated mice as compared with controls on day 30. This effect appears to be dose dependent. When peripheral blood analysis for FoxP3-positive cells was performed, there was no significant difference observed in the RAPA-treated mice as compared with control mice. These data show a novel mechanism of rapamycin in GVHD, accumulation of regulatory T cells in the GVHD target tissue: the skin.

Response and toxicity of donor lymphocyte infusions following T-cell depleted non-myeloablative allogeneic hematopoietic SCT from 3-6/6 HLA matched donors.

We report the outcome of early donor lymphocyte infusions (DLIs) after T-cell depleted non-myeloablative transplantation using stem cells from HLA-matched or mismatched donors. Sixty-nine patients with high-risk hematologic malignancies received DLI following fludarabine, CY and alemtuzumab with infusion of stem cells from a matched sibling (52) or partially matched family member donor (17). Patients received the first infusion at a median of 50 days after transplant, and doses ranged from 1 x 10(4) CD3+ cells/kg to 3.27 x 10(8) CD3+ cells/kg, depending on clinical status and the physician's discretion. A median cell dose of 1 x 10(5) CD3+ cells/kg in the mismatched setting and 1 x 10(6) CD3+ cells/kg in the matched sibling setting appears safe with only 1 of 7 (14%) and 4 of 31 patients (13%), respectively, experiencing severe acute GVHD at these doses. Importantly, 38% of patients with persistent disease before DLI attained a remission after infusion. Nine of the 69 patients remain alive and disease-free 32-71 months after the first DLI. In conclusion, low doses of DLI can be safely provided soon after T-cell depleted non-myeloablative therapy and provide a chance of remission. However, long-term survival still remains poor, primarily because of relapse in these patients.

Outcomes of a second non-myeloablative allogeneic stem cell transplantation following graft rejection.

Following initial graft rejection, a second attempt at allogeneic immunotherapy is often contemplated, but data on the success is limited. We therefore report on 11 patients with hematologic malignancies, renal cell cancer or marrow failure who underwent a second reduced-intensity regimen for primary or secondary graft failure. Nine of the 11 patients initially engrafted with the second attempt including two of four who used the same donor. One of the patients engrafted after the third attempt using a different donor and conditioning regimen. There were two treatment-related deaths. Four patients died from progressive disease 1-9 months after the second transplant. Two patients are still in recovery phase less than 1 year from the second transplant. Long-term remission is possible and three patients are alive in complete remission.

Non-comparative evaluation of the safety of aerosolized amphotericin B lipid complex in patients undergoing allogeneic hematopoietic stem cell transplantation.

Allogeneic hematopoietic stem cell transplant (HSCT) recipients are at increased risk for invasive fungal infections (IFIs) over prolonged periods of time. Aerosolized amphotericin B lipid complex (ABLC) has shown promise in lung transplant recipients as a convenient means of delivering protective drug to the upper airways avoiding systemic toxicities. The safety and tolerability of aerosolized ABLC in 40 subjects undergoing allogeneic HSCT was prospectively investigated in an open-labeled, non-comparative study. Subjects received aerosolized ABLC treatment once daily for 4 days, then once weekly for 13 weeks; fluconazole was administered daily as standard of care through post-transplant day 100. Pulmonary mechanics were measured before and after each dose of inhaled ABLC; adverse events (AEs) and the development of IFI were also monitored. Cough, nausea, taste disturbance, or vomiting followed 2.2% of 458 total inhaled ABLC administrations; 5.2% of inhaled ABLC administrations were associated with >or=20% decrease in pulmonary function measurements (forced expiratory volume in 1 second or forced vital capacity) and none required treatment with bronchodilators or withdrawal from study. Four mild AEs were considered possibly or probably related to study treatment; no deaths or withdrawals from treatment were attributed to study drug. Of 3 proven IFIs occurring during the study period, only 1, a catheter-related case of disseminated fusariosis, occurred while the subject was receiving study medication. Aerosolized ABLC was well tolerated in allogeneic HSCT recipients. With only 1 of 40 subjects developing IFI while receiving treatment, the combination of fluconazole and inhaled ABLC warrants further study as antifungal prophylaxis following allogeneic HSCT.

Selective elimination of alloreactivity from immunotherapeutic T cells by photodynamic cell purging and memory T-cell sorting.

Allogeneic stem cell transplantation (alloSCT), especially in the mismatched setting, carries a high risk of life-threatening GvHD because of activation of donor T cells by Ag present on host cells. Removal of mature donor T cells can prevent GvHD but leads to delayed immune reconstitution, and an increased incidence of opportunistic infections and disease relapse. These findings demonstrate the vital role of donor T cells in providing graft-versus-tumor (GvT) and anti-pathogen effects as well as facilitating immune reconstitution. It has been well documented that GvHD can be separated from GvT effects, making it possible potentially to eliminate GvHD while preserving the immunotherapeutic benefits of donor T cells. Over the past decade, major attempts have been made to reduce GvHD incidence without loss of GvT effect, especially in the haplo-identical setting. Novel techniques to deplete host-reactive donor T cells selectively have been explored. This review focuses on the use of the photodynamic cell purging (PDP) process and of sorting memory T cells for the selective elimination of alloreactivity. Minimizing the threat of GvHD while maximizing the beneficial GvT effect would broaden the scope and effectiveness of alloSCT.

Lipid formulations of amphotericin B preserve and stabilize renal function in HSCT recipients.

The current study assessed renal function based on medical records in adult hematopoietic stem cell transplant (HSCT) recipients with proven or probable invasive fungal infection (IFI) transplanted between 1995 and 2000. We confirm that amphotericin B deoxycholate (AmB-d) is nephrotoxic in a large percentage of HSCT recipients. Due to nephrotoxicity, defined as serum creatinine (SCr) >2.5 mg/dl or a 100% increase in SCr from baseline, 88% of patients treated with AmB-d were switched to a lipid formulation of amphotericin B (LFAB). In total, 53% of patients initiated on AmB-d were switched within the first week of therapy. Significantly more patients (70.6%) treated with AmB-d experienced a 100% increase in SCr from baseline compared to patients treated with either AmBisome (44.4%) or Abelcet (41.2%). A Cox Proportional Hazards Model revealed that, compared to patients initiated on AmBisome or Abelcet, the risk of nephrotoxicity (RR=1.5 vs AmBisome; RR=1.7 vs Abelcet), dialysis (RR=2.4 vs AmBisome; RR=1.4 vs Abelcet), and death (RR=2.0 vs AmBisome; RR=1.1 vs Abelcet) were all increased for patients initiated on AmB-d. Study results suggest that renal function improves and mortality declines when an LFAB is given to HSCT patients as initial therapy rather than as second-line therapy, the current practice.

Successful allogeneic engraftment of mismatched unrelated cord blood following a nonmyeloablative preparative regimen.

Reduction in the toxicity of allogeneic transplantation with nonmyeloablative induction regimens has expanded the scope of practice to older and more debilitated patients. However, the limited availability of matched sibling donors requires that alternative donor sources be investigated. Reported here are 2 cases of patients with advanced hematologic malignancies without matched siblings, partially matched family members, or matched unrelated donors who successfully underwent nonmyeloablative conditioning therapy followed by infusion of partially matched, unrelated-donor cord blood cells. The patients are in remission and remain 100% donor as assessed by short tandem repeat analysis of the marrow 6 and 12 months following transplantation.

T-Cell recovery in adults and children following umbilical cord blood transplantation.

T-cell reconstitution following allogeneic stem cell transplantation may involve thymic education of donor-derived precursors or peripheral expansion of mature T cells transferred in the graft. T cell-receptor excision circles (sjTRECs) are generated within the thymus and identify new thymic emigrants and those that have not divided. We measured quantitative and qualitative immunologic reconstitution and sjTREC levels in adult and pediatric recipients of umbilical cord blood transplants (UCBTs). sjTRECs were detected at normal levels in all children, starting 12 months after transplantation. sjTRECs were not detected until 18 months after transplantation in adults, and then only at a 3-fold lower level than expected for age. We used complementarity-determining region 3 (CDR3) spectratyping to measure changes in T cell-receptor diversity occurring with restoration of thymic function. T-cell repertoires were skewed in adults and children at 12 to 18 months after transplantation but recovered to near-normal diversity at 2 to 3 years post-UCBT. T-cell repertoires appeared more diverse earlier in children (at 1 to 2 years post-UCBT) than in adults (at 3 to 4 years post-UCBT). We conclude that early T-cell recovery after UCBT occurs primarily through peripheral expansion of adoptively transferred donor T cells and results in skewing of the T-cell repertoire. The reappearance of sjTREC-containing cells after UCBT is associated with increasing numbers of phenotypicaly naive T cells, improved mitogen and recall antigen responses, and diversification of the T-cell repertoire. The delay in central T-cell recovery in adults relative to children may be due to differences in thymic function resulting from age-related atrophy, graft-versus-host disease, or the pharmacologic effects of prophylaxis and treatment of graft-versus-host disease.

Randomized, placebo-controlled, double-blind study of a cytomegalovirus-specific monoclonal antibody (MSL-109) for prevention of cytomegalovirus infection after allogeneic hematopoietic stem cell transplantation.

MSL-109 is a monoclonal antibody specific to the cytomegalovirus (CMV) glycoprotein H with high neutralizing capacity. In a prospective, randomized, double-blind study, allogeneic hematopoietic stem cell transplantation (HSCT) recipients with positive donor and/or recipient serology for CMV before transplantation received either 60 mg/kg MSL-109 (n = 59), 15 mg/kg MSL-109 (n = 60), or placebo (n = 60) intravenously every 2 weeks from day -1 until day 84 after transplantation. CMV pp65 antigenemia, CMV-DNA load in plasma, and viremia by culture were tested weekly. Primary end points were development of pp65 antigenemia at any level and/or viremia for which ganciclovir was given. There was no statistically significant difference in CMV pp65 antigenemia or viremia among patients in the 60-mg group (pp65 antigenemia, 47%; viremia, 15%), the 15-mg group (52%; 23%), and the placebo group (45%; 17%). There was also no difference in maximum levels of pp65 antigenemia, time to clearance of pp65 antigenemia after start of ganciclovir, CMV disease, invasive bacterial and fungal infections, time to neutrophil and platelet engraftment, acute graft-versus-host disease, days of hospitalization, and overall survival rate among the 3 groups. However, a subgroup analysis of CMV-seronegative recipients with a seropositive donor (D+/R-) showed a transiently improved survival rate by day 100 in MSL-109 recipients (mortality: 60-mg group, 1/13; 15-mg group, 1/12; placebo group, 6/10 [P = .02 for 60-mg versus placebo groups; P = .08 for 15-mg versus placebo groups]); by the end of follow-up, the difference was no longer statistically significant. The improved survival rate in D+/R- patients could not be attributed to a reduction in CMV disease; however, MSL-109 was associated with improved platelet engraftment and less grade III to IV acute graft-versus-host disease in this subgroup. In a subgroup analysis of CMV-seropositive recipients of MSL-109 (D+/R+ and D-/R+), overall mortality was increased compared to that of the placebo group (P = .12 for the 60-mg versus placebo groups, P = .05 for the 15-mg versus placebo groups, and P = .04 for the dose levels combined versus placebo). MSL-109 was well tolerated and no immune response to the drug was observed. Thus, MSL-109 was safe but did not reduce CMV infection in allogeneic HSCT recipients. The transient survival advantage seen early after transplantation in CMV D+/R- patients and the negative effect on survival in seropositive patients remain unexplained. Thus, there is no evidence that MSL-109 is beneficial in CMV-seropositive HSCT recipients.

Acute graft-vs-host disease: pathobiology and management.

Acute graft-vs-host disease (GVHD) is a major obstacle to safe allogeneic hematopoietic stem cell transplantation (HSCT), leading to a significant morbidity and mortality. GVHD occurs when transplanted donor T lymphocytes react to foreign host cells. It causes a wide variety of host tissue injuries. This review focuses on the pathobiological basis, clinical aspects, and current management strategies of acute GVHD. Afferent phase of acute GVHD starts with myeloablative conditioning, i.e., before the infusion of the graft. Total-body irradiation (TBI) or high-dose chemotherapy regimens cause extensive damage and activation in host tissues, which release inflammatory cytokines and enhance recipient major histocompatibility complex (MHC) antigens. Recognition of the foreign host antigens by donor T cells and activation, stimulation, and proliferation of T cells is crucial in the afferent phase. Effector phase of acute GVHD results in direct and indirect damage to host cells. The skin, gastrointestinal tract, and liver are major target organs of acute GVHD. Combination drug prophylaxis in GVHD is essential in all patients undergoing allogeneic HSCT. Steroids have remained the standard for the treatment of acute GVHD. Several clinical trials have evaluated monoclonal antibodies or receptor antagonist therapy for steroid-resistant acute GVHD, with different successes in a variety of settings. There are some newer promising agents like mycophenolate mofetil, glutamic acid-lysine-alanine-tyrosine (GLAT), rapamycin, and trimetrexate currently entering in the clinical studies, and other agents are in development. Future experimental and clinical studies on GVHD will shed further light on the better understanding of the disease pathobiology and generate the tools to treat malignant disorders with allogeneic HSCT with specific graft-vs-tumor effects devoid of GVHD.

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.