A large single-center experience with allogeneic stem-cell transplantation for peripheral T-cell non-Hodgkin lymphoma and advanced mycosis fungoides/Sezary syndrome.

BACKGROUND: The prognosis for patients with most forms of T-cell lymphoma is poor. Allogeneic hematopoietic stem-cell transplantation (HSCT) may improve the outcome. PATIENTS AND METHODS: This study examines the outcome of 52 patients who underwent ablative or nonablative allogeneic HSCT for peripheral T-cell lymphoma (PTCL) or advanced mycosis fungoides/Sezary syndrome over a 12-year period at a single institution. We divided the patients into those with predominantly nodal histologies: peripheral T-cell not otherwise specified (PTCL NOS), angioimmunoblastic (AITL), or anaplastic large cell lymphoma, T/null type (systemic) (ALCL), and predominantly extranodal histologies: natural killer (NK)/T cell, enteropathy type, hepatosplenic, subcutaneous panniculitic, mycosis fungoides, or T cell or NK cell other. RESULTS: Median follow-up of survivors is 49 months. Non-relapse mortality and relapse at 3 years was 27% and 43%, respectively. The incidence of grade II-IV acute graft-versus-host disease (GVHD) was 21%. The incidence of extensive chronic GVHD at 2 years was 27%. The 3-year progression-free survival was 30%: 45% in patients with predominantly nodal histologies (PTCL NOS, AITL, and ALCL) and 6% in patients with predominantly extranodal histologies (P = 0.016). Overall survival at 3 years was 41% for all patients. CONCLUSION: Allogeneic HSCT can produce long-term remissions in relapsed/refractory T-cell lymphoma, especially those with nodal histologies.

Preinfusion variables predict the predominant unit in the setting of reduced-intensity double cord blood transplantation.

Double cord blood transplantation (DCBT) may overcome the slow hematopoietic recovery and engraftment failure associated with infusion of a single cord blood unit. In DCBT, only one unit typically contributes to long-term hematopoiesis, but little is known about factors affecting cord predominance. As results from a phase I trial suggested that order of infusion may affect cord predominance, we analyzed the effect of preinfusion variables on chimerism patterns of 38 patients enrolled in the initial study and a subsequent phase II trial. All patients were treated with a reduced-intensity conditioning (RIC) regimen of fludarabine, melphalan and thymoglobulin followed by DCBT. By day 100, 66% of patients had hematopoiesis derived from a single cord blood unit. Higher post-thaw total nucleated cell and CD34+ cell dose were associated with cord predominance and in 68% of patients (P=0.03); the predominant cord blood unit was infused first. Only the post-thaw CD34+ cell dose of the predominant unit predicted time to both neutrophil and platelet engraftment. Although based on a small number of patients, our results identify parameters that may affect cord predominance and engraftment in the setting of DCBT following RIC and suggest possible strategies for selecting infusion order for cord blood units.

Characterization of T cell repertoire in patients with graft-versus-leukemia after donor lymphocyte infusion.

The clinical efficacy of donor lymphocyte infusions (DLI) in patients with relapsed chronic myelocytic leukemia after allogeneic bone marrow transplantation has been demonstrated in several recent studies. Although it is presumed that allogeneic T cells mediate this graft-versus-leukemia (GVL) effect, the influence of DLI on the T cell compartment of recipients has not been determined. To characterize the immunologic effects of DLI and to identify T cell changes selectively associated with the GVL response, we analyzed the T cell receptor (TCR) repertoire in four patients with relapsed chronic myelocytic leukemia who achieved a complete remission after infusion of CD4+ lymphocytes from HLA-identical sibling donors. Only one of the four patients developed clinically significant graft-versus-host disease (GVHD) after infusion of donor lymphocytes. TCR repertoire was examined after PCR amplification of 24 Vbeta gene subfamilies in serial samples obtained over a 1-yr period before and after DLI. Results were compared to 10 normal donors. Before DLI, all four patients were found to have abnormal TCR Vbeta repertoire in peripheral T cells, associated with a large number of clonal and oligoclonal patterns. Abnormal TCR patterns persisted for at least 3 mo after DLI, but thereafter gradually began to normalize. By 1 yr after DLI, all patients demonstrated almost complete normalization of Vbeta repertoire with polyclonal representation within almost all Vbeta gene subfamilies. We also examined changes in the TCR Vbeta repertoire associated with the disappearance of Ph+ cells. In each patient, we were able to identify the expansion of at least 1 Vbeta gene subfamily that coincided with the time of the cytogenetic response. In one patient who was studied in greater detail, CDR3 size analysis of serial samples after DLI indicated that these changes were associated with the appearance of clonal T cells. This finding was confirmed through CDR3 sequence analysis and use of CDR3 clone-specific oligonucleotide probes. A putative GVL clone identified by this technique was not detectable in either donor or patient T cells before DLI, but persisted in peripheral T cells for approximately 1 yr. These experiments therefore provide evidence for the clonal expansion of allogeneic T cells that may be selective mediators of antileukemia activity without also mediating graft-versus-host disease.

Detection of a potent humoral response associated with immune-induced remission of chronic myelogenous leukemia.

The effectiveness of donor-lymphocyte infusion (DLI) for treatment of relapsed chronic myelogenous leukemia (CML) after allogeneic bone marrow transplantation is a clear demonstration of the graft-versus-leukemia (GVL) effect. T cells are critical mediators of GVL, but the antigenic targets of this response are unknown. To determine whether patients who respond to DLI also develop B-cell immunity to CML-associated antigens, we analyzed sera from three patients with relapsed CML who achieved a complete molecular remission after infusion of donor T cells. Sera from these individuals recognized 13 distinct gene products represented in a CML-derived cDNA library. Two proteins, Jkappa-recombination signal-binding protein (RBP-Jkappa) and related adhesion focal tyrosine kinase (RAFTK), were recognized by sera from three of 19 DLI responders. None of these antigens were recognized by sera from healthy donors or patients with chronic graft-versus-host disease. Four gene products were recognized by sera from CML patients treated with hydroxyurea and nine were detected by sera from CML patients who responded to IFN-alpha. Antibody titers specific for RAFTK, but not for RBP-Jkappa, were found to be temporally associated with the response to DLI. These results demonstrate that patients who respond to DLI generate potent antibody responses to CML-associated antigens, suggesting the development of coordinated T- and B-cell immunity. The characterization of B cell-defined antigens may help identify clinically relevant targets of the GVL response in vivo.

Lower costs associated with hematopoietic cell transplantation using reduced intensity vs high-dose regimens for hematological malignancy.

We compared inpatient and outpatient costs alongside clinical outcomes associated with hematopoietic cell transplantation between 2000 and 2003 with high-dose regimens (HDCT, n=185) and with reduced intensity regimens (RICT, n=90) from human leukocyte antigen (HLA)-matched donors for patients with hematological malignancies. With a comparable median follow-up of 3 years, long-term clinical outcomes, including cumulative incidence of chronic graft-vs-host disease, disease-free survival and overall survival, were similar between the two groups. In the univariate analysis, median costs for the first 100 days ($104,380 vs $42,149) and 1 year ($128,253 vs $80,499) in the HDCT group were higher than those in the RICT group. Median days of hospitalization are also higher for HDCT recipients (39 vs 21), although the number of outpatient clinic visits for HDCT recipients were fewer compared to that for RICT recipients (16 vs 25) during the first year. Adjusting for patient characteristics, RICT recipients had approximately 16 fewer days of hospitalization and cost $53,030 less than HDCT recipients within the first year after transplantation. Our data suggest that substantially lower costs and fewer days of hospitalization within the first year after RICT procedures can be obtained with no compromise of long-term clinical outcomes compared to HDCT procedures.

Quality of life associated with acute and chronic graft-versus-host disease.

Acute and chronic graft-versus-host diseases (GVHD) are associated with increased morbidity and mortality after hematopoietic stem cell transplantation (HCT). We prospectively measured the quality of life (QOL) of patients undergoing allogeneic transplantation. Ninety-six subjects completed self-assessment surveys before HCT, and at 6 and/or 12 months post-HCT that included the Medical Outcomes Study Short Form 12 (SF12) and the Functional Assessment of Cancer Therapy-Bone Marrow Transplant scale. Eighty-three percent of survivors responded at 6 and 12 months. Physical and mental functioning assessed by the SF12 was not associated with either acute or chronic GVHD. In contrast, the trial outcome index (TOI) of the Functional Assessment of Cancer Therapy-Bone Marrow Transplant was sensitive to occurrence of either acute or chronic GVHD. GVHD is a major determinant of the long-term QOL of survivors. The adverse effects of acute GVHD are detectable with the TOI at 6 months post transplantation after which development of chronic GVHD is the most strongly correlated with worse QOL.

HLA-C mismatch is associated with inferior survival after unrelated donor non-myeloablative hematopoietic stem cell transplantation.

HLA-C matching is an important determinant of outcome after myeloablative unrelated donor (URD) hematopoietic stem cell transplantation. However, its importance in non-myeloablative stem cell transplantation (NST) is not known. We report a retrospective analysis of 111 patients who underwent URD NST, of whom 78 were 10/10 matched at HLA-A, B, C, DRB1, DQB1 and 33 were mismatched at one or more HLA-C antigen/allele (24 HLA-C only; nine HLA-C+other locus mismatch). Patients were conditioned with busulfan (0.8 mg/kg/day i.v. x 4 days) and fludarabine (30 mg/m(2)/day i.v. x 4 days). Graft-versus-host disease prophylaxis included cyclosporine/prednisone- or tacrolimus/mini-methotrexate-based regimens. HLA-C disparity did not impair engraftment. Median marrow donor chimerisms were >or=90% donor at day+30 and +100 in both groups. Overall survival at 2 years was 30% in HLA-C-mismatched and 51% in 10/10-matched patients (P=0.008). In Cox regression, HLA-C mismatch was an independent predictor of death (hazard ratio 1.85, P=0.04). Treatment-related mortality was higher in the HLA-C-mismatched group: 48 versus 16% (P=0.0001). Cumulative relapse incidence was 35% in the HLA-C-mismatched and 55% in the 10/10-matched cohort, P=0.09. HLA-C mismatch is associated with inferior survival after URD NST.

Distinct patterns of minimal residual disease associated with graft-versus-host disease after allogeneic bone marrow transplantation for chronic myelogenous leukemia.

PURPOSE: Allogeneic bone marrow transplantation (BMT) has been shown to provide effective therapy for chronic myelogenous leukemia (CML), but previous reports have also demonstrated the persistence of bcr-abl-positive cells for months to years after BMT in the majority of patients. To evaluate the biologic significance of persistent bcr-abl-positive cells, we examined the relationship between clinical parameters known to affect the risk of relapse and the ability to detect bcr-abl-positive cells post-BMT. PATIENTS AND METHODS: We analyzed 480 samples from 92 patients at two transplant centers for the presence of bcr-abl-positive cells by polymerase chain reaction (PCR). Two different BMT preparative regimens and protocols for prevention of graft-versus-host disease (GVHD) were used. One center used cyclophosphamide plus total-body irradiation (CY/TBI) and T-cell-depleted marrow; the second center used busulfan plus cyclophosphamide (Bu/CY) and untreated marrow with cyclosporine and methotrexate (Csp/MTX) as GVHD prophylaxis. RESULTS: We first determined the percent of patients at each center with > or = one PCR-positive (PCR+) result at defined intervals post-BMT. Between 0 and 6 months post-BMT, the majority of patients (80% to 83%) in both populations had PCR-detectable bcr-abl-positive cells. Between 6 and 24 months post-BMT, 80% to 88% of patients who received T-cell-depleted marrow remained PCR+, as compared with 26% to 30% of patients who received unmodified marrow. After 24 months post-BMT, the percentage of PCR+ patients was not significantly different in the two populations. This pattern of detection of bcr-abl-positive cells post-BMT followed the development of chronic GVHD in patients who received unmodified marrow. All patients were also divided into three groups based on post-BMT PCR results as follows: (1) persistent PCR+ (n = 29), (2) intermittent PCR-negative ([PCR-] n = 40), and (3) persistent PCR- (n = 23). These three groups were found to have a low, intermediate, and high probability of maintaining remission and disease-free survival, respectively (P = .0001). Intermittent or persistent PCR- results, which reflect levels of minimal residual disease < or = the limit of detection by PCR, were clearly associated with both acute (P = .004) and chronic (P = .000005) GVHD. Nevertheless, 44% of patients without GVHD also had intermittent or persistent PCR- assays. CONCLUSION: The persistence of PCR-detectable bcr-abl-positive cells early post-BMT in more than 80% of patients suggests that neither BMT preparative regimen effectively eradicates CML cells in most patients. Subsequently, acute and/or chronic GVHD are associated with a decreased ability to detect residual bcr-abl-positive cells, which suggests that immunologic mechanisms mediated by donor cells are important for inducing long-term remissions after BMT. The demonstration that 44% of patients without GVHD had either low or undetectable levels of residual leukemia suggests the presence of mechanisms capable of suppression or eradication of CML independent of GVHD.

Comparative outcomes of T-cell-depleted and non-T-cell-depleted allogeneic bone marrow transplantation for chronic myelogenous leukemia: impact of donor lymphocyte infusion.

PURPOSE: Donor lymphocyte infusion (DLI) can restore complete remission in patients with chronic myelogenous leukemia (CML) who have relapsed after T-cell-depleted (TCD) allogeneic bone marrow transplantation (BMT). The existence of salvage treatment for patients with DLI after TCD allogeneic BMT prompted an evaluation of overall outcome after CD6+ -TCD allogeneic BMT for patients treated during the time when DLI has been available. PATIENTS AND METHODS: We performed a retrospective analysis of outcomes of 46 patients who underwent TCD allogeneic BMT for stable-phase CML and compared these outcomes with those of 40 patients who underwent non-TCD allogeneic BMT. All subjects were patients at one of two neighboring institutions during a period when DLI was available. All patients received marrow from HLA-identical sibling donors, underwent similar myeloablative regimens, and had similar pretreatment characteristics. RESULTS: After BMT, the TCD group had a lower incidence of grade 2 to 4 acute (15% v 37%, P = .026) and chronic graft-versus-host disease (GVHD) (18% v 42%, P = .024) than did the non-TCD group. The 1-year treatment-related mortality rates for the TCD group and the non-TCD group were 13% and 29%, respectively (P = .07). The estimated 3-year probability of relapse (cytogenetic or hematologic) was higher for patients in the TCD group than for patients in the non-TCD group (62% v 24%, P = .0003). Twenty-three patients (20 in the TCD group and three in the non-TCD group) received and were assessable for response to DLI. After DLI, 17 of 20 patients in the TCD group and two of three patients in the non-TCD group achieved complete remission. Donor lymphocyte infusion induced GVHD in nine of 23 patients. Thirty (65%) of 46 patients in the TCD group and 27 (69%) of 39 assessable patients in the non-TCD group remained alive without evidence of disease. The estimated 3-year overall survival rates were similar for the TCD group and the non-TCD group (72% v 68%, respectively; P = .38). At last follow-up, there was no difference in the overall prevalence of GVHD or the proportion of patients requiring immunosuppressive agents between groups. CONCLUSION: These results suggest that the combination of T-cell depletion and post-BMT DLI is a viable treatment option for patients undergoing allogeneic BMT for CML and should be prospectively compared with traditional forms of GVHD prophylaxis.

CD6+ donor marrow T-cell depletion as the sole form of graft-versus-host disease prophylaxis in patients undergoing allogeneic bone marrow transplant from unrelated donors.

PURPOSE: The role of donor marrow T-cell depletion (TCD) in preventing graft-versus-host disease (GVHD) after transplantation of unrelated allogeneic marrow remains undefined. Because different TCD methodologies differ in the degree and specificity with which T cells are removed, it is likely that transplant outcomes would depend on which technique is used. Herein, we report results in the first 48 recipients of unrelated marrow using CD6+ TCD as the sole form of GVHD prophylaxis. PATIENTS AND METHODS: Median age of patients was 46 years (20 to 58 years). Donors were matched at A/B HLA loci. Ablation consisted of cyclophosphamide and fractionated total-body irradiation (TBI; 14 Gy). To facilitate engraftment, patients also received 7.5 Gy (22 patients) [corrected] or 4.5 Gy (26 patients) [corrected] of total lymphoid irradiation (TLI) before admission. No additional immune suppressive prophylaxis was administered. Granulocyte colony-stimulating factor was administered daily from day +1 to engraftment. RESULTS: All 48 patients demonstrated neutrophil engraftment. An absolute neutrophil count of 500 x 10(6)/L was achieved at a median of 12 days (range, 9 to 23 days). There were no cases of late graft failure. The number of CD34+ cells infused/kg was associated with speed of platelet and neutrophil recovery. The dose of TLI did not influence engraftment. Grades 2-4 acute GVHD occurred in 42% of patients (95% confidence interval [CI], 0.28 to 0.57). Mortality at day 100 was 19%. There have been only five relapses. Estimated 2-year survival was 44% (95% CI, 0.28 to 0.59) for the entire group, 58% for patients less than 50 years of age. In multivariable analysis, age less than 50 years (P =.002), cytomegalovirus seronegative status (P =.04), and early disease status at bone marrow transplant (P =.05) were associated with superior survival. CONCLUSION: CD6+ TCD does not impede engraftment of unrelated bone marrow after low-dose TLI, cyclophosphamide, and TBI. CD6+ TCD as the sole form of GVHD prophylaxis results in an incidence of GVHD that compares favorably with many adult studies of unrelated transplantation using unmanipulated marrow and immune-suppressive medications, especially in light of the median age of our patients (46 years). Although event-free survival in patients less than 50 years of age is very encouraging, older patients experience frequent transplantation-related complications despite TCD.

Routine screening for psychosocial distress following hematopoietic stem cell transplantation.

The diagnosis and treatment of cancer is often associated with high levels of psychosocial distress, yet exploration of these issues is rarely included in routine oncologic care. We conducted a pilot study to evaluate the feasibility of screening for psychosocial distress after autologous and allogeneic stem cell transplantation. A total of 80 adults were enrolled in Boston, MA, USA. Subjects completed self-administered assessments prior to hospital admission, at their first clinic visit after hospital discharge, and at 100 days post transplant. Assessments included validated instruments assessing psychosocial distress and quality of life (QOL). Elevated levels of anxiety and/or depression were detected in 55% of those providing pre-transplant assessments and were associated with compromised QOL. Post transplant screening was successfully performed in 69% of subjects and identified that 44% had symptoms of depression, anxiety or post traumatic stress disorder. Pre-transplant distress was associated with detection of distress after transplantation (81 vs 13%, P< 0.0001). In summary, we detected high levels of distress in transplant patients using self-administered tools. Pre-transplant distress appears to be highly predictive of distress post transplant and is a feasible marker to target screening and intervention programs.

Reperfusion-induced arrhythmias are not prevented by ibuprofen in isolated rat heart.

Free radicals have been implicated in the genesis of reperfusion-induced arrhythmias and the cyclooxygenase pathway has been suggested as a potential source. We have therefore assessed whether a cyclooxygenase inhibitor, ibuprofen, is able to reduce reperfusion-induced injury in the isolated perfused rat heart. A duration of 10 min of regional ischemia, which resulted in a high (83%) incidence of ventricular fibrillation, was selected and hearts (n = 12/group) were perfused with ibuprofen (2, 20, or 30 mg/L) throughout the experiment. Ibuprofen did not affect heart rate, although it did produce a dose-dependent increase in coronary flow. However, at all doses studied, ibuprofen had no effect upon the time to onset, incidence, or duration of arrhythmias. In subsequent studies with 30 min of regional ischemia, ibuprofen (30 mg/L) again caused vasodilatation but without effect upon heart rate or severity of arrhythmias. In conclusion, we were unable to obtain evidence in support of the concept that cyclooxygenase activity or cyclooxygenase-derived free radicals are involved in the genesis of ischemia- and reperfusion-induced arrhythmias.

Guillain-Barré syndrome following allogeneic bone marrow transplantation.

We describe four patients who developed Guillain-Barré syndrome (GBS) following allogeneic bone marrow transplantation (BMT). All four patients had a febrile illness before developing GBS. Two patients had mild graft-versus-host disease but did not require immunosuppression. These patients add to the increasing number of BMT patients whose courses have been complicated by GBS and raise the possibility that BMT patients, especially those undergoing allogeneic BMT, may have a higher risk of developing GBS.

A CD4+ T cell clone selected from a CML patient after donor lymphocyte infusion recognizes BCR-ABL breakpoint peptides but not tumor cells.

BACKGROUND: In patients with chronic myelocytic leukemia (CML), the breakpoint cluster region and fusion between the BCR and the c-ABL genes (BCR-ABL) oncogen product is a potential tumor-specific antigen. Previous studies have shown that T cells specific for the junctional region peptides of the BCR-ABL oncoprotein can be detected in healthy individuals as well as in patients with CML in chronic phase. We assessed whether BCR-ABL- specific T cells could be found in a patient achieving a complete cytogenetic remission after CD4+ donor lymphocyte infusion. METHODS: Using dendritic cells pulsed with BCR-ABL breakpoint peptides as antigen-presenting cells, we stimulated patient peripheral blood lymphocytes to isolate peptide-specific T cell clones present at the time of the cytogenetic response. T cell clones were isolated and the cellular specificity of these cells was examined. RESULTS: A CD3+ CD4+ T cell clone (1F7) that recognizes overlapping p210 junctional peptides presented by HLA-DR molecules was identified and expanded in vitro. Clone 1F7 failed to recognize autologous tumor cells as well as dendritic cells derived from patient CML cells. Clone 1F7 did not inhibit the growth and differentiation of CML precursor cells in a standard colony formation assay. Finally, using a clone-specific probe, 1F7 cells could not be detected in patient peripheral blood at the time of the donor lymphocyte infusion response. CONCLUSIONS: These results suggest that clone 1F7 was selected in vitro using highly potent peptide pulsed dendritic cells but was not representative of the anti-leukemia immune response in vivo. Based on these findings, CD4+ T cells with BCR-ABL specificity do not appear to be mediators of the anti-leukemia response in vivo after donor lymphocyte infusion.

CD8+ cell depletion of donor lymphocyte infusions using cd8 monoclonal antibody-coated high-density microparticles (CD8-HDM) after allogeneic hematopoietic stem cell transplantation: a pilot study.

A CD8 murine monoclonal antibody-coated high-density microparticle (HDM) has been developed, which allows for the rapid depletion of CD8+ T cells from apheresis products by gravity sedimentation. We conducted a study to determine the efficacy and safety of CD8 depletion of donor lymphocyte infusions (DLI) to treat relapse after stem cell transplantation using the Eligix CD8-HDM Cell Separation System. Patients were targeted to receive 3 x 10(7) CD4+ T cells/kg. Nine patients were enrolled, three with CML, three myeloma, two CLL, and one NHL. A median of 1 x 10(10) mononuclear cells were obtained by apheresis and processed. The median depletion of CD8+ cells was 99.3% (97.8->99.5%). CD8 depletion was highly specific, with a median recovery of CD4+ cells of 75%. A median of 2.9 x 10(7) CD4+ cells/kg was infused. No infusional toxicity was noted. All CML patients achieved a complete molecular remission. A CLL patient demonstrated a complete response. One patient developed GVHD (grade II acute GVHD and subsequently chronic GVHD). The CD8-HDM Cell Separation System appears to be highly selective and effective in depleting CD8+ T cells from DLI apheresis products, and CD8-depleted DLI is capable of mediating a graft-versus-leukemia effect while minimizing GVHD.

Changes in T cell receptor repertoire associated with graft-versus-tumor effect and graft-versus-host disease in patients with relapsed multiple myeloma after donor lymphocyte infusion.

Recent reports of clinical responses following donor lymphocyte infusions (DLI) in patients with relapsed multiple myeloma (MM) after allogeneic BMT have demonstrated the ability of allogeneic cells to mediate a graft-versus-myeloma (GVM) effect, but the mechanisms involved have not been determined. To identify changes in the T cell compartment associated with DLI, we performed a molecular analysis of the T cell receptor (TCR) repertoire in four patients with relapsed MM who received infusions of CD4+ lymphocytes from HLA-identical sibling donors. Three of the four patients demonstrated a clinical anti-myeloma response following DLI but also developed graft-versus-host disease (GVHD). The TCR repertoire was examined after PCR amplification of 24 Vbeta gene subfamilies. This method determines the relative utilization of each Vbeta gene subfamily and also allows the identification of clonal and oligoclonal T cell populations through analysis of CDR3 regions for each TCR Vbeta gene subfamily. Serial blood samples were obtained over at least a 1 year period before and after DLI and results compared to 10 normal donors. Serial analysis of CDR3 size profiles demonstrated the appearance of clonal T cell populations after DLI in each of the three responding patients. The appearance of some clones was noted within the first 3 months after DLI and coincided with decreasing levels of monoclonal paraprotein indicating an ongoing GVM response. Other T cell clones appeared at later time points and coincided with the development of GVHD. These findings demonstrate that T cell clones with different patterns of onset can be identified in the peripheral blood of MM patients following DLI. Further functional characterization of these distinct clonal expansions will be required to determine whether these T cell clones are mediators of either anti-myeloma or anti-host activity.

Partial CD8+ T-cell depletion of allogeneic peripheral blood stem cell transplantation is insufficient to prevent graft-versus-host disease.

Prior studies suggest that depletion of CD8+ T cells from donor bone marrow or donor lymphocyte infusions can reduce graft-versus-host disease (GVHD) without compromising graft-versus-leukemia. We explored CD8 depletion in patients undergoing matched related donor (MRD, n=25) and unrelated donor (URD, n=16) peripheral blood stem cell transplantation following myeloablative conditioning with cyclophosphamide (60 mg/kg/day i.v. x 2) and total body irradiation (200 cGy x 7 fractions). Ex vivo incubation of mobilized donor peripheral blood cells with anti-CD8 antibody coated high-density microparticles removed 99% of CD8+ cells. The median number of CD8+ cells infused was 3.9 x 10(5) cells/kg (2.2 x 10(5) in MRD, and 8.1 x 10(5) in URD patients). Post transplant immune suppression included tacrolimus in the MRD cohort, and tacrolimus plus mini-methotrexate (5 mg/m2 days +1, 3, 6, 11) in the URD cohort. All 41 patients engrafted. Grade 2-4 acute GVHD incidence was 61% (44% MRD, 88% URD). Chronic GVHD incidence was 50% (48% MRD, 55% URD). Relapse incidence was 4.9%. Estimated event-free and overall survival rates were 65 and 63%, respectively, at 1 year and 56 and 57%, respectively, at 2 years. There was no correlation between CD8+ number and GVHD or survival. A 2-log depletion of CD8+ cells from PBSC is insufficient to prevent GVHD.

CD6+ T cell-depleted allogeneic bone marrow transplantation for non-Hodgkin's lymphoma.

For patients with non-Hodgkin's lymphoma (NHL) undergoing blood or bone marrow transplantation (BMT), the use of autologous grafts has often been preferred to that of allogeneic stem cells because of a significantly lower incidence of non-relapse mortality. If complications associated with allo-BMT could be minimized without compromising efficacy, then it might become a preferred strategy for certain subsets of patients. In this report, we describe the toxicity and long-term efficacy of T cell-depleted allogeneic BMT using anti-CD6 monoclonal antibody and complement alone to reduce the risk of GVHD and its sequelae. Twenty-two patients, aged 18-60 years, with high (n = 10), intermediate (n = 9), or low (n = 3) grade NHL underwent HLA-identical allogeneic BMT from siblings. Patients had either relapsed after at least one remission or never achieved a full remission with chemotherapy. Twenty patients had a history of marrow involvement. Bone marrow was depleted of CD6+ T cells with T12 monoclonal antibody and complement as the sole form of GVHD prophylaxis. Stable hematopoietic engraftment occurred in all 22 patients. Four patients developed grade 2 and 1 patient grade 3 GVHD (23% grades 2-4 GVHD). Chronic GVHD has occurred in three patients. Treatment-related mortality was very low. Only one patient died while in remission. Thirteen patients are alive and free of disease with a median follow-up of 30 months. Estimated event-free and overall survivals are 54 and 59%, respectively. CD6 allogeneic marrow transplantation is associated with a low risk of transplant-related complications and may offer advantages for certain patients with recurrent NHL felt to be at high risk for relapse after autologous transplantation.

Long-term follow-up of reduced-intensity allogeneic stem cell transplantation for chronic lymphocytic leukemia: prognostic model to predict outcome.

Chronic lymphocytic leukemia (CLL) remains incurable with chemoimmunotherapy, and allogeneic hematopoietic stem cell transplantation (HSCT) offers the potential for cure. We assessed the outcomes of 108 CLL patients undergoing first allogeneic HSCTs, 76 with reduced-intensity (RIC) and 32 with myeloablative conditioning (MAC) between 1998 and 2009 at Dana-Farber Cancer Institute. With median follow-up of 5.9 years in surviving patients, the 5-year overall survival (OS) for the entire cohort is 63% for RIC regimens and 49% for MAC regimens (P=0.18). The risk of death declined significantly starting in 2004, and we found that 5-year OS for HSCT between 2004 and 2009 was 83% for RIC regimens compared with 47% for MAC regimens (P=0.003). For RIC transplantation, we developed a prognostic model based on predictors of progression-free survival (PFS), specifically remission status, lactate dehydrogenase, comorbidity score and lymphocyte count, and found 5-year PFS to be 83% for Score 0, 63% for Score 1, 24% for Score 2 and 6% for Score ≥3 (P<0.0001). We conclude that RIC HSCT for CLL in the current era is associated with excellent long-term PFS and OS, and, as potentially curative therapy, should be considered early in the disease course of relapsed high-risk CLL patients.