ALBERT

Description: Disease type and status at the time of allogeneic hematopoietic stem cell transplantation (HSCT) dominantly influence HSCT outcome. It is therefore important to stratify patients by disease risk in any retrospective or prospective transplantation study that enrolls patients across multiple disease types or status. We previously proposed a Disease Risk Index for this purpose, based on a retrospective study of patients transplanted at 2 institutions (Armand et al, Blood 2012;120:905). Here we present the results of a study designed to validate and refine the DRI in a larger multicenter population. We included 13,131 adult patients who underwent HSCT for hematologic malignancies, excluding very rare diseases, between 2008 and 2010 and were reported to the CIBMTR. Their median age was 52 (range, 18-80) years. The cohort included a broad representation of diseases, disease status, donor types, and graft sources. 53% of patients were conditioned with a myeloablative regimen. The median follow-up for survivors was 24 months. The original DRI stratified patients into 4 groups with 2y OS of 64% in the low-risk, 51% in the intermediate, 34% in the high, and 24% in very high risk group (p

Description: Non-myeloablative (NST) transplantation is increasingly used in the treatment of patients with AML and MDS who are not candidates for myeloblative transplant. Relapse of disease remains a major cause of treatment failure after NST. Predictive factors to identify patients at high risk of relapse are needed to identify patients who would benefit from additional interventions. Attainment of a high degree of donor engraftment achieved early after transplantation may indicate the presence of a more significant allo-immune effect. We have performed a retrospective analysis of 64 patients with AML and MDS receiving NST, assessing the impact of donor chimerism when measured early after transplantation on outcome. Overall survival (OS), progression free survival (PFS) and risk of graft versus host disease (GVHD) were compared for patients achieving ≥90 % or

Description: Abstract 4476 Chronic graft-versus-host disease (cGVHD) is a serious and frequent complication of allogeneic hematopoietic stem cell transplantation (HSCT). It is not known why some patients develop cGVHD and others do not, but identifying predictive biomarkers would facilitate the development of pre-emptive therapeutic strategies. Investigation into the pathophysiology of cGVHD has revealed different patterns of immune reconstitution in patients who develop cGVHD following HSCT. This suggests that the development of cGVHD occurs as a result of altered immune homeostasis and the inability to establish B and T cell tolerance. We prospectively examined 88 patients with hematologic malignancies following allogeneic HSCT at the Brigham and Woman's Hospital/Dana-Farber Cancer Institute between the years 2004 and 2008 and measured plasma cytokines known to modulate effector T cell, regulatory T cell, and B cell homeostasis and function. Seventy-six patients (86%) received reduced intensity conditioning; 84 (95%) received filgrastim-mobilized peripheral blood stem cells. Median follow-up for all patients was 5 years (range 2.9 to 7.3 years). Fifty-nine percent developed cGVHD. Plasma samples were collected at 1, 3, 6, and 12 months after HSCT and multiplex Luminex bead assays were used to measure levels of the following cytokines: Interferon-γ, IL-2, IL-7, IL-1β, IL-12, TNFα, IL-4, IL-5, IL-6, IL-10, and GM-CSF. Cytokine levels in patients who developed cGVHD were compared to patients who did not develop cGVHD. Results are shown in figure 1. Significantly higher levels of IL-4, IL-6, IL-12, and IL-1β were observed at 1 and/or 3 months after transplantation in patients who subsequently developed cGVHD. IL-4 and IL-6 are characteristic of T-helper-2 (TH2) cellular and humoral immune responses previously associated with cGVHD and fibrogenesis. IL-12 and IL-1β have heterogeneous functions including stimulating interferon-γ and TNFα production, enhancing cytotoxic and helper T cells, and promotion of autoimmunity. IL-1α also stimulates IL-6 production and activates fibroblasts. Finally, GM-CSF was significantly elevated in patients who do not develop cGVHD at 1 year following HSCT (2.5 v 1.46 pg/mL, p=0.017). As shown in figure 1, we observed a general pattern for many cytokines, including IFNγ, IL-2, IL-4, IL-5, IL-6, and IL-1β, in which these cytokines are initially similar in both groups, or lower in patients without cGVHD, but gradually increase over time in patients who do not develop cGVHD. In contrast, cytokine levels remain stable in patients with cGVHD and are generally lower 1 year after transplantation in these patients. These late differences may reflect immune suppressive therapies as well as persistent abnormalities of immune homeostasis. Taken together, these results support the hypothesis that alterations in immune homeostasis early after allogeneic HSCT are significantly associated with the subsequent development of cGVHD. Manipulation of the cytokine environment early after HSCT can modulate immune homeostasis and may be of potential prophylactic value. Administration of homeostatic cytokines late after HSCT may also have therapeutic benefit. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction Umbilical cord blood (UCB) transplantation yields survival comparable to adult stem cell transplantation, but there is significant variability among UCB products, in large part because of differences in processing conditions from collection to cryopreservation at cord banks. While impact of processing conditions on the actual UCB product has been reported, there is a little information regarding impact on patient-level outcomes. We report a retrospective exploratory analysis of processing performed at cord banks prior to freezing of UCB units and the impact on clinical outcomes such as engraftment, cord dominance, transplant-related mortality (TRM) and overall survival (OS) in 133 UCB recipients. Methods All adult recipients of unmanipulated double UCB transplantation (dUCBT) for hematologic malignancy from 2003 to 2011 at the 3 Harvard Cancer Center sites (Dana-Farber Cancer Institute, Massachusetts General Hospital, and Beth Israel Deaconess Medical Center) were included. All UCB units were thawed and washed prior to infusion. Multivariate analyses controlled for prognostic factors including age, malignancy, conditioning intensity, degree of HLA matching, presence of anti-HLA antibodies, order of cord infusion, TNC/kg, and CD34+/kg infused. Time to engraftment and treatment-related mortality were analyzed in the competing risks regression setting and survival was analyzed using proportional hazards models. Results 98 recipients underwent reduced-intensity conditioning, primarily fludarabine, melphalan and anti-thymocyte globulin. 35 underwent myeloablative conditioning, primarily cyclophosphamide and total body irradiation. Of the 48 banks contributing cords to this study, 42% employed simple cryopreservation and 23% employed plasma/volume reduction only, at some point during operation. These 2 methods were considered “RBC replete”. Of the 34 banks sharing their current practices, simple cryopreservation is no longer practiced by any; 12% practice plasma/volume reduction alone. 88% of the banks now employ RBC depletion, of which 67% use hydroxyethyl starch for RBC sedimentation and 67% use automated processing systems. Engraftment – Neutrophil and platelet engraftment were not impacted by RBC depletion, sedimentation with hydroxyethyl starch, automated processing, HLA matching or CD34+/kg dose in multivariate analyses. An anti-HLA antibody against one or more cords (p

Description: Investigation of the effects of rituximab (anti-CD20) on B-cell-activating factor of the tumor necrosis factor family (BAFF) and B cells would better define the significance of B-cell homeostasis in chronic graft-versus-host disease (cGVHD) pathophysiology. We studied 20 cGVHD patients at a median of 25 months after rituximab treatment when most patients had recovered total B-cell numbers. A total of 55% of patients had stable/improved cGVHD, and total B-cell numbers in these patients were significantly higher compared with rituximab-unresponsive patients. Although total B-cell number did not differ significantly between cGVHD groups before rituximab, there was a proportional increase in B-cell precursors in patients who later had stable/improved cGVHD. After rituximab, BAFF levels increased in all patients. Coincident with B-cell recovery in the stable/improved group, BAFF/B-cell ratios and CD27+ B-cell frequencies decreased significantly. The peripheral B-cell pool in stable/improved cGVHD patients was largely composed of naive IgD+ B cells. By contrast, rituximab-unresponsive cGVHD patients had persistent elevation of BAFF and a predominance of circulating B cells possessing an activated BAFF-RLoCD20Lo cell surface phenotype. Thus, naive B-cell reconstitution and decreased BAFF/B-cell ratios were associated with clinical response after rituximab in cGVHD. Our findings begin to delineate B-cell homeostatic mechanisms important for human immune tolerance.

Description: Sirolimus-based immunosuppressive regimens in organ transplantation have been associated with a lower than expected incidence of cytomegalovirus (CMV) disease. Whether sirolimus has a similar effect on CMV reactivation after allogeneic hematopoietic stem cell transplantation (HSCT) is not known. We evaluated 606 patients who underwent HSCT between April 2000 and June 2004 to identify risk factors for CMV reactivation 100 days after transplantation. The cohort included 252 patients who received sirolimus-tacrolimus for graft-versus-host disease (GVHD) prophylaxis; the rest received non–sirolimus-based regimens. An initial positive CMV DNA hybrid capture assay was observed in 225 patients (37.1%) at a median 39 days after HSCT for an incidence rate of 0.50 cases/100 patient-days (95% confidence interval [CI], 0.44-0.57). Multivariable Cox modeling adjusting for CMV donor-recipient serostatus pairs, incident acute GVHD, as well as other important covariates, confirmed a significant reduction in CMV reactivation associated with sirolimus-tacrolimus–based GVHD prophylaxis, with an adjusted HR of 0.46 (95% CI, 0.27-0.78; P = .004). The adjusted HR was 0.22 (95% CI, 0.09-0.55; P = .001) when persistent CMV viremia was modeled. Tacrolimus use without sirolimus was not significantly protective in either model (adjusted HR, 0.66; P = .14 and P = .35, respectively). The protective effect of sirolimus-containing GVHD prophylaxis regimens on CMV reactivation should be confirmed in randomized trials.

Description: Abstract 3029 Background: In patients with hematologic malignancies undergoing myeloablative hematopoietic stem cell transplantation (HSCT), an elevated serum ferritin prior to HSCT has been consistently associated with increased mortality. While serum ferritin is strongly correlated with liver iron content (LIC), to date no study has directly examined the effect of elevated LIC on HSCT outcomes. Furthermore, there are no studies of pre-transplantation chelation in this population. We conducted 2 prospective studies in patients with AML, ALL, or MDS undergoing HSCT. In the first, 45 patients were followed for 〉1 year with serial measurements of serum iron parameters and liver and cardiac iron (by MRI). In the second, we treated patients with severe iron overload (ferritin ≥ 1000 ng/ml and liver iron content (LIC) ≥ 5 mg/gdw) with deferoxamine 50 mg/kg/d starting in the weeks prior to transplantation and continuing until day -1, with the goal of controlling labile plasma iron (LPI) and especially the expected conditioning-induced rise in LPI. Results: The baseline characteristics of the patients on the observational study have been described in a prior publication (Armand et al., BBMT 2011). 5 patients (2 with AML in CR, 2 with AML and active disease, 1 with MDS) were enrolled on the chelation study; the median serum ferritin was 3, 746 ng/ml, and LIC 11.7 mg/gdw. They received deferoxamine for a median of 19 days before stem cell infusion. No significant drug-related toxicity occurred except for one episode of transient hypotension. There was no significant change in LIC after this short course of chelation. None of the 5 patients had a positive LPI assay before chelation or at the onset of conditioning; however, despite deferoxamine treatment, 2/5 had elevated LPI post-conditioning. Among those 5 patients, there was no disease relapse or death at a median follow-up of 20 months; only 1 patient developed grade II acute GVHD, and no patient developed VOD. Among the 50 patients in both studies combined, there was no significant change in serum ferritin, LIC or cardiac T2* in the first year after HSCT. After a median follow-up of 24 months, the estimated 2y overall survival (OS) and progression-free survival were 54% and 46%, respectively. When patients on the chelation study were excluded, there was a significant difference in OS for patients with pre-HSCT ferritin 〉 2, 500 ng/ml (2y OS 21% versus 62%, p =0.03) (Figure, panel A), similar to prior studies. However, there was no difference in OS, PFS, relapse or NRM for patients stratified by pre-HSCT LIC, regardless of the cutoff used and whether or not chelated patients were included (Figure, panel B). There was also no discernible impact of LIC on acute GVHD or VOD incidence. The difference in OS based on ferritin was apparent even among the patients with LIC

Description: Key Points Homeostatic recovery after allogeneic HSCT favors the production, expansion, and survival of effector T cells over CD4Tregs. Unbalanced reconstitution of regulatory and effector T-cell subsets contributes to the development of chronic graft-versus-host disease.

Description: The treatment of hematological malignancies with umbilical cord blood transplantation (UCBT) is rapidly increasing for adult patients. Disadvantages of UCBT include insufficient cell numbers for adult patient reconstitution, a lack of antigen experienced cells, and deficits in T cell signal transduction mechanisms. Consequently, UCBT is frequently associated with impaired immune function and high infection-related mortality. To counter these difficulties, transplantation with two UCB units has been employed to improve immune reconstitution in adult patients. We evaluated both the quantitative and functional reconstitution of cellular immunity in a group of adult patients undergoing UCBT. Thirty-two patients with a median age of 50 years with hematopoietic malignancies were treated with reduced intensity conditioning (Flu/Mel/rATG) followed by infusion with two sequential UCB grafts and GvHD prophylaxis with tacrolimus and sirolimus. The grafts were at least a 4/6 match with each other and the recipient. Here we report the results of 27 patients who have completed at least one year of follow up. Assessments were done prior to transplant and at various time intervals until 12 months post UCBT. Neutrophil and platelet engraftment occurred at a median of 21 days and 42 days, respectively. CD3+ populations remained severely depressed until 8 wks post-transplant when they gradually began to re-emerge. However the CD4+ and CD8+ populations demonstrated distinctly different reconstitution kinetics. At 6 months the median value of absolute numbers of CD4+ lymphocytes was 35% of pre-transplant levels increasing to 42% at 1 yr post-transplant, a median value far below the normal range for adults. In contrast, at 6 months post-transplant CD8+ lymphocytes remained severely depressed to 12% of pre-transplant levels, but dramatically increased and reached normal levels by 1 yr after UCBT. Interestingly, both the CD14+ monocyte and the CD16+CD56+ NK cell populations expanded dramatically at 4 wks post-transplant and reached pre-transplant levels and were within the normal range by 6 months. CD20+ B cell repopulation began at 8 wks post-transplant, displayed a striking expansion leading to a 17-fold increase in the median value for B cell numbers over pre-transplant values at 1 year and resulting in a median value of absolute numbers near the top of the normal range. To evaluate functional T cell immune reconstitution in vivo, we performed IFN-γ ELISpot analysis on CMV stimulated PBLs and compared the results to a PCR-based assay for CMV viremia. Additionally, we assessed the reconstitution of thymopoiesis with the T cell receptor excision circle (TREC) assay and real-time PCR. 16/27 patients and 26/52 UCB products were CMV seropositive prior to transplant. In the post-UCB period, development of CMV-specific effectors as determined by ELISpot did not always correlate with clearance of CMV viremia. Specifically, prior to 8 weeks post-UCBT, 8 out of 12 (67%) patients with CMV-positive ELISpot displayed CMV viremia, between 8 weeks and 100 days post-UCBT 4 out of 11 (36%) patients with CMV-positive ELISpot displayed CMV viremia and after 100 days post-UCBT only 3 out of 10 patients (30%) who developed CMV-positive ELISpot remained positive for CMV viremia. Identification of functional CMV effectors was only associated with the numbers of CD8+CD45RA+ cells (p=0.01) and the development of high TREC concentrations (p=0.01) that were detected after 6 months of UCBT, and was independent of GvHD or mixed chimerism. Taken together these results indicate that reconstitution of T cell immunity after UCBT is characterized by delayed recovery of CD4+ and CD8+ T cells and correlates with reconstitution of thymopoiesis and increase of naïve CD8+CD45RA+ T cells that can develop into efficient pathogen-specific effectors.

Description: CLL remains an incurable disease with standard chemotherapy. Although recent data suggest that CLL can respond to graft vs leukemia effects, myeloablative allogeneic stem cell transplantation is associated with a high transplant-related mortality in this population of older, heavily pretreated patients. We report the outcomes of 50 patients with advanced CLL who underwent NST between January 2001 and August 2004. All patients received fludarabine 30 mg/m2 x 4 days and intravenous busulfan 0.8 mg/kg/d x 4 days. 94% received G-CSF mobilized peripheral blood stem cells while 6% received bone marrow. Graft vs host disease (GVHD) prophylaxis included tacrolimus plus low dose methotrexate (56%) or cyclosporine plus prednisone (30%) based regimens. Most patients had a HLA-matched unrelated donor (62%), 30% a HLA-matched related donor, and 8% a HLA-mismatched donor. The median age of the patients was 53 years (range 35–67), with a median time from diagnosis to NST of 6.4 years (range 0.2–14.7). The patients were heavily pretreated, with a median of 5 prior therapies; 98% of patients had received fludarabine, 96% alkylating agents, 80% rituximab, and 32% alemtuzumab. 22% of patients had relapsed after prior autologous stem cell transplant. Most patients had active disease at time of NST, with only 16% in complete remission and 26% in partial remission. 52% of patients were in active relapse and 6% had failed to respond to any attempted therapy (induction failures). 50% of patients developed grade 4 neutropenia and their median time to neutrophil engraftment was 11.5 days. The incidence of grade 2–4 acute GVHD was 36%, and of chronic extensive GVHD 33%. Eleven of 25 patients (44%) in active relapse or induction failure at time of NST achieved an objective response. The median follow-up of surviving patients is 12.4 months (range 5.6 mos-4.0 yrs), with one-and two-year PFS 38% (95% CI 24–52%) and 28% (13–42%). The one- and two-year OS in this highly refractory population is 59% (95% CI 44–75%) and 48% (31–65%). Patients achieving 〉75% donor-derived hematopoiesis 1–2 months post-NST had a 30% risk of relapse or death from disease, as compared to 72% for those with lower donor chimerism (p= 0.007). Relapse was the principal cause of treatment failure, resulting in 10 deaths; other deaths were due to infection (n = 5), GVHD (n = 3) and respiratory failure (n = 1). In Cox proportional hazards regression analysis considering pre-transplant parameters such as age, sex mismatch, disease status (CR/PR vs relapse/induction failure), donor type, aGVHD prophylactic regimen and Rai stage, only disease status was an independent risk factor for poor OS (HR 4.7, p= 0.02). Both older age and disease status (HR 2.7, p= 0.02) were associated with poor PFS. Although treatment-responsive disease was the primary predictor of outcome, nonetheless 44% of patients with refractory disease still achieved objective responses after NST. High levels of donor chimerism 1–2 months post-NST were associated with a reduced risk of relapse or death from disease. These results suggest that NST is a reasonable treatment option for patients with advanced CLL, and that strategies to augment donor chimerism early after NST may result in improved long-term outcomes.