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Venetoclax combination therapies are becoming the standard of care in acute myeloid leukemia (AML). However, the therapeutic benefit of these drugs in older/unfit patients is limited to only a few months, highlighting the need for more effective therapies. Protein phosphatase 2A (PP2A) is a tumor suppressor phosphatase with pleiotropic functions that becomes inactivated in ∼70% of AML cases. PP2A promotes cancer cell death by modulating the phosphorylation state in a variety of proteins along the mitochondrial apoptotic pathway. We therefore hypothesized that pharmacological PP2A reactivation could increase BCL2 dependency in AML cells and, thus, potentiate venetoclax–induced cell death. Here, by using 3 structurally distinct PP2A-activating drugs, we show that PP2A reactivation synergistically enhances venetoclax activity in AML cell lines, primary cells, and xenograft models. Through the use of gene editing tools and pharmacological approaches, we demonstrate that the observed therapeutic synergy relies on PP2A complexes containing the B56α regulatory subunit, of which expression dictates response to the combination therapy. Mechanistically, PP2A reactivation enhances venetoclax-driven apoptosis through simultaneous inhibition of antiapoptotic BCL2 and extracellular signal-regulated kinase signaling, with the latter decreasing MCL1 protein stability. Finally, PP2A targeting increases the efficacy of the clinically approved venetoclax and azacitidine combination in vitro, in primary cells, and in an AML patient-derived xenograft model. These preclinical results provide a scientific rationale for testing PP2A-activating drugs with venetoclax combinations in AML.

Autologous stem cell transplantation (ASCT) has been successfully used in HIV-related lymphoma (HIV-Ly) patients on highly active antiretroviral therapy. We report the first comparative analysis between HIV-Ly and a matched cohort of HIV−lymphoma patients. This retrospective European Group for Blood and Marrow Transplantation study included 53 patients (66% non-Hodgkin and 34% Hodgkin lymphoma) within each cohort. Both groups were comparable except for the higher proportion of males, mixed-cellularity Hodgkin lymphoma and patients receiving granulocyte colony-stimulating factor before engraftment and a smaller proportion receiving total body irradiation-based conditioning within the HIV-Ly cohort. Incidence of relapse, overall survival, and progression-free survival were similar in both cohorts. A higher nonrelapse mortality within the first year after ASCT was observed in the HIV-Ly group (8% vs 2%), predominantly because of early bacterial infections, although this was not statistically significant and did not influence survival. Thus, within the highly active antiretroviral therapy era, HIV patients should be considered for ASCT according to the same criteria adopted for HIV−lymphoma patients.

Autologous stem cell transplantation (ASCT) has been successfully used in HIV-related lymphoma (HIV-Ly) patients on highly active antiretroviral therapy. We report the first comparative analysis between HIV-Ly and a matched cohort of HIV− lymphoma patients. This retrospective European Group for Blood and Marrow Transplantation study included 53 patients (66% non-Hodgkin and 34% Hodgkin lymphoma) within each cohort. Both groups were comparable except for the higher proportion of males, mixed-cellularity Hodgkin lymphoma and patients receiving granulocyte colony-stimulating factor before engraftment and a smaller proportion receiving total body irradiation-based conditioning within the HIV-Ly cohort. Incidence of relapse, overall survival, and progression-free survival were similar in both cohorts. A higher nonrelapse mortality within the first year after ASCT was observed in the HIV-Ly group (8% vs 2%), predominantly because of early bacterial infections, although this was not statistically significant and did not influence survival. Thus, within the highly active antiretroviral therapy era, HIV patients should be considered for ASCT according to the same criteria adopted for HIV− lymphoma patients.

Venetoclax-combination therapies are becoming the standard-of-care in acute myeloid leukemia (AML). However, the therapeutic benefit of these drugs in older/unfit patients is limited to only a few months, highlighting the need for more effective therapies. PP2A is a tumor suppressor phosphatase with pleiotropic functions that becomes inactivated in ∼70% of AML cases. PP2A promotes cancer cell death by modulating the phosphorylation state in a variety of proteins along the mitochondrial apoptotic pathway. We therefore hypothesized that pharmacological PP2A reactivation could increase BCL2 dependency in AML cells and thus potentiate venetoclax-induced cell death. Here, by using three structurally distinct PP2A-activating drugs, we show that PP2A reactivation synergistically enhances venetoclax activity in AML cell lines, primary cells, and xenograft models. Through the use of CRISPR-Cas9 models and pharmacologic approaches, we demonstrate that the observed therapeutic synergy relies on PP2A complexes containing the B56α regulatory subunit, which expression dictates response to the combination therapy. Mechanistically, PP2A reactivation enhances venetoclax-driven apoptosis through simultaneous inhibition of anti-apoptotic BCL2 and ERK signaling, the later decreasing MCL1 protein stability. Finally, PP2A targeting increases the efficacy of the clinically approved venetoclax and azacitidine combination in vitro,in primary cells, and in an AML patient-derived xenograft model. These preclinical results provide a scientific rationale for testing PP2A-activating drugs with venetoclax combinations in AML.

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Introduction

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Intoduction:

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Kröger: Sanofi: Honoraria, Research Funding; Neovii: Honoraria, Research Funding; Riemser: Honoraria, Research Funding; Novartis: Honoraria, Research Funding. Montoto:Roche: Honoraria; Gilead: Research Funding. Dreger:Novartis: Consultancy; Gilead: Speakers Bureau; Novartis: Speakers Bureau; Gilead: Consultancy; Janssen: Consultancy; Roche: Consultancy.

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INTRODUCTION

Introduction:

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Introduction

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Alloreactivity triggered by interaction of Killer immunoglobulin-like receptors (KIRs) on donor Natural killer (NK) cells and their ligands on recipients plays a role in the graft-versus-tumour effect. Different predictive models have been postulated for measuring alloreactivity: ligand incompatibility model, receptor-ligand model, missing ligand model and KIR gene-gene model. Our aim in this study is to evaluate the importance of differences in KIR and HLA genotype between donor and recipient (missing ligand model and KIR gene-gene model) in the setting of non T cell depleted haploidentical haematopoietic stem cell transplantation (HSCT) with high-dose, post-infusion cyclophosphamide (Cy)33 consecutive patients with haematological malignancies who received haploidentical HSCT with high-dose Cy post-transplantation between 2007 and 2013, and their donors were included for analysis (Table 1). HLA typing was used to identify KIR ligands HLA-B and HLA-C. KIR genotype was analyzed by PCR (KIR Typing, Miltenyi Biotec) on genomic DNA (Maxwell 16 Blood DNA Kit, Promega) from peripheral blood samples, and revealed with ethidium bromide after agarose gel electrophoresis.Demographic data and KIR genotype characteristics of donors and recipients are listed in Table 1. We found that KIR ligands mismatch between donor and recipient is related with improve of OS (52% vs. 82%; p=0,041) and DFS (63% vs. 22%; p=0,037) a year after transplant (Figure 1). Mismatch of inhibitors KIR receptors (iKIR) gene content between donors and recipients is also related with an improvement of OS (94% vs. 75%; p=0,049) and DFS (13% vs. 61%; p= 0,028) compared with no mismatch pairs. In the multivariable analysis, both KIR ligands mismatches (HR=4,38 CI:0.9-21; p=0,061) as well as iKIR mismatches (HR=4,15 CI:1-16; p=0,047), show a tendency to be independent variables for the reduction of disease relapse rate. Cumulative incidence of relapse for both variables studied is shown in Figure 2. Conspicuously, a sub-analysis in Hodgkin Lymphoma patients group shows and improve in DFS a year after transplant in patients with KIR ligands mismatches ( 100% vs. 48% p: 0,006) and iKIR mismatches (100% vs. % 33% p: 0,049), despite the small number of patients. Contrary to data published by other groups, patients receiving donor’s progenitors with Bx haplotype with centromeric genes (Cen-BB) did not show a benefit in survival (SG 85% vs. 90%, p= 0,05 and DFS 66% vs. 10%, p=0,047) a year after transplantOur data suggest that in the setting of non T cell depleted haploidentical HSCT with high dose Cy post-infusion, KIR ligands and iKIR mismatch are related with an improve in survival, specially in the sub-group of patients with Hodgkin diseaseNo relevant conflicts of interest to declare.

Allogeneic transplantation is the only curative option for patients with high risk hematologic malignancies. Only one third of them have an HLA identical sibling donor and around 60-70% will find an unrelated donor, that´s why HAPLO-HSCT offers a therapeutic option to most of these patients with the advantages of quick availability, easy programation and logistics, and a committed donor.We retrospectively evaluate the results of HAPLO-HSCT with reduced conditioning or myeloablative regimens and GVHD prophylaxis based on HD-CY (50 mg/kg on days +3 and +4) and a calcineurin inhibitor plus mycophenolate from day +5 performed in GETH centers.From Dec-2007, 80 HAPLO-HSCT have been done in 14 centers. Median age was 37 years (16-66), 67.5% were males and all were in advanced phases of their disease or presented high risk features (29 Hodgkin´s, 22 AML, 9 ALL, 8 MDS, 5 NHL, 4 myeloma and 2 myelofibrosis). Previous HSCT has been employed in 65%, autologous in 38 and allogeneic in 15 (5 siblings, 3 unrelated and 7 cord blood transplants), and in 35% the HAPLO-HSCT was their first transplant. Disease status at HAPLO-HSCT was CR in 45%, with persistent disease in 55%. Bone marrow was the graft source for 51% and peripheral blood for 49%, non T-cell depleted in all cases. The haploidentical donor was the patient´s mother (21), father (7), brother/sister (35) or offspring (17). Non-myeloablative conditioning was employed in 77.5% and myeloblative in 22.5%. Median neutrophils engraftment was reached at day +18 (13-45) and platelets >50K at day +27 (11-150). Main toxic complications were grade II-III muchositis in 36%, febrile neutropenia in 75% and CMV reactivations in 62%, with a transplant related mortality rate of 12.5% at day +100 and 19% at 6 months post-transplant. Acute GVHD grade II-IV affected to 24/73 patients at risk (33%), with grade III-IV in 10/73 (14%). Chronic GVHD was present in 12/51 (24%), being extensive in 6/51 (12%). After a median follow-up of 9 months (0.3-49), 26/80 patiens have died due to relapse in 13, infections in 10 and GVHD in 3 cases. Event-free survival and overall survival at 1 year were 48% and 60% respectively. Immune reconstitution was fast and complete in those evaluated.HAPLO-HSCT with HD-CY is a useful tool in the treatment of high risk hematologic malignancies, rendering long-lasting remissions with limited toxicity, low GVHD incidence and early immune reconstitution.No relevant conflicts of interest to declare.

Favourable immune reconstitution (IR) has been reported after reduced intensity conditioning (RIC) Unmanipulated Haploidentical Stem cell transplantation (Haplo SCT) with high dose post-transplant cyclophosphamide, and it has been suggested as a relevant factor for the good clinical outcomes observed. Due to the encouraging results in our centre the intensity of conditioning regimen has been increased in some patients with high risk of relapse. The aim of this study is to analyze whether the increase in intensity of conditioning influences immune reconstitution after Haplo-SCT.

Graft versus host disease (GvHD) is the main cause of morbimortality after allogeneic stem cell transplantation (allo-SCT). Several single-nucleotide polymorphisms (SNPs) in in the promoter region of cytokine genes have shown to alter their expression and are therefore associated with donor-recipient alloreactivity and, ultimately, with SCT outcome. Interleukin 17 (IL-17) is secreted by CD4+ T-cells and has been implicated in the pathogenesis of various autoimmune diseases but its importance in SCT is not well-known.

The main functions of Natural Killer (NK) cells are early protection against viruses or tumour cells and production of cytokines that regulate immune functions. NK cells are the first lymphoid cells to repopulate the marrow after Stem Cell Transplantation (SCT) and reach normal levels within 1 month after transplant. Acquisition of both, inhibiting and activating receptors on developing NK cells is an important step in their functional maturation. Previous studies showed the beneficial effect of NK alloreactivity in prevention of relapse, especially in the setting of haploidentical SCT. The aim of this study is to compare the reconstitution of the NK cell compartment during the first 3 months after unmanipulated haploidentical peripheral blood SCT (Haplo) and HLA-identical sibling peripheral blood SCT (HLA-id).11 adult patients received SCT (7 Haplo and 4 HLA-id) at Gregorio Marañón Hospital (Madrid-Spain) from November 2012 to April 2013. Conditioning regimen comprised fludarabine, cyclophosphamide and busulfan for Haplo SCT and fludarabine and busulfan or fludaribine and melphalan for HLA-id SCT. Prophylaxis for acute graft-versus-host disease consisted of high dose cyclophosphamide on days +3 and +4, cyclosporine A and mycophenolate mofetil for Haplo and Cyclosporine A and methotrexate for HLA-id. Patient´s characteristics and transplant outcomes are shown in table 1. We analysed reconstitution patterns and phenotype of NK at day +15, +30, +60, and +90 after transplantation by multi-color flow cytometry on FC500 Beckman Coulter® cytometer using the following anti-human monoclonal antibodies: CD3 FITC, CD56 ECD, CD45 PC7, NKG2A PC7, NKp30 PC5, NKp44 PE, Nkp46 PC5, and NKG2D PE (Beckman Coulter®). For comparison between the two groups Mann–Whitney U-test was used.2/7 patients who received Haplo SCT died early in the post-transplantation period (day +50 and +66), and were excluded of the analysis because NK cells were not recovered by those days. NK cells reached normal levels by day +30: median 71 cells/µl (21-1089)) after Haplo; median 213.5 cells/µl (113-499) after HLA-id, and remained at high levels through follow up, with no significant differences between the two groups. Similarly to previous studies, a large percentage of NKbright cells was observed at day +30 after Haplo (median 89% of NK cells (55-97%)), a percentage that tended to decrease at day +60 (30% (7-38%)) and +90 (35% (10-45%)). Interestingly the percentage of NKbright cells after HLA-id SCT at day +30 (median 14.5% of NK cells (6-30%)) compared with Haplo, was significantly lower (p=0.016). This was accompanied by a significantly lower expression of inhibitory receptor NKG2A after HLA-id SCT than after Haplo: 59.5% (50-62%) versus 92.5% (50-62%) at day +30; 54% (38-61%) versus 86% (70-88%) versus at day +60 (p=0.016). Activating receptors NKp44 and NKp30 showed a low expression after both types of SCT throughout the first 3 months after transplantation. By contrast, activating receptor NKp46 levels were significantly higher at day +30 after Haplo than after HLA-id SCT (93% (87-98%) versus 50% (37-51%)) (p=0.016). Finally, high and similar proportions of activating receptor NKG2D were observed in both types of SCT. Figure 1 illustrates the recovery of the NK cell receptor phenotype for each type of SCT.Our data showed an early and fast recovery of NK cells after Haplo and HLA-id SCT. However, phenotypic maturation of NK cells appears to be different for each type of transplant. NK cells generated after Haplo exhibit a more immature phenotype, characterized by a higher proportion of NKbright cells, and a higher expression of NKG2A at day +30. Interestingly expression of NKp46 was significantly higher after Haplo than after HLA-id SCT. Other authors have reported cytotoxic activity of these NK cells with high expression of NKp46, suggesting that cytotoxicity may be preserved in these immature NK cells. NKp30, NKG2D and NKp44 expression is less affected by the type of SCT.This work has been partially supported by Project “Evaluación de la reconstitución inmune después del trasplante haploidéntico de progenitores hemopoyéticos sin depleción T” from Fundación Mutua Madrileña.No relevant conflicts of interest to declare.

Allogeneic transplantation is the only curative option for patients with high risk hematologic malignancies. HAPLO-HSCT offers a therapeutic option to most of these patients with the advantages of quick availability, easy programation and logistics, and a committed donor. This procedure has shown promissing results in patients diagnosed with relapsed or refractory Hodgkin´s disease (Burroughs LM et al. Biol Blood Marrow Transplant 2008; 14:1279-1287).

The safety and usefulness of unrelated umbilical cord blood (CB) stem cell transplantation (SCT) in patients candidates for allogeneic SCT and HIV infection is unknown. Single CB with the co-infusion of CD34+ cells from a third party HLA-mismatched donor (TPD), or Haplo-cord SCT, has shown to reduce the period of post-transplant neutropenia and related early complications associated with single CB transplantation. This platform could potentially reduce the risk of early infections in this particular group of patients. On the other hand, the use of a cell source homozygous for the CCR5 delta32 allele mutation, which confers high resistance against HIV-1 acquisition, is of particular interest in HIV+ patients.

*The MRD negative group includes 2 MAC SCU-dual cases with primary graft failure rescued immediatly by a second graft (1 Dual and 1 Haplo) using a RIC regimen. The MRD positive group includes 1 MAC SCU-dual case rescued immediatly by a second graft (1 Haplo).No relevant conflicts of interest to declare.

The success of allogeneic stem cell transplantation (allo-SCT) relies on the result of the immune reactions between donor and recipient lymphohemopoietic systems. Chimerism quantification and monitoring post allo-SCT allows to estimate such immune reactions. In recent years, there has been a growing interest in the analysis of circulating cell-free nucleic acids in plasma. Although the ultimate origin of such nucleic acids is unknown, the most plausible hypothesis proposes cell disruption as the cause for the presence of nucleic acids in plasma. Analysis of chimerism in cell-free plasma DNA would complement the results of cell chimerism for a better prediction of different complications (engraftment failure, rejection, graft versus host disease…etc.).Our goal was to quantitatively monitor chimerism in cell-free plasma DNA and to evaluate its usefulness for the prediction/early diagnosis of complications after allo-SCT that would favour early therapeutic intervention.The study comprised 270 plasma samples from 29 allo-SCT patients. With a median follow up of 45,8 months (14,6– 74,7).Whole blood (WB) (10 mL) was collected in EDTA containing tubes and was processed immediately after collection. Plasma was separated from the blood cells by centrifugation at 1600g for 10 min and cell-free plasma DNA was extracted according to the blood and body fluid protocol of the QIAamp DNA Blood Mini Kit (Qiagen). Quantitative chimerism analysis was performed by microsatellite PCR (STR; AmpFlSTR SGM plus, Applied Biosystems) in whole blood (WB), T-cells (CD3+) purified using immunomagnetic means (Miltenyi Biotec) and cell-free plasma DNA.Chimerism was monitored at regular intervals post-transplant (+30,+60, +90, +180, +365). Sensitivity of the technique is 1% in WB and cell-free plasma DNA, and 5% in T-cells (derived from a 95% purity of enriched samples).During the first year of allo-SCT, the number of patients with mixed chimerism in cell-free plasma DNA was higher than in WB and T-cells (Table 1). Cell-free plasma DNA mixed chimerism was observed for a longer timer after transplant than “cellular” mixed chimerism, with a median of 105 vs. 40 and 27 days for cell-free plasma DNA, T-cells and WB, respectively.Chimerism analysis revealed two groups of patients, one with mixed chimerism in both cell-free plasma DNA and “cellular DNA”, in which the percentage of recipient plasma DNA ranged between 10–30%, probably mostly derived from hematopoietic cells. The other group presented mixed chimerism in cell-free plasma DNA but complete “cellular” chimerism (100% donor) in which cells the percentage of recipient plasma DNA was lower than in the former group (1–10%).A greater number of patients with graft versus host disease (GVHD),mainly acute but also chronic, presented mixed chimerism in cell-free plasma DNA and complete chimerism in WB and T-cells (Table 2). The presence of recipient cell-free plasma DNA could be derived by cell disruption in GVHD target organs.Quantitative follow-up of chimerism in cell-free plasma DNA, does not reproduce the results of “cellular” chimerism, as reported previously, and therefore, could not replace it for post-SCT follow-up. On the other hand, chimerism analysis in cell-free plasma DNA could be combined with the conventional follow-up of “cellular” chimerism for an improved diagnosis of life-threatening complications such as acute and chronic GVHD.No relevant conflicts of interest to declare.

Allogeneic transplantation is the only curative option in the treatment of multiple high risk hematologic neoplasms. Only 25–30% of patients have an HLA identical sibling donor and searching for a compatible unrelated donor or cord blood renders satisfactory results in around 60–70%. Haploidentical transplantation (HAPLO) offers a therapeutic alternative to more than 95% of such patients with the advantages of quick availability, easy programming and a committed donor.We evaluate the results of HAPLO with a reduced intensity conditioning regimen (Fludarabine 30 mg/m2 ×5 days (-6 to -2), Cyclophosphamide 14,5 mg/kg ×2 days (-6 and -5), IV Busulfan 3,2 mg/kg × 1–3 days (BUX, days -4 to -2) employing high doses of Cyclophosphamide post graft infussion (50 mg/kg days +3 and +4) as GVHD prophylaxis together with standard doses of cyclosporine and mycophenolate from day +5.From Dec-2007, we have done 26 HAPLO in 4 spanish centers. Median age was 38 years (16–57), 20 were male and all were in advanced phases of their diseases (12 Hodgkin′s, 6 AML, 3 ALL, 2 MM, 1 MDS, 1 MF y 1 NHL). Previous autologous HSCT has been employed in 13 and allogeneic HSCT in 6 (2 MURD and 4 UCB). Disease status at HAPLO was CR in 8, PR in 14 and refractory in 4. Bone marrow was used in 16 and unmodified peripheral blood in 10. The haploidentical donor was patient′s mother (8), father (3), siblings (11) or other relatives (4). BUX was used in 1 dose (15), 2 doses (8) or 3 doses (2) and TBI 200 cGy in 1 case. Mean neutrophils engraftment was achieved on day +18 (13–26) and platelets >50K on day +27 (17–150) in all but 2 cases of graft failure (7.7%) due to progression (MF) or relapse (M7-AML). Main toxicities were grade 1–2 mucositis in 50%, febrile neutropenia in 75% and CMV reactivations in 58% with a 100 days NRM of 3.8% (1/26, VOD and MOF) and 10% NRM at 6 months (2/20). Grade II-IV acute GVHD appeared in 10/23 patients at risk (43%) and grade III-IV in 4/23 (17%). Chronic GVHD affected to 4/15 (27%), being extensive in 1/15 (6.7%). With a median follow-up of 9 months (1–38), 13/22 (59%) are alive in CR, progression or relapse has ocurred in 6/24 (25%). Immune reconstitution seems fast and complete in those evaluated.HAPLO with high-dose cyclophosphamide as GVHD prophylaxis is a useful alternative in the treatment of high risk hematologic tumours, with low toxicity, acceptable GVHD incidence and severity, long lasting remissions, and fast immunological reconstitution.No relevant conflicts of interest to declare.

Little is known about immune reconstitution (IR) of HIV+ adult patients treated with HAART and high-dose chemotherapy followed by autologous stem cell transplantation (ASCT).To compare the IR in HIV+ and HIV- patients treated with ASCT, and to correlate it with clinical outcome.From January 2007 to January 2011 all HIV+ patients with lymphoma or multiple myeloma treated with ASCT where prospectively included. HIV- patients with lymphoma or multiple myeloma treated with ASCT were included as control. IR lymphocytes (Ly) subsets in peripheral blood were quantified by flow cytometry (FACScan, Becton-Dickinson Immunocytometry Systems, San Jose, CA). Naïve ly, memory ly, memory-activated ly, effector ly, NK cytotoxic ly, B naïve ly and B memory ly were quantified at the time of transplantation as well as at 3, 6, 12 and 18 months after ASCT. Additionally, immunoglobulin value, neutrophil and platelet engraftment (>0.5×109/L and >20×109/L respectively) and infectious complications were recorded in both groups. The study was approved by the local Ethics Committee.We included 14 patients, 6 HIV+ and 8 HIV-. All this patients were in complete remission at the time of the ASCT. All patients received BEAM conditioning regimen, except for Melphalan 200 in the case of MM. The median infused CD34 was 4,08×10e6 in HIV+ patients and 5.2 x10e6 in control patients. All HIV+ patients had undetectable viral load at the time of the ASCT. Values of ly populations are shown in Table 1. Median neutrophils days of engraftment: 11.5 days (11–13.75) in HIV- and 14 in HIV+ (12.75–17), platelets: 15 (13–28) and 30 (17–78) (p:≤0.05) respectively. Both groups reached IR at third month, while HIV+ group showed lower values especially for the T CD4 ly subgroup (not statistically significant). HIV+ patients had statistically significant lower values of CD4 memory ly and activated CD4 ly at 6th month, and lower values of NK ly at 3th month. On the other hand, we found lower values of B naïve Ly in HIV- patients at 6th month. There was no difference in the median value of immunoglobulin at 3, 6 and 12 months between both groups. Infections were more frequents in HIV+ patients: positive Aspergillus antigenemia (3/6 vs. 1/8), positive CMV antigenemia (3/6 vs. 1/6), fungal infection (2/6 vs. 0/8) and bacterial infections (5/ 6 vs. 2/8), nevertheless severe episodes didn't shown differences, as well as disease free survival and mortality.In this series, IR was reached at the third month in both HIV + and HIV- patients, with non-significant lower values for HIV+ patients. Despite infections were more frequent in HIV+ patients, this was not associated with a higher mortality.Median values of lymphocytes population studied. Yellow box remarked correspondsTo the statistically significant results (p:≤0,05)No relevant conflicts of interest to declare.

The FOXP3 gene encodes for a protein (Foxp3) involved in the development and functional activity of regulatory T cells (CD4+/CD25+/Foxp3+, Tregs) which exert regulatory and suppressive roles over the immune system. After allogeneic stem cell transplantation (allo-SCT), Tregs are known to mitigate graft versus host disease (GVHD) while maintaining a graft versus leukemia effect (GVL). Allele (GT)15 for the functional (GT)n polymorphism in the promoter/enhancer of the FOXP3 gene is associated with a higher expression of FOXP3 and production of a greater amount of Tregs. However, its impact in the allo-SCT setting has not been analyzed.To analyze the impact of the (GT)n polymorphism in the promoter/enhancer of the FOXP3 gene on the development of complications and ultimately on the success of conventional HLA-identical allo-SCT.The study includes 33 patients with hematological malignancies, treated with myeloablative HLA-identical peripheral blood allo-SCT (Table 1). Diagnosis, classification and grading of GVHD were made by clinical criteria and confirmed when necessary by pathological examination of histological samples from gut, skin, liver or lung, according to international consensus criteria. Donor and recipient genomic DNA was purified from EDTA anticoagulated peripheral blood before allo-SCT and using QIAamp Blood DNA extraction kit (Qiagen). Genotyping of the (GT)n microsatellite polymorphism in the FOXP3 gene was performed by a fluorescence-based short tandem repeat-polymerase chain reaction (STR-PCR) method (GeneAmp 7900; Applied Biosystems) and sized by capillary electrophoresis (POP7 - ABI PRISM 3130 xL Genetic Analyzer; Applied Biosystems) followed by fragment analysis (GeneMapper 4.0 Software; Applied Biosystems) as previously described [Bassuny WM, et al. Immunogenetics. 2003;55 :149–56].The median follow-up time for the cohort was 34 months (range 9.5–110). Allelic frequencies observed were similar to those previously reported (50.5% (GT)15, 41% (GT)16 and 7% (GT)17; no (GT)14 or (GT)18 alleles were found). Patients transplanted from donors harboring allele (GT)15 showed a lower incidence of grades II-IV acute GVHD (29% vs 67%; p =0.049). These patients also showed a trend to a lower incidence of severe (grades III-IV) GVHD (12% vs 33%; p =0.167) as well as chronic GVHD (75% vs 100%; p =0.143; Table 1, Figure 1). No statistically differences were found between patients transplanted from (GT)15 and non-(GT)15 donors in terms of relapse rate (38% vs 33%; p =0.825; Table 1) or cumulative incidence of relapse (CIR at 2 years 35.3% vs 37.5%, Figure 2). Finally, survival analysis did not show statistically significant differences between the two groups of patients in terms of median event (relapse) free survival (EFS, 15.6 months vs 4.5 months, p =0.686) or overall survival (OS, 29 months vs not reached, p =0.610).Tregs are known to modulate the allotolerance-alloreactivity balance between donor and recipient in the allo-SCT setting, mitigating GVHD while preserving the anti-tumor effect (GVL) of the donor graft. In the present study, the presence of allele (GT)15 in the donor, which promotes a higher expression of FOXP3 and greater amount of Tregs, affected allo-SCT outcome by decreasing grades II-IV acute GVHD and chronic GVHD, without affecting GVL (no differences in CIR and OS). Analysis of this polymorphism can help in appropriate donor selection and, more importantly, drive a tailored management of patients submitted to allo-SCT.No relevant conflicts of interest to declare.

Cytokine gene polymorphisms are well know to be associated with functional differences in cytokine regulation and altered clinical performance in a variety of diseases. They seem to play an important role in allogeneic stem cell transplantation (allo-SCT), mostly in the incidence and severity of graft-versus -host disease (GVHD) which is one of the most common serious complications of allo-SCT. Interleukin-6 (IL-6) is a proinflamatory cytokine known to be implicated in the pathogenesis of aGVHD with increasing serum levels during the development. The IL6−174 (G/C) single nucleotide polymorphism (SNP), localized in the promoter region (7p21) has been linked to in vitro and in vivo productions, associating the presence of allele G with significantly higher levels of IL-6 and a trend to have higher grades of aGVHD.To analyze the influence of Donor (D) and Recipient (R) genotype for the polymorphism IL6−174 (G/C) on the outcome of HLA-identical related stem cell transplantation.The study comprised 171 allo-SCT (342 D/R samples) included in the Spanish Group for Haematopoietic Stem cell Transplantation (GETH) DNA bank. Genomic DNA was purified from peripheral blood samples obtained pre-SCT from patients and donors, after written informed consent. The IL6−174 (G/C) SNP genotype was determined by allele-specific PCR (Cavet et al, Blood 98, 2001). Results were analyzed using the Pearson's Chi-square Test and survival estimation by Kaplan-Meier curves.Genotypes for D and R as well as D/R combinations (table 1), were in accordance with previous reports. Homozygous recipients for IL6−174GG polymorphism showed a trend to higher incidence of grade III-IV aGVHD than those with other genotypes (19.9% vs 9.1%) p=0.14. No significant differences were found in terms of cGHVD, relapse or mortality rates. On the other hand, patients transplanted from homozygous GG Donors showed a higher incidence of extense cGVHD (20/52 (38%) vs 21/87 (24%) p=0.07), lower relapse rates (10/59 (23.8%) vs 32/105 (76.2%) p=0.041) and better global mortality rates (23/62 (36.9%) vs 51/106 (69%) p=0.11). Survival analysis with Kaplan-Meier curves in this group of patients (IL6−174GG homozygotes in the Donor) revealed a lower cumulative incidence of relapse (CIR) (NR vs 567 days p=0.028) a better event free survival (EFS) (732 days vs 380 days p=0.02) and showed a trend to a better overall survival (OS) (1235 days vs 836 days p=0.157); (Figure1).IL6 cytokine is known to be implicated in the pathogenesis of aGHVD with increasing serum levels during its development. The presence of allele G for the polymorphism of IL6−174(G/C) which is associated with higher levels of IL6, has shown to influence the outcome of our cohort of HLA-identical related stem cell transplantation. Since acute GHVD is mainly influenced by R genotype and chronic GHVD by D genotype, the present study revealed that homocigous presence in the R of allele G was associated with higher incidence of aGHVD. Moreover when this allele is homozigously present in the D, patients show greater extense cGHVD and better EFS and OS. Genotyping for this polymorphism could aid in D selection or even more interestingly drive a risk-adapted management of transplanted patients.No relevant conflicts of interest to declare.

Plasmablastic lymphoma (PBL) is a distinct subtype of B-cell lymphoma strongly associated with HIV infection with no more than 150 cases reported in the literature. We conducted a retrospective study to evaluate clinicopathological characteristics and determine prognostic factors in HIV-associated PBL (HIV PBL).Institutions in the United States (US) and internationally submitted clinical and pathological patient-level data on HIV-positive individuals who had a pathological diagnosis of PBL. According to WHO criteria, all the cases were required to have a plasmablastic morphology, be CD20-negative and to express at least one plasmacytic marker (i.e. CD38, CD138 and/or MUM1/IRF4). Continuous and categorical variables are presented using descriptive statistics. Univariate survival analyses were performed using the Kaplan-Meier method and the log-rank test. Cox proportional-hazard regression test was used for the multivariate survival analysis. P-values of less than 0.05 were considered statistically significant.Thus far, data on 45 patients have been obtained from 11 institutions. Twenty cases (44%) were from Europe, 17 (38%) from the US, 4 (9%) from Africa and 4 (9%) from South America. The median age was 43 years (range: 19–66 years). Of 45 patients studied, 78% (n=35) were men. The median CD4+ count was 177 cells/mm3 (range: 17–683 cells/mm3). The median duration of HIV infection prior to PBL diagnosis was 6 years (range 0–26 years), and 80% (n=36) received HAART. PBL was the initial presentation of HIV infection in 29% (n=13) of the patients. The median viral load at presentation was 45,000 copies/ml (range: undetectable to 4.7 million copies/ml). At presentation, 69% (n=25) of patients exhibited B symptoms, 44% (n=20) had extranodal involvement, 65% (n=28) presented with stage III or IV disease, 20% (n=9) had oral involvement and 39% (n=12) had an absolute lymphocyte count (ALC) <1000 cells/mm3. EBV-encoded RNA was expressed in 94% (n=31), Ki67 >90% was seen in 66% (n=21) and MYC rearrangement was detected in 50% (n=10) of tested patients. Chemotherapy was employed in 89% (n=39) of patients, with 59% (n=23) receiving CHOP. A minority (n=4; 10%) underwent HSCT. Complete response (CR) was obtained in 69% (n=22); however, after 48 months of follow-up, 66% of patients (n=29) have died. The median overall survival (OS) was 11 months (95% CI 7–20 months) from diagnosis. The most common cause of death was PBL progression (n=18; 62%). At the univariate level, adverse prognostic factors for survival included non-CR to chemotherapy (p =0.002), ALC <1000 cells/mm3 (p =0.006), MYC rearrangement (p =0.0005), ECOG performance status >1 (p =0.048), female sex (p =0.02), and advanced stage (p =0.047). At the multivariate level, ALC <1000 cells/mm3 and non-CR were independent adverse prognostic factors in patients with HIV PBL (p =0.01 and p =0.02, respectively).PBL is a rare aggressive B-cell lymphoma, which tends to affect young HIV-positive men who have CD4+ counts <200 cells/mm3. Advanced stage, extranodal involvement, and tumors with EBER expression, MYC rearrangements and Ki67 >90% at presentation are common features of HIV PBL. Although showing a 69% CR to chemotherapy, the median OS remains poor at 11 months. In the multivariate survival analysis, ALC <1000 cells/mm3 and lack of achievement of CR to chemotherapy were independent adverse prognostic factors in HIV PBL. In the HAART era, HIV PBL seems to have a shorter median OS than other HIV-associated aggressive B-cell lymphomas.Montoto: Genentech: Research Funding; Roche: Honoraria. Vose:GSK: Research Funding; Millenium: Research Funding; Celgene: Research Funding; BMS: Research Funding; Exelixis: Research Funding; SBio: Research Funding; Pharmacyclics: Research Funding; Genentech: Research Funding. Castillo:GlaxoSmithKline: Research Funding; MIllennium Pharmaceuticals: Research Funding.

Natural killer (NK) cells are innate immune effectors that directly lyse virally infected or malignant cells. There are 2 different subsets of NK cells with distinct phenotypic and functional characteristics: the CD56dim subset, which composes 90% of peripheral blood NK cells and has a cytotoxic function, and the CD56bright subset, which cooperates with dendritic cells and T cells in lymph nodes to secrete interferon and promote adaptive immune responses. NK cells are the first donor-derived lymphocyte subset to reconstitute after hematopoietic stem cell transplantation, reaching normal levels after 1 month. Nearly all phenotyping studies of NK subsets after haploidentical hematopoietic stem cell transplantation (HHSCT) reveal a rapid reconstitution of NK cells towards the CD56bright subset. In addition, Y.-J. Chang et al found the highest 2-year survival in patients with a high number of CD56bright NK cells after unmanipulated HHSCT.We analyzed reconstitution of the NK compartment between days 90 and 180 after unmanipulated bone marrow HHSCT with reduced intensity conditioning (RIC).Six adults received unmanipulated bone marrow HHSCT after RIC (fludarabine 30 mg/m2 [day –6 to –2], cyclophosphamide 14.5 mg/kg [day –6 and –5], and busulfan i.v. 3.2mg/kg [day –3]) at our institution between July 2007 and July 2010. Prophylaxis for acute graft-versus-host disease (GvHD) consisted of cyclophosphamide 50mg/kg (days +3 and +4) and cyclosporine A and mycophenolate mofetil from day +5 onwards. We monitored the reconstitution kinetics of circulating NK cells (CD56+, CD3–), and the CD56bright and CD56dim subsets by multiparametric flow cytometry (FC 500 Beckman® Coulter) at day +90 and day +180 after transplantation. Patient characteristics and clinical outcomes are shown in Table 1. 6 patients who underwent allogeneic HLA-identical sibling HSCT with RIC during the same period were used as controls.After HHSCT, NK cells reached normal levels in all patients but one at day +90, with a median number of NK cells of 111/mm3 (range, 25–195/mm3). At day +180 the median number of NK cells was 92/mm3 (range, 4–272/mm3).When we analyzed the absolute number of CD56bright and CD56dim subsets at day +90, we observed 2 patterns: Two patients showed skewed NK cell reconstitution towards CD56bright (Patient no. 3: 54 CD56bright/mm3; 11 CD56dim/mm3. Patient no. 4: 70 CD56bright/mm3; 17 CD56dim/mm3). Three patients reconstituted with a CD56dim/CD56bright ratio towards the CD56dim cell subset, similar to that of healthy adults (Patient no. 1: 17 CD56bright/mm3; 178 CD56dim/mm3. Patient no. 5: 9 CD56brigh/mm3; 135 CD56dim/mm3. Patient no. 6: 20 CD56bright/mm3; 116 CD56dim/mm3). One patient did not achieve adequate NK cell reconstitution (Patient no. 2: 15 CD56bright/mm3; 10 CD56dim/mm3). In contrast, in the control group, an increase in the CD56bright NK cell subset was not observed in any of the patients at any point.It is worth noting that 2 of the 3 patients with better clinical outcome (no GvHD, no relapse), namely patients no. 3 and no. 4 were the ones with skewed NK cell reconstitution towards the CD56bright NK cell subset. The other patient with a better clinical outcome (patient no. 6) had a normal CD56dim/CD56bright ratio at day +90. However, he showed an early CD56bright reconstitution (363 CD56bright/mm3; 34 CD56dim/mm3) in an additional determination on day +30. NK cell subsets reconstitution kinetics is shown in Figure 1.In our experience, NK cell reconstitution is adequate after RIC unmanipulated bone marrow HHSCT.Some patients recovered with a high proportion of CD56bright NK cells, as previously reported in other studies on HHSCT.Although limited by the sample size, our results are consistent with the previously observed survival advantage of patients with high early levels of CD56bright NK cells after unmanipulated haploidentical transplantation.No relevant conflicts of interest to declare.

Most patients with classical Hodgkin's Lymphoma (CHL) are cured with primary treatment. However, a proportion of them fail to first line treatment needing to be rescued with subsequent lines of chemotherapy and/or autologous or allogeneic stem cell transplantation (auto-SCT and allo-SCT, respectively). The identification of clinical and biological characteristics of these patients at diagnosis is still a challenge and most prognostic systems fail to identify a proportion of patients with worse prognosis. In this context, different groups are currently analyzing several biological markers as determinants of clinical outcome. It has been reported that Bcl-2 immunohistochemical expression in Hodgkinxs Reed Sternberg cells (HRSC) might confer a worse prognosis.To analyze clinical outcomes following 1st line chemotherapy according to Bcl-2 expression at diagnosis of CHL.CHL patients, older than 16 years old, receiving at least 1 line of treatment, were retrospectively studied for Bcl-2 expression in diagnostic samples. For this purpose, tissue sections were immunostained and semiquantitatively assessed for this marker. Cumulative incidence (CI) of treatment failure, treatment failure free survival (TfFS) and overall survival (OS) were defined as primary outcomes. Treatment failure was considered when a different treatment regimen was set up due to relapse after CR or failing to achieve CR following 1st line.103 patients (55 Bcl-2 positive patients and 48 Bcl-2 negative patients) were analyzed. Main patient and clinical features are shown in Table 1. Both cohorts were well balanced for the main prognostic factors. At a median follow up of 36m (2-221), 34m (2-140) for Bcl-2 negative patients and 38m (4.5-221) for Bcl-2 positive patients, CI of 3 years treatment failure was 19% and 50% for the negative and positive cohorts, respectively (p=0.02). 3 years TfFS after diagnosis was 75% for Bcl-2 negative patients vs 47% for Bcl-2 positive patients (p=0.1). Within the cohort of Bcl-2 negative patients, 9/48 (19%) underwent auto-SCT as part of rescue treatment while 18/55 (33%) of Bcl-2 positive patients received an SCT (13 auto-SCT and 5 allo-SCT) and 3 of them, a second SCT (allo) for the treatment of post-auto-SCT relapse. 3 years OS was 84.5% for negative and 86% for positive patients (p=NS).According to these preliminary results, Bcl-2 expression in HRSC at diagnosis may constitute an independent biological prognostic marker in CHL patients, seemingly associated with worse outcome and need of second line chemotherapy. More studies and a longer follow up is needed in order to confirm that aggressive treatment strategies such as SCT may overcome the negative impact in survival of Bcl-2 expression in this population.No relevant conflicts of interest to declare.

Abstract 3051

Between 2005 and 2010, 16 consecutive patients with high risk disease underwent a total of 18 dual transplants and 17 patients, with similar pre-SCT characteristics recieved a myeloablative MUD transplantation with 12/12 HLA identity in a single centre (Table 1). Transplants performed before 2005, those with manipulated grafts and with HLA mismatches were excluded.There were no significant differences in age, gender, pre-SCT disease status and previous therapy lines between both groups. Three cases among the dual group showed primary graft failure (2 of them showing third party donor cells engraftment) who were rescued by a second CB transplant in two cases and a MUD in one case (succesfull in 2). There were no graft failures in the MUD group. GVHD rates are shown in table 1. OS was 50% in the dual group and 53% in the MUD group with a median follow-up of 33 (1-67) y 13 months (1,1-48,5) respectively (Figure 1). The cumulative relapse incidence at 2 years was 54% in the dual group and 53% in the MUD group. There were no relpses after 2 years in both groups. All the transplant related deaths (TRM) took place within the first year after transplantation with no significant differences in cumulative incidence between both groups (p=0,69).In our experience, CB transplantion together with the co-infusion of CD34+ cells from a third party HLA-mismatched donor offers OS and DFS rates comparable to those from myeloablative HLA 12/12 MUD trasnplantation with an acceptable TRM. Therefore, dual transplantion is still our first choice for patients without an available MUD or for whom trasplant is urgent.No relevant conflicts of interest to declare.

CD4+CD25+ regulatory T-cells (Treg) play an important role in inducing and maintaining allogeneic tolerance and can inhibit graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). However, the dynamics of donor and recipient Treg cell populations after Allo-SCT has not been studied yet.To analyze the dynamics of chimerism in Tregs and compare it to that of T lymphocytes (TL; CD3+) and whole blood leukocytes (WBL).The study includes 53 patients subjected to Allo-SCT (myeloablative and non-myeloablative). PB samples were obtained weekly during the first month and every 14 days after day +30 until complete chimerism (CC) was achieved, and at fixed time-points (+30, +60, +90, +180, +365) thereafter. TL and Tregs were purified from PB until CC was achieved using inmunomagnetic technology (Miltenyi Biotec; CD3+ Microbeads and CD4+/CD25+ Treg Isolation Kit, respectively). Chimerism analysis was performed by microsatellite PCR (STR-PCR; AmpFlSTR SGM Plus; Applied Biosystems) on genomic DNA obtained from WBL as well as on cell lysates obtained from purified TL and Tregs. Complete chimerism was considered in samples with percentage of recipient cells <1% (sensitivity of the STR-PCR) for WBL samples and <5% (minimum purity of 95% as estimated by flow cytometry) for purified cell lineages.Median follow up for the whole cohort of patients was 338 days. CC was spontaneously achieved in WBL, TL and Tregs in 45/53 patients (85%) in a median time of 35.41, 38.8 and 42.5 days respectively. 5/3 patients (9%) suffered from graft failure/rejection showing mixed chimerism (MC) with increasing percentages of recipient cells both in WBL and leukocyte lineages. 3/53 patients (6%) maintained mixed chimerism (MC) in WBL and leukocyte lineages at day +180, with no signs of graft rejection or disease relapse. Analysis of the chimerism dynamics of those patients who spontaneously achieve CC revealed two different groups: Group 1 included 25/45 patients who achieved CC at the same time in WBL, TL and Tregs. Group 2 included 20/45 patients who achieved CC in WBL while maintaining MC in TL and Tregs. Interestingly enough, 9/20 patients from Group 2 maintained MC in Tregs 7–75 days after achieving CC in both WBL and TL (Figure 1). In a preliminary analysis, the small sample size precluded from obtaining statistically significant associations between the dynamics of chimerism in Tregs and the development of complications such as relapse or GVHD after SCT.To our knowledge, this is the first study dealing with Treg chimerism after SCT. We have shown it is feasible and can be performed on a routine basis together with standard lineage specific chimerism follow up. Although there is an association between chimerism dynamics in Tregs and TL, this is not absolute and a percentage of patients maintain residual Tregs of recipient origin after WTL and TL have become of complete donor origin. In this small cohort, Treg chimerism did not influence the development of post-SCT complications. Analysis of a larger and more homogeneous cohort would allow establishing the usefulness of Treg chimerism testing for the management of transplanted patients.No relevant conflicts of interest to declare.

Autologous stem cell (SC) transplantation (ASCT) is a potentially curative treatment for several hematologic malignancies and has been demostrated feasible and effective in HIV-related lymphoma (ARL). Peripheral blood SC collection could represent a major issue in the use of ASCT in HIV infected patients (pts).To evaluate the feasibility and efficacy of SC mobilization in HIV positive (pos) pts with lymphoma and identify factors influencing harvest results. Potential “ongoing” predictors of collection were also assessed.We retrospectively analysed 98 consecutive pts with ARL, candidates to ASCT, who underwent SC mobilization at 3 Italian and 2 Spanish centers from 2000 to 2010. A collection less than 2×106 CD34+ cells/kg was defined as “mobilization failure”, between 2–5 as “suboptimal collection” and more than 5 as “good collection”. Several parameters were evaluated for correlation with outcome: age, sex, lymphoma histopathology, disease status, WBC and Plt count at start of mobilization, type of mobilizing therapy, marrow disease, previous mobilization failure, n° of previous chemotherapy (CT) lines, months from first detection of HIV positivity, CD4 count and HIV-viremia. Moreover, circulating CD34+ and WBC count on the first day of CD34+ monitoring and their ratio (SC ratio = CD34/WBC) were assessed as “ongoing” outcome predictors.A total of 127 attempts of SC harvest in 98 pts were analysed. Median age was 41.5 ys (28-65). Lymphoma diagnosis was DLBCL in 42% of cases, Burkitt 10%, plasmablastic 10%, HL 31%, anaplastic 5%, follicular lymphoma 1% and PEL 1%. Disease status was complete remission in 36%, chemosensitive disease in 53% and refractory disease in 10% of cases. In 3 cases bone marrow was involved and mobilizations failed. In 18% of cases pts received mobilizing therapy after 1 previous CT line, in 67% after 2 and in 16% after 3 or more. All pts but 2 were on antiretroviral therapy. Median CD4 count was 231/mcl (50-1146) and HIV-viremia was detectable in 22%. Median time from first HIV detection was 79.5 ms (3-295). In 24% of cases G-CSF alone (10-20 mcg/Kg) was used as mobilizing treatment, while CT + G-CSF (5-10 mcg/Kg) in 76%, including single-agent Cyclophosphamide (CTX) 1.5 gr/ms (13%), CTX >3 gr/ms (27%), platinum containing regimens (20%), ifosfamide containing regimens (11%) and others (5%). Mobilization failure occurred in 40% of procedures, a collection between 2–5 × 10^6 CD34/Kg in 24% and > 5 in 35%. Finally, of 98 pts who underwent SC mobilization, 22% failed to collect enough cell to perform ASCT, 12 pts even after repeated attempts, 33% had a suboptimal and 45% a good collection (4 and 5 pts respectively after repeated mobilizations). At univariate analysis failure was significantly associated with refractory disease, Plt < 150.000/cmm, CTX 1.5 gr/ms as mobilizing treatment, previous mobilization failure and circulating CD34+ cell < 7.4/mcl on the first day of monitoring; whereas CTX > 3 gr/ms, CD4 count and SC ratio > 0.002 were associated with a reduced risk of failure. In multivariate analysis refractory disease (p<0.0001) and CTX 1.5 gr/ms (p=0.003) were indipendent predictors for failure and SC ratio > 0.002 (p<0.0001) a protective factor. A good collection was predicted at univariate analysis by Plt and CD4 count, age, months from first HIV detection, CT + G-CSF as mobilizing therapy, CTX > 3 gr/ms, WBC count and circulating CD34+ cells >29,7/mcl at the first day of monitoring and SC ratio > 0,002, whereas G-CSF alone and previous mobilization failure were negative predictive factors. Multivariate analysis confirmed CTX > 3 (p<0.0001), CD34+ cells > 29,7 (p=0.0003) and SC ratio > 0,002 (0.0036) as indipendent factors for good collection.In this series of 98 ARL and 127 SC mobilization attempts, a substantial number of pts failed SC harvest (22%) whereas 33% had a suboptimal and 45% a good collection. Lymphoma status and mobilizing treatment seems the strongest predictors for outcome, with refractory disease and low CTX dose (1.5 gr/ms) significantly associated with failure and CTX > 3 gr/ms predictor for good collection. A high ratio between circulating CD34+ cells and WBC on the planned day of first apheresis might represent a useful “ongoing” parameter to predict the outcome. These data might help to decide the mobilizing strategy in ARL and could provide the framework to rationally explore the use of new mobilizing agentsNo relevant conflicts of interest to declare.

Interleukin 17 (IL-17) is a pro-inflammatory cytokine secreted by CD4+ helper T (TH) cells, TH17 cells. IL-17F is the most recently discovered member of the IL-17 cytokine family. IL-17F induces several cell types to express cytokines, chemokines, growth factors, and adhesion molecules, which are crucial molecules in leukocyte recruitment and activation. On this basis, IL-17F has been associated with the pathogenesis of multiple autoimmune diseases. Allele G for the polymorphism A7488G seems to play a protective role for the development of such diseases. However, no data is available about the possible impact of this polymorphism on the development of complications after allogeneic stem cell transplantation (allo-SCT). To analyze the influence of the donor (Dn) and recipient (Rc) genotype for the polymorphism A7488G in the IL-17F gene on the outcome of HLA-identical related allo-SCT. The study comprised 143 allo-SCT patients and their donors (286 samples) included in the Spanish Group for Hematopoietic Stem cell Transplantation (GETH) DNA bank. Genomic DNA was purified from peripheral blood samples obtained, after written informed consent, from patients pre-SCT and donors. The A7488G polymorphism of the IL-17F gene was analyzed by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) following the procedure developed by Tahara et al. (J Clin Immunol 2008, 28:44-49). Results were analyzed using the Pearson's Chi-square Test. In accordance with previous reports, allele G was present in a reduced number of individuals, 30/286 (10.5%) corresponding to 19/143 Allo-SCT (13.3%). The genotypes of the Dn were 129/143 (90.2%) AA and 14/143 (9.8%) AG, while those of the Rc were 127/143 (88.8%) AA and 16/143 (11.2%) AG. No Dn or Rc with GG genotype was found. Dn and Rc genotype combinations were as follows: DnAA-RcAA, 124/143 (86.7%); DnAG-RcAG, 11/143 (7.7%), DnAA-RcAG, 5/143 (3.5%), DnAG-RcAA, 3/143 (2.1%). The genotype of the donor influenced transplant outcome in terms of relapse (35/129 (27.1%) when the donor was AA vs. 1/14 (7.1%) when the donor was AG; p=0.119) and survival (exitus 64/129 (49.6%) when the donor was AA vs. 3/14 (21.4%) when the donor was AG; p=0,045). No association between Dn or Rc genotype and graft versus host disease (acute or chronic) or other complications was observed. The differences observed in relapse and survival according to the genotype of the donor, were especially true for AG genotype patients (no significant differences were observed in AA genotype patients). In fact, relapse (3/5 (60%) when the Dn was AA vs. 0/11 (0%) when the Dn was AG; p=0.004) and survival (exitus 5/5 (100%) when the Dn was AA vs. 1/11 (9,1%) when the Dn was AG; p<0.001) showed large differences depending on the genotype of the donor in this subgroup of patients. Kaplan-Meier estimates (Figure 1) showed a trend to a better disease free survival (EFS; not reached (NR) vs. 692 days p=0.083)) and overall survival (OS; NR vs. 913 days p=0.175) in patients transplanted with AG genotype Dn and a statistically significant better EFS (NR vs. 114 days p=0.014) and OS (NR vs. 193 days p=0.022) when AG genotype patients were transplanted with AG genotype Dn.The polymorphism A7488G of the IL-17F gene, which causes a His-to-Argsubstitution at amino acid 161 (H161R), influences the outcome of HLA-identical related allo-SCT. The presence of allele G in the Dn had a favourable effect on transplant outcome, in terms of lower relapse rate and better survival. Analysis of a larger set of Rc/Dn pairs is ongoing which will allow to increase the number of individuals harboring allele G and, ultimately, to confirm the results shown here. In such case, genotyping for the polymorphism A7488G of the IL-17F gene could aid in donor selection or drive a risk-adapted management of transplanted patients.No relevant conflicts of interest to declare.

The majority of patients with classical Hodgkinxs Lymphoma (cHL) are cured with primary treatment. However, a significant proportion of patients will not achieve a complete response (CR) or relapse after completion of initial therapy and need to be rescued with high-dose chemotherapy and stem cell transplantation (SCT): autologous (aSCT) and/or alogeneic (Alo-SCT). The identification of clinical and biological characteristics of these patients at diagnosis is still a challenge and the most prognostic systems used to date fail to identify a proportion of patients with worse prognosis. The best understanding of the biology of cHL could help to identify these patients and different groups works in the use of biological marker as determinants of clinical outcome. Bcl2 over-expression has been described in cHL and seems to be an independent marker associated to bad prognosis in probably relation with alterations in apoptosis regulatory molecules.To retrospectively analyze the frequency of Bcl2 protein over-expression in tissue biopsies of patients diagnosed with cHL, which required intensive treatment in our centre.We revised clinical data and samples at diagnosis of patients with cHL who received SCT (aSCT or/and Allo-SCT) due to partial remission, relapse or progression and we determined Bcl2 expression protein by immunohistochemistry. All patients received at least 2 lines of treatment previous to intensive treatment with SCT. We analyzed the expression of Bcl2 according to each patient histology: Nodular Sclerosis (NE), Mixed cellularity (MC), Lymphocyte-rich (LR), and Lymphocyte-depleted (LD).Between September 1997 and May 2010, 39 patients with cHL required intensive treatment in our center: 32 aSCT and 7 Allo-SCT due to partial remission, refractory, relapse or progression after first line of treatment. Average age was 32 years (range: 18–64), males: 25/females 14. The characteristics of patients and remission status at transplant are described in table 1. We had available samples at diagnosis from 31 out of 39 patients (80%): 20 NE, 5 MC, 6 LR and we found over-expression of Bcl2 in 17/20 (85%) NE; 5/5(100%) MC and 2/6 LR (33%).Our results suggest that over-expression of Bcl2 is frequent in patients with cHL which needed intensive treatment after failure of the first line of therapy (particularly with NE and MC). Further studies are needed to confirm the worse prognosis of Bcl2 expression in cHL and if may be useful at diagnosis in association with other clinical parameters to identify patients with poor prognosis.Alo-SCT: Alogeneic stem cell transplant; aSCT: autologous stem cell transplant; CR: Complete Remission; F: female; LD: Lymphocyte-deplete; LR: Lymphocyte rich; M: male; MC: mixed cellularity Md: median; n: number; NE: nodular sclerosis; Nv: negative; P: positive; PR: Parcial remision R: range; RF: refractoryNo relevant conflicts of interest to declare.

Retrospective, registry-based, matched cohort study. ASCT cohort: patients with diffuse large B-cell (DLBC) or plasmablastic NHL treated with ASCT in 1st CR after standard chemo and reported to the EBMT Registry. Chemo cohort: For each patient within the ASCT cohort we selected two controls from the HIV+ patients with NHL GESIDA/PETHEMA registry. Patients in both cohorts were in 1st CR following front-line or rescue (for partially responding patients) chemo and were matched according to histology, IPI and the use of Rituximab. We compared overall survival (OS), disease free survival (DFS) and cumulative incidence (CI) of relapse between both cohorts. These primary outcomes were defined according to the EBMT. OS was computed from diagnosis while DFS and CI of relapse were computed from 3 weeks after the last standard chemo cycle administered (end of chemo).The ASCT cohort included 10 patients diagnosed between 1999 and 2005. The Chemo cohort included 20 patients, 16 diagnosed between 1999 and 2005. Both cohorts were comparable for the main clinical and patient features (Table 1). The median (range) follow-up (FU) time since the end of chemo for surviving patients was 56 months (mo) (24-106) in the ASCT cohort vs 37 mo (8-107.5) in the Chemo cohort; P=.28. Five years (yr) OS for the ASCT cohort and the Chemo cohort were 68.5% [CI95%: 39-98] and 46.5% [CI95%: 18-75], respectively; P=.6. Three yr DFS for the ASCT cohort and the Chemo cohort were 70% [CI95%: 41.5-98.5] and 59.5% [CI95%: 29-86]; respectively; P=.4. The CI of relapse in the ASCT cohort and the Chemo cohort were 21% [CI95%: 0-47] and 27% [CI95%: 2-51], respectively; P=.8In this retrospective registry-based, matched cohort study of HIV+ patients with large B-cell NHL we found a non-significant effect of ASCT as consolidation treatment in 1st CR patients, in terms of survival and relapse incidence. Nevertheless, due to the observed favorable tendency, future analysis including a higher number of patients and, eventually, randomized clinical studies, should be performed to further clarify these observations.No relevant conflicts of interest to declare.

Complications after Allogenic Stem Cell Transplantation (Allo-SCT) are influenced by the immunological fenomena associated to the alloreactivity/allotolerance between donor and recepient. In this context, the usefulness of chimerism quantification in T lymphocytes for the prediction of complications after Allo-SCT is well known. However, to our knowledge, there is no information on the utility of chimerism analysis in activated lymphocytes (CD25+).To stablish an asociation betwen the more common complications post Allo-Tph (aGVHD, cGVHD, relapse, reject), and the chimerism dynamics in CD25+ activated lymphocytes in the early period post-transplantation, trying to predict the patients with more risk of suffering from this complications.The study included 38 Allo-SCT (17 NMA, 21 MA; 7 Haploidentical, 13 non-related donor, 18 identical donor; 7 UCB, 5 BM, 26 PB). Chimerism analysis was performed every 2 weeks until complete chimerism (CC) was achieved, and every 3 months thereafter. Follow up was censored when patients received DLI or 2nd Allo-SCT.Chimerism quantification was performed by microsatellite PCR (STR-PCR; AmpFlSTR SGM Plus; Applied Biosystems) on DNA obtained from peripheral blood and purified cell lineages (95% putity) by immunomagnetic technology (Miltenyi Biotec).Table 1 shows the results at day +30 for T and activated lymphocytes (CD3+ and CD25+) allocating patients in two groups depending on the relative percentage of recipient cells (% rec) in both cell lineages. 20 patients were in CC in CD25+, maintening this CC during the study. 18 patients were found in MC in CD25+ (18/38 MC). 1/18 was in CC in CD3+ TL, and 10/18 were in CC in whole blood. 17/18 were in MC both in CD3+ and CD25+ lymphocytes,Although no statistical significance is achieved due to the reduced sample size, patients in the first group (% rec higher in activated that in T lymphocytes) tend to achieve CC later and to show higher risk of developing complications such as acute and chronic GVHD, relapse or rejection.A higher incidence of complications post Allo-SCT (aGVHD, cGVHD, relapse, rejection) in patients with % of recipient in CD25+> % recipient in CD3 at day 30. Chimerism analysis in activated lymphocytes (CD25+) is of great utility after Allo-SCT since it allows beter prediction of complications than standard follow up of whole blood or T lymphocytes.No relevant conflicts of interest to declare.

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