HLA-identical Allogeneic Stem Cell Transplantation Research Articles

Randomized Trial of Prophylactic Donor Lymphocyte Infusion with Positively Selected CD4+ T Cells after HLA-Identical Allogeneic Stem Cell Transplantation

Introduction Allogeneic stem cell transplantation (alloSCT) can cure patients with hematological malignancies by T-cell mediated alloreactivity against patient hematopoiesis, the graft-versus-leukemia (GvL) effect. GvL can coincide with graft-versus-host disease (GvHD) when donor T cells target non-hematopoietic tissues. Increase of donor chimerism in bone marrow (BM) or peripheral blood (PB) after alloSCT indicates GvL response. After T-cell depleted alloSCT, donor lymphocyte infusion (DLI) can restore GvL. Dose and timing of DLI influence the degree of alloreactivity. Low dose of unmodified DLI as low as 0.3x10 6 T cells/kg 3 months after alloSCT appeared not to cause GvHD. (Zouwen et al. Ann Hematol, 2023) We hypothesized that infusion of a higher dose of purified CD4+ donor T cells would not cause GvHD, while inducing GvL by selective targeting of the MHC class II positive hematopoietic cells. Method A randomized controlled phase 2 trial was conducted in patients with hematological malignancies after HLA-identical sibling alloSCT with alemtuzumab added to the graft. Patients without GvHD or relapse were randomized at 2.5 months for prophylactic DLI with 1.0x10 6/kg CD4+ T cells (CD4+ DLI) 3 months after alloSCT or conventional care without DLI (CC). Both groups were eligible for prophylactic unmodified DLI at 6 months. Cumulative incidence (CI) of GvHD requiring immunosuppressive treatment 3 months after randomization was the primary endpoint. Changes in the trajectory of chimerism in BM and subsets in PB (CD4+ T cells, CD8+ T cells, NK cells, B cells and monocytes) were compared by means of mixed effects beta regression as secondary endpoints. Results 66 patients were included (table 1). CI of GvHD did not differ between groups (CD4+DLI: 6.1% vs CC: 9.1%, Gray's test p>0.9). Relapse was comparable (CD4+DLI: 15% vs CC: 12%), although heterogeneity of diseases prevented a formal comparison. In the CD4+ DLI group, BM chimerism was full donor (FD, >95% donor) at baseline in 23/33 patients, while 10/33 had mixed chimerism (MC, ≤95%). In the CC group, 23/33 were FD and 10/33 MC. Some patients with MC at baseline converted to FD in both groups (CD4+ DLI: 1/10 vs CC: 1/10). Changes in BM chimerism did not differ between CD4+ DLI and CC (p = 0.9). Chimerism of B cells, NK cells and monocytes in PB resembled bone marrow chimerism with most patients being FD at baseline. Changes in chimerism did not differ between CD4+ DLI and CC (p = 1.0, 0.5 and 0.9 for B cells, NK cells and monocytes respectively). In the CD4+ DLI group, 25/30 evaluable patients were MC in the CD4+ T-cell subset in PB at baseline. 3 month after randomization 7/25 had converted to FD, 17/25 remained MC and 1/25 was unevaluable. Of the 17 patient who remained MC, CD4+ donor chimerism increased (absolute increase >5%) in 13, decreased (>5%) in 2 and was stable in 2. In the CC group, 26/32 were MC in CD4+ T cells at baseline, of which 6 converted to FD, 18 remained MC and 2 were unevaluable. Of the 18 patients remaining MC, CD4+ chimerism increased in 5, decreased in 9 and remained stable in 4. The CD4+ donor chimerism increased significantly after CD4+ DLI compared to CC (p = 0.01) (Figure 1). In the CD4+ DLI group, 23/29 evaluable patients were MC in the CD8 subset at baseline. 7/23 converted to FD, 15/23 remained MC and 1 was unevaluable. Of these 15 MC patients at 3 months, 9 had increasing, 5 stable and 1 decreasing donor chimerism after 3 months. In CC, 22/31 were MC at baseline. 4/22 converted to FD at 3 months and 17/22 remained in MC. Of the 17 MC patients, 6 had increasing, 3 decreasing and 8 stable chimerism. The CD8+ donor chimerism increased significantly in the CD4+ DLI group compared to CC (p = 0.03). Conclusion CD4+ selected DLI at a dose of 1x10 6 CD4+/kg 3 months after HLA identical T-cell depleted alloSCT did not cause GvHD. Chimerism in BM leukocytes, B cells, NK cells or monocytes did not indicate GvL mediated by CD4+ DLI, possibly because most patients were already FD at baseline. CD4+ and CD8+ T-cell donor chimerism increased significantly after CD4+ DLI, suggesting a GVL-effect - earlier demonstrated in vitro for 4 selected patients. (Van Balen et al. Front Immunol, 2018) However, most patients did not convert to FD in the T-cell compartment, suggesting the GvL-effect of CD4+ DLI was limited. We considered this GvL-effect insufficient to prevent relapse and stress the importance of CD8+ donor T cells as main drivers of alloreactivity after DLI following HLA-identical alloSCT.

Impact of in vivo T cell depletion in HLA-identical allogeneic stem cell transplantation for acute myeloid leukemia in first complete remission conditioned with a fludarabine iv-busulfan myeloablative regimen: a report from the EBMT Acute Leukemia Working Party

BackgroundThe impact of the use of anti-thymocyte globulin (ATG) in allogeneic stem cell transplantation performed with HLA-identical sibling donors following fludarabine and 4 days intravenous busulfan myeloablative conditioning regimen has been poorly explored.MethodsWe retrospectively analyzed 566 patients who underwent a first HLA-identical allogeneic stem cell transplantation with this conditioning regimen for acute myeloid leukemia in first complete remission between 2006 and 2013 and compared the outcomes of 145 (25.6%) patients who received ATG (ATG group) to 421 (74.4%) who did not (no-ATG group). The Kaplan-Meier estimator, the cumulative incidence function, and Cox proportional hazards regression models were used where appropriate.ResultsPatients in the ATG group were older, received more frequently peripheral blood stem cell grafts from older donors, and were transplanted more recently. With a median follow-up of 19 months, patients in the ATG group had reduced 2-year cumulative incidence of chronic graft-versus-host disease (GVHD) (31 vs. 52%, p = 0.0002) and of its extensive form (8 vs. 26%, p < 0.0001) but similar relapse incidence (22 vs. 27%, p = 0.23) leading to improved GVHD and relapse-free survival (GRFS) (60 vs. 40%, p = 0.0001). In multivariate analyses, the addition of ATG was independently associated with lower chronic GVHD (HR = 0.46, p = 0.0001), improved leukemia-free survival (HR = 0.67, p = 0.027), overall survival (HR = 0.65, p = 0.027), and GRFS (HR = 0.51, p = 4 × 10−5). Recipient age above 50 years was the only other factor associated with worse survivals.ConclusionsThese results suggest that the use of ATG with fludarabine and 4 days intravenous busulfan followed by HLA-identical sibling donor allogeneic stem cell transplantation for acute myeloid leukemia improves overall transplant outcomes due to reduced incidence of chronic GVHD without increased relapse risk.

The Genotype of the Donor for the (GT)n Polymorphism in the Promoter/Enhancer of FOXP3 Is Associated with the Development of Severe Acute GVHD but Does Not Affect the GVL Effect after Myeloablative HLA-Identical Allogeneic Stem Cell Transplantation.

The FOXP3 gene encodes for a protein (Foxp3) involved in the development and functional activity of regulatory T cells (CD4+/CD25+/Foxp3+), which exert regulatory and suppressive roles over the immune system. After allogeneic stem cell transplantation, regulatory T cells are known to mitigate graft versus host disease while probably maintaining a graft versus leukemia effect. Short alleles (≤(GT)15) for the (GT)n polymorphism in the promoter/enhancer of FOXP3 are associated with a higher expression of FOXP3, and hypothetically with an increase of regulatory T cell activity. This polymorphism has been related to the development of auto- or alloimmune conditions including type 1 diabetes or graft rejection in renal transplant recipients. However, its impact in the allo-transplant setting has not been analyzed. In the present study, which includes 252 myeloablative HLA-identical allo-transplants, multivariate analysis revealed a lower incidence of grade III-IV acute graft versus host disease (GVHD) in patients transplanted from donors harboring short alleles (OR = 0.26, CI 0.08–0.82, p = 0.021); without affecting chronic GVHD or graft versus leukemia effect, since cumulative incidence of relapse, event free survival and overall survival rates are similar in both groups of patients.

Donor and Recipient Genotypes for Interleukin 1 Gene Single Nucleotide Polymorphisms (SNPs) Allow Anticipation of Acute Graft Versus Host Disease after HLA-Identical Allogeneic Stem Cell Transplantation (allo-SCT)

Introduction.Graft versus host disease (GvHD) is the main cause of morbimortality after allogeneic stem cell transplantation (allo-SCT). Several single-nucleotide polymorphisms (SNPs) in cytokine genes have shown to influence gene expression and are therefore associated with donor-recipient alloreactivity and, ultimately, with SCT outcome. Interleukin 1 (IL1) is a proinflammatory cytokine that induces the production of cytokines and chemokines and plays an important role in the inflammatory processes. IL1 is involved in various cellular functions, including cell proliferation, differentiation, and apoptosis. The IL1 family consists of two biologically actives forms (IL1A and IL1B). Several polymorphisms of these genes have been implicated in the pathogenesis of autoimmune diseases, however, their importance in SCT is not well-known.ObjectiveTo investigate the relationship between 4 SNPs in IL1A and IL1B genes and the susceptibility to the development of GvHD and other complications after HLA-identical allo-SCT.Patients and methodsGenomic DNA obtained from peripheral blood samples belonging to 509 patients and their HLA-identical sibling donors (Table 1) included in the DNA Bank of the Spanish Group for Hematopoietic Stem Cell Transplantation (GETH). One SNP, rs1800587 (-889 C>T), in the promoter region of the IL1A gene and three SNPs in the IL1B gene (two in the promoter region rs16944 (-511C>T), rs1143627 (-31 T>C) and one in exon 5 rs1143634 (+3954 C>T) were genotyped by multiplex primer extension followed by mass spectrometry (MALDI-TOF; Sequenom MassArray).Univariate and multivariate regression analysis were performed using Cox regression in the presence of competing risks except for chronic GvHD for which we used logistic regression model. All variables with p≤0.10 according to univariate analysis were included in the multivariate analysis. For multivariate analyses, p values were two sided and the outcomes were considered to be significant for p<0.05. All analyses were performed by R Statistical Software ver. 2.15.0.ResultsGenotypic frequencies observed for the 4 SNPs analyzed were in accordance with the Hardy-Weinberg equilibrium and were similar to those previously reported. Results of the multivariate analysisof the association between IL1A and IL1B genotypes and complications after allo-SCT are shown in Table 2.No association between the SNPs analyzed and complications other than acute GVHD were found. Patients with the alloreactive TT genotype for the SNP rs1143627 show increased risk of grade II-IV and III-IV acute GvHD (HR=6.87 and HR=19.19 respectively). In addition the presence of the rs16944 alloreactive A allele in the recipient was also associated with a significantly higher incidence of grade II-IV and mainly III-IV acute GvHD (HR=11.85 for grade II-IV and HR=53.48 for grade III-IV) Finally a higher risk of grades III-IV acute GvHD was observed in patients harboring alloreactive TT genotype for SNP rs1800587 (HR=3.12).ConclusionsThese results further support the idea of a genetic predisposition to certain complications after allo-SCT especially GvHD. IL1A and IL1B SNP genotyping might be useful to anticipate complications after sibling HLA-identical allo-SCT and, therefore to tailor the use of immunomodulatory approaches and, ultimately, to improve the clinical management of transplanted patients. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Identification of minor histocompatibility antigens based on the 1000 Genomes Project.

Minor histocompatibility antigens are highly immunogeneic polymorphic peptides playing crucial roles in the clinical outcome of HLA-identical allogeneic stem cell transplantation. Although the introduction of genome-wide association-based strategies significantly has accelerated the identification of minor histocompatibility antigens over the past years, more efficient, rapid and robust identification techniques are required for a better understanding of the immunobiology of minor histocompatibility antigens and for their optimal clinical application in the treatment of hematologic malignancies. To develop a strategy that can overcome the drawbacks of all earlier strategies, we now integrated our previously developed genetic correlation analysis methodology with the comprehensive genomic databases from the 1000 Genomes Project. We show that the data set of the 1000 Genomes Project is suitable to identify all of the previously known minor histocompatibility antigens. Moreover, we demonstrate the power of this novel approach by the identification of the new HLA-DP4 restricted minor histocompatibility antigen UTDP4-1, which despite extensive efforts could not be identified using any of the previously developed biochemical, molecular biological or genetic strategies. The 1000 Genomes Project-based identification of minor histocompatibility antigens thus represents a very convenient and robust method for the identification of new targets for cancer therapy after allogeneic stem cell transplantation.

Donor Genotypes For Interleukin-17A Gene Single Nucleotide Polymorphisms (SNPs) Allow Anticipation Of Complications After HLA-Identical Allogeneic Stem Cell Transplantation (allo-SCT)

Introduction 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. Objective To analyse the influence of IL-17A SNP genotypes on the risk and severity of GvHD and other complications after HLA-identical allo-SCT. Patients and Methods Genomic DNA obtained from peripheral blood samples belonging to 546 patients and their HLA-identical sibling donors (Table 1) included in the DNA Bank of the Spanish Group for Hematopoietic Stem Cell Transplantation (GETH). Genotyping of the polymorphisms of interest, rs8193036 (-737C&gt;T), rs2275913 (-197G&gt;A), rs3819024 (-444A&gt;G), rs4711998 (-877A&gt;G), were performed by multiplex primer extension followed by mass spectrometry (MALDI-TOF; Sequenom MassArray). Results Genotype frequencies are shown in Table 2 and the association between IL-17A genotypes and complications after allo-SCT are shown in Table 3. Patients transplanted from donors harboring genotype CC for the SNP rs8193036 show increased risk of grade III-IV acute GvHD (7/26 vs 47/397, p=0.035) and of grade II-IV acute GvHD (13/26 vs 133/409, p=0.048). Patients transplanted from donors harboring allele A in the SNP rs4711998 show increased risk of extensive chronic GvHD (53/161 vs 43/177, p=0.045). Relapse rate was not related with IL-17A SNP genotypes. Finally a higher risk of toxicity-related mortality (TRM) was observed in patients transplanted from donors harboring allele A for SNP rs2275913 (78/293 vs 46/227, p=0.048), donors harboring allele G for SNP rs3819024 (78/279 vs 46/242, p=0.011) and donors harboring allele A for SNP rs4711998 (68/250 vs 55/229, p=0.044). Conclusions IL-17A SNP genotyping might be useful to anticipate complications after sibling HLA-identical allo-SCT and, therefore, to improve the clinical management of transplanted patients. This results further support the idea of a genetic predisposition to certain complications after allo-SCT. Paper presented on behalf of the GvHD/Immunotherapy committee of the Spanish Group for Hematopoietic Transplantation (GETH). Disclosures: No relevant conflicts of interest to declare.

The Genotype of the Donor for the (GT)n Polymorphism in the Promoter/Enhancer of the FOXP3 Gene Influences Graft Versus Host Disease without Affecting Graft Versus Leukemia Effect After Myeloablative HLA-Identical Allogeneic Stem Cell Transplantation

Abstract 3051 INTRODUCTIONThe 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. OBJECTIVETo 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. MATERIALS AND METHODSThe 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]. RESULTSThe 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). [Display omitted] CONCLUSIONSTregs 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. Disclosures:No relevant conflicts of interest to declare.

HLA-Identical Allogeneic Stem Cell Transplantation (alloSCT) for Patients With Primary Cutaneous T-Cell Lymphoma (CTCL): A Retrospective Analysis of the Lymphoma Working Party of the European Blood and Marrow Transplantation Group (EBMT-LWP)

HLA-Identical Allogeneic Stem Cell Transplantation (alloSCT) for Patients With Primary Cutaneous T-Cell Lymphoma (CTCL): A Retrospective Analysis of the Lymphoma Working Party of the European Blood and Marrow Transplantation Group (EBMT-LWP)

HLA-Identical Allogeneic Stem Cell Transplantation (alloSCT) for Patients with Primary Cutaneous T-Cell Lymphoma (CTCL): A Retrospective Analysis of the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation (EBMT-LWP).

Patients with aggressive forms of Mycosis Fungoides (MF), Sézary syndrome (SS) and other less common subtypes of primary CTCL have a dismal prognosis with conventional therapy. A potential role for alloSCT in these patients has been suggested by a number of case-reports and small series. We conducted a retrospective registry analysis of 64 recipients who received an alloSCT from HLA-identical donors (52 related, 12 unrelated) for advanced CTCL reported to EBMT between 1997 and 2006: 23 MF, 21 SS, 16 primary cutaneous anaplastic large cell lymphoma and 4 subcutaneous panniculitis-like T-cell lymphoma; 38 patients were male, 26 were female; median age was 46 years (5–65); median follow up of survivors was 28 months. AlloSCT was performed at a median of 22 (3–313) months from initial diagnosis, following a median of 3 (1–8) prior lines of therapy, the stem cell source was PB in 54 cases and BM in 10 cases, reduced-intensity conditioning (RIC) was used in 41 (64%) cases. Twenty-three percent of patients were in complete response (CR) and 26% in partial response (PR) at the time of alloSCT. All other patients were primary refractory (RE, 25%) or progressed after a previous response (PG, 26%). Non-relapse mortality was 24% at 3 years, and appeared higher in patients receiving myeloablative conditioning (MAC) than in those receiving RIC alloSCT (35% vs 16%; p=0.06). Acute graft versus host disease (GVHD) occurred in 37% of patients at risk, and chronic GVHD in 69% of patients alive at day +100. The cumulative incidence of disease relapse (36% at 3 years) was significantly higher in patients with advanced disease status at alloSCT (RE/PG 46% vs CR/PR 21%; p=0.01), but similar in patients with related and unrelated donors (p=0.39) and receiving MAC or RIC (p=0.6). Progression free survival (PFS) at 3 years was 41%, with a significant advantage for patients in CR/PR at alloSCT (58% vs 26%; p<0.01), but not for type of conditioning (MAC 45% vs RIC 44%; p=0.4) or donor type (related 46% vs unrelated 33%; p=0.2). Out of 22 patients who relapsed, 10 remain alive and 4 of these were in CR at last follow up, possibly indicating that a proportion of patients achieved a better control of CTCL following relapse after alloSCT. Overall survival for the whole series was 55% at 3 years, with a trend towards an improved OS for patients with disease in CR/PR at transplant (65% vs 46%; p=0.1). Overall, outcome after allogeneic transplantation appears superior to that expected for such patients under conventional therapy. Our analysis reinforces the important role of alloSCT in advanced stage CTCL in a relatively large registry-based series.

Refinement of molecular approaches to improve the chance of identification of hematopoietic-restricted minor histocompatibility antigens

Minor histocompatibility antigens (mHAgs) constitute the target antigens of the T cell-mediated graft-versus-leukemia response after HLA-identical allogeneic stem cell transplantation (SCT). Several human mHAgs have been identified, but only a few are selectively expressed by hematopoietic cells representing potential targets for specific immunotherapy. Molecular approaches including cDNA library screening and genetic linkage analysis have been successfully applied to identify T cell-defined mHAgs, but each approach has its drawbacks which may lead to mis-identification of the mHAg of interest. We improved both molecular strategies to facilitate more robust identification of hematopoietic-restricted mHAgs. First, we adapted cDNA library cloning by using 293T cells with stable expression of the relevant MHC class I allele, CD80 and CD54. We demonstrated that cDNA library screening using this 293T expression system results in strong activation of cytotoxic T lymphocytes, which significantly contributes to improvement of the assay sensitivity. Second, we refined genetic linkage analysis using single nucleotide polymorphism (SNP) genotyping to narrow down the defined genetic region that holds the mHAg-encoding gene. We showed that SNP marker analysis provides additional information about the genetic position of the antigen-encoding gene. Application of these optimized molecular approaches will lead to more rapid and reliable molecular identification of hematopoietic-restricted mHAgs.

Glutamine Dipeptide Enriched Parenteral Nutrition Significantly Increase Short-Term Survival after HLA-Identical Allogeneic Stem Cell Transplantation.

Sixty-one consecutive patients with hematologic malignancies submitted to HLA-identical sibling allogeneic stem cell transplantation (allo-SCT) were followed in order to evaluate the relationship between the use of glutamine as part of parenteral nutrition (PN) and death/complications related to the procedure. Patients were randomly and blindly assigned to receive either glutamine enriched PN (group 1) or regular PN (group 2). The glutamine dipeptide (Dipeptiven® - Fresenius Kabi) was associated with parenteral nutrition in the first week following transplantation (D0−D+6). Infectious complications, acute GVHD, length of stay (LOS), deaths on D+100 and D+180 and, when possible, intestinal permeability as measured by urinary excretion of lactulosis and mannitol (on admission, D+6 and D+14) were the end-points. Eight patients were excluded from randomization because they refuse to take glutamine or glutamine was not available on D0, but were followed and analyzed as controls, so that group 1 comprised 27 patients and group 2 thirty-four (26+8). Demographics did not differ between groups (age - 37 ± 11 versus 36 ± 8.7, and gender - 14 versus 18 females). Diseases (CML n=37; AML n=12; ALL n=7; MDS n=4; MM n=1) were equally distributed between groups. Patients on group 1 received an average of 23.4g of glutamine/day, corresponding to 49% of the average protein delivery through PN (total 47.9g, against 50 g/day on group2, NS). They were allowed to eat ad libitum. Infection and acute GVHD incidences, and LOS median (36 versus 36.5) were similar on both groups. Intestinal permeability, which showed to be already affected on admission, was not affected by the use of glutamine, but consistently worsened throughout the study, from admission to D+14. Transplant-related mortality (TRM) rate was 29.5% on D+100 (18 deaths, 4 on group 1 and 14 on group 2) and 40.1% on D+180 (25 deaths, 7 on group 1 and 18 on group 2). Survival analysis showed statistical difference on univariate analysis, with a better survival for Group 1 both on D+100 (p= 0.02, log-rank) and D+180 (p=0.02). A Cox regression model was applied using variables that showed a p value of less than 0.2 (diagnosis-related risk, graft source - peripheral blood or bone marrow, conditioning regimen and use of glutamine). Use of glutamine, both on D+100 (HR 6.4; CI95% 1.81–22.44 - p=0.004) and D+180 (HR 4.9; CI95% 1.76–13.61 - p=0.002) was associated with a significantly higher chance of survival. Statistical significance is maintained if the cases excluded from randomization are also excluded from analysis. The results showed that glutamine dipeptide enriched PN plays a role on increasing short-term survival after allo-SCT. Benefits of glutamine dipeptide seems to be independent of mucosal damage/recovery, at least on short term, as intestinal permeability between admission and D +14 was not affected by its use.

A frameshift polymorphism in P2X5 elicits an allogeneic cytotoxic T lymphocyte response associated with remission of chronic myeloid leukemia

Minor histocompatibility antigens (mHAgs) constitute the targets of the graft-versus-leukemia response after HLA-identical allogeneic stem cell transplantation. Here, we have used genetic linkage analysis to identify a novel mHAg, designated lymphoid-restricted histocompatibility antigen-1 (LRH-1), which is encoded by the P2X5 gene and elicited an allogeneic CTL response in a patient with chronic myeloid leukemia after donor lymphocyte infusion. We demonstrate that immunogenicity for LRH-1 is due to differential protein expression in recipient and donor cells as a consequence of a homozygous frameshift polymorphism in the donor. Tetramer analysis showed that emergence of LRH-1-specific CD8+ cytotoxic T cells in peripheral blood and bone marrow correlated with complete remission of chronic myeloid leukemia. Furthermore, the restricted expression of LRH-1 in hematopoietic cells including leukemic CD34+ progenitor cells provides evidence of a role for LRH-1-specific CD8+ cytotoxic T cells in selective graft-versus-leukemia reactivity in the absence of severe graft-versus-host disease. These findings illustrate that the P2X5-encoded mHAg LRH-1 could be an attractive target for specific immunotherapy to treat hematological malignancies recurring after allogeneic stem cell transplantation.

Variable Number of Tandem Repeat (VNTR) Disparity between Donor and Recipient Has Potential To Predict Outcomes of HLA-Identical Allogeneic Stem Cell Transplantation.

Background: Detecting the variable number of tandem repeats (VNTRs) between the recipient and the donor has already been adopted to monitor the degree of chimerism after allogeneic stem cell transplantation (SCT). In allogeneic SCT, besides MHC-disparity, the disparity of various polymorphous proteins encoded by several genes may play a critical role in the pathogenesis of graft-versus-host disease (GVHD). However, the biologic effect of VNTR disparity has scarcely been studied.Materials & Methods: Eighty-four patients receiving an SCT from HLA-identical sibling (n=68) or unrelated donors (n=16) were analyzed. The enrolled diseases included AML 48, ALL 8, CML 15, NHL 10, and high-risk MDS 3. A PCR was performed to amplify 3 VNTR regions (D1S80, D1S111, and D17S5). The disparity was classified as fully matched, partially matched, or mismatched pairs.Results: A strong correlation was observed between the D1S80 disparity and the transplant outcomes in terms of OS (p=0.0179) and NRM (p=0.0305), yet not for the D1S111 or D17S5 disparity. The fully matched D1S80 pairs showed a better OS (72% vs 38%) and lower NRM (17% vs 50%) compared to the partially matched or mismatched pairs. In multivariate analyses, a fully matched D1S80 pair was found to be an independent favorable prognostic factor for OS (p=0.03) and NRM (p=0.05). In addition, D1S80 disparity was significantly associated with the occurrence of gut chronic GVHD (p=0.05).Conclusion: The present data suggest that disparities in D1S80 - located in chromosome 1 - seemed to be associated with an increased incidence of gut chronic GVHD and NRM. [Display omitted]

Variable Number of Tandem Repeats (VNTR) Disparity between Donor and Recipient has a Potential to Predict the Outcomes of HLA-identical Allogeneic Stem Cell Transplantation

Variable Number of Tandem Repeats (VNTR) Disparity between Donor and Recipient has a Potential to Predict the Outcomes of HLA-identical Allogeneic Stem Cell Transplantation

Targeting alloreactive donor T-cells to hematopoietic system-restricted minor histocompatibility antigens to dissect graft-versus-leukemia effects from graft-versus-host disease after allogeneic stem cell transplantation.

The graft-versus-leukemia (GVL) effect of HLA-identical allogeneic stem cell transplantation is mainly mediated by alloreactive T-cells directed at the minor histocompatibility antigens (H ags) expressed on the leukemic cells of the recipient. Minor H ags are major histocompatibility complex-bound polymorphic peptides that are derived from intracellular proteins and that can show ubiquitous or hematopoietic system-restricted expression. Whereas ubiquitous minor H ags are involved both in the GVL effect and in graft-versus-host disease (GVHD), hematopoietic system-specific minor H ags expressed on leukemic cells are considered important targets for leukemia-specific cellular immunotherapy with a low risk of GVHD. This review will summarize the current knowledge of the immunobiology of minor H ags and discuss the advantages and drawbacks of cellular immunotherapy strategies that aim to separate the GVL effect from GVHD by targeting donor T-cells to hematopoietic system-specific minor H ags.

The hematopoietic system-specific minor histocompatibility antigen HA-1 shows aberrant expression in epithelial cancer cells.

Allogeneic stem cell transplantation (SCT) can induce curative graft-versus-tumor reactions in patients with hematological malignancies and solid tumors. The graft-versus-tumor reaction after human histocompatibility leukocyte antigen (HLA)-identical SCT is mediated by alloimmune donor T cells specific for polymorphic minor histocompatibility antigens (mHags). Among these, the mHag HA-1 was found to be restricted to the hematopoietic system. Here, we report on the HA-1 ribonucleic acid expression by microdissected carcinoma tissues and by single disseminated tumor cells isolated from patients with various epithelial tumors. The HA-1 peptide is molecularly defined, as it forms an immunogenic peptide ligand with HLA-A2 on the cell membrane of carcinoma cell lines. HA-1–specific cytotoxic T cells lyse epithelial tumor cell lines in vitro, whereas normal epithelial cells are not recognized. Thus, HA-1–specific immunotherapy combined with HLA-identical allogeneic SCT may now be feasible for patients with HA-1+ carcinomas.