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Patients with essential thrombocythemia (ET) and polycythemia vera (PV) have an increased incidence of acute myeloid leukemia and new nonhematologic malignancies compared with the general population. However, information on the factors determining the risk for such complications is limited. In the present study, we investigated whether constitutional genetic variations in DNA repair predispose to leukemic transformation and new nonmyeloid neoplasias in patients with ET and PV. Case-control studies for predisposition to both types of malignancies were nested in a cohort of 422 subjects diagnosed with ET or PV during the period 1973-2010 in several institutions in Spain. A total of 64 incidence cases of leukemia and 50 cases of primary nonmyeloid cancers were accrued. At conditional regression analysis, the Gln/Gln genotype in the XPD codon 751 showed the strongest association with both leukemic transformation (odds ratio [OR] = 4.9; 95% confidence interval [95% CI], 2.0-12) and development of nonmyeloid malignancies (OR = 4.2; 95% CI, 1.5-12). Additional predictive factors were exposure to cytoreductive agents for leukemic transformation (OR = 3.5; 95% CI, 2.0-6.2) and age for nonmyeloid malignancies (OR = 2.0; 95% CI, 1.4-2.8). These findings provide further evidence about the contribution of inherited genetic variations to the pathogenesis and clinical course of myeloproliferative neoplasms.

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. Objective To 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 methods Genomic 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 Results Genotypic 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). Conclusions These 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. Figure 1 Figure 1. Figure 2 Figure 2. Disclosures No relevant conflicts of interest to declare.

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>T), rs2275913 (-197G>A), rs3819024 (-444A>G), rs4711998 (-877A>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.

Abstract 1302 Introduction: 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). Objective: 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. Material and Methods: 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. Results: 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 Conclusions: 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. Disclosures: No relevant conflicts of interest to declare.

Introduction: Polymorphisms in certain genes involved on chemo/radio therapy response, as genes involved on DNA synthesis and repair, oxidative stress and drug detoxification, could be related to increased risk of develop t-AML. Objectives: To identified SNPs on genes that could be involved on putative risk of developing t-AML. To analyse the influence of relevant polymorphisms between groups of patients depending of the intensity and the type of treatment received. Material and Methods: Twelve polymorphisms located on genes from drug detoxification pathways (NOQ1, GSTP1), DNA repair (XPC[3], XRCC1[2], NBS1, ERCC5 and XRCC3) and DNA synthesis (MTHFR[2]) were studied. The analysis was carried out by restriction fragment length polymorphisms (RFLP). The analysed groups were A) 29 patients with t- AML: 19 haematological malignancies (A1) and 10 breast cancers (A2); B) control group, composed by 38 patients treated of a primary cancer with chemo/radio therapy ± autologous stem cell transplantation (ASCT) which after a period of ten years have not developed a t-AML: 26 haematological malignancies (B1) and 12 breast cancers (B2); C) 50 healthy individuals. Results : Five SNPs were found to be relevant, as is shown in the table. The two SNPs on MTHFR gene (667C/T y 1298A/C) displayed remarkably different allele frequencies between the groups of breast cancer patients (with and without t-AML), while no significant differences were observed when those primary cancer were haematological. XRCC1 displayed a low frequency of A in t-AML patients with haematological cancer when are treated with ASCT, compared with those not ASCT treated. This difference is also relevant when all group of patients with hematological malignancies are analysed (A1+B1+ASCT vs no ASCT) (p=0.014). Differences on allele frequencies in SNPs of ERCC5 and NBS1 genes between t-AML and non t-AML patients we observed only when haematological neoplasia patients are ASCT treated. Relevant SNPs found in t-AML | SNPs/Groups (n) | A2 (10) | B2 (12) | p | C (50) | |:--------------- | ------------ | ------------ | ------ | ------ | | MTHFR 667 | 75 | 20 | 0,0006 | 45 | | MTHFR 1298 | 5 | 50 | 0,0011 | 35 | | | A1+ASCT (10) | A1-ASCT (9) | p | C (50) | | XRCC1E10 | 20 | 55 | 0,029 | 34 | | | A1+ASCT (10) | B1+ASCT (14) | p | C (50) | | ERCC5 E15 | 50 | 14 | 0,020 | 24 | | NBS1E5 | 45 | 17 | 0,084 | 45 | Conclusions: The SNPs on MTHFR gene seem to be related on gene predisposition to t-AML only on breast cancer patients. In haematological malignancies, XRCC1 E10 genotype seems be related with survival in ASCT treated patients and risk of developing t-AML for those patients treated with lower intensity. The SNPs on ERCC5 and NBS1 genes seem to be involved on t-AML predisposition in ASCT treated patients. Thus, while XRCC1, NBS1 and ERCC5 SNPs are related with the development of t-AML on those patients with previous haematological malignancies (treated mainly with alkylating agents), MTHFR SNPs are related with t-AML on those patients with previous breast cancer (treated mainly with topoisomerase II inhibitors), suggesting that the relevance of each SNP depends on differences on type of chemotherapy, intensity and the metabolic route in which they are involved. Supported by FIS G03/008 project.