The importance of transferrin-bound iron for the proliferation of mouse T-lymphocytes in vitro

Abstract Not Provided

Genome-wide association analysis implicates dysregulation of immunity genes in chronic lymphocytic leukaemia

Several chronic lymphocytic leukaemia (CLL) susceptibility loci have been reported; however, much of the heritable risk remains unidentified. Here we perform a meta-analysis of six genome-wide association studies, imputed using a merged reference panel of 1,000 Genomes and UK10K data, totalling 6,200 cases and 17,598 controls after replication. We identify nine risk loci at 1p36.11 (rs34676223, P=5.04 × 10−13), 1q42.13 (rs41271473, P=1.06 × 10−10), 4q24 (rs71597109, P=1.37 × 10−10), 4q35.1 (rs57214277, P=3.69 × 10−8), 6p21.31 (rs3800461, P=1.97 × 10−8), 11q23.2 (rs61904987, P=2.64 × 10−11), 18q21.1 (rs1036935, P=3.27 × 10−8), 19p13.3 (rs7254272, P=4.67 × 10−8) and 22q13.33 (rs140522, P=2.70 × 10−9). These new and established risk loci map to areas of active chromatin and show an over-representation of transcription factor binding for the key determinants of B-cell development and immune response

Genome-wide association analysis implicates dysregulation of immunity genes in chronic lymphocytic leukaemia

Several chronic lymphocytic leukaemia (CLL) susceptibility loci have been reported; however, much of the heritable risk remains unidentified. Here we perform a meta-analysis of six genome-wide association studies, imputed using a merged reference panel of 1,000 Genomes and UK10K data, totalling 6,200 cases and 17,598 controls after replication. We identify nine risk loci at 1p36.11 (rs34676223, P=5.04 × 10−13), 1q42.13 (rs41271473, P=1.06 × 10−10), 4q24 (rs71597109, P=1.37 × 10−10), 4q35.1 (rs57214277, P=3.69 × 10−8), 6p21.31 (rs3800461, P=1.97 × 10−8), 11q23.2 (rs61904987, P=2.64 × 10−11), 18q21.1 (rs1036935, P=3.27 × 10−8), 19p13.3 (rs7254272, P=4.67 × 10−8) and 22q13.33 (rs140522, P=2.70 × 10−9). These new and established risk loci map to areas of active chromatin and show an over-representation of transcription factor binding for the key determinants of B-cell development and immune response

A Novel Bayesian Prognostic Index for Diffuse Large B-Cell Lymphoma: A New Powerful Tool for Prediction of Outcome.

Abstract 1666 Poster Board I-692 Diffuse large B-cell lymphoma (DLBCL) is primarily treated with Rituximab – CHOP immunochemotherapy with varying results. Improved prediction at diagnosis of outcome for an individual patient remains a key goal in DLBCL management. This would allow the selection of patients who could benefit from new therapies. A large amount of data on new immunohistochemical and molecular factors has been collected in the last decade, but the International Prognostic Index (IPI) and Revised IPI are still mostly used for identification of prognostic groups. Both of these indices have important limitations. They rely on a small number of dichotomised predictive variables and patients are assigned to one of a small number of risk groups rather than giving a direct prediction, such as a predictive survival probability or a predictive median lifetime, on a continuous scale for each patient. We have developed a new prognostic index based on Bayesian survival modelling. This has allowed an increase in the number of predictive variables and removal of the need to dichotomise them. Importantly, the new index can give predictions for patients where not all of the predictive variables are observed. It can easily be modified in the future by the addition of new variables, e.g. molecular factors or new treatment regimens. The index was developed using data on a population-based cohort of DLBCL patients prospectively registered with the Scotland and Newcastle Lymphoma Group (SNLG) between 1990 and 2003. The complete data on patients' outcomes were available for 1863 from 2025 registered patients and of this cohort 1391 patients were treated with anthracycline-based chemotherapy and the new index is based on this group. Bayesian statistical inference was used with a three-component Weibull mixture model in which both the hazard multiplier and the component membership probabilities depend on the predictive covariates. The three mixture components correspond to the following three groups: patients who will suffer from primary progressive disease or relapse within one year from diagnosis; patients who will relapse at a later point; those who will have no relapse. A novel method of modelling to deal with cases with missing covariates was used. Both time to first relapse (TFR) and overall survival (OS) were modelled. The following factors were included in the current version of the model: age, sex, performance status by ECOG, clinical stage, B-symptoms, extranodal and bone marrow involvement, Hb, WBC, lactate dehydrogenase, albumin, alkaline phosphatase and urea. The new index is available in the form of a simple computer program and can predict the outcome of patients as: a predicted TFR and OS or a probability of belonging to one of the three groups. In order to check the index, the whole cohort of patients was separated randomly with stratification by IPI into a training-prediction set (2/3 of patients) and a validation-observed set (1/3 of patients). Fig 1 shows the Kaplan-Meyer plots for TRF and OS for both sets. The index was successfully validated. Our new Bayesian prognostic index for DLBCL gives more reliable predictions at diagnosis for individual patients. In future the model can be modified for new treatment regimens or factors. Presently our group is investigating this issue for patients treated with CHOP-R. Fig1 Kaplan-Meyer plots for TFR and OS in training-prediction (TFRP and OSP) and validation-observed set (TFRO and OSO). Fig1. Kaplan-Meyer plots for TFR and OS in training-prediction (TFRP and OSP) and validation-observed set (TFRO and OSO). Disclosures No relevant conflicts of interest to declare

Methylation markers identify high risk patients in IGHV mutated chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) exhibits a highly variable clinical course. Altered DNA methylation of genes has shown promise as a source of novel prognostic makers in a number of cancers. Here we have studied the potential utility of a panel of methylation markers (CD38, HOXA4 and BTG4) in 118 CLL patients. Each of the three loci assessed exhibited frequent methylation, as determined by COBRA analysis and individually correlated with either good (CD38, BTG4 methylation) or poor (HOXA4 methylation) prognosis. Using a combined approach to produce an overall methylation score, we found that methylation score was significantly associated with time to first treatment in CLL patients. Multivariate Cox regression analysis revealed that methylation score was the strongest predictor of time to first treatment and was independent of IGHV gene mutational status and CD38 expression. This study provides proof of principle that a panel of methylation markers can be used for additional risk stratification of CLL patients

Multicentre Genome Wide Association Study Identifies Risk Alleles for Progressive Chronic Lymphocytic Leukaemia [Conference Abstract]

The increased incidence of chronic lymphocytic leukemia (CLL) in first-degree relatives of affected patients indicates an element of genetic susceptibility to this malignancy, borne out in large scale genome-wide association studies (GWAS), which have identified over 40 constitutional risk alleles. Given the important genetic contribution to CLL susceptibility we hypothesized that constitutional genetic variants also affect disease progression. We employed GWAS methods in a large United Kingdom multi-center cohort study of well-characterized predominantly early-stage CLL cases to identify risk alleles for progressive CLL. We conducted six GWAS for single nucleotide polymorphisms (SNPs) associating with progressive CLL incorporating a total of 774 cases of European ancestry recruited to 6 clinical centers across the United Kingdom. CLL cases were genotyped on the Illumina OmniExpress platform and genotypes were determined using Illumina GenomeStudio software. After imputation, we combined the association test statistic for 5,199,911 autosomal SNPs common to all 6 GWAS after exclusion of those with an imputation quality score of <0.9 and a minor allele frequency (MAF) of < 2.5%, and conducted a meta-analysis under a fixed-effect model. The primary outcome assessed was time to first treatment (TTFT), defined as the interval between CLL diagnosis and first treatment or last follow-up. Pooling data from the 6 GWAS identified 5 SNPs at two genomic locations that surpassed genome-wide significance (P ≤ 5 x 10-8) for association with TTFT. The strongest statistical evidence for an association with progressive disease was for rs736456 (hazard ratio (HR) = 1.76, 95% confidence interval (CI) = 1.45-2.14; P = 1.26 x 10-8), which maps to chromosome 10q26.13. The second strongest association with progressive disease was for rs3778076 (HR = 2.03, 95% CI = 1.58-2.62; P = 3.89 x 10-8) which maps to chromosome 6p. Both markers showed consistent direction and magnitude of effect sizes across all six GWAS with no evidence of heterogeneity, and retained prognostic significance in multivariate models for disease progression, particularly in models restricted to Binet A patients. Whilst not as powerful as IGVH status, rs736456 and rs3778076 had prognostic utility equivalent to CD38 status, and are particularly powerful when considered together, identifying 5% of CLL patients carrying 2 or more risk alleles at high risk of progressive disease (Figure). To identify cis-regulated genes at each locus associated with progressive disease we interrogated gene expression data derived from a meta-analysis of 31,624 blood samples collated by the eQTLGen consortium. Of the thirteen genes annotated to within 1Mb of the chromosome 10 association signal rs736456 is eQTL for the PLEKHA1 gene (TAPP-1)(Benjamini-Hochberg corrected P-value [P BH] = 1.29 x 10-15). Of the 27 genes annotated to within 1Mb of the chromosome 6 signal, rs3778076 is eQTL for 5 genes including UHRF1BP1 (PBH = 6.73 x 10-139) and C6ORF106 (PBH = 3.54 x 10-64). Annotated genes at both loci have been implicated in modulating B-cell receptor or innate immune responses, key pathways in CLL pathogenesis. Data on post-treatment survival were available on 390 CLL cases, with 231 deaths and 159 censored at last follow-up, and neither the lead SNP at chromosome 10 or chromosome 6 were significantly associated with post-treatment survival in patients primarily treated with regimens that included chlorambucil, fludarabine or cyclophosphamide. It will be important to determine whether these markers predict overall survival in patients treated with novel targeted therapies. Taken together, these data identify rs736456 and rs3778076 as prognostic in early stage CLL patients demonstrating that progression of CLL from asymptomatic to symptomatic disease is determined by constitutional genetic variation as well as the more established somatic drivers. Constitutional genetic markers have the advantage of being easy to perform, highly reproducible and inexpensive making them ideal for incorporation into multivariate prognostication models for early stage CLL. Figure Disclosures Fegan: Roche: Honoraria; Janssen: Honoraria; Gilead: Honoraria; Abbvie: Consultancy, Other: Conference attendance sponsorship. Forconi: Gilead Sciences: Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Novartis: Honoraria; Menarini: Consultancy; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Roche: Honoraria. Schuh: AbbVie: Consultancy, Speakers Bureau; Genentech: Consultancy, Speakers Bureau; Pharmacyclics: Consultancy, Speakers Bureau; Verastem: Speakers Bureau; Gilead: Speakers Bureau; Seattle Genetics: Speakers Bureau; Jazz Pharmaceuticals: Speakers Bureau; Bristol-Myers Squibb: Research Funding; Janssen: Speakers Bureau; Kite: Speakers Bureau. Hillmen: Pharmacyclics LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel Expenses, Research Funding; Roche: Research Funding; Gilead: Research Funding; Apellis: Research Funding; Acerta: Membership on an entity's Board of Directors or advisory committees. Pratt: Binding Site, Amgen, Takeda, Janssen, Gilead: Consultancy, Honoraria, Other: Travel support