ALBERT

Description: The GFI1 gene encodes a transcriptional repressor, which regulates myeloid differentiation. In the mouse, Gfi1 deficiency causes neutropenia and an accumulation of granulomonocytic precursor cells that is reminiscent of a myelodysplastic syndrome. We report here that a variant allele of GFI1 (GFI136N) is associated with acute myeloid leukemia (AML) in white subjects with an odds ratio of 1.6 (P 〈 8 × 10−5). The GFI136N variant occurred in 1806 AML patients with an allele frequency of 0.055 compared with 0.035 in 1691 healthy control patients in 2 independent cohorts. We observed that both GFI1 variants maintain the same activity as transcriptional repressors but differ in their regulation by the AML1/ETO (RUNX1/RUNX1T1) fusion protein produced in AML patients with a t(8;21) translocation. AML1/ETO interacts and colocalizes with the more common GFI136S form in the nucleus and inhibits its repressor activity. However, the variant GFI136N protein has a different subnuclear localization than GFI136S. As a consequence, AML1/ETO does not colocalize with GFI136N and is unable to inhibit its repressor activity. We conclude that both variants of GFI1 differ in their ability to be regulated by interacting proteins and that the GFI136N variant form exhibits distinct biochemical features that may confer a predisposition to AML.

Description: Background: The human leukocyte antigen (HLA)-G molecule exhibits limited tissue distribution and exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells which may favor their escape from antitumor immune responses. The role of HLA-G in B cell chronic lymphocytic leukemia (B-CLL) has not been defined. Experimental design: HLA-G expression was studied retrospectively in circulating B-CLL cells from 47 patients by flow cytometry using the MEM/G9 monoclonal antibody. Results: The proportion of leukemic cells expressing HLA-G varied from 1% to 54%. Patients with 〈 23% HLA-G positive cells (according to ROC analysis; designated as the HLA-G negative group) had a significantly longer progression-free survival (PFS) time than patients with 〉 23% of positive cells (median PFS 120 versus 23 months, p=0.0001). Multivariate analysis revealed that HLA-G expression (hazard ratio 4.81; p=0.002) was next to the initial staging according to Binet (hazard ratio 8.6; p=0.0001) the best independent prognostic factor compared to other known prognostic factors like ZAP-70 status (hazard ratio 3.6; p=0.029) or CD38 status (hazard ratio 1.83; p=0.37). Humoral and cellular immunosuppression was significantly more prominent in HLA-G positive as compared to HLA-G negative patients group (median immunglobuline G (g/l) 4.3 versus 7.3; median total T-cells (per μl) 824 versus 2540). Conclusions: In B-CLL the level of HLA-G expression is correlated with the degree of immunosuppression and prognosis. To our knowledge this is the first report that describes an association of HLA-G antigen expression and the course of the disease in B-CLL patients. Thus, HLA-G may contribute to the impairment of immune responses against tumor cells and infections. These findings need to be confirmed in a prospective study.

Description: Heterotrimeric G proteins mediate intracellular transduction of many hormone-receptor interactions. Activation of the G protein αs subunit (Gαs) upon stimulation of specific G Protein coupled receptors results in increased levels of the second messenger cAMP which has been shown to induce apoptosis in B-cells. On this background we investigated a potential association of a common silent single-nucleotid polymorphism (T393C) in the gene GNAS1 on chromosome 20 encoding Gαs with disease progression in patients with chronic lymphocytic leukemia (CLL). We genotyped the DNA from 109 patients with CLL and 100 healthy controls using PCR amplification followed by restriction analysis. Comparing the CLL patients with healthy controls we found no significant differences in allele frequencies or genotype distributions (CLL patients: 393CC 34 vs CT 51 vs TT 24; healthy controls: 393CC 25 vs CT 50 vs TT 25). However, progression-free survival (PFS) was significantly shorter in 393CC patients compared to T393 allele carriers (median PFS CC: 36 months; T-allele: median PFS not reached; log rank test: p=0.029; adjusted for Binet stage) after 5 years observation time. In multivariate analysis the T393C polymorphism was an independent prognostic factor for PFS. Our data suggest that the GNAS1 T393C polymorphism is not associated with the risk for B-CLL. However, the T393C polymorphism may be a prognostic marker for PFS. It is hypothesized that the 393T-allele is associated with increased cAMP concentrations and, therefore, with higher rates of apoptosis. Further studies assessing differences in the signaling pathway dependent on genotype are underway.

Description: Bcl-2 plays a key role in the regulation of apoptosis. We investigated the role of a novel regulatory single nucleotide polymorphism in the BCL2 gene (−938C〉A) in B-CLL. Bcl-2 protein expression in B-cells from CLL patients carrying the −938 AA genotype was significantly increased compared to AC and CC genotypes. Moreover, the −938C- and A-alleles differed with regard to the binding of nuclear proteins. Genotype distributions between 123 CLL patients (42 AA, 55 AC, 26 CC) and in 109 age-matched healthy controls (38 AA, 55 AC, 16 CC) were not significantly different suggesting that this polymorphism does not increase the susceptibility for B-CLL. However, time from first diagnosis to initiation of chemotherapy was significantly shorter in patients with −938AA genotype (38 months) compared to AC/CC genotypes (120 months; p=0.0077), especially in CD38 and ZAP-70 negative CLL patients. Multivariate Cox regression identified the BCL2 −938AA genotype as an independent prognostic factor for progression-free survival (hazard ratio, HR, 1.9; p=0.034) together with disease stage at diagnosis (HR 1.6; p=0.018) and ZAP-70 status (HR 2.9; p=0.001). Furthermore, the BCL2 −938C〉A polymorphism in combination with the two common prognostic factors CD38 and ZAP70 status provides additional prognostic information beyond that obtained from single or double marker analysis. To the best of our knowledge this is the first report demonstrating the influence of a novel regulatory polymorphism in the BCL2 gene upon the progression of B-CLL, which, of course, requires confirmation from independent studies. On the other hand, the results presented here appear plausible with regard to differences on the protein level depending on genotype and the known impact of Bcl-2 on disease progression. Thus, our report exceeds other genetic association studies in that a mechanistic link between genotype and observed phenotype can be proposed. In conclusion, carriage of the BCL2 −938AA genotype is a novel unfavorable genetic marker in patients with B-CLL associated with increased Bcl-2 expression.

Description: Introduction: The PETAL trial is a multicenter randomized controlled study for patients with aggressive lymphomas of diverse histologies (EudraCT 2006-001641-33, NCT00554164). In the study population as a whole interim PET (iPET) reliably predicted time to treatment failure (TTTF) and overall survival (OS). Interim PET-based treatment changes, however, had no impact on outcome (ASH 2014, abstract 391). Here we report the exploratory analysis for aggressive B cell lymphomas. Methods: Pts. aged 18 to 80 yrs. with newly diagnosed aggressive lymphomas and a positive baseline PET received 2 cycles of rituximab (R), cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) followed by iPET. The conditions of iPET were strictly defined: 3-week interval between the 2nd R-CHOP cycle and iPET to avoid inflammatory reactions (Eur J Nucl Med Mol Imaging 30:682, 2003), no G-CSF after the 2nd cycle to avoid altered glucose biodistribution (J Nucl Med 47:950, 2006), standardized uptake value (SUV)-based PET interpretation to improve reproducibility (favorable iPET response: reduction of maximum SUV by 〉 66 % compared to baseline; J Nucl Med 48:1626, 2007). Pts. with CD20+ lymphomas and a favorable iPET were randomized to receive 4 more cycles of R-CHOP or the same treatment plus 2 extra doses of R (part A of the trial). Pts. with an unfavorable iPET were randomized to continue R-CHOP for 6 additional cycles or receive 6 blocks of a more complex methotrexate-, cytarabine- and etoposide-based regimen originally designed for Burkitt lymphoma (Blood 124: 3870, 2014; part B). R was omitted in pts. with CD20- lymphomas. Sample size of the entire study population was based on the empirically derived assumption that treatment failure after 2 yrs. (TF: progression, relapse, treatment discontinuation due to toxicity, start of alternative therapy, death of any cause) could be improved from 80 % to 90 % in part A and from 30 % to 45 % in part B (alpha=0.05, power=0.8). Secondary endpoints included OS and toxicity. Results: Fifty-seven oncological centers and 23 nuclear medicine institutions participated in the trial. Between 2007 and 2012 1072 pts. were registered, and 862 (80.4 %) had a positive baseline PET, received 2 cycles R-CHOP, underwent iPET and were allocated to one of the post-iPET treatment arms detailed above. Reference pathology was available in 98 %, and median follow-up is 52 months. All in all, there were 779 patients with CD20+ aggressive B-cell lymphomas (90.4 % of all treated pts.) of whom 606 had diffuse large B-cell lymphoma (DLBCL), 42 primary mediastinal B-cell lymphoma (PMBCL) and 42 follicular lymphoma grade 3 (FL3). Interim PET was favorable in 691 pts. (88.7 %) and unfavorable in 88 pts. with CD20+ lymphomas (11.3 %). It was highly predictive of TTTF for CD20+ lymphomas in general and for each of the DLBCL, PMBCL and FL3 subgroups (Table). In CD20+ lymphomas and DLBCL, the iPET response predicted TF independently of the International Prognostic Index, and it was also predictive of OS. The groups of PMBCL and FL3 were too small for multivariate analyses. In part A, adding 2 extra doses of R failed to improve TTTF and OS in all histological entities. Separate analyses for subgroups defined by sex, age (〈 vs. 〉 60 yrs.) or a combination of the two showed no statistically significant benefit of extra doses of R in any of the subgroups. In pts. with an unfavorable iPET response, a switch from R-CHOP to the Burkitt regimen failed to improve TTTF or OS in CD20+ lymphomas in general (Figure) and in the DLBCL, PMBCL and FL3 subgroups. In part B, the Burkitt protocol was associated with more grade 3/4 leukopenia (82 % vs. 57 %, p=0.02), thrombocytopenia (59 % vs. 18 %, p=0.0001), infection (41 % vs. 16 %, p=0.017) and mucositis (39 % vs. 7 %, p=0.0007) than R-CHOP, but treatment-related mortality was similar in both arms (1 death each). Conclusion: In this large multicenter trial iPET proved highly predictive of outcome in pts. with CD20+ aggressive B-cell lymphomas, DLBCL, PMBCL or FL3 treated with R-CHOP. In pts. with a favorable iPET response, addition of 2 extra doses of R to 6 cycles R-CHOP failed to improve outcome in CD20+ lymphomas in general and in subgroups defined by histology, sex or age. In pts. with an unfavorable iPET response, switching to a more aggressive protocol also failed to improve outcome in any of the entities. Novel strategies are required for aggressive B-cell lymphomas failing to respond to the first 2 cycles of R-CHOP. Table Table. Figure Figure. Disclosures Duehrsen: Roche: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Alexion Pharmaceuticals: Honoraria, Research Funding. Giagounidis:Celgene Corporation: Consultancy. Grube:BMS, Sanofi: Consultancy. Klapper:Roche, Novartis, Amgen, Takeda: Research Funding. Hüttmann:Bristol-Myers Squibb, Takeda, Celgene, Roche: Honoraria; Gilead, Amgen: Other: Travel cost.

Description: BACKGROUND: In contrast to other B-cell neoplasias, chronic lymphocytic leukemia (CLL) is not only characterized by a clonal expansion of specific B-cells, but also by an increase in non-leukemic T-cells, most likely involved in sustaining the growth of the leukemic B-cell clone. Based on ZAP-70, CD38 and the IgVH mutation status, two prognostic groups of CLL patients can be identified. Our aim was to characterize the replicative histories of the B- and T-cells in the two groups of CLL patients compared to healthy individuals. PATIENTS and METHODS: Blood samples from 73 patients with CLL (ZAP-70−/CD38−: n = 29, ZAP-70+/CD38+: n = 30, ZAP-70/CD38 discordant: n = 14) were analyzed. The quantity and characteristics of the lymphocyte subsets was assessed by a cell counter and by immunophenotypic analysis. The replicative histories of naive and memory T-cells as well as B-cells was determined by measurements of telomere length in peripheral blood leukocytes of CLL patients and healthy individuals by automated multicolor flow-FISH. RESULTS: As expected, the average telomere length of the clonal B-cells was short. The telomere length was, however, significantly shorter for the ZAP-70+/CD38+ patient samples (2.46 ± 1.08 kb) than for the ZAP-70−/CD38− patient samples (5.06 ± 1.76 kb, p 〈 6.7 x 10−9). Interestingly, also the naive and memory T-cells from ZAP-70+/CD38+ CLL patients exhibited significantly shorter average telomere lengths (mean ± std: 4.85 ± 1.58 kb; 4.39 ± 1.09 kb) than T-cells from ZAP-70−/CD38− CLL patients (6.64 ± 1.72 kb, p 〈 2.2 x 10−4; 6.22 ± 1.5 kb, p 〈 7.4 x 10−6). These results are in line with the observed higher absolute T-cell numbers in the ZAP-70+/CD38+ CLL patients compared to ZAP-70−/CD38− CLL patients. Moreover, the average telomere loss in relation to time from primary diagnosis to sample date was higher for naive T-cells than memory T-cells in ZAP-70+/CD38+ patients (7.8 vs. 5.8 bp/month). When we compared the telomere length to age-related percentiles calculated from over 400 healthy individuals aged 0–102 years practically all telomere length values of the naive and memory T-cells from the ZAP-70+/CD38+ CLL patients fell below the 50th percentile, whereas the values of naive and memory T-cells from the ZAP-70−/CD38− CLL patients were within the normal distribution. CONCLUSIONS: We can confirm significantly shorter telomere length values for the B-cells of the ZAP-70+/CD38+ CLL patients. In addition, we can also demonstrate significantly shorter telomeres in T-cells of ZAP-70+/CD38+ CLL patients, which are below the 50th percentile compared to controls, and a higher telomere loss over time for naive T-cells of ZAP-70+/CD38+ CLL patients. As telomere length shortens approximately 50 to 100 bp per cell division the observed decrease in telomere length of the T-cells in ZAP-70+/CD38+ CLL patients equals to approximately 18 to 36 population doublings. This is by far more than expected by the slightly higher T-cell numbers in the peripheral blood. Our observations imply an extensive expansion of the T-cell compartment in ZAP-70+/CD38+ CLL patients and suggest an important role of T-cells in this subgroup of CLL patients.

Description: Abstract 2640 Poster Board II-616 Introduction: Deletion of 13q14 (del13q14) is the most common abnormality of B-chronic lymphocytic leukemia (CLL). However, for a long time investigations of this region did not detect the relevant pathogenetic mechanism. Micro-RNA genes MIRN15a and MIRN16-1 located on 13q14.3 were postulated to close this gap. Down-regulated expression of these miRNAs was shown to increase the anti apoptotic B cell lymphoma 2 (Bcl2) proteins. However, relevance and frequency of deregulated micro-RNA genes was differentially described. To understand the influence of deletion of chromosomal region 13q14 on gene expression, chromosomal abnormalities detected by single nucleotide polymorphism (SNP) chips were compared with gene expression analyzed by gene expression profiling in CLL. Furthermore, impact of deletion 13q14 on MIRN15A and MIRN16-1 expression and correlation to BCL2 protein expression were investigated. Methods: 15 B-CLL cases harboring del 13q14 were investigated for the extend of deletion with the 50k Xbal SNP array. Gene expression of the genes located in the aberrant region evaluated by Affymetrix U133A gene chip of 13 of these cases was compared between cases with and without this aberration. FISH analysis was done to validate SNP-data. Expression of MIRN15a and MIRN16-1 was evaluated by real-time PCR from further 20 B-CLL with TaqMan MicroRNA assays. From the 25 cases Western blot analysis for Bcl2 was performed. Results: SNP-chip and FISH analysis with probes for regions RB1, D13S25 and D13S319 gave consistent results. The minimal deleted region of del13q14 reaches from physical position 49543165 to 50272626 and mostly includes the location of MIRN15a and 16-1. 10 gene probes were located in the aberrant chromosomal 13q14 region and entered statistical analysis. In 4 of 5 genes with monoallelic deletions gene expression was significantly reduced. In regions harbouring mono- and biallelic deletions in 4 of 5 genes the monoallelic deleted cases showed decreased expression compared to the normal cases. Evaluation of MIRN15a and MIRN16-1 revealed strong down-regulation of expression in CLL harbouring biallelic del13q14 compared to other CLL and healthy B-cells (p=0.002; p=0.002), whereas there were no statistically significant differences between CLL with or without monoallelic deletion or healthy B-cells (p=0.534; p=0.665). Bcl2 Western blot analysis revealed stronger Bcl2 expression in CLL harbouring del13q14 in contrast to CLL without this abnormality (p=0.002). However, no difference between cases with mono- or biallelic del13q14 was detected (p=0.400). Conclusion: SNP chip analysis is a helpful tool to detect chromosomal abnormalities on a high resolution. Although detailed genetic analyses failed to demonstrate the consistent involvement of any of the genes located in the deleted region of B-CLL harboring del13q14, reduced expression occurred in most of these genes indicating gene dosage effects. MIRN15a and MIRN16-1 expression are frequently reduced in B-CLL with biallelic but not monoallelic deletion of 13q14 without an influence on Bcl2 protein levels. Disclosures: Off Label Use: intrapleural and intraperitoneal use of rituximab.

Description: BACKGROUND: In chronic lymphocytic leukemia (CLL) short telomeres were shown to be associated with mutational status, progression free survival (PFS) and overall survival (Damle et al., 2004). Chromosomal instability increases with shortening of telomeres. Recently, a relationship between telomere length and number of chromosomal aberrations has been shown if telomere length was investigated by quantitative real-time polymerase chain reaction (Tel-PCR) (Roos et al., 2008). The aim of the present study was to correlate average telomere length of individual cells measured by multicolor flow-FISH to established prognostic factors and genomic aberrations. PATIENTS and METHODS: Blood samples from 64 patients with CLL were analyzed. Flow cytometry was performed for quantification of ZAP-70 and CD 38 expression with a cut off at 20%. Immunoglobulin variable heavy chain (IGVH) genes were sequenced. An IGVH gene sequence with less than 98% homology with the corresponding germ-line sequence was considered to be mutated. Chromosomal alterations were investigated by fluorescence in situ hybridization (FISH) with the following gene probes: LSI 13q14, LSI 13q34, CEP 12, LSI 17p13, LSI 11q22–23. Copy number changes were also detected in 18 samples by SNP-chip analysis. The average length of telomere repeats at chromosome ends was measured by multicolor flow-FISH. Values of telomere length from CLL cells were correlated to values of telomere lengths of B lymphocytes from healthy age matched individuals (delta telomere length=Δtel). RESULTS: The average telomere length of the clonal B-cells was short. Patient samples from advanced Binet stages (B/C) had significantly shorter telomeres (Δtel −4.8 ± 1.0 kb) than patients samples from Binet A (Δtel −3.4 ± 1.2 kb, p=0.03). The average telomere length was significantly shorter for ZAP-70+ (Δtel −5.0 ± 0.5 kb) and CD38+ (Δtel −4.9 ± 0.7 kb) patient samples than for ZAP-70− (Δtel −2.4 ± 0.8 kb) and CD38− (Δtel −3.0 ± 1.0 kb) patient samples, respectively (p