IgVH Genes Research Articles

Venous thromboembolism in patients with chronic lymphocytic leukemia

IntroductionVenous thromboembolism (VTE) is a major cause of morbidity and mortality in patients (pts) with malignant tumors. Increased risk of VTE is well described in a variety of hematologic malignancies; however, data regarding VTE in chronic lymphocytic leukemia (CLL) is very limited. Patients and methods: We retrospectively analyzed clinical and laboratory data of 346 consecutive pts with CLL followed up at 4th Department of Internal Medicine - Hematology, University Hospital, Hradec Kralove, Czech Republic, diagnosed between 1999 and 2011 (males, 64%; median age, 64years; low/intermediate/high Rai modified risk in 41/47/12%). Results: After a median follow-up of 72months (range, 26-138), at least one episode of VTE occurred in 38 patients (11%). VTE developed after a median of 34months from CLL diagnosis. Incidence of VTE was 1.67% per patient year of follow-up. There was a high proportion of unfavourable prognostic factors (advanced Rai stages, unmutated IgVH genes, unfavourable cytogenetics) in pts with VTE. The presence of 0/1/2/3 additional risk factors for VTE was identified in 2/16/14/6 patients. The most common risk factors for VTE besides age (n=24) were corticosteroid therapy (n=13), other malignancies (n=9) and obesity (n=7). Recurrence of VTE was diagnosed in 7 pts. Performance status≥2 and inherited thrombophilia were significant risk factors for VTE development in univariate and multivariate analysis. VTE was not associated with shorter overall survival. Conclusion: Based on our results, VTE is a relatively frequent complication in patients with CLL. Although most patients had other known risk factors for VTE including CLL treatment, 29% had no risk factors or only age≥60years. These findings demonstrate the possible role of CLL in the development of VTE.

Molecular analysis of immunoglobulin genes in the tumor B cells in splenic marginal zone lymphoma

To determine the immunoglobulin variable heavy chain (gVH) genes and their somatic mutations and to compare these data with the clinical and laboratory parameters of patients and the outcomes of the disease. The investigation enrolled 24 patients (9 men and 15 women whose age was 32 to 77 years (median age, 60 years) with splenic marginal zone B-cell lymphoma (SMZBCL). The latter was diagnosed on the basis of histological and immunohistochemical examinations of a bone marrow trephine biopsy specimen, immunophenotyping of peripheral lymphoid cells or bone marrow aspirates. The mutational status of the IgVH genes was analyzed in all the 24 patients. It was found that the tumor cells contained mutated IgVH genes (the VH1-family genes participated in most cases) in 15 (62.5%) patients with SMZBCL and unmutated ones in 9 (37.5%). There was a tendency towards more common tumor progression in patients with unmutated IgVH genes than in those with mutated ones. The presence of SMZBCL cases with both mutated and unmutated IgVH genes and the higher frequency of the VH1-2 gene are likely to indicate the molecular heterogeneity of the origin of this lymphoma.

Accumulation of self-reactive naïve and memory B cell reveals sequential defects in B cell tolerance checkpoints in Sjögren's syndrome.

Sjögren’s syndrome (SS) is an autoimmune disease characterised by breach of self-tolerance towards nuclear antigens resulting in high affinity circulating autoantibodies. Although peripheral B cell disturbances have been described in SS, with predominance of naïve and reduction of memory B cells, the stage at which errors in B cell tolerance checkpoints accumulate in SS is unknown. Here we determined the frequency of self- and poly-reactive B cells in the circulating naïve and memory compartment of SS patients. Single CD27−IgD+ naïve, CD27+IgD+ memory unswitched and CD27+IgD− memory switched B cells were sorted by FACS from the peripheral blood of 7 SS patients. To detect the frequency of polyreactive and autoreactive clones, paired Ig VH and VL genes were amplified, cloned and expressed as recombinant monoclonal antibodies (rmAbs) displaying identical specificity of the original B cells. IgVH and VL gene usage and immunoreactivity of SS rmAbs were compared with those obtained from healthy donors (HD). From a total of 353 VH and 293 VL individual sequences, we obtained 114 rmAbs from circulating naïve (n = 66) and memory (n = 48) B cells of SS patients. Analysis of the Ig V gene repertoire did not show significant differences in SS vs. HD B cells. In SS patients, circulating naïve B cells (with germline VH and VL genes) displayed a significant accumulation of clones autoreactive against Hep-2 cells compared to HD (43.1% vs. 25%). Moreover, we demonstrated a progressive increase in the frequency of circulating anti-nuclear naïve (9.3%), memory unswitched (22.2%) and memory switched (27.3%) B cells in SS patients. Overall, these data provide novel evidence supporting the existence of both early and late defects in B cell tolerance checkpoints in patients with SS resulting in the accumulation of autoreactive naïve and memory B cells.

Double IGHV Gene Rearrangements in Chronic Lymphocytic Leukemia

Background: Chronic lymphocytic leukemia (CLL) is an incurable cancer of mature B-lymphocytes that infil­trate the bone marrow, secondary lymphoid organs, and blood. Much progress has been made during the past decade in understanding the pathogenesis and prognosis in CLL. Patients with unmutated immunoglobulin gene heavy chain variable region (IGHV) genes have inferior clinical outcomes when compared to patients with mutated IGHV. While there is robust data regarding clinical outcomes in patients with single IGHV rear­range­ments in CLL, there is limited data regarding double IGHV rearrangements. Thus, we investigated the preva­lence of double IGHV rearrangements in our institutional cohort to determine molecular features and the prog­nos­tic significance of CLL cases with double IGHV rearrangements.Methods: Patients with CLL receiving care at Duke University and Durham Veterans Affairs (VA) Medical Centers were enrolled into a longitudinal cohort study between 1999 and 2014. IGHV mutation analysis was performed on DNA from all study patients. Patients were followed clinically for disease progression, need for treatment, and overall survival. The primary end points were time to treatment (TTT) or overall survival (OS). Survival curves were estimated using Kaplan-Meier method. Statistical differences were tested using propor­tional hazards tests for a clinical significance of p < 0.05. CLL cell isolation and IGHV mutational analysis were done as we have previously described (BLOOD 109:1559-1567, 2007). Statistical analysis was performed using SAS enterprise guide 5.1 and JMP Pro 11.Results: A total of 489 CLL patients were studied. Of these, 420 had one IGVH gene rearrangement (single IGHV; 86%). In 69 patients (14%), we amplified two IGHV rearrangements, indicating likely biallelic IGHV. The median TTT for the single IGHV group was 5.4 years, and the median OS for the single IGHV group was 15.3 years. For the double IGHV group, the mean TTT was 6.5 years (p = 0.44), and the median OS was 15.8 years (p = 0.73). Patients with single mutated IGHV (m) had better survival (median OS = 20.1 years) than those with single unmutated IGHV (u) (median OS = 11.3 yrs; p <0.001). There can be three possible combinations in the double IGHV group: double mutated (mm), mutated-unmutated (mu), and double unmutated (uu). The Table displays the differences in TTT and OS for the groups. In our cohort, the median TTT for those with a mutated double IGHV was longer (16.3 years) than for those with an unmutated double IGHV [median = 3.2 years; p < 0.01)]. Similarly, the median OS for those with mutated double IGHV was 33.6 years, while for those without a mutation it was 9.6 years (p < 0.01). In general, the TTT and OS were longer in those patients that had a mutated IGHV versus those without. The number of mutated genes did not make a statistical difference in the patient outcomes. Similarly, when comparing the uu and u groups, there was no statistical difference in survival.Conclusions: This is the largest single center study to date that examines double IGHV gene rearrangements and patient prognosis in CLL. The mutational status of the immunoglobulin heavy chain was a very important predictor of TTT and OS, mutated longer than ummutated. There was no significant survival difference between patients with single or double rearrangements in their IGHV chains. Our data demonstrates that the presence of at least one mutated IGHV gene confers a better prognosis for patients diagnosed with CLL. Thus, patients who have double IGHV rearrangements with at least one that is mutated, should be counseled as if they have a mutated rearrangement.Table:Statistical Analyses for Mutated and Unmutated IGHV for Time to Treatment and Overall SurvivalTime to TreatmentTTT (years)mmuuuup value (comparison between groups)mm18.50.1560.168<.0001<.0001m9.40.603<.00010.0001mu7.90.0610.007u3.00.285uu3.2Overall SurvivalOS(years)mmuuuup value (comparison between groups)mm33.60.48990.6230.0070.016m20.10.612<.00010.001mu20.80.0960.053u11.30.099uu9.6 [Display omitted] DisclosuresLanasa:MedImmune: Employment.

Good Tolerance of Lenalidomide Maintenance Therapy in Patients with High Risk Profile Chronic Lymphocytic Leukemia (CLL) after Frontline Chemoimmunotherapy: Preliminary Safety Overview of the CLLM1 Trial of the German CLL Study Group (GCLLSG)

Introduction: CLL patients (pts) with persistence of minimal residual disease (MRD) after frontline chemoimmunotherapy or an unfavourable genetic profile have a high risk of early relapse and a short survival (Fink et al., Leukemia 2013). Therefore, the GCLLSG designed the CLLM1 trial, a phase 3, randomized, double-blinded, placebo-controlled study to investigate the efficacy and safety of lenalidomide maintenance therapy for high–risk (HR) CLL following first-line chemoimmunotherapy. HR is defined by the presence of MRD at levels of ≥10-2 or the combination of MRD levels of ≥10-4 to <10-2 with an unmutated IGHV status, or del(17p) or TP53 mutations.Methods and patients: Prior to randomization pts underwent central screening procedures including the assessment of all risk factors and eligibility in particular response to first-line therapy. MRD levels were centrally analyzed. Pts were randomly assigned to receive either placebo or lenalidomide 5 mg p.o. daily for the first 28-day cycle, 10 mg p.o. daily for cycle 2-6, and the target dose of 15 mg for cycle 7-12. Further escalations up to 25 mg were allowed in MRD-positive pts if the study drug was well tolerated. Pts were treated until progression. Between July 2012 and June 2014 535 pts were registered from 130 sites in five countries (Austria, Germany, Italy, Netherlands and Spain). 126 (23.6%) of the pts were excluded before proceeding to MRD-analysis after first-line therapy due to misdiagnosis of other B-cell lymphoma (N=18), withdrawal of consent (N=44), comorbidities (N=5), hepatitis B infections (N=2) or other reasons (N=57). A total of 239 pts completed the screening. 186 (77.8%) achieved MRD negativity and were therefore ineligible for the study, and 8 (3.3%) pts are awaiting randomization. Pts remained blinded for this analysis.Results: To date, 45 HR pts were randomized. First-line therapy according to investigator’s choice included FCR in 17 (37.8%), BR in 27 (60.0%) and FC in 1 (2.2%) of 45 pts. Before first-line therapy, 9 of 45 (20.0%) pts had Binet A, 19 (43.2%) Binet B and 16 (36.4%) Binet C stage of disease, respectively. The median age was 66 years (range 44-80), median CIRS score was 2 (range 0-6). 33 of 45 pts (73.3%) showed MRD levels between ≥10-4 to <10-2 combined with by high risk genetics, and 12 (26.7%) showed MRD levels ≥10-2. 43 (95.1%) pts had unmutated IGVH genes. Del(17p) was detected in 4 (8.9%) and TP53 mutation in 6 (13.3%) pts, while 2 (4.4%) pts carried both abnormalities.At the time point of analysis 195 treatment cycles [60.2% of 324 expected cycles] were documented in 26 of 45 (57.8%) randomized pts. The median number of administered cycles was 6.5 (range 1-20). 115 of 195 treatment cycles (59.0%) were administered without the occurrence of any adverse event (AE). In 80 treatment cycles (41.0%) at least one AE was documented. 133 adverse events (AEs) of all CTC grades (1 to 4) occurred in 19 of 26 pts (73.1%). Eleven pts (42.3%) experienced at least one AE of CTC grade 3 or 4. The most common AEs were related to haematological parameters [9 (34.6%) pts, 7 (26.9%) with CTC grade 3/4], infections [8 (30.7%), all CTC grade 1/2], gastrointestinal [9 (34.6%), all CTC grade 1/2], respiratory/thoracic/mediastinal [4 (15.4%), all CTC grade 1/2] and skin disorders [9 (34.6%), 2 (7.6%) with CTC grade 3]. AEs led to the discontinuation of study treatment in 3 pts (11.5%) including fatigue [N=1, CTC grade 3] and allergic dermatitis [N=2, both CTC grade 3]. In total 13 of 45 pts (28.9%) treated in both arms have discontinued the study caused by withdrawal of consent (N=5) disease progression (N=4), toxicity (N=3) and technical reasons (N=1). To date, no treatment-related death has been reported in both treatment arms. Seven SAEs have been reported so far, three of them related to treatment including septic arthritis due to staphylococcal infection, autoimmune haemolytic anemia and cholecystitis, the latter resulted in study discontinuation.Conclusion: So far, maintenance therapy with lenalidomide or placebo appears to be a safe treatment option as the majority of adverse events reported during the maintenance therapy were mild or moderate (CTC grade 1/2). Severe adverse events (CTC grade 3/4) were observed solely with skin reactions and cytopenia. Reasons for discontinuation were mostly non-serious events including skin reactions and fatigue. Later analyses will clarify the impact of lenalidomide maintenance on relapse-free survival in high-risk CLL. DisclosuresEichhorst:Roche: Research Funding; Mundipharma: Research Funding. Off Label Use: Lenalidomide is not approved for maintenance treatment in CLL. Fink:Celgene: Other. Maschmeyer:Celgene: Consultancy. Westermann:Celgene: Other. Zey:Celgene: Other. Fischer:Roche: Other. Wendtner:Celgene: Consultancy, Honoraria, Research Funding. Ghia:Merck: Consultancy; GSK, Roche Italia: Consultancy; Gilead, Pharmacyclics, Boehringer Ingelheim, Celgene, Roche Italia: Membership on an entity’s Board of Directors or advisory committees. Bosch:Celgene: Consultancy, Honoraria, Research Funding; Roche: Consultancy, Honoraria, Research Funding. Döhner:Celgene: Research Funding. Stilgenbauer:Celgene: Consultancy, Honoraria, Research Funding. Boettcher:Roche: Honoraria, Research Funding; Celgene: Research Funding. Hallek:Celgene: Consultancy, Honoraria, Research Funding.

Immunoglobulin heavy chain variable region and major histocompatibility region genes are linked to induced graves' disease in females from two very large families of recombinant inbred mice.

Graves' hyperthyroidism is caused by antibodies to the TSH receptor (TSHR) that mimic thyroid stimulation by TSH. Stimulating TSHR antibodies and hyperthyroidism can be induced by immunizing mice with adenovirus expressing the human TSHR A-subunit. Prior analysis of induced Graves' disease in small families of recombinant inbred (RI) female mice demonstrated strong genetic control but did not resolve trait loci for TSHR antibodies or elevated serum T4. We investigated the genetic basis for induced Graves' disease in female mice of two large RI families and combined data with earlier findings to provide phenotypes for 178 genotypes. TSHR antibodies measured by inhibition of TSH binding to its receptor were highly significantly linked in the BXD set to the major histocompatibility region (chromosome 17), consistent with observations in 3 other RI families. In the LXS family, we detected linkage between T4 levels after TSHR-adenovirus immunization and the Ig heavy chain variable region (Igvh, chromosome 12). This observation is a key finding because components of the antigen binding region of Igs determine antibody specificity and have been previously linked to induced thyroid-stimulating antibodies. Data from the LXS family provide the first evidence in mice of a direct link between induced hyperthyroidism and Igvh genes. A role for major histocompatibility genes has now been established for genetic susceptibility to Graves' disease in both humans and mice. Future studies using arrays incorporating variation in the complex human Ig gene locus will be necessary to determine whether Igvh genes are also linked to Graves' disease in humans.

OP0266 Monoclonal Antibodies Derived from Single CD19+ Synovial B Cells of RA Patients with Tertiary Lymphoid Structures Display Preferential Immunoreactivity towards Citrullinated Proteins of Nets

BackgroundRheumatoid arthritis (RA) is characterised by breach of self-tolerance towards citrullinated proteins. Up to 50% of RA patients display synovial tertiary lymphoid structures (TLS) with functional B cell follicles supporting...

Immunoglobulin isotype switching during early B cell development (IRM8P.702)

Abstract During B cell lymphopoiesis in the bone marrow (BM), V(D)J joining assembles immunoglobulin (Ig) VH and VL genes mediated by RAG recombinase. Mature splenic B cells undergo class switch recombination (CSR) and somatic hypermutation initiated by activation induced deaminase (AID). However, the strict ontological separation of these processes may breakdown under some circumstances. Several immunodeficiencies including Omenn syndrome display increased serum IgE despite undetectable numbers of B cells. We hypothesized that CSR occurs in BM pro- or pre-B cells. Earlier, we showed that Rag1 and Mb1 deficient pro-B cells can be induced to undergo robust CSR, albeit to a restricted subset of IgH isotypes, including IgG2b and IgE. Immunization of Rag1-/- mice with LPS, promoted IgG2b switching in BM pro-B cells. We demonstrated that V(D)J joining can be induced to follow CSR. We found a unique stage specific chromatin conformation of Igh locus in pro-B cells that may repress IgG3 and IgG1 switching (Genes Dev. 27:2439). Here we show that CSR is inducible in WT pro-B cells. Using an elegant mouse model to irreversibly mark AID expressing cells, a knockin carrying AIDcre/+RosaYFP (Nat Imm. 10:1292), we assess the frequency of AID expression in BM pro-B cells activated in vitro and in vivo with LPS. These findings have implications for the hyper-IgE phenotype in Omenn syndrome, autoimmune repertoire development and leukemagenesis via the co-expression of the RAG and AID recombinases.

The BLNK adaptor protein has a nonredundant role in human B-cell differentiation

Expression of the pre-B-cell receptor (pre-BCR) by pre-BII cells constitutes a crucial checkpoint in B-cell differentiation. Mutations that affect the pre-B-cell receptor result in early B-cell differentiation blockades that lead to primary B-cell immunodeficiencies. BLNK adaptor protein has a key role in the pre-B-cell receptor signaling cascade, as illustrated by the abnormal B-cell development in the 4 patients with BLNK gene defects reported to date. However, the BLNK protein's precise function in human B-cell differentiation has not been completely specified. B-cell development, including IgVH and Vk chain repertoires analysis, was studied in the bone marrow of a new case of BLNK deficiency in vitro and in vivo. Here, we report on a patient with agammaglobulinemia, with a total absence of circulating B cells. We detected a homozygous mutation in BLNK, which leads to the complete abrogation of BLNK protein expression. In the bone marrow, we identified a severe differentiation blockade at the pre-BI- to pre-BII-cell transition. IgVH gene rearrangements and selection of the IgH repertoire were normal, whereas the patient's pre-BI cells showed very restricted usage of the IgVκ repertoire. Complementation of bone marrow progenitors from the patient with the BLNK gene and transplantation into NOD/SCID/γcko mice allowed the complete restoration of B-cell differentiation and a normal usage of the IgVκ genes.

A1.31 Monoclonal antibodies from CD19+ synovial B cells of RA patients with tertiary lymphoid structures display a strong immunoreactivity towards citrullinated histones from neutrophils NETs

Background and ObjectivesRheumatoid arthritis (RA) is characterised by breach of self-tolerance towards citrullinated proteins. Moreover, RA patients are characterised by increased neutrophils in their synovial fluid, in particular at early...

Clonal heterogeneity of thymic B cells from early-onset myasthenia gravis patients with antibodies against the acetylcholine receptor

Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR–MG) is considered as a prototypic autoimmune disease. The thymus is important in the pathophysiology of the disease since thymus hyperplasia is a characteristic of early-onset AChR–MG and patients often improve after thymectomy. We hypothesized that thymic B cell and antibody repertoires of AChR–MG patients differ intrinsically from those of control individuals. Using immortalization with Epstein–Barr Virus and Toll-like receptor 9 activation, we isolated and characterized monoclonal B cell lines from 5 MG patients and 8 controls. Only 2 of 570 immortalized B cell clones from MG patients produced antibodies against the AChR (both clones were from the same patient), suggesting that AChR-specific B cells are not enriched in the thymus. Surprisingly, many B cell lines from both AChR–MG and control thymus samples displayed reactivity against striated muscle proteins. Striational antibodies were produced by 15% of B cell clones from AChR–MG versus 6% in control thymus. The IgVH gene sequence analysis showed remarkable similarities, concerning VH family gene distribution, mutation frequency and CDR3 composition, between B cells of AChR–MG patients and controls. MG patients showed clear evidence of clonal B cell expansion in contrast to controls. In this latter aspect, MG resembles multiple sclerosis and clinically isolated syndrome, but differs from systemic lupus erythematosus.Our results support an antigen driven immune response in the MG thymus, but the paucity of AChR-specific B cells, in combination with the observed polyclonal expansions suggest a more diverse immune response than expected.

Prognostic relevance of angiopoietin-2, fibroblast growth factor-2 and endoglin mRNA expressions in chronic lymphocytic leukemia.

Elevated levels of circulating angiogenic cytokines and increased expression of genes encoding angiogenic factors have been reported in recent years in patients with chronic lymphocytic leukemia (CLL) but data regarding prognostic and predictive significance are still limited. Therefore, in the present study based upon our prior pilot results, we measured mRNA expressions of angiopoietin-2 (Ang-2), fibroblast growth factor-2 (FGF-2) and endoglin (CD105) by reverse transcription quantitative PCR in purified CD19+ cells from 70 untreated CLL patients (median age, 63 years; males, 64%; Rai III/IV stages, 29 %; unmutated IgVH genes, 60 %) and evaluated their possible association with established prognostic factors and clinical course of the disease. Higher expression of Ang-2 was significantly associated with unmutated IgVH genes (n = 55, p = 0.003). Higher CD105 expression was significantly associated with unmutated IgVH genes (n = 55, p < 0.001), high CD38 expression (n = 66, p = 0.022), high ZAP-70 expression (n = 66, p = 0.010), Rai stage I-IV (n = 70, p < 0.001), progressive clinical course of CLL (n = 70, p = 0.001) and shorter time to treatment (n = 70; p < 0.001). Expression of FGF-2 was not significantly associated with any of the prognostic markers. These results indicate that elevated expression of Ang-2 and in particular CD105 by CLL cells is associated with unfavorable prognostic features and clinical outcome; thus, both cytokines appear to play an important role in biology and progression of CLL and warrant further investigation.

Ofatumumab Added To Dexamethasone In Patients With Relapsed Or Refractory Chronic Lymphocytic Leukemia. Results From a Phase II Study Of The Czech Leukemia Study Group For Life

The treatment of relapsed/refractory chronic lymphocytic leukemia (CLL) remains a challenging clinical issue despite remarkable improvements in prognostication and therapy. One emerging treatment option for relapsed/refractory CLL is the use of high-dose corticosteroids. High-dose methylprednisolone or dexamethasone combined with rituximab are active in relapsed/refractory CLL, but serious infections are frequent and progression-free survival (PFS) is short. The purpose of this clinical trial was to determine the efficacy and toxicity of ofatumumab-dexamethason (O-dex) combination in relapsed or refractory CLL population.The trial was an open-label, multi-center, non-randomized, phase II study. The O-dex regimen consisted of intravenous ofatumumab (Cycle 1: 300mg on day 1, 2000mg on days 8, 15, 22; Cycles 2-6: 1000mg on days 1, 8, 15, 22) and oral dexamethasone (40mg on days 1-4 and 15-18; Cycles 1-6). Premedication consisted of glucocorticoid, paracetamol, and antihistamine before each ofatumumab infusion. All patients received allopurinol, omeprazol, co-trimoxazole, and fluconazole for prophylaxis of tumor lysis syndrome and infections. The O-dex regimen was given for a minimum of 3 cycles, until best response, or a maximum of 6 cycles.Between July 2010 and December 2012, 32 patients (pts.) were recruited at 3 centers. Basic patient characteristics at the start of O-dex therapy were as follows: median age 66 years (range, 50-77); 24 males, 8 females; median CIRS score 7 (0-15); median previous treatment lines 3 (1-10); 30 (94%) pts. were pretreated with fludarabine and 12 (38%) with alemtuzumab; Rai III/IV stage was present in 20 (63%) pts.; 6 (19%) pts. had bulky lymphadenopathy; IgVH genes were unmutated in 30 (94%) pts.; del 11q was present in 6 (19%) and p53 defects (del 17p and/or TP53 mutation) in 8 (25%) pts.The median number of O-dex cycles administered was 6 (1-6). Twenty two (69%) pts. completed at least 3 cycles of therapy. The remaining 9 patients were prematurely discontinued due to CTCAE grade 3/4 infections (7 pts.), disease progression (1 pt.), or uncontrollable diabetes mellitus (1 pt.). Overall responses/complete remissions (ORR/CR) were achieved in 22/5 pts. (69/16%). One patient achieved minimal residual disease negativity (measured by 4-color flow cytometry) at the end of therapy. Median PFS was 10 months. In patients with p53 defects, ORR/CR were achieved in 5/2 pts. (63/25%). The Median PFS was 10.5 months for this subgroup. Median overall survival (OS) has not yet been reached.During therapy, CTCAE grade 3/4 toxicity consisted of bacterial infections (25%), ofatumumab infusion-related side-effects (9%), neutropenia (9%), hyperglycemia (6%), and anemia (3%). No reactivation of herpetic viral infection was observed during the course of therapy. Nine patients died during the follow-up as a result of disease progression (6 pts.), infections (2 pts.), or complications after allogeneic stem cell transplantation (1 relapsed pt.).The median CD20 antigen density in CLL cells was 4766 (881-18515) MESF (molecules of equivalent soluble fluorochrome) units at baseline. At the end of therapy, CD20 density had significantly decreased (median 821 MESF; 443-2637); nevertheless, it was high once more at relapse (median 6619 MESF; 628-21359).In vitro testing of malignant pts. cells sensitivity to dexamethasone and ofatumumab did not show synergistic or additive effect of these compounds in majority of patients. Also, in vitro testing did not clearly predict the outcome of O-dex therapy. ConclusionsThe O-dex regimen shows relatively high ORR and CR, with promising findings for PFS and OS (including pts. harboring p53 defects), as compared to published data on rituximab plus dexamethasone regimen or ofatumumab in monotherapy. The infectious toxicity in 1/4 of pts. represents the most frequent side effect for this regimen.The study was registered at www.clinicaltrials.gov (NCT01310101). Disclosures:Doubek:GlaxoSmithKline: Research Funding. Mayer:Roche: Consultancy, Research Funding; Glaxo: Consultancy, Research Funding.

Distinct IGHV Repertoire Features In Chinese Chronic Lymphocytic Leukemia Patients

Mounting evidence indicates that immunoglobulin variable heavy-chain (IGHV) repertoire and mutational status in chronic lymphocytic leukemia (CLL) patients are prognostically relevant. However, rare data is available in Chinese CLL population. Our group investigated 270 Chinese CLL patients for their IGHV sequences and discovered significant differences between Chinese and European CLL patients. First of all, 169 (62.6%) patients in our group got mutated IGHV and 101 (37.4%) were unmutated, rendering a considerable higher percentage of mutated subgroup compared with European patients (55%) (Figure 1). While IGVH3 is still the most frequently used IGVH gene in Chinese CLL patients (135/270, 50%), discrepancy occurs in the usage of IGVH1 gene, which only presents in 13.7% (37/274) patients in our cohort whereas 23.79% for European (Figure 2). Regarding IGHV subgroups, IGHV3-23 and IGHV4-34 are more often used in Chinese CLL patients (10.7% and 10.4%, respectively). Remarkably, IGHV1-69, the most prevalent IGHV subgroup in European CLL patients (12.81%), only accounts for 5.2% (14/270) Chinese cases. [Display omitted] [Display omitted] [Display omitted] We further studied the distribution of stereotyped BCR in our cohort. Thirty-eight patients (14.07%) with stereotyped BCR that belonged to 21 subsets were identified, with 1 to 7 sequences contained each. Among them, subset 1 and subset 8 are the most common types with 6 and 7 cases respectively. Three new subsets were discovered (Table 1). Notably, only 1 case belonged to subset 2, the subset with largest group size in western world. Hence, we conclude that Chinese CLL patients show unique IGHV repertoire features compared to patients from western countries. While the mechanism within remains unknown, the discrepancy might due to antigenic difference in geographically remote areas.Table 1Three new subsets of BCR stereotypy in Chinese CLL patientsNO.IGHVIGHDIGHJM/UMIdentityHCDR3 AA sequenceLengthNovel 1NJ-15IGHV4-59*083-22*016*03UM100,00%ARGNYYDSSGYYYVGYYYYYMDV23NJ-31IGHV4-59*013-22*016*03UM99,65%ARGDYYDSSGYYYVGYYYYYMDV23Novel 2NJ-186IGHV3-23*013-22*014*02M96.60%AKGYRDNYDGDQSSVFDS18NJ-23IGHV3-23*012-21*014*02M96,53%AKGYRDNYDGDQSSVFDS18Novel 3NJ-36IGHV4-34*016-6*015*02M93,33%AKLMAGRPNWFDP13NJ-123IGHV4-34*016-6*015*02M91,67%AKLMAGRPNWFDP13 Disclosures:No relevant conflicts of interest to declare.

P53 Functional Assessment and Correlation With 17p Deletion and/Or TP53 Mutation Status In Chronic Lymphocytic Leukemia (CLL). A Preliminary Report Of The ICLL001 Bomp Trial On Behalf Of The French CLL Intergroup (GCFLLC/MW - GOELAMS)

Despite improvement in treatment strategies, virtually all chronic lymphocytic leukemia (CLL) patients will relapse and experience tumor resistance. The 17p deletion resulting in loss of the TP53 gene, found in up to 20-40% of relapsing patients, is strongly associated with impaired response to genotoxic agents, reduced progression free survival and poor overall survival. The 17p deletion usually coincides with TP53 mutation, leading to the impairment of the p53-associated pathway. In addition, sole TP53 mutations (without 17p deletion) appear also associated with poor outcome in prospective trials. However, TP53 mutation screening is time consuming, can be not exhaustive, and the respective impact of different patterns of TP53 gene impairment on p53 function and prognostic remains unclear. We previously developed a functional assay to detect p53 dysfunction (Le Garff-Tavernier, 2011) and we aim to validate this analysis on a large prospective trial.Clinical and laboratory data were collected from CLL patients (pts) enrolled in the ICLL001 – BOMP phase II trial of the French CLL intergroup (NCT01612988) evaluating a prephase of ofatumumab (300 mg) followed by 6 monthly courses of BOMP including bendamustine (70 mg/m2 d1-2), ofatumumab 1000 mg TD (d1 and d15 on 1st and 2nd courses) and high dose methylprednisolone (1 g/m2 d1-3) in fit patients with relapsing CLL and IWCLL treatment criteria. In addition to conventional screening, we focused on p53 evaluation. FISH analysis for 17p deletion was done with a 10% cut-off for positive result, TP53 gene mutation screening was performed using Sanger sequencing of the entire coding region (exons 2–11) and the p53 functional status in CLL cells was determined by a flow cytometry assay based on induction of p53 and p21 protein expression after etoposide and nutlin-3a exposition.Data from the first 55 enrolled pts are available. Sex ratio M/F was 3.3 and median age was 63.8 yrs (44.6-76.4). CLL diagnostic had been done 7,2 (1,9-16,8) years before inclusion. All patients had according to IWCLL criteria an active disease of Binet stage of A (11%), B (57%) and C (32%) respectively. Patients had been previously pretreated with a median of 1 (1-3) lines, including FCR (or FCR-like) in 51 (93%) pts and 22 (42%) pts had experienced high-risk relapses within 24 months post-FCR, with 7 (13%) pts being fludarabine refractory (less than PR after fludarabine regiment and/or response lasting less than 6 months). IGVH gene status was unmutated in 90%, elevated β2-microglobulin (>4) was found in 52%. Karyotypes were complex (≥ 3 abnormalities) in 18/46 (39%) successful cases. Using FISH, we found 15/55 (27%) del17p (median of positive cells 71%, range 10-98), 6/55 (11%) tri12, 18/55 (33%) del11q, 35/55 (64%) del13q. Results of p53 functional assay was available for 52 pts with the following results: normal in 31 pts and abnormal in 21 pts including type A (n=4), type B (n=13) and type C (n=4) dysfunction. Mutation screening was available in 55 pts. No mutation were detected in 38 pts, one significant mutation was detected in 14 pts within exon 5 (n=1), exon 6 (n=2), exon 7 (n=2), exon 8 (n=6), exon 10 (n=1) and intronic splice site (n=2) ; 3 pts had 2 mutations within exons 7 and 8 (n=1), exons 7 and 10 (n=1), exons 5 and 7 (n=1). Among the 52 pts with available functional results we found the 7 following groups (Table). In this study, the sensitivity and specificity of the p53 functional test to detect patient with 17p deletion and/or TP53 mutation was 89.5% (66.9 –99.7) and 87.9% (71.8 – 96.6) respectively.Response to p53/21 functional assay17p deletionTP53 mutationn%Group 1NormalNoNo2956Group 2AbnormalYesYes1325Group 3AbnormalYesNo12Group 4AbnormalNoYes35.5Group 5AbnormalNoNo47.5Group 6NormalYesNo12Group 7NormalNoYes12This study shows that an in vitro p53 functional analysis can predict with an acceptable sensitivity the presence of TP53 gene disruption and could be useful to identify pts with TP53 mutation without 17p deletion. Interestingly, this functional assay coupled with cytogenetic and mutational screening could reveal 3 sub-groups of pts with potential clinical consequences: i) normal p53 function despite a del17p deletion (group 6) ii) normal p53 function despite a TP53 mutation (group 7) and in contrast iii) abnormal p53 function without any TP53 gene disruption (group 5) allowing to describe alternative alterations of p53 pathway. Disclosures:Dilhuydy:Roche: Honoraria. Leblond:Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Mundipharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Feugier:Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees. Tournilhac:MUNDIPHARMA: Consultancy, travel funding Other; GSK: Consultancy, travel funding, travel funding Other; Celgene: Consultancy, teaching, teaching Other.

Lenalidomide and Rituximab For The Treatment Of Patients With Relapsed Or Refractory Chronic Lymphocytic Leukemia: Results Of Planned Interim Analysis

Based on data previously presented by our group demonstrating the safety and efficacy of lenalidomide (L) and rituximab (R) in the upfront setting, we are conducting an open-label, phase 2 trial single center trial to evaluate this combination as treatment for patients with relapsed or refractory CLL. MethodsPatients started L at 5 mg per day and could escalate to 25 mg/day if tolerated. Patients received L for 21 of 35 days for cycle 1, then 21 of 28 days for cycles 2 to 7. Rituximab was started at the end of C1 at 50 mg/m2 on Day 29, 325 mg/m2 on day 31 and 33, then 375mg/m2 weekly x4 for cycle 2, and on day 1 for cycles 3-7. Patients who achieved a response but had residual disease after 7 cycles were given the option to continue single-agent L in a consolidative manner for 6 additional cycles. All patients received allopurinol 300mg daily and aspirin 81mg daily, unless contraindicated. The primary endpoint was overall response rate by iwCLL guidelines following 7 cycles. This abstract reports on the planned interim analysis of the safety and efficacy. ResultsBy April 2013, 24 patients were enrolled and received treatment. 63% of patients were male (15/24). The median age at the start of study treatment was 67 years (range 53-83), with median 2.5 prior therapies (range 1-7). 75% (18/24) had CLL cells that expressed unmutated IgVH genes or high levels of ZAP-70. 25% (6/24) had unfavorable cytogenetics (del 17p or del 11q).5 patients stopped therapy early due to toxicity. 2 patients stopped treatment due to grade 3 tumor flare reaction. 1 patient developed grade 4 tumor lysis requiring hemodialysis. 1 patient had grade 4 neutropenia within days of starting L. 1 patient developed a deep vein thrombosis during cycle 2 while off aspirin for transient thrombocytopenia. These patients tended to have a higher baseline absolute lymphocyte count, but this association did not meet statistical significance. Treatment was otherwise well tolerated. Neutropenia was the most common adverse event (AE), with grade 4 (by CTCAE 4) in 9 patients, and grade 3 in 6 patients out of 21 evaluable patients. There was a single instance of grade 4 thrombocytopenia, and 4 patients had grade 3 thrombocytopenia. 3 patients had grade 3 anemia. The only other grade 3 or higher AE was fatigue (5%). Of note, grade 2 superficial thrombophlebitis occurred in 3 patients.Out of the 20 patients whose primary endpoints were assessed, the overall response rate (ORR) was 70% (14/20) with 15% nodular partial response (3 patients) and 55% partial response (PR) (11 patients). 30% (6/20) were non-responders (NR). Only 1 of the 6 patients with NR had objective progressive disease (PD). The other 5 patients stopped treatment early due to toxicity and were designed as non-responders. Of the responder patients, 8 elected to receive an additional 6 months of consolidation lenalidomide. All maintained the same response without meeting objective criteria for either PD or complete response. After a median follow-up of 17 months from the start of treatment, there have been no deaths among the 24 patients. For the 20 evaluable patients, the median progression free survival (PFS) was 18.4 months and the median treatment free survival was 13.5 months.We did not find any significant association between response, toxicity, or PFS and any demographic or prognostic variable analyzed, including age, ZAP-70, IgVH mutation, cytogenetics, splenomegaly, or CLL cell immunophenotype. ConclusionsThe combination of lenalidomide and rituximab is an effective regimen for the treatment of patients with relapsed or refractory CLL with an ORR and PFS that rivals novel CLL therapies, especially for patients continued on lenalidomide consolidation therapy. The median PFS for all patients is in excess of 1.5 years after a median follow-up of 17 months. A subset of patients encountered adverse events requiring early treatment cessation, but only 1 patient progressed on treatment. Continued accrual will facilitate the identification of biologic or clinical factors that may predict such outcomes. Disclosures:Choi:Celgene: Research Funding. Castro:Celgene: Research Funding. Kipps:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

Vegf and bFGF Single-Nucleotide Polymorphisms In Chronic Lymphocytic Leukemia: Impact On Susceptibility

BackgroundB-cell chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease with a highly variable clinical outcome. Recent studies have identified a number of different molecular prognostic markers (including mutational status of the IgVH gene, ZAP70 and CD38 expression) that allow to discriminate patients in prognostic subgroups. However, different expression patterns of angiogenic factors as VEGF, VEGFR1 and bFGF have been related with B-CLL susceptibility and treatment requirements. We have analyzed the polymorphisms: -710 C/T in VEGFR1, rs1109324, rs1547651, rs3025039 (936C/T) and rs833052 in VEGF and rs1449683 (223 C/T) in bFGF in order to determine the possible association with susceptibility in B-CLL. MethodsPeripheral blood samples from 230 B-CLL patients and 476 healthy controls were genotyped using probes TaqMan SNP Genotyping Assays. Samples were providing from the Hospital Clinic of Valencia. Four SNPs in the VEGF gene, one SNP in the bFGF gene and one SNP in the VEGFR1 gene were evaluated. Statistical analysis was performed using SNPStats program (Catalan Institute of Oncology) and Fisher's exact test was applied to evaluate the significance. ResultsWe have observed an increased frequency of the T allele in the rs1449683 SNP [OR 1.62 (95% CI: 0.98-2.66) p-value =0.063] and in the rs1547651 SNP [OR 0.72 (95% CI: 0.51-1.03), p-value=0.072] in our B-LLC patients when compared to control subjects. Moreover we observed that T allele carriers of rs3025039 (VEGF) have a significant protective effect concerning this disease [OR 0.59 (95% CI: 0.39-0.89) p-value=0.009]. ConclusionOur data indicate an increased frequency of the T allele in polymorphisms rs1449683 (bFGF) and rs1547651 (VEGF) in the group of patients, which possibly account for the individual susceptibility to develop B-CLL. On the other hand the data provided suggest that the T allele of VEGF rs3025039 is likely important genetic marker of susceptibility to B-CLL.Further studies regarding the role of pro-angiogenic markers in B-CLL would be beneficial to help elucidate pathogenic pathways in this disease. Disclosures:No relevant conflicts of interest to declare.

Deep sequencing and Circos analyses of antibody libraries reveal antigen-driven selection of Ig VH genes during HIV-1 infection

The vast diversity of antibody repertoires is largely attributed to heavy chain (VH) recombination of variable (V), diversity (D) and joining (J) gene segments. We used 454 sequencing information of the variable domains of the antibody heavy chain repertoires from neonates, normal adults and an HIV-1-infected individual, to analyze, with Circos software, the VDJ pairing patterns at birth, adulthood and a time-dependent response to HIV-1 infection. Our comparative analyses of the Ig VDJ repertoires from these libraries indicated that, from birth to adulthood, VDJ recombination patterns remain the same with some slight changes, whereas some VH families are selected and preferentially expressed after long-term infection with HIV-1. We also demonstrated that the immune system responds to HIV-1 chronic infection by selectively expanding certain HV families in an attempt to combat infection. Our findings may have implications for understanding immune responses in pathology as well as for development of new therapeutics and vaccines.

Subclonal evolution of a classical Hodgkin lymphoma from a germinal center B‐cell‐derived mantle cell lymphoma

Composite lymphomas (CL) represent the occurrence of two distinct lymphomas in the same patient. Often, CL share a common cellular origin, thus representing a unique model to investigate the multistep genetic path leading to lymphomagenesis in general and to the specific development of each distinct lymphoma component in particular. Here, we present the molecular analysis of a case consisting of an unusual Hodgkin lymphoma (HL) and a mantle cell lymphoma (MCL), intimately admixed within one another in lymph nodes and bone marrow yet phenotypically distinct, in a patient who first presented with splenic/leukemic MCL two years earlier. MCL and Hodgkin and Reed/Sternberg (HRS) cells harbored identical immunoglobulin (Ig) VH gene rearrangements with shared somatic mutations, proving their common clonal origin from a (post-)germinal center (GC) B cell. This also demonstrates the (post-)GC origin of MCL with mutated IgV genes. Both lymphomas carried the same CCND1/IGH translocation and, unexpectedly for HL, expressed cyclin D1 and OCT2. Thus, HRS cells are able to preserve IGH locus activity (otherwise usually silenced in HL) to promote expression of an oncogene translocated into this locus. Both lymphoma populations further showed an identical TP53 function-impairing mutation, and later acquired a TP53 heterozygous deletion independently from one another (convergent evolution). The surprisingly close genetic relationship of the lymphomas, together with their histological intermingling and the clinical history of the patient, suggests subclonal evolution of HL from MCL as a plausible pathway in alternative to that so far described in CL, i.e. separate development from a common precursor.

AB0022 Accumulation of circulating autoreactive naïve b cells reveal defects of early b cell tolerance checkpoints in patients with sjögren’s syndrome

BackgroundSjögren’s syndrome (SS) is an autoimmune disease characterised by high affinity circulating autoantibodies and peripheral B cell disturbances with predominance of naïve and reduction of memory B cells.ObjectivesThe stage at...