Reappraising Immunoglobulin Repertoire Restrictions in Chronic Lymphocytic Leukemia: Focus on Major Stereotyped Subsets and Closely Related Satellites

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4376-4376 ◽  
Author(s):  
Andreas Agathangelidis ◽  
Anastasia Hadzidimitriou ◽  
Eva Minga ◽  
Lesley-Ann Sutton ◽  
Eleftheria Polychronidou ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Research Funding ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Sequence Motif ◽  
Cdr3 Length ◽  
Major Subset ◽  
Distinct Disease ◽  
Aggressive Clinical Course ◽  
Support Research

Abstract The existence of stereotyped B cell receptor immunoglobulins (BcR IG) in chronic lymphocytic leukemia (CLL) strongly implicated antigen selection in disease ontogeny. We have previously shown that the stereotyped fraction encompasses ~30% of all CLL and includes multiple subsets with distinct BcR IG configuration and variable size. Eventually, certain major subsets emerged as distinct clinical entities, exemplified by subset #2 (IGHV3-21/IGLV3-21, ~2.5-3% of all CLL, mixed somatic hypermutation (SHM) status) of a particularly aggressive clinical course, thus, sharply contrasting subset #4 (IGHV4-34/IGKV2-30, ~1% of all CLL, mutated IGHV genes, M-CLL), a prototype for indolent disease. Here, taking advantage of a multi-institutional cohort of 21,123 CLL IG rearrangements, almost three times the size of the largest previous study, and the availability of validated, purpose-built immunoinformatics methods, we reappraised BcR IG stereotypy especially focusing on major subsets and the degree of their sequence similarity to related minor subsets. Stereotypy discovery was performed with ARResT/Teiresias, while stereotypy assignment to existing subsets previously deemed as major was performed with ARResT/AssignSubsets (http://bat.infspire.org/arrest/). In the present study, a subset was characterized as major if representing > 0.2% of the cohort (i.e. at least 50 cases). Minor subsets closely related to major ones (termed satellite) were identified applying the following criteria: (i) usage of IGHV genes from the same phylogenetic clan; (ii) VH CDR3 length difference ranging from -2 to +2 compared to the respective major subset; (iii) shared VH CDR3 sequence motif; and, (iv) -2 to +2 difference in the offset of the VH CDR3 motif compared to the respective major subset. In total, 7378/21123 (34.9%) IG sequences were grouped into subsets with stereotyped VH CDR3, with the previously characterized 19 major subsets accounting collectively for 2594 sequences (12.3%) of the cohort: of these, 12 included cases with unmutated IGHV genes (U-CLL), 6 concerned M-CLL and 1 (subset #2) included cases with mixed SHM status. Four additional subsets exceeded 50 cases, and, thus, were also considered as 'major'. These results reinforce the notion that not all CLL will end up being stereotyped but rather that a plateau for stereotypy exists at ~1/3 of the cohort. Subset #2 was the largest subset (n=572, 2.7%), while subset #1 (IGHV clan I (IGHV1,5,7 subgroups)/IGKV1(D)-39) was the most frequent subset within U-CLL (n=515, 2.4%) and subset #4 the most common M-CLL subset (n=192, 0.9%), hence displaying remarkable consistency regarding their frequency in all cohorts published since the pioneering studies. Altogether, Teiresias and AssignSubsets gave concordant results for previously identified major subsets, illustrating the validity of our approach. Satellite subsets were sought for individually for each major subset. In general, few satellite subsets were identified, most of which concerned U-CLL major subsets. That notwithstanding, notable cases of satellite subsets were exemplified by major subset #1 and its satellite subset #99 from which it differed only in VH CDR3 length (13 aminoacids in subset #1 versus 14 in subset #99); interestingly, both subsets displayed equally aggressive clinical course. Another example concerned subset #8 (IGHV4-39/IGKV1(D)-39, U-CLL), an aggressive subset with very high risk for Richter's transformation, that, except for a one-aminoacid difference in VH CDR3 length, was otherwise identical to satellite subset #215, also displaying clinical aggressiveness. Overall, our results confirm that major subsets can be robustly identified and are consistent in relative size, hence representing distinct disease subgroups amenable to compartmentalized research with the potential of overcoming the pronounced heterogeneity of CLL. Most major subsets display unique sequence motifs, however satellite subsets exist, especially within U-CLL. Considering ever-increasing evidence that major stereotyped subsets may represent distinct disease subgroups, the existence of satellite subsets reveals a novel aspect of repertoire restriction and has implications for refined molecular classification of CLL. Disclosures Shanafelt: Genentech: Research Funding; GlaxoSmithkKine: Research Funding; Celgene: Research Funding; Janssen: Research Funding; Pharmacyclics: Research Funding; Cephalon: Research Funding; Hospira: Research Funding. Gaidano:Roche: Consultancy, Honoraria, Speakers Bureau; Karyopharm: Consultancy, Honoraria; Morphosys: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Niemann:Janssen: Consultancy; Abbvie: Consultancy; Roche: Consultancy; Gilead: Consultancy. Langerak:F. Hofmann-LaRoche, Genentech: Research Funding; InVivoScribe Technologies: Patents & Royalties: Royalties are provided to European Network (EuroClonality). Jaeger:Roche: Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Kater:Celgene: Research Funding; Gilead: Research Funding; Janssen: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Abbvie: Consultancy, Research Funding. Stilgenbauer:Amgen: Consultancy, Honoraria, Other: Travel grants, Research Funding; Gilead: Consultancy, Honoraria, Other: Travel grants , Research Funding; Genentech: Consultancy, Honoraria, Other: Travel grants , Research Funding; Celgene: Consultancy, Honoraria, Other: Travel grants , Research Funding; Boehringer Ingelheim: Consultancy, Honoraria, Other: Travel grants , Research Funding; Genzyme: Consultancy, Honoraria, Other: Travel grants , Research Funding; AbbVie: Consultancy, Honoraria, Other: Travel grants, Research Funding; GSK: Consultancy, Honoraria, Other: Travel grants , Research Funding; Janssen: Consultancy, Honoraria, Other: Travel grants , Research Funding; Mundipharma: Consultancy, Honoraria, Other: Travel grants , Research Funding; Novartis: Consultancy, Honoraria, Other: Travel grants , Research Funding; Pharmacyclics: Consultancy, Honoraria, Other: Travel grants , Research Funding; Hoffmann-La Roche: Consultancy, Honoraria, Other: Travel grants , Research Funding; Sanofi: Consultancy, Honoraria, Other: Travel grants , Research Funding. Hallek:Gilead: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Amgen: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau. Rosenquist:Gilead Sciences: Speakers Bureau. Ghia:Gilead: Consultancy, Honoraria, Research Funding, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Roche: Honoraria, Research Funding; Adaptive: Consultancy; Abbvie: Consultancy, Honoraria. Stamatopoulos:Novartis: Honoraria, Research Funding; Abbvie: Honoraria, Other: Travel expenses; Janssen: Honoraria, Other: Travel expenses, Research Funding; Gilead: Consultancy, Honoraria, Research Funding.

B-Cell Receptor Recognition of Multiple Epitopes Correlates with An Aggressive Clinical Course of Chronic Lymphocytic Leukemia.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 56-56
Author(s):  
Mascha Binder ◽  
Antje Jackst ◽  
Barbara Léchenne ◽  
Fabian Mueller ◽  
Hendrik Veelken ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Large Set ◽  
Epitope Recognition ◽  
Fab Fragments ◽  
Recognition Pattern ◽  
Aggressive Clinical Course ◽  
Mimicking Peptides

Abstract Abstract 56 INTRODUCTION: The malignant B-cells in chronic lymphocytic leukemia (CLL) express membrane immunoglobulins (B-cell receptors; BCR) which are specific for the leukemic clone of each individual patient. Emerging evidence suggests that the development and course of CLL may be driven by antigenic stimulation through the BCR. Here we set up a model system of epitope recognition in CLL to explore how diverse epitope recognition in CLL is and whether the epitope recognition pattern has clinical relevance. METHODS: BCRs from six randomly chosen CLL patients were cloned and recombinantly expressed as IgG1 Fab fragments. Combinatorial phage-displayed peptide libraries with five different insert designs were constructed and used for the selection of epitope-mimicking peptides on the Fab fragments. We tested the binding of phage displayed epitope mimics to the respective Fab fragment by ELISA as well as to the native BCR on the cells of CLL patients. Therefore, cell-bound phage displayed epitope mimics were separated from unbound phage by differential centrifugation and bound phage were quantified by bacterial infection. The binding of six ‘index‘ epitope mimics representative for each BCR was evaluated in a set of 100 unrelated CLL cell samples. Epitope recognition patterns of CLL BCRs were correlated with the clinical course of the disease by standard biostatistical analysis including Kaplan-Meier estimator, log-rank test, cox regression analysis and Chi-square test. RESULTS: We selected epitope-mimicking peptides from phage display libraries on six CLL BCRs from randomly chosen patients. The selected peptides bound to the recombinant BCRs as well as to the native BCRs on the respective CLL cells. To model epitope recognition in a larger cohort of CLL patients we chose six representative index epitope mimics and evaluated their binding in a large set of 100 unrelated CLL cases. Surprisingly, all CLL samples recognized one or several index epitopes. Some of the CLL samples showed marked polyreactivity whereas other samples were mono- or oligoreactive. We determined whether the degree of BCR polyreactivity correlates with the clinical course of the disease using time to first treatment (TTFT) as surrogate marker of disease progression. We found that CLL patients expressing BCRs reactive with each of the epitope mimics had a significantly worse clinical course than less reactive control patients (median TTFT 27 months versus 87 months). Moreover, CLL patients whose cells express BCRs reactive with five or more epitope mimics were also characterized by an aggressive clinical course as compared to patients reacting with less than five epitopes (median TTFT 24 months versus 97 months). These outcomes were unrelated to known prognostic markers such as BCR mutational status and high risk receptor configurations. CONCLUSIONS: We introduce a system for modelling and monitoring of BCR epitope reactivity in CLL. Our findings indicate that a polyreactive epitope recognition pattern may be a determinant of an aggressive clinical course in this disease. These findings further emphasize the functional and prognostic relevance of BCR epitope recognition patterns in CLL. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Expression of the PIM2 gene is associated with more aggressive clinical course in patients with chronic lymphocytic leukemia

2018 ◽  
Vol 28 (3) ◽  
pp. 385-390
Author(s):  
Katarzyna Kapelko-Slowik ◽  
Jarosław Dybko ◽  
Krzysztof Grzymajło ◽  
Bożena Jaźwiec ◽  
Donata Urbaniak-Kujda ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Aggressive Clinical Course

Biological and Clinical Features of Patients with Chronic Lymphocytic Leukemia Bearing Trisomy 12

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3907-3907
Author(s):  
Paolo Strati ◽  
Lynne V. Abruzzo ◽  
William Wierda ◽  
Susan Lerner ◽  
Susan M. O'Brien ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Board Of Directors ◽  
Median Time ◽  
Research Funding ◽  
Progressive Disease ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Interphase Nuclei ◽  
Advisory Committees ◽  
Trisomy 12

Abstract Abstract 3907 Cytogenetic abnormalities are among the most important predictors of clinical course and response to therapy in patients (pts) with chronic lymphocytic leukemia (CLL). Conventional chromosome banding (CBA) and fluorescence in situ hybridization (FISH) analyses detect abnormalities in 40–50% and 80% of pts, respectively. Trisomy 12 (+12), observed in ∼20% of CLL pts by FISH, is associated with atypical morphology and immunophenotype, and a more aggressive clinical course. We, therefore, review the clinical characteristics and outcome of 312 CLL pts with +12 evaluated at our center between 1988 and 2011. FISH analysis for common abnormalities associated with CLL was performed on interphase nuclei obtained from cultured bone marrow cells using a multi-color probe panel designed to detect deletions of 11q22.3 (ATM), 13q14.3 (D13S319), 13q34 (LAMP1), 17p13.1 (TP53) and trisomy 12 (12p11.1-q11) (Abbott Molecular, Abbott Park, IL). Survival curves were calculated using Kaplan-Meier estimates and compared using the log-rank test. Differences were considered significant for p < 0.05. Patient characteristics at diagnosis are presented in Table 1. Of 215 pts assessed by both CBA and FISH, 105 were positive for +12 by both analyses and 110 were positive only by FISH. By CBA (112 pts, including 7 assessed only by CBA), +12 was the sole abnormality in 52 pts (47%); +12 was associated with +19 in 17 pts (16%), with del(14q) in 9 pts (8%), with +18 in 8 pts (7%), with +8 in 3 pts (3%), with del(13q) in 3 pts (3%), with t(14;19)(q32;q13) in 3 pts (3%) and with other abnormalities in 17 pts (13%). By FISH (287 pts), +12 was the sole abnormality in 225 pts (78%) and was associated with del(13q) in 62 pts (22%). The median number of interphase nuclei positive for +12 by FISH was 47% (range, 5–93%). One-hundred-eighty-seven pts (60%) needed treatment, with a median Time-To-Treatment (TTT) of 46 months (range, 35–56). The TTT was significantly shorter in pts with Rai stage III-IV disease, splenomegaly, lymphadenopathy, B2m > 4 mg/L, CD38+, ZAP70+, +12 detected by both CBA and FISH, and +12 associated with del(14q) or t(14;19). All 187 pts with progressive disease received treatment: 105 with an FCR-based regimen, 28 with rituximab(R)-based therapy (R+ GM-CSF or R+ methylprednisolone), and 28 with investigational drugs (Lenalidomide, R+ lenalidomide, GS101, or Ibrutinib). Overall response rate was 98%, 89% and 96%, respectively, whereas complete remission rate was 87%, 11% and 36%, respectively. Fifty-five pts failed first-line treatment; their median Failure-Free Survival (FFS) was 27 months (range, 0–87). The FFS was significantly longer in pts who received FCR-based regimens (p<0.001)(Fig 1). The median overall survival (OS) has not been reached, and only 33 pts have died. The OS was significantly shorter in pts older than 65 years, with ALC > 30,000, and with a median +12 positivity in >30% of interphase nuclei by FISH. A trend toward longer OS was observed for pts with +12 associated with +19 (p=0.07). Richter's Syndrome (RS) and second malignancies (SM) were the leading causes of death (5 and 13 of 33 deaths, respectively). RS was reported in 12 pts (4%), after a median time of 36 months from diagnosis. SM was reported in 31 pts (10%), after a median time of 30 months from diagnosis. At the time of diagnosis of SM, 13 patients had received a therapy for CLL and 18 were untreated. In conclusion, pts with CLL and +12 have unique laboratory and clinical features. A high proportion develops progressive disease and requires treatment. Among available therapies, FCR-based regimens are associated with a longer FFS. A high rate of SM is observed in pts with +12, including in pts who have not received prior treatment Disclosures: Wierda: Abbott Laboratories: Research Funding. O'Brien:Avila: Research Funding; Bayer: Consultancy; Bristol-Myers Squibb: Research Funding; Gilead Sciences: Consultancy, Research Funding; Celgene: Consultancy; Cephalon: Consultancy; CII Global Research Foundation: Membership on an entity's Board of Directors or advisory committees; Genentech BioOncology: Research Funding; Genzyme: Consultancy; GlaxoSmithKline: Consultancy; MorphoSys: Consultancy; Novartis: Consultancy; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy; Seattle Genetics, Inc.: Consultancy; Sigma Tau Pharmaceuticals: Consultancy; Talon: Research Funding; The Medal Group: Speakers Bureau.

scholarly journals Incidental Richter transformation in chronic lymphocytic leukemia patients during temporary interruption of ibrutinib

2020 ◽  
Vol 4 (18) ◽  
pp. 4508-4511
Author(s):  
Paul J. Hampel ◽  
Hua-Jay J. Cherng ◽  
Timothy G. Call ◽  
Wei Ding ◽  
Mahsa Khanlari ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Histologic Diagnosis ◽  
Key Points ◽  
Aggressive Clinical Course

Key Points An incidental histologic diagnosis of DLBCL was identified during temporary interruption of ibrutinib treatment in patients with CLL. In contrast to an aggressive clinical course typical of Richter transformation, these patients responded to reinitiation of ibrutinib alone.

scholarly journals Characterization of Long Non-Coding RNAs in Chronic Lymphocytic Leukemia: Evidence for Association with Disease Progression in Trisomy 12 Patients

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3281-3281
Author(s):  
Renee C. Tschumper ◽  
Tait D. Shanafelt ◽  
Neil E. Kay ◽  
Diane F. Jelinek
Keyword(s):  
B Cells ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Disease Progression ◽  
Research Funding ◽  
Clinical Course ◽  
Lymphocytic Leukemia ◽  
Lncrna Expression ◽  
Trisomy 12 ◽  
Non Coding Rnas

Abstract BACKGROUND: Chronic lymphocytic leukemia (CLL) is a heterogeneous B cell malignancy with patients being categorized into disease subsets based on several key biologic parameters, e.g., mutation status (mutated, M; or unmutated, UM) of the immunoglobulin heavy chain variable region (IGHV), acquired chromosomal abnormalities, and expression of CD38 and CD49d. Furthermore, about one third of CLL patients express stereotyped B cell receptors and/or may acquire high risk common mutations in genes such as NOTCH1 and SF3B1 suggesting ongoing genetic evolution as drivers of disease development. Critical to this concept, those CLL patients with trisomy 12 (T12) defects have a higher incidence of mutations in NOTCH1 and often have a stereotyped receptor. However, T12 patients may have a variable clinical course that appears to be unrelated to these 2 drivers suggesting an additional, possibly non-coding genetic component that may further impact disease progression in these patients. One potentially relevant genetic factor that could influence T12 clinical course is long non-coding RNAs (lncRNAs). LncRNAs are transcripts longer than 200 nucleotides that can affect a number of cellular processes. Importantly, lncRNAs have been implicated in various cancers including malignant hematopoiesis indicating they could be therapeutic targets and/or clinically useful biomarkers. METHODS: To pursue a role for lncRNAs in T12 we used v3.0 Arraystar Human LncRNA Microarrays to assess the global profile of lncRNA expression in CLL with an emphasis on patients with T12. Two cohorts of 6 patients with T12 were selected for comparison: one defined as progressive with a short time to treatment (TTT) (treatment ≤1 year after diagnosis) and one as indolent (no treatment > 5 years after diagnosis). Each cohort included 3 patients with M and 3 with UM IGHV status. RNA from normal CD5+ and CD5- B cells was included as a control. To compensate for the small sample size in each cohort, a significant difference in lncRNA expression between the groups was defined as a fold change (FC) ≥5.0, p-value ≤0.05 and false discovery rate (FDR) ≤ 0.05. RESULTS: An initial global comparison of CD5+/CD5- normal B cells vs all CLL samples found that 609 lncRNAs were differentially expressed using the criteria listed above with 158 lncRNAs having a FC>10. Notable lncRNAs in this group included: LOC541472 (down in CLL and associated with the IL-6 gene), D63785 (up in CLL and associated with TBC1D3C, an oncoprotein), CTC-459I6.1 (up in CLL and associated with RASGRF2) and AC002480.5 (down in CLL and associated with STEAP1B, shown to be overexpressed in prostate cancer). We next evaluated T12 samples and identified 90 candidate lncRNAs that may discriminate between progressive and indolent T12 cases. Within this group were 11 lncRNAs with a FC > 10, 5 of which have no known associated gene. Of those associated with known genes, 3 were ultra-conserved region encoding lncRNAs down-regulated in progressive T12 patients (TTT ≤1 yr) and linked to hephaestin-like protein 1 precursor, pannexin-1, and tubulin beta-3 chain isoform 1. Of potential high relevance we found that the lncRNA LPP-AS1 was down-regulated in progressive T12 patients (TTT ≤1 yr) and known to be associated with the LIM-containing lipoma preferred partner (LPP) gene (p=0.028; FDR=0.03 and FC=18.3). Looking specifically at IGHV M progressive T12 patients (T12M≤1 yr) vs IGHV M indolent T12 patients (T12M>5 yrs), we again found the LPP-AS1 lncRNA was highly down-regulated in T12M≤1 (p=0.00046; FDR=0.006 and FC=34.5) but it was not found to be differentially expressed in the UM T12≤1 yr vs UM T12>5 yr comparison. The LPP gene has been shown to play a role in cell-cell adhesion, motility and signaling, and is often the fusion partner for the mixed lineage leukemia (MLL) gene in secondary acute leukemia. Furthermore, LLP may play a role in breast cancer cell invasion. LPP-AS1 may be participating in IGHV M T12 progression by affecting LPP and thus influencing migration through the lymph node microenvironment. CONCLUSION: While candidate lncRNAs in T12 CLL need to be validated, the LPP-AS1 lncRNA shows promise as a possible marker and potential treatment target for those patients with T12 and M IGHV that may progress rapidly. Further studies are needed to evaluate the impact of lncRNAs on clinical outcome of T12 CLL patients. Disclosures Shanafelt: Hospiria: Research Funding; Pharmacyclics/Jannsen: Research Funding; Cephalon: Research Funding; Celgene: Research Funding; glaxoSmithKline: Research Funding; Genetech: Research Funding; Polyphenon E Int'l: Research Funding. Kay:Celgene: Research Funding.

Transformation of Chronic Lymphocytic Leukemia Towards Richter´s Syndrome Is Induced By AKT Activation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2031-2031
Author(s):  
Nadine Nickel ◽  
Mona Al-Maarri ◽  
Martin Pal ◽  
Andreas Roth ◽  
Gero Knittel ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Research Funding ◽  
Akt Signaling ◽  
Lymphocytic Leukemia ◽  
Transformed Cells ◽  
Positive Staining ◽  
Akt Activation ◽  
Richter Syndrome ◽  
Support Research

Abstract Richter's syndrome (RS) is an aggressive transformation of Chronic Lymphocytic Leukemia (CLL) to Diffuse Large B Cell Lymphoma (DLBCL) refractory to current therapies with dismal prognosis. Richter Syndrome arises from CLL cells independent of common DLBCL mutations. Frequently, mutations in p53, CDKN2 or cMyc genes are involved, but a significant proportion displays no specifically acquired driver mutation. We could observe activation of AKT in 6 out 48 Richter syndrome biopsies by positive staining for active phosphorylated AKT while in CLL lymph nodes, DLBCL and Burkitt´s Lymphoma no phospho-AKT by IHC could be observed. However in primary patient CLL cases we could detect varying levels of pAKT by Western blot, elevated levels were identified predominantly in patients harboring high-risk mutations such p53, ATM, NOTCH1 and XPO1. Furthermore, B-cell receptor mediated stimulation of the PI3K/AKT axis provided protection towards genotoxic stress induced apoptosis via post-translation stabilization of MCL1. This provides subsequently a synergistic induction of apoptosis by combining idelalisib and bendamustin. Thus we analyzed the functional impact of AKT signaling using a conditional constitutive allele for AKT (AKT-C) specifically activated using CD19-Cre and Cγ1-Cre fro post-GC-activation. AKT activation alone could not induce a malignant phenotype, however we could demonstrate that Eµ-Tcl-1 mice with AKT-C develop Richter Syndrome. Both in EµTCL1:CD19-CreAKT-C (TCA) and EµTCL1:Cγ1- CreAKT-C (TCγ1A) mice developed a high-grade lymphoma phenotype leading to decreased survival. Transformed cells displayed blastoid characteristics with significantly increased cellular size and the histomorphological features of DLBCL. Large transformed cells show high percentage of KI67-positive staining (>90%) and frequent mitotic figures. Here, AKT-mediated GSK-3b inhibition and subsequent cMyc and Mcl-1 stabilization might transform CLL to RS cells and combinatory treatments with DNA-damaging and PI3K-inhibiting compounds revealed promising therapeutic results. Collectively, we have identified AKT signaling as an oncogenic signaling pathway in progression of CLL towards Richter´s syndrome and generated the first murine Richter Syndrome model (TCA and TCγ1A) providing novel mechanistic insights into the molecular understanding of Richter's transformation that is amenable to model therapeutic strategies and to address the efficacy of synergistic treatment combinations. Disclosures Klapper: Roche, Novartis, Amgen, Takeda: Research Funding. Hallek:Amgen: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Mundipharma: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding, Speakers Bureau.

Chronic lymphocytic leukemia patients with highly stable and indolent disease show distinctive phenotypic and genotypic features

Blood ◽  
2003 ◽  
Vol 102 (3) ◽  
pp. 1035-1041 ◽  
Author(s):  
Anna Guarini ◽  
Gianluca Gaidano ◽  
Francesca Romana Mauro ◽  
Daniela Capello ◽  
Francesca Mancini ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Clinical Course ◽  
Clinical Stage ◽  
Lymphocytic Leukemia ◽  
P53 Mutations ◽  
Distinctive Features ◽  
Indolent Disease ◽  
Aggressive Clinical Course ◽  
Cd38 Antigen ◽  
Autoimmune Phenomena

Abstract Different biologic features have been associated with a more or less aggressive clinical course in chronic lymphocytic leukemia (CLL). In the present study, 20 patients with highly stable CLL observed at a single institution over a period of 10 to 23 years and who never required treatment were extensively characterized. The aim was to identify a distinct and reproducible biologic profile associated with disease stability that may be used to recognize at presentation CLL patients who are likely to have a very benign clinical course and for whom treatment is not indicated. The results obtained indicate that numerous parameters are closely associated with disease stability: a typical CLL morphology and immunophenotype, the lack of expression of the CD38 antigen, the mutated immunoglobulin (Ig) heavy (H) chain variable (V) pattern, the absence of p53 mutations, a CD4/CD8 ratio more than 1, the lack of 17p and 11q deletions and of complex karyotypic aberrations, and the occurrence of the 13q14 deletion. No case displayed the VH3-21 gene, linked in mutated CLL with a poor outcome. In addition, the VH1-69 gene associated with unmutated CLL cases was never detected. These biologic features were coupled with an indolent clinical course characterized by an unmodified clinical stage over time, and by lack of autoimmune phenomena and of major infections requiring parental antibiotics. At a time when aggressive therapeutic strategies are always more frequently used in the management of CLL, the distinctive features of patients with long-lived stable disease should be prospectively identified at presentation.

scholarly journals Mechanisms of Adaptation to Ibrutinib in High Risk Chronic Lymphocytic Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 585-585 ◽  
Author(s):  
Valeria Spina ◽  
Gabriela Forestieri ◽  
Antonella Zucchetto ◽  
Alessio Bruscaggin ◽  
Tamara Bittolo ◽  
...  
Keyword(s):  
High Risk ◽  
Chronic Lymphocytic Leukemia ◽  
Nuclear Localization ◽  
Peripheral Blood ◽  
Research Funding ◽  
Clonal Evolution ◽  
Lymphocytic Leukemia ◽  
Adaptation Process ◽  
Over Time ◽  
Stimulation Of

Abstract Introduction. Ibrutinib inhibits the BTK molecule downstream the B-cell receptor (BCR). Though highly active in high risk chronic lymphocytic leukemia (CLL), the most typical response achievable in patients is a minimal residual disease (MRD) positive partial remission (PR) which is maintained until the development of genetically driven resistance caused by the acquisition of mutations in the BTK or PLCG2 genes. The study aims at characterizing the adaptation process allowing residual CLL cells to persist despite BTK inhibition. Methods. The IOSI-EMA-001 study (NCT02827617) is an observational study consisting in the prospective and longitudinal collection of peripheral blood samples and clinical data from high risk CLL patients treated with ibrutinib. Peripheral blood CLL cells longitudinally drawn from patients before treatment start and at fixed timepoints under ibrutinib were monitored by: i) next generation flow cytometry approaches for changes in proliferation rate, surfaceome, and pathway activation; and ii) CAPP-seq targeted deep next generation (sensitivity ~10-3) for clonal evolution. Results. The study cohort comprised 31 high risk CLL patients, including 15 treatment naïve, 16 relapsed, 80% IGHV unmutated, 42% 17p deleted and 55% TP53 mutated. Median duration of ibrutinib treatment was 45 weeks (24-72 weeks). All patients obtained a MRD positive PR that was maintained in all but one who progressed with a PLCG2 mutation (VAF 3%). Compared to baseline, under ibrutinib therapy CLL cells slowed down their proliferation, as suggested by the decreased expression of Ki-67, the reduction of the proliferating fraction (CXCR4dimCD5bright), and the increase of the resting fraction (CXCR4brightCD5dim). Compared to baseline, under ibrutinib therapy CLL cells also upregulated BCR and adhesion/homing proteins, and decreased the expression of BCR inhibitor proteins. Upon stimulation of the BCR with anti-IgM, the downstream path through pBTK and pPLCG2 was inhibited by ibrutinib, while conversely the downstream path through pAKT and pERK was still inducible throughout all the assessed timepoints. The proportion of CLL cells harboring nuclear localization of NF-kB progressively increased over time under ibrutinib. NF-kB nuclear localization was inducible throughout all the assessed timepoints by CD40L stimulation of the non-canonical NF-kB pathway, but not by anti-IgM stimulation of the BCR/canonical NF-kB pathway. Overall, 880 individual mutations were longitudinally discovered and monitored across a total of 121 sequential timepoints collected during ibrutinib treatment. Clonal evolution was observed in (67.7%) cases, a proportion rate previously documented in CLL treated with chemoimmunotherapy. Clonal evolution appeared to be heterogeneous involving different genes without a stereotypic targeting. Consistently, none of the main driver gene mutations was homogeneously selected or suppressed by ibrutinib suggesting that the biological adaptation of CLL cells under ibrutinib is not genetically driven. Clonal evolution propensity was not associated with any of the biomarkers of the disease, and it did not decrease over time under ibrutinib. Conclusions. Taken together these results suggest that residual CLL cells persisting under ibrutinib therapy adapt their phenotype by upregulating adhesion molecules, chemokine receptors and BCR molecules, and by maintaining a competence of BCR signaling through the PI3K/AKT/ERK pathway. The progressive selection of CLL cells having NF-kB in the nucleus, likely due to the BTK independent non-canonical NF-kB pathway, might explain their survival despite ibrutinib therapy. Finally, clonal evolution is not suppressed by ibrutinib chemotherapy, and despite does not seem to be directly involved in such adaptation process, may ultimately favor the acquisition of BTK and PLCG2 ibrutinib resistance mutations. Disclosures Zucca: Celltrion: Consultancy; AstraZeneca: Consultancy. Ghia:Sunesis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie, Inc: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding. Montillo:Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Research Funding. Tedeschi:Janssen: Consultancy, Speakers Bureau; Gilead: Consultancy; AbbVie: Consultancy. Gaidano:AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Honoraria; Roche: Consultancy, Honoraria.

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