| 61. |
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| 62. |
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| 63. |
- Bhoi, Sujata, et al.
(författare)
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Prognostic impact of epigenetic classification in chronic lymphocytic leukemia : The case of subset #2
- 2016
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Ingår i: Epigenetics. - : Informa UK Limited. - 1559-2294 .- 1559-2308. ; 11:6, s. 449-455
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Tidskriftsartikel (refereegranskat)abstract
- Based on the methylation status of 5 single CpG sites, a novel epigenetic classification of chronic lymphocytic leukemia (CLL) was recently proposed, classifying CLL patients into 3 clinico-biological subgroups with different outcome, termed memory like CLL (m-CLL), naive like CLL (n-CLL), and a third intermediate CLL subgroup (i-CLL). While m-CLL and n-CLL patients at large corresponded to patients carrying mutated and unmutated IGHV genes, respectively, limited information exists regarding the less defined i-CLL group. Using pyrosequencing, we investigated the prognostic impact of the proposed 5 CpG signature in a well-characterized CLL cohort (135 cases), including IGHV-mutated and unmutated patients as well as clinically aggressive stereotyped subset #2 patients. Overall, we confirmed the signature's association with established prognostic markers. Moreover, in the presence of the IGHV mutational status, the epigenetic signature remained independently associated with both time-to-first-treatment and overall survival in multivariate analyses. As a prime finding, we observed that subset #2 patients were predominantly classified as i-CLL, probably reflecting their borderline IGHV mutational status (97-99% germline identity), though having a similarly poor prognosis as n-CLL patients. In summary, we validated the epigenetic classifier as an independent factor in CLL prognostication and provide further evidence that subset #2 is a member of the i-CLL group, hence supporting the existence of a third, intermediate epigenetic subgroup.
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| 64. |
- Bhoi, Sujata
(författare)
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Prognostic markers and DNA methylation profiling in lymphoid malignancies
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, great progress has been achieved towards identifying novel biomarkers in lymphoid malignancies, including chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), at the genomic, transcriptomic and epigenomic level for accurate risk-stratification and prediction of treatment response. In paper I, we validated the prognostic relevance of a recently proposed RNA-based marker in CLL, UGT2B17, and analyzed its expression levels in 253 early-stage patients. Besides confirming its prognostic impact in multivariate analysis, we could identify 30% of IGHV-mutated CLL (M-CLL) cases with high expression and poor outcome, which otherwise lacked any other poor-prognostic marker. In paper II, we investigated the prognostic impact of a previously reported 5 CpG signature that divides CLL patients into three clinico-biological subgroups, namely naive B-cell-like CLL (n-CLL), memory B-cell-like CLL (m-CLL) and intermediate CLL (i-CLL), in 135 CLL patients using pyrosequencing. We validated the signature as an independent marker in multivariate analysis and further reported that subset #2 cases were predominantly classified as i-CLL, although displaying a similar outcome as n-CLL. In paper III, we investigated the methylation status and expression level of miR26A1 in both CLL (n=70) and MCL (n=65) cohorts. High miR26A1 methylation was associated with IGHV-unmutated (U-CLL) and shorter overall survival (OS) in CLL, while it was uniformly hypermethylated in MCL. Furthermore, overexpression of miR26A1 resulted in significant downregulation of EZH2 that in turn led to increased apoptosis. In paper IV, we performed DNA methylation profiling in 176 CLL cases assigned to one of 8 major stereotyped subsets (#1-8) in relation to non-subset CLL (n=325) and different normal B-cell subpopulations. Principal component analysis of subset vs. non-subset CLL revealed that U-CLL and M-CLL subsets generally clustered with n-CLL and m-CLL, respectively, indicating common cellular origins. In contrast, subset #2 emerged as the first defined member of the i-CLL subgroup, which in turn alludes to a distinct cellular origin for subset #2 and i-CLL patients. Altogether, this thesis confirms the prognostic significance of RNA and epigenetic-based markers in CLL, provides insight into the mechanism of miRNA deregulation in lymphoid malignancies and further unravels the DNA methylation landscape in stereotyped subsets of CLL.
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| 65. |
- Bikos, Vasilis, et al.
(författare)
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An Immunogenetic Signature of Ongoing Antigen Interactions in Splenic Marginal Zone Lymphoma Expressing IGHV1-2*04 Receptors
- 2016
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 22:8, s. 2032-2040
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Prompted by the extensive biases in the immunoglobulin (IG) gene repertoire of splenic marginal-zone lymphoma (SMZL), supporting antigen selection in SMZL ontogeny, we sought to investigate whether antigen involvement is also relevant post-transformation. Experimental Design: We conducted a large-scale subcloning study of the IG rearrangements of 40 SMZL cases aimed at assessing intraclonal diversification (ID) due to ongoing somatic hypermutation (SHM). Results: ID was identified in 17 of 21 (81%) rearrangements using the immunoglobulin heavy variable (IGHV) 1-2*04 gene versus 8 of 19 (40%) rearrangements utilizing other IGHV genes (P = 0.001). ID was also evident in most analyzed IG light chain gene rearrangements, albeit was more limited compared with IG heavy chains. Identical sequence changes were shared by subclones from different patients utilizing the IGHV1-2*04 gene, confirming restricted ongoing SHM profiles. Non-IGHV1-2*04 cases displayed both a lower number of ongoing SHMs and a lack of shared mutations (per group of cases utilizing the same IGHV gene). Conclusions: These findings support ongoing antigen involvement in a sizable portion of SMZL and further argue that IGHV1-2*04 SMZL may represent a distinct molecular subtype of the disease.
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| 66. |
- Bomben, Riccardo, et al.
(författare)
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Comprehensive characterization of IGHV3-21-expressing B-cell chronic lymphocytic leukemia : an Italian multicenter study
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 109:7, s. 2989-2998
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Tidskriftsartikel (refereegranskat)abstract
- IGHV3-21-using chronic lymphocytic leukemia (CLL) is a distinct entity with restricted immunoglobulin gene features and poor prognosis and is more frequently encountered in Northern than Southern Europe. To further investigate this subset and its geographic distribution in the context of a country (Italy) with both continental and Mediterranean areas, 37 IGHV3-21 CLLs were collected out of 1076 cases enrolled by different institutions from Northern or Central Southern Italy. Of the 37 cases, 18 were identified as homologous (hom)HCDR3-IGHV3-21 CLLs and were found almost exclusively (16 of 18) in Northern Italy; in contrast, 19 nonhomHCDR3-IGHV3-21 cases were evenly distributed throughout Italy. Clinically, poor survivals were documented for IGHV3-21 CLLs as well as for subgroups of mutated and homHCDR3-IGHV3-21 CLLs. Negative prognosticators CD38, ZAP-70, CD49d, and CD79b were expressed at higher levels in homHCDR3 than nonhomHCDR3-IGHV3-21 cases. Differential gene expression profiling (GEP) of 13 IGHV3-21 versus 52 non-IGHV3-21 CLLs identified, among 122 best-correlated genes, TGFB2 and VIPR1 as down- and up-regulated in IGHV3-21 CLL cases, respectively. Moreover, GEP of 7 homHCDR3 versus 6 nonhomHCDR3-IGHV3-21 CLLs yielded 20 differentially expressed genes, with WNT-16 being that expressed at the highest levels in homHCDR3-IGHV3-21 CLLs. Altogether, IGHV3-21 CLLs, including those with homHCDR3, had a peculiar global phenotype in part explaining their worse clinical outcome.
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| 67. |
- Bonfiglio, Silvia, et al.
(författare)
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BTK and PLCG2 remain unmutated in one-third of patients with CLL relapsing on ibrutinib
- 2023
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Ingår i: Blood Advances. - : American Society of Hematology. - 2473-9529 .- 2473-9537. ; 7:12, s. 2794-2806
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Tidskriftsartikel (refereegranskat)abstract
- Patients with chronic lymphocytic leukemia (CLL) progressing on ibrutinib constitute an unmet need. Though Bruton tyrosine kinase (BTK) and PLCG2 mutations are associated with ibrutinib resistance, their frequency and relevance to progression are not fully understood. In this multicenter retrospective observational study, we analyzed 98 patients with CLL on ibrutinib (49 relapsing after an initial response and 49 still responding after ≥1 year of continuous treatment) using a next-generation sequencing (NGS) panel (1% sensitivity) comprising 13 CLL-relevant genes including BTK and PLCG2. BTK hotspot mutations were validated by droplet digital polymerase chain reaction (ddPCR) (0.1% sensitivity). By integrating NGS and ddPCR results, 32 of 49 relapsing cases (65%) carried at least 1 hotspot BTK and/or PLCG2 mutation(s); in 6 of 32, BTK mutations were only detected by ddPCR (variant allele frequency [VAF] 0.1% to 1.2%). BTK/PLCG2 mutations were also identified in 6 of 49 responding patients (12%; 5/6 VAF <10%), of whom 2 progressed later. Among the relapsing patients, the BTK-mutated (BTKmut) group was enriched for EGR2 mutations, whereas BTK-wildtype (BTKwt) cases more frequently displayed BIRC3 and NFKBIE mutations. Using an extended capture-based panel, only BRAF and IKZF3 mutations showed a predominance in relapsing cases, who were enriched for del(8p) (n = 11; 3 BTKwt). Finally, no difference in TP53 mutation burden was observed between BTKmut and BTKwt relapsing cases, and ibrutinib treatment did not favor selection of TP53-aberrant clones. In conclusion, we show that BTK/PLCG2 mutations were absent in a substantial fraction (35%) of a real-world cohort failing ibrutinib, and propose additional mechanisms contributing to resistance.
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| 68. |
- Boström, Hans, et al.
(författare)
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U-2973, a novel B-cell line established from a patient with a mature B-cell leukemia displaying concurrent t(14;18) and MYC translocation to a non-IG gene partner
- 2008
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Ingår i: European Journal of Haematology. - : Wiley. - 0902-4441 .- 1600-0609. ; 81:3, s. 218-225
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Tidskriftsartikel (refereegranskat)abstract
- B-cell lymphomas/leukemias with simultaneous t(14;18)(q32;q21) and MYC rearrangements have recently been shown to constitute a separate diagnostic entity, presenting with a rapid clinical course and a very poor prognosis. We describe the establishment of an Epstein-Barr virus negative cell line, designated U-2973, from a male patient with a de novo aggressive B-cell lymphoma/leukemia and very high peripheral blast cell count. Flow cytometry of bone marrow cells and U-2973 displayed a mature B-cell phenotype, and immunostaining showed expression of MYC and BCL2. IG gene rearrangement data were consistent with a lymphoid neoplasm of germinal centre derivation. Cytogenetic studies using conventional G-banding, fluorescent in situ hybridization, spectral karyotyping and single nucleotide polymorphism array demonstrated a complex karyotype with both a t(14;18) and double translocations between MYC and a non-IG gene partner located at chromosome 12p12.1.
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| 69. |
- Brieghel, Christian, et al.
(författare)
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Identifying patients with chronic lymphocytic leukemia without need of treatment : End of endless watch and wait?
- 2022
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Ingår i: European Journal of Haematology. - : John Wiley & Sons. - 0902-4441 .- 1600-0609. ; 108:5, s. 369-378
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Tidskriftsartikel (refereegranskat)abstract
- Introduction Early-stage chronic lymphocytic leukemia (CLL) challenges specialized management and follow-up.Methods We developed and validated a prognostic index to identify newly diagnosed patients without need of treatment (CLL-WONT) by a training/validation approach using data on 4708 patients. Composite scores derived from weighted hazards by multivariable analysis defined CLL-WONT risk groups.Results Age (>65 years: 1 point), Binet stage (B: 2 points), lactate dehydrogenase (LDH) (>205 U/L: 1 point), absolute lymphocyte count (15-30 x 10(9)/L: 1 point; >30 x 10(9)/L; 2 points), beta 2-microglobulin (>4 mg/L: 1 point), IGHV mutation status (unmutated: 1 point), and 11q or 17p deletion (1 point) were independently associated with shorter time to first treatment (TTFT). Low-risk patients demonstrated 5-year TTFT of 2% by internal validation, but 7-19% by external validation. Including all patients with complete scores, the 5-year TTFT was 10% for the 756 (39%) CLL-WONT low-risk patients, and the 704 (37%) patients who were both CLL-WONT and CLL-IPI low risk demonstrated even lower 5-year TTFT (8%).Conclusion We have adopted the CLL-WONT at an institution covering 1 800 000 individuals to allow patients with both low-risk CLL-WONT and CLL-IPI to be managed by primary healthcare providers, thereby prioritizing specialized hematology services for patients in dire need.
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| 70. |
- Brieghel, Christian, et al.
(författare)
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The Number of Signaling Pathways Altered by Driver Mutations in Chronic Lymphocytic Leukemia Impacts Disease Outcome
- 2020
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Ingår i: Clinical Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 1078-0432 .- 1557-3265. ; 26:6, s. 1507-1515
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: Investigation of signaling pathways altered by recurrent gene mutations and their clinical impact in a consecutive cohort of patients with newly diagnosed chronic lymphocytic leukemia (CLL). The heterogeneous clinical course and genetic complexity of CLL warrant improved molecular prognostication. However, the prognostic value of recurrent mutations at the time of diagnosis remains unclear. Experimental Design: We sequenced samples from 314 consecutive, newly diagnosed patients with CLL to investigate the clinical impact of 56 recurrently mutated genes assessed by next-generation sequencing. Results: Mutations were identified in 70% of patients with enrichment among IGHV unmutated cases. With 6.5 years of follow-up, 15 mutated genes investigated at the time of diagnosis demonstrated significant impact on time to first treatment (TTFT). Carrying driver mutations was associated with shorter TTFT and poor overall survival. For outcome from CLL diagnosis, the number of signaling pathways altered by driver mutations stratified patients better than the number of driver mutations. Moreover, we demonstrated gradual impact on TTFT with increasing number of altered pathways independent of CLL-IPI risk. Thus, a 25-gene, pathway-based biomarker assessing recurrent mutations refines prognostication in CLL, in particular for CLL-IPI low- and intermediate-risk patients. External validation emphasized that a broad gene panel including low burden mutations was key for the biomarker based on altered pathways. Conclusions: We propose to include the number of pathways altered by driver mutations as a biomarker together with CLL-IPI in prospective studies of CLL from time of diagnosis for incorporation into clinical care and personalized follow-up and treatment.
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