In chronic lymphocytic leukemia, the reliability of next-generation sequencing (NGS) to detect TP53 variants ≤10% allelic frequency (low-VAF) is debated. We tested the ability to detect 23 such variants in 41 different laboratories using their NGS method of choice. The sensitivity was 85.6%, 94.5%, and 94.8% at 1%, 2%, and 3% VAF cut-off, respectively. While only one false positive (FP) result was reported at >2% VAF, it was more challenging to distinguish true variants <2% VAF from background noise (37 FPs reported by 9 laboratories). The impact of low-VAF variants on time-to-second-treatment (TTST) and overall survival (OS) was investigated in a series of 1092 patients. Among patients not treated with targeted agents, patients with low-VAF TP53 variants had shorter TTST and OS versus wt-TP53 patients, and the relative risk of second-line treatment or death increased continuously with increasing VAF. Targeted therapy in ≥2 line diminished the difference in OS between patients with low-VAF TP53 variants and wt-TP53 patients, while patients with high-VAF TP53 variants had inferior OS compared to wild type-TP53 cases. Altogether, NGS-based approaches are technically capable of detecting low-VAF variants. No strict threshold can be suggested from a technical standpoint, laboratories reporting TP53 mutations should participate in a standardized validation set-up. Finally, whereas low-VAF variants affected outcomes in patients receiving chemoimmunotherapy, their impact on those treated with novel therapies remains undetermined. Our results pave the way for the harmonized and accurate TP53 assessment, which is indispensable for elucidating the role of TP53 mutations in targeted treatment.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Patients with chronic lymphocytic leukemia (CLL) have a higher risk of developing other malignancies (OMs) compared to the general population. However, the impact of CLL-related risk factors and CLL-directed treatment is still unclear and represents the focus of this work. METHODS: We conducted a retrospective international multicenter study to assess the incidence of OMs and detect potential risk factors in 19,705 patients with CLL, small lymphocytic lymphoma, or high-count CLL-like monoclonal B-cell lymphocytosis, diagnosed between 2000 and 2016. Data collection took place between October 2020 and March 2022. FINDINGS: In 129,254 years of follow-up after CLL diagnosis, 3513 OMs were diagnosed (27.2 OMs/1000 person-years). The most common hematological OMs were Richter transformation, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Non-melanoma skin (NMSC) and prostate cancers were the most common solid tumors (STs).The only predictor for MDS and AML development was treatment with fludarabine and cyclophosphamide with/without rituximab (FC ± R) (OR = 3.7; 95% CI = 2.79-4.91; p < 0.001). STs were more frequent in males and patients with unmutated immunoglobulin heavy variable genes (OR = 1.77; 95% CI = 1.49-2.11; p < 0.001/OR = 1.89; 95% CI = 1.6-2.24; p < 0.001).CLL-directed treatment was associated with non-melanoma skin and prostate cancers (OR = 1.8; 95% CI = 1.36-2.41; p < 0.001/OR = 2.11; 95% CI = 1.12-3.97; p = 0.021). In contrast, breast cancers were more frequent in untreated patients (OR = 0.17; 95% CI = 0.08-0.33; p < 0.001).Patients with CLL and an OM had inferior overall survival (OS) than those without. AML and MDS conferred the worst OS (p < 0.001). INTERPRETATION: OMs in CLL impact on OS. Treatment for CLL increased the risk for AML/MDS, prostate cancer, and NMSC. FCR was associated with increased risk for AML/MDS. FUNDING: AbbVie, and EU/EFPIAInnovative Medicines Initiative Joint Undertaking HARMONY grant n° 116026.
- Publikační typ
- časopisecké články MeSH
Chronic lymphocytic leukemia (CLL) major stereotyped subset 2 (IGHV3-21/IGLV3-21, ∼2.5% of all cases of CLL) is an aggressive disease variant, irrespective of the somatic hypermutation (SHM) status of the clonotypic IGHV gene. Minor stereotyped subset 169 (IGHV3-48/IGLV3-21, ∼0.2% of all cases of CLL) is related to subset 2, as it displays a highly similar variable antigen-binding site. We further explored this relationship through next-generation sequencing and crystallographic analysis of the clonotypic B-cell receptor immunoglobulin. Branching evolution of the predominant clonotype through intraclonal diversification in the context of ongoing SHM was evident in both heavy and light chain genes of both subsets. Molecular similarities between the 2 subsets were highlighted by the finding of shared SHMs within both the heavy and light chain genes in all analyzed cases at either the clonal or subclonal level. Particularly noteworthy in this respect was a ubiquitous SHM at the linker region between the variable and the constant domain of the IGLV3-21 light chains, previously reported as critical for immunoglobulin homotypic interactions underlying cell-autonomous signaling capacity. Notably, crystallographic analysis revealed that the IGLV3-21-bearing CLL subset 169 immunoglobulin retains the same geometry and contact residues for the homotypic intermolecular interaction observed in subset 2, including the SHM at the linker region, and, from a molecular standpoint, belong to a common structural mode of autologous recognition. Collectively, our findings document that stereotyped subsets 2 and 169 are very closely related, displaying shared immunoglobulin features that can be explained only in the context of shared functional selection.
- MeSH
- chronická lymfatická leukemie genetika MeSH
- genová přestavba MeSH
- geny pro těžké řetězce imunoglobulinů genetika MeSH
- HEK293 buňky MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- molekulární modely MeSH
- proteinové domény MeSH
- receptory antigenů B-buněk chemie genetika MeSH
- regulace genové exprese u leukemie MeSH
- somatická hypermutace imunoglobulinových genů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Chronic lymphocytic leukemia (CLL) is characterized by the existence of subsets of patients with (quasi)identical, stereotyped B-cell receptor (BcR) immunoglobulins. Patients in certain major stereotyped subsets often display remarkably consistent clinicobiological profiles, suggesting that the study of BcR immunoglobulin stereotypy in CLL has important implications for understanding disease pathophysiology and refining clinical decision-making. Nevertheless, several issues remain open, especially pertaining to the actual frequency of BcR immunoglobulin stereotypy and major subsets, as well as the existence of higher-order connections between individual subsets. To address these issues, we investigated clonotypic IGHV-IGHD-IGHJ gene rearrangements in a series of 29 856 patients with CLL, by far the largest series worldwide. We report that the stereotyped fraction of CLL peaks at 41% of the entire cohort and that all 19 previously identified major subsets retained their relative size and ranking, while 10 new ones emerged; overall, major stereotyped subsets had a cumulative frequency of 13.5%. Higher-level relationships were evident between subsets, particularly for major stereotyped subsets with unmutated IGHV genes (U-CLL), for which close relations with other subsets, termed "satellites," were identified. Satellite subsets accounted for 3% of the entire cohort. These results confirm our previous notion that major subsets can be robustly identified and are consistent in relative size, hence representing distinct disease variants amenable to compartmentalized research with the potential of overcoming the pronounced heterogeneity of CLL. Furthermore, the existence of satellite subsets reveals a novel aspect of repertoire restriction with implications for refined molecular classification of CLL.
- MeSH
- chronická lymfatická leukemie genetika MeSH
- frekvence genu MeSH
- genová přestavba MeSH
- lidé MeSH
- somatická hypermutace imunoglobulinových genů MeSH
- těžké řetězce imunoglobulinů genetika MeSH
- variabilní oblast imunoglobulinu genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
