Anna Puiggros

Aggressive large B-cell lymphomas (LBCL) are a heterogeneous group of lymphomas with variable biological characteristics, for which the identification of MYC rearrangements (MYCr) is a defining and prognostic feature. Both the International Consensus Classification and the 5th edition of the World Health Organization Classification of Hematolymphoid Tumors recommend performing cytogenetic studies in all aggressive LBCL to detect MYCr. Since MYCr incidence is low, cost-effective screening tools are necessary. We asked whether the immunohistochemical combined profile of CD10, LMO2, and MYC could be a useful tool to screen for MYCr. For this purpose, we used two strategies: first, a scoring system assigning 0 points each for CD10 − , LMO2 + , and MYC − and 1 point for CD10 + , LMO2 − , and MYC + , adding the results, and second, an algorithm that selected tumors with CD10 + /LMO2 − profile and/or MYC overexpression. All analyses were performed in a training series including 482 cases from a single center and a validation series of 124 patients from two centers. The resulting system classified cases in scores from 0 to 3. Scores 0 and 1 had low MYCr (0/92 and 7/224, 3%, respectively), being higher for scores 2 (40/98, 41%) and 3 (61/68, 90%) (P < 0.001) in the training cohort. The incidence of MYCr in the validation series was as follows: score 0, 0/29 cases; score 1, 3/64 (5%); score 2, 10/23 (43.5%); score 3, 8/8 (P < 0.001). Sensitivity and negative predictive values were respectively 93.5% and 97.8% for the training and 85.7% and 96.8% for the validation cohorts. The algorithm rescued 2 and 1 MYCr cases included in score 1 from both series. In conclusion, we suggest that both approaches combining the interpretation of CD10/LMO2/MYC by immunohistochemistry are useful to screen for MYCr.

Current CLL guidelines recommend a two parallel cultures assessment using TPA and IL2+DSP30 mitogens for complex karyotype (CK) detection. Studies comparing both mitogens for CK identification in the same cohort are lacking. We analyzed the global performance, CK detection, and concordance in the complexity assessment of two cytogenetic cultures from 255 CLL patients. IL2+DSP30 identified more altered karyotypes than TPA (50 vs. 39%, p = 0.031). Moreover, in 71% of those abnormal by both, IL2+DSP30 identified more abnormalities and/or abnormal metaphases. CK detection was similar for TPA and IL2+DSP30 (10% vs. 11%). However, 11/33 CKs (33%) were discordant, mainly due to the detection of a normal karyotype or no metaphases in the other culture. Patients requiring treatment within 12 months after sampling (active CLL) displayed significantly more CKs than those showing a stable disease (55% vs. 12%, p < 0.001). Disease status did not impact cultures’ concordance (κ index: 0.735 and 0.754 for stable and active). Although CK was associated with shorter time to first treatment (TTFT) using both methods, IL2+DSP30 displayed better accuracy than TPA for predicting TTFT (C-index: 0.605 vs. 0.580, respectively). In summary, the analysis of two parallel cultures is the best option to detect CKs in CLL. Nonetheless, IL2+DSP30 could be prioritized above TPA to optimize cytogenetic assessment in clinical practice.

Background: Previous investigations pointed out a role for antigen stimulation in Sezary syndrome (SS). High‐throughput sequencing of the T cell receptor (TR) offers several applications beyond diagnostic purposes, including the study of T cell pathogenesis.Methods: We performed high‐throughput RNA sequencing of the TR alpha (TRA) and beta (TRB) genes focusing on the complementarity‐determining region 3 (CDR3) in 11 SS and one erythrodermic mycosis fungoides (MF) patients. Five psoriasis patients were employed as controls. Peripheral blood CD4⁺ cells were isolated and RNA sequenced (HiSeq2500). High‐resolution HLA typing was performed in neoplastic patients.Results: Highly expanded predominant TRA and TRB CDR3 were only found in SS patients (median frequency: 94.4% and 93.7%). No remarkable CDR3 expansions were observed in psoriasis patients (median frequency of predominant TRA and TRB CDR3: 0.87% and 0.69%, p < 0.001 compared to SS). CDR3 almost identical to the predominant were identified within each SS patient and were exponentially correlated with frequencies of the predominant CDR3 (R² = 0.918, p < 0.001). Forty‐six different CDR3 were shared between SS patients displaying HLA similarities, including predominant TRA and TRB CDR3 in one patient that were found in other three patients. Additionally, 351 antigen matches were detected (Cytomegalovirus, Epstein–Barr, Influenza virus, and self‐antigens), and the predominant CDR3 of two different SS patients matched CDR3 with specificity for Influenza and Epstein–Barr viruses.Conclusions: Besides detecting clonality, these findings shed light on the nature of SS‐related antigens, pointing to RNA sequencing as a useful tool for simultaneous clonality and biological analysis in SS.

Waldenström Macroglobulinemia (WM) is a lymphoplasmacytic lymphoma with bone marrow (BM) involvement and IgM monoclonal gammopathy. To date, no studies have focused specifically on peripheral blood (PB) involvement. In this study, 100 patients diagnosed with WM according to the World Health Organization (WHO) criteria were included based on the demonstration of MYD88mut in BM and the availability of PB multiparametric flow cytometry (MFC) analysis. Leukemic involvement by MFC was detected in 50/100 patients. A low percentage of mature small lymphocytes in PB smears was observed in only 15 cases. MYD88mut by AS-qPCR was detected in PB in 65/100 cases. In cases with leukemic expression by MFC, MYD88mut was detected in all cases, and IGH was rearranged in 44/49 cases. In 21/50 patients without PB involvement by MFC, molecular data were consistent with circulating disease (MYD88mut by AS-qPCR 3/50, IGH rearranged 6/50, both 12/50). Therefore, PB involvement by standard techniques was detected in 71/100 patients. MYD88mut was detected in PB by dPCR in 9/29 triple negative cases. Overall, 80% of the patients presented PB involvement by any technique. Our findings support the role of PB MFC in the evaluation of patients with IgM monoclonal gammopathy and provide reliable information on correlation with molecular features. The development of a feasible MFC assay may stand as an objective tool in the classification of mature B cell neoplasms presenting with IgM monoclonal gammopathy.

Chronic lymphocytic leukemia (CLL) is the most common leukemia among adults worldwide. Although genome-wide association studies (GWAS) have uncovered the germline genetic component underlying CLL susceptibility, the potential use of GWAS-identified risk variants to predict disease progression and patient survival remains unexplored. Here, we evaluated whether 41 GWAS-identified risk variants for CLL could influence overall survival (OS) and disease progression, defined as time to first treatment (TTFT) in a cohort of 1039 CLL cases ascertained through the CRuCIAL consortium. Although this is the largest study assessing the effect of GWAS-identified susceptibility variants for CLL on OS, we only found a weak association of ten single nucleotide polymorphisms (SNPs) with OS (p < 0.05) that did not remain significant after correction for multiple testing. In line with these results, polygenic risk scores (PRSs) built with these SNPs in the CRuCIAL cohort showed a modest association with OS and a low capacity to predict patient survival, with an area under the receiver operating characteristic curve (AUROC) of 0.57. Similarly, seven SNPs were associated with TTFT (p < 0.05); however, these did not reach the multiple testing significance threshold, and the meta-analysis with previous published data did not confirm any of the associations. As expected, PRSs built with these SNPs showed reduced accuracy in prediction of disease progression (AUROC = 0.62). These results suggest that susceptibility variants for CLL do not impact overall survival and disease progression in CLL patients.

Studies prior to next-generation sequencing (NGS) showed that the frequent indolent course of chronic lymphocytic leukaemia (CLL) is related to most cells remaining quiescent in the G(0)-G(1) cell cycle phase, due to the expression of dysregulated cyclin genes. Of note, the activating nature of the NOTCH1 mutation in T lymphoblastic leukaemia also drives the dysregulation of cell cycle genes. Our goal was to comprehensively revisit the cell cycle in NOTCH1-mutated CLL (NOTCH1(MUT)) to test for potential therapeutic targets. Among 378 NGS-annotated CLL cases, NOTCH1(MUT) cells displayed a unique transcriptome profile of G(0)-G(1) cell cycle components, with an overexpression of early-phase effectors, reaching a 38-, 27- and ninefold change increase for the complex elements CCND3, CDK4 and CDK6, respectively. This NOTCH1(MUT) cells' profile was related to more cells traversing through the cell cycle. In-vitro targeted inhibition of NOTCH1 gamma-secretase and CDK4/6 reversed the distribution of cells through the cycle phases and enhanced the killing of NOTCH1(MUT) CLL cells, suggesting new therapeutic approaches.

Chromothripsis (cth) has been associated with a dismal outcome and poor prognosis factors in patients with chronic lymphocytic leukemia (CLL). Despite being correlated with high genome instability, previous studies have not assessed the role of cth in the context of genomic complexity. Herein, we analyzed a cohort of 33 CLL patients with cth and compared them against a cohort of 129 non-cth cases with complex karyotypes. Nine cth cases were analyzed using optical genome mapping (OGM). Patterns detected by genomic microarrays were compared and the prognostic value of cth was analyzed. Cth was distributed throughout the genome, with chromosomes 3, 6 and 13 being those most frequently affected. OGM detected 88.1% of the previously known copy number alterations and several additional cth-related rearrangements (median: 9, range: 3–26). Two patterns were identified: one with rearrangements clustered in the region with cth (3/9) and the other involving both chromothriptic and non-chromothriptic chromosomes (6/9). Cases with cth showed a shorter time to first treatment (TTFT) than non-cth patients (median TTFT: 2 m vs. 15 m; p = 0.013). However, when stratifying patients based on TP53 status, cth did not affect TTFT. Only TP53 maintained its significance in the multivariate analysis for TTFT, including cth and genome complexity defined by genomic microarrays (HR: 1.60; p = 0.029). Our findings suggest that TP53 abnormalities, rather than cth itself, underlie the poor prognosis observed in this subset.