The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib is inducing durable responses in chronic lymphocytic leukemia (CLL) patients with refractory/relapsed disease or with TP53 defect, with BTK and phospholipase C gamma 2 (PLCG2) mutations representing the predominant mechanisms conferring secondary ibrutinib resistance.
Forty percent of chronic lymphocytic leukemia patients with TP53 alterations demonstrated atypical lymphocytes with cleaved/irregularly shaped nuclei and/or large atypical lymphoid cells with abundant cytoplasm in the peripheral blood.
We review studies in CLL which utilize the 17p deletion or TP53 mutations for prognostic stratification with specific focus on the technologies used for detection, the thresholds established for clinical significance, and the clinical contexts in which these alterations are identified.
The different types of drug resistance encountered in chronic lymphocytic leukemia (CLL) cannot be fully accounted for by the 17p deletion (and/or TP53 mutation), a complex karyotype (CK), immunoglobulin heavy-chain variable region genes (IGHV) status and gene mutations.
Here, we present two distinct methodologies which can be used to identify TP53 mutations in CLL patients; both protocols are primarily intended for research purposes.
Between Oct 23, 2014, and April 23, 2018, 85 patients with chronic lymphocytic leukaemia were enrolled. del(17p) was detected in four (5%) of 83 patients and TP53 mutations were noted in three (4%) of 81 patients; two patients had both del(17p) and TP53 mutations.
The variable clinical course in chronic lymphocytic leukaemia (CLL) largely depends on p53 functionality and B-cell receptor (BCR) signalling propensity; however, it is unclear if there is any crosstalk between these pathways.
In conclusion, CLL patients with several chromosomal gains exhibit high genetic instability, with mutations in CLL driver genes and high-risk genetic alterations involving ATM and/or TP53 genes.
In our study, we focused on CLL patients with an intact TP53 gene and investigated four recurrently mutated genes in CLL, genomic aberrations by FISH, and IGHV status with the aim of analyzing their impact on progression-free survival (PFS) after front-line therapy with FCR (fludarabine, cyclophosphamide, rituximab) or BR (bendamustine, rituximab) regimens.
Although the detailed molecular mechanisms are still to be defined, our work shows for the first time that in primary B cells, metabolic stressors enhance BTK signaling and suggest that metabolic rewiring to hyperglycemia affects ibrutinib resistance in TP53 deficient chronic lymphocytic leukemia (CLL) lymphocytes.
As such, the tremendous efforts made to better understand the functions of p53 in CLL have contributed substantially to recent advances in treating patients with p53-pathway-deficient CLL.
Eligible patients were at least 18 years old and previously untreated, and had immunophenotypically confirmed B-cell chronic lymphocytic leukaemia; an Eastern Cooperative Oncology Group (ECOG) performance status score of less than 2; a Binet stage C according to IWCLL 2008 criteria or Binet stage A and B with active disease; no 17p deletion or absence of p53 mutation; and were considered medically fit.
Here we present an unusual case of a patient with TP53-mutated chronic lymphocytic leukemia (CLL) treated with a PI3Kδ inhibitor evolving to clonally related Langerhans cell histiocytosis (LCH) with acquired BRAF V600E and STK11 mutations and loss of expression of PAX-5 and other examined B cell markers.
TP53 Gene 72 Arg/Pro (rs1042522) Single Nucleotide Polymorphism Contribute to Increase the Risk of B-Chronic Lymphocytic Leukemia in the Sudanese Population
Subanalysis of major subsets identified three ultra-HR-CLL groups: men with TP53 disruption with/without CK, women with TP53 disruption with CK and men/women with CK + del(11q) with poor short-term outcomes (25% deaths/12 mo).
A major revolution in the treatment of chronic lymphocytic leukemia (CLL) began with the approval of ibrutinib, a first-in-class oral inhibitor of Bruton tyrosine kinase (BTK), for the treatment of relapsed/refractory (R/R) and/or TP53 mutated patients with CLL.
When we investigated the molecular mechanisms of this bad prognosis, we observed a reduction in the expression of 2 p53 target genes, <i>p21</i> and ∆<i>Np73</i>, in CLL primary cells transfected with <i>FANCA</i>.
We hypothesized that ofatumumab with sequential methylprednisolone - alemtuzumab would be an effective and tolerable regimen for patients with high-risk chronic lymphocytic leukemia (CLL) with TP53 dysfunction.
Most important markers in chronic lymphocytic leukemia (CLL) are TP53 abnormalities, including mutations and deletions, and the mutational status of immunoglobulin heavy chain (IGHV) genes.
Hence, with its novel mechanism of action and convenient oral once-daily regimen, venetoclax monotherapy or fixed 24-month combination therapy with rituximab represents an important option for treating RR CLL, including in patients with del(17p) or TP53 mutation and those failing a B cell receptor (BCR) inhibitor and/or chemotherapy.