Context Of Chronic Lymphocytic Leukemia Research Articles

Expression of ZAP 70 in Chronic Lymphocytic Leukemia (CLL) and its Correlation with Clinical Stages

Objective: To ascertain the levels of ZAP-70 expression within the context of Chronic Lymphocytic Leukemia (CLL) patients and to subsequently analyze the potential correlations between ZAP-70 expression and the clinical staging of the disease. Study Design & Setting: Cross-sectional, descriptive study. Department of Hematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi from July 2021 to December 2021. Methodology: We included 73 CLL patients of various ages and both genders. and patients having lymphoproliferative disorders other than CLL were excluded. Sysmex XN-3000 was used to do complete blood counts. Diagnosis of CLL was confirmed immunophenotypically by flow cytometry. Samples were processed by standard methods for ZAP70 analysis. Descriptive statistics were expressed in terms of mean ± standard deviation (SD). A Chi-square test was conducted, with a significance level of p-value =0.05 being considered significant. Results: Among 73 patients, 24 were females (32.9%) and 49 were males (67.1%). Females had a mean age of 69.00±9.47 years, whereas males had a mean age of 65.73±11.12 years. ZAP-70 expression was positive in 8 (11%) and negative in 65 (89.0%) cases. The expression of ZAP-70 in CLL and its correlation with Binet Stages was significant (p=0.002). ZAP- 70 expression in males and females showed no significant difference (p 0.059). ZAP-70 analysis showed no significant difference in patients with age more than 60 years from = 60 years of age (p= 0.275) Conclusion: ZAP-70 gene expression should be used in routine laboratory settings and can be correlated with the clinical stages of CLL

Targeting the p53 Pathway in CLL: State of the Art and Future Perspectives.

Simple SummaryThe p53 pathway plays a fundamental role in preventing the accumulation of unrepaired DNA damage. Unsurprisingly, cancer cells often break this protective barrier by inactivating either p53 itself or other proteins along this pathway, such as ATM. This facilitates the acquisition of further alterations that are required for unperturbed cancer growth and the development of chemoresistance. Over the years, there has been substantial scientific investment in creating new cancer therapies that can overcome functional loss of the p53 pathway. In this review, we will discuss different therapeutic approaches towards achieving this goal within the context of chronic lymphocytic leukemia (CLL), a cancer type with a p53-deficient subset that remains challenging to treat.The p53 pathway is a desirable therapeutic target, owing to its critical role in the maintenance of genome integrity. This is exemplified in chronic lymphocytic leukemia (CLL), one of the most common adult hematologic malignancies, in which functional loss of p53 arising from genomic aberrations are frequently associated with clonal evolution, disease progression, and therapeutic resistance, even in the contemporary era of CLL targeted therapy and immunotherapy. Targeting the ‘undruggable’ p53 pathway therefore arguably represents the holy grail of cancer research. In recent years, several strategies have been proposed to exploit p53 pathway defects for cancer treatment. Such strategies include upregulating wild-type p53, restoring tumor suppressive function in mutant p53, inducing synthetic lethality by targeting collateral genome maintenance pathways, and harnessing the immunogenicity of p53 pathway aberrations. In this review, we will examine the biological and clinical implications of p53 pathway defects, as well as our progress towards development of therapeutic approaches targeting the p53 pathway, specifically within the context of CLL. We will appraise the opportunities and pitfalls associated with these therapeutic strategies, and evaluate their place amongst the array of new biological therapies for CLL.

Clinicopathological characterization of chronic lymphocytic leukemia with MYD88 mutations: L265P and non-L265P mutations are associated with different features

MYD88 mutations in chronic lymphocytic leukemia (CLL) are not well characterized. Earlier reports yielded conflicting results in terms of clinicopathologic presentation and prognostic impact of MYD88 mutations in CLL patients. In addition, the morphological and immunophenotypic features of CLL cases carrying MYD88 mutations have not been explored. Finally, the clinical or biologic implications of the canonical L265P MYD88 mutation vs. mutations in other sites of MYD88 within the context of CLL are also unknown. In this study, a cohort of 1779 CLL patients underwent mutational analysis, and 56 (3.1%) cases were found to have MYD88 mutations, including 38 with L265P mutations (designated here as group A) and 18 with non-L265P mutations (group B). Cases with wild type MYD88 were included as controls. There was no morphological difference in cases with and without MYD88 mutations. Immunophenotypically, cases with mutated MYD88 (both groups A and B) more frequently had an atypical immunophenotype when compared to wild type cases. Group A patients were younger and were associated with variable favorable prognostic factors, including less elevated β2-microglobulin level, negative CD38 and ZAP70, higher frequency of mutated IGHV and isolated del(13q14.3), and lower frequency of del(11q22.3) and mutations of NOTCH1 and SF3B1. In contrast, group B patients were more similar to CLL patients with wild type MYD88. There was no difference in time to first treatment when comparing MYD88-mutated vs. wild type CLL patients before and after stratification according to IGHV mutation status. In summary, MYD88 mutations are uncommon in CLL and cases with L265P mutation have distinctive clinical, immunophenotypic, cytogenetic, and molecular features. There is no significant impact of MYD88 mutations on time to first treatment in CLL.

Clonal lineage analysis of CLL research samples by IGH chain sequencing to reveal novel CLL subgroups defined by ongoing class-switch recombination and somatic hypermutation.

e20001 Background: B cell somatic hypermutation (SHM) and class switch recombination (CSR) are mechanistically related but distinct processes requiring precisely targeted generation and repair of single and double strand DNA breaks. Within the context of chronic lymphocytic leukemia (CLL), the presence of ongoing SHM or CSR may reveal the functionality of DNA damage repair pathways, with potential relevance to therapeutic strategies involving the generation of DNA breaks or inhibition of DNA repair machinery. Here we apply clonal lineage analysis of IGH chain sequencing data to evaluate CSR and SHM in a cohort of CLL and splenic marginal zone lymphoma (SMZL) research samples. We present evidence of ongoing CSR and SHM in a significant subset of samples. Methods: Multiplex primers targeting the IGH framework 1 region and isotype region (Oncomine IGH-LR assay; detection of all nine isotypes) were used for IGH repertoire sequencing via the Ion Gene Studio S5 from 25ng peripheral blood total RNA derived from 63 individuals with CLL and 4 individuals with SMZL. Clonotyping and clonal lineage analysis was performed by Ion Reporter, whereby clonal lineages are defined as sets of unique rearrangements having a shared variable and joining gene, the same CDR3 length, and a minimum CDR3 nucleotide similarity of 85%. Ongoing CSR was defined as the presence of IgM/IgD and at least one switched isotype (IgG, IgA, or IgE), or a combination of switched isotypes, within the same lineage. Ongoing SHM was defined as the presence of subclones that differ within the VDJ region sequence compared to other clonal lineage members. Results: 11/68 cases showed evidence of ongoing CSR or SHM. Of the 57 cases showing no evidence of ongoing CSR or SHM, variable gene mutation analysis revealed the presence of three distinct subgroups having either no SHM, intermediate SHM (average 98% sequence identity) or high SHM < 94% identity). 3 of 4 SMZL cases showed evidence of ongoing CSR or SHM. Conclusions: These results reveal previously underappreciated heterogeneity within CLL and suggest the subdivision of CLL based on a combination of IGHV mutation level and presence of ongoing SHM or CSR. The described heterogeneity may serve as a valuable criterion for stratifying CLL patients in the future.

Identification of Distinct Cytokine and Chemokine Clusters That Correlate with Outcome In B-Cell Chronic Lymphocytic Leukemia: Implications for Disease Pathogenesis

AbstractAbstract 1368The growth and accumulation of B-cell chronic lymphocytic leukemia (CLL) cells requires survival and migratory signals supplied by endogenously produced cytokines and chemokines. Multiplex cytokine and chemokine analyses revealed that CCL2, CCL3, CCL4, IL-1b, IL-2, IL-5, IL-6, IL-8, IL-10, IL-12, CXCL9, CXCL11, TNFa, IFNg, IFNa, and IL-17 levels are significantly elevated in the serum of CLL patients (84 total) as compared to healthy age-matched subjects (48 total; p<0.01 for all). Random Forest analysis was used to rank these serum factors with respect to their importance in discriminating CLL patients from normal controls. This approach revealed 8 cytokines and chemokines (CCL3, IL-10, IL-5, CCL4, CXCL11, IL-8, CCL2, and IL-17) that distinguish CLL and controls, with CCL3 being the discriminating factor with the highest weight. The Kaplan-Meier method and log-rank test were used to compare median survival in CLL patients with high (>median) versus low (<median) levels for each cytokine. This analysis revealed that high levels of CXCL10, CXCL11, and IL-1b independently correlated with poor survival (p<0.05). Unsupervised cluster analysis was performed to identify groups of cytokines and chemokines that might work in concert to modulate CLL cell biology. As expected, CLL patients and healthy subjects clustered together on different ends of the dendogram. Furthermore, CLL patients with short TFT clustered together, and expressed high levels of a discrete group of cytokines (CCL3, CCL4, CCL19, CXCL9, CXCL10, CXCL11, IFNg, IL-5, IL-10, and IL-12). We termed this group “Clus1”. Certain members of this group have previously been shown to relate to CLL pathogenesis. CCL3 and CCL4, inflammatory chemokines that regulate cell recruitment and activation, are secreted by CLL cells and trigger a cascade of events that supports the CLL survival. IL-10 and the CXCR3 ligands CXCL9, CXCL10, CXCL11, are elevated in CLL and may contribute anti-apoptotic and growth-promoting signals that promote CLL cell survival. But, our data show for the first time that this set of cytokines and chemokines may be functionally linked. Cluster analysis also revealed a group of CLL patients that had moderate levels of Clus1 in combination with a second discrete cluster of cytokines (“Clus2”; GM-CSF, IL-8, TNFa, and IL-6). Since this group of patients had a relatively long TFT, even in the presence of detectable levels of Clus1, we hypothesized that they might play a direct protective role in CLL or alternatively might serve to regulate the actions of Clus1 cytokines. Lastly, cluster analysis revealed a third group of patients that were characterized by elevated serum levels of another discrete set of cytokines and chemokines (“Clus3”; IL-1b, IL-2, IL-4, IL-15, IL-17, and IFNa). The Kaplan-Meier method and log-rank test were used to compare median survival in patients expressing higher levels of Clus1, Clus2, or Clus3 cytokines and combinations of these clusters. This analysis revealed that high serum levels of Clus1 cytokines independently correlated with shorter survival times (Clus1HI12.5 yr versus Clus1LOW >21.5 yr; p=0.01), while high serum levels of Clus3 cytokines independently correlated with longer survival times (Clus3HI 21.6 yr versus Clus3LOW 12.5 years; p=0.05). The levels of Clus2 did not correlate with CLL patient survival. Combination analyses revealed that patients with high levels of Clus1 in the absence of Clus2 had significantly shorter survival times (10 yr) relative to patients with high levels of Clus1 cytokines in the presence of Clus2 (10yr vs 16yr; p=0.0018). In contrast, there was no significant difference between survival in patients with high levels of Clus1 in either the presence or absence of Clus3HI. Taken together, this suggests a beneficial modulatory role of cluster 2 cytokines. CONCLUSIONS: Application of multiplex bead immunoassays has allowed us to identify a set of cytokines and chemokines that are elevated within the context of CLL, to rank these secreted factors with respect to their importance in discriminating CLL from controls, and to identify those factors whose expression correlates with CLL disease prognosis. Complementary bioinformatics analysis allowed identification of three distinct clusters of cytokines and chemokines whose integrated expression levels reflect different CLL patient outcomes. Disclosures:No relevant conflicts of interest to declare.

Pseudo-hyperkaliémie et leucémie lymphoïde chronique: à propos d'un cas

Mrs D., 82 years old, is addressed to the emergency department for back pain and dyspnea associated with heart failure. This patient had a venous potassium to 7.4 mmol/L (without hemolysis) without clinical repercussions or electrocardiographic signs. A significant gap is found with arterial kaliema (4.3 mmol/L) determined using gazometric apparatus. This gap is explained by the high leukocytosis of this patient (561 G/L) within a context of chronic lymphocytic leukemia as well as by the fragility of these cells revealed by specific rules for samples transport between the clinical departments and the central laboratory. An efficient talk between biologist and clinician identified this phenomenon for this patient and avoid mistakenly initiation of treatment. This event allows us to recall the different causes leading to overestimate the true value of kaliema when samples are managed at the central laboratory, and to describe the care of patients with true hyperkalemia.

Recent advances in immunotherapy of B-CLL using ex vivo modified dendritic cells

Chronic lymphocytic leukemia (CLL) results from the relentless accumulation of small mature, slowly dividing, monoclonal B-lymphocytes. The clinical course is heterogeneous, some patients with aggressive form of the disease progressing rapidly with early death while others exhibit a more stable, possibly, non-progressing indolent type of the disease lasting many years. Despite progress in modern treatment modalities, relapse invariably occurs and disease still remains incurable. The clinical management of CLL is therefore challenging and considerable effort has been directed towards novel therapeutic strategies aimed at reducing minimal residual disease which can increase remission duration. Recent insight into the role of dendritic cells (DCs) as pivotal antigen presenting cells that initiate immune responses may provide the basis for generating more specific and effective immune responses. Ex-vivo modified and monocyte-derived DCs represents a promising approach within the context of CLL. However, understanding the relationship between DCs and the cellular immune response is crucial in devising strategies for manipulating immune responses. After a brief survey of general properties of DCs, this review focuses on the different approaches exploiting monocyte-derived DCs in CLL, which may help to design novel strategies for phase-I clinical trials.