The importance of IGHV mutational status in del(11q) and del(17p) chronic lymphocytic leukemia

Immunomolecular evaluation of dihydroartemisinin effects on apoptosis in chronic lymphocytic leukemia cell lines

INTRODUCTION

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has recently shown to induce apoptosis in many types of cancer cells. In this study, we aimed to determine the effects of DHA on apoptosis in human chronic lymphocytic leukemia (CLL) cell lines.

METHODS

The cells were treated separately and combined by DHA and Fludurabine (FLU) during 24, 48 and 72 hours. The cell viabilities determined by XTT method. Following separate and combined treatment of IC50 concentrations of DHA and FLU to the cells during 24 hours, the cells were analyzed by flow cytometry to determine the effects on apopotis staining with AnnexinV FITC and PI. mRNA and protein expression levels of TCTP, Mcl-1, Bcl-2, Bax and Caspase-3 were analyzed to find out the molecular mechanisms of apoptosis by using quantitative real-time PCR and flow cytometric methods.

RESULTS

Treatment with DHA alone or in combination with FLU induced apoptosis in a dose dependent manner in CLL cells. DHA alone was more effective than FLU alone or combined treatment with DHA and FLU. Our results suggest that Bcl-2 protein family member Bax was active in the apoptotic response of CLL cells after DHA treatment. Moreover, the apoptotic response induced by DHA was independent from the p53 mutation status of the CLL cells.

CONCLUSION

DHA might be a potential anti-cancer therapeutic for CLL.

Metabolic rewiring beyond Warburg in chronic lymphocytic leukemia: How much do we actually know?

Chronic Lymphocytic Leukemia (CLL) is the most common adult leukemia in the western world. CLL consists of the accumulation of malignant B-cells in the blood stream and homing tissues. Although treatable, this disease is not curable, and resistance or relapse is often present. In many cancers, the study of metabolic reprograming has uncovered novel targets that are already being exploited in the clinic. However, CLL metabolism is still poorly understood. The ability of CLL lymphocytes to adapt to diverse microenvironments is accompanied by modifications in cell metabolism, revealing the challenge of targeting the CLL lymphocytes present in all different compartments. Despite this, the study of CLL metabolism led to an ongoing clinical trial using glucose uptake and mitochondrial respiration inhibitors. In contrast, glutamine and fatty acid metabolism remain to be further exploited in CLL. Here, we summarize the present knowledge of CLL metabolism, as well as the metabolic influence of Myc, ATM and p53 on CLL lymphocytes.

The International Prognostic Index for Patients with Chronic Lymphocytic Leukemia Has the Higher Value in Predicting Overall Outcome Compared with the Barcelona-Brno Biomarkers Only Prognostic Model and the MD Anderson Cancer Center Prognostic Index

In recent years, new prognostic indexes (PIs) for chronic lymphocytic leukemia (CLL), which include clinical, biological, and genetic variables, have been validated, highlighting the MD Anderson Cancer Center prognostic index (MDACC PI), the CLL-international prognostic index (CLL-IPI), and the Barcelona-Brno biomarkers only prognostic model. The aim of this study is to compare the utility of these PIs in a cohort of Spanish patients. A retrospective analysis of 696 unselected CLL patients newly diagnosed and previously untreated from different Spanish institutions was performed. The MDACC PI, the CLL-IPI, and the biomarkers only PI were applied to these patients, and a comparison of the three PIs was performed. With a median follow-up time of 46 months, 394 patients were alive and 187 had received treatment. The median overall survival (OS) was 173 months and the median time to first therapy (TTFT) was 32 months. Significant differences were obtained in OS and TTFT for all subgroups when applying these PIs, with the CLL-IPI being the one with the higher c-index (0.676 for OS and 0.757 for TTFT). The three PIs were able to discriminate patients in different prognostic subgroups. In our cohort, the CLL-IPI showed higher power in predicting TTFT and OS.

Thompson P, Jain N, Luthra R, Quesada A, Sanchez-Petitto G, Ferrajoli A, Burger J, Kantarjian H, Cortes J, O’Brien S, Keating MJ, Estrov Z. The absolute percent deviation of IGHV mutation rather than a 98% cut-off predicts survival of chronic lymphocytic leukaemia patients treated with fludarabine, cyclophosphamide and rituximab

The degree of somatic hypermutation, determined as percent deviation of immunoglobulin heavy chain gene variable region sequence from the germline (IGHV%), is an important prognostic factor in chronic lymphocytic leukaemia (CLL). Currently, a cut-off of 2% deviation or 98% sequence identity to germline in IGHV sequence is routinely used to dichotomize CLL patients into mutated and unmutated groups. Because dissimilar IGHV% cut-offs of 1-5% were identified in different studies, we wondered whether no cut-off should be applied and IGHV% treated as a continuous variable. We analysed the significance of IGHV% in 203 CLL patients enrolled on the original frontline fludarabine, cyclophosphamide and rituximab (FCR) trial with a median of 10 years follow-up. Using the Cox Proportional Hazard model, IGHV% was identified as a continuous variable that is significantly associated with progression-free (PFS) and overall survival (OS) (P < 0·001). Furthermore, we validated this finding in 323 patients treated with FCR off-protocol and in the total cohort (n = 535). Multivariate analysis revealed a continuous trend. Higher IGHV% levels were incrementally associated with favorable PFS and OS in both FCR-treated cohorts (P < 0·001, both cohorts). Taken together, our data suggest that IGHV% is a continuous variable in CLL patients treated with FCR.

IGHV mutational status testing in chronic lymphocytic leukemia

As the therapeutic landscape for chronic lymphocytic leukemia (CLL) continues to expand, biological predictors of response to therapy are becoming increasingly important. One such predictive biomarker is the mutational status of the variable region of the immunoglobulin heavy chain (IGHV) gene, which is a powerful predictor of duration of response and overall survival with chemoimmunotherapy (CIT). As this test may influence choice of therapy between CIT and novel agents, it is critical that providers understand how mutational status is determined and the limitations of testing. Here, we describe the details of IGHV mutational status testing, highlighting the appropriate way to interpret this information and best apply it to the care of patients with CLL.

Chronic Lymphocytic Leukemia Prognostic Index: A New Integrated Scoring System to Predict the Time to First Treatment in Chinese Patients with Chronic Lymphocytic Leukemia

BACKGROUND

The established clinical staging systems (Rai/Binet) of chronic lymphocytic leukemia (CLL) cannot accurately predict the appropriate treatment of patients in the earlier stages. In the past two decades, several prognostic factors have been identified to predict the outcome of patients with CLL, but only a few studies investigated more markers together. To predict the time to first treatment (TTFT) in patients of early stages, we evaluated the prognostic role of conventional markers as well as cytogenetic abnormalities and combined them together in a new prognostic scoring system, the CLL prognostic index (CLL-PI).

METHODS

Taking advantage of a population of 406 untreated Chinese patients with CLL at early and advanced stage of disease, we identified the strongest prognostic markers of TTFT and, subsequently, in a cohort of 173 patients who had complete data for all 3 variables, we integrated the data of traditional staging system, cytogenetic aberrations, and mutational status of immunoglobulin heavy chain variable region (IGHV) in CLL-PI. The median follow-up time was 45 months and the end point was TTFT.

RESULTS

The median TTFT was 38 months and the 5-year overall survival was 80%. According to univariate analysis, patients of advanced Rai stages (P < 0.001) or with 11q- (P = 0.002), 17p- (P < 0.001), unmutated IGHV (P < 0.001), negative 13q- (P = 0.007) and elevated lactate dehydrogenase levels (P = 0.001) tended to have a significantly shorter TTFT. And subsequently, based on multivariate Cox regression analysis, three independent factors for TTFT were identified: advanced clinical stage (P = 0.002), 17p- (P = 0.050) and unmutated IGHV (P = 0.049). Applying weighted grading of these independent factors, a CLL-PI was constructed based on regression parameters, which could categorize four different risk groups (low risk [score 0], intermediate low [score 1], intermediate high [score 2] and high risk [score 3-6]) with significantly different TTFT (median TTFT of not reached (NR), 65.0 months, 36.0 months and 19.0 months, respectively, P < 0.001).

CONCLUSIONS

This study developed a weighted, integrated CLL-PI prognostic system of CLL patients which combines the critical genetic prognostic markers with traditional clinical stage. This novel modified PI system could be used to discriminate among groups and may help predict the TTFT and prognosis of patients with CLL.

Change in IgHV Mutational Status of CLL Suggests Origin From Multiple Clones

BACKGROUND

Fluorescence in situ hybridization and immunoglobulin (Ig) heavy-chain variable-region (IgHV) mutational status are used to predict outcome in chronic lymphocytic leukemia (CLL). Although DNA aberrations change over time, IgHV sequences and mutational status are considered stable.

PATIENTS AND METHODS

In a retrospective review, 409 CLL patients, between 2008 and 2015, had IgHV analysis: 56 patients had multiple analyses performed. Seven patients' IgHV results changed: 2 from unmutated to mutated and 5 from mutated to unmutated IgHV sequence.

RESULTS

Three concurrently changed their variable heavy-chain sequence. Secondary to allelic exclusion, 2 of the new variable heavy chains produced were biologically nonplausible.

CONCLUSION

The existence of these new nonplausible heavy-chain variable regions suggests either the CLL cancer stem-cell maintains the ability to rearrange a previously silenced IgH allele or more likely that the cancer stem-cell produced at least 2 subclones, suggesting that the CLL cancer stem cell exists before the process of allelic exclusion occurs.

Integrated CLL Scoring System, a New and Simple Index to Predict Time to Treatment and Overall Survival in Patients With Chronic Lymphocytic Leukemia

INTRODUCTION

Several prognostic factors have been identified to predict the outcome of patients with chronic lymphocytic leukemia (CLL), but only a few studies analyzed more markers together.

PATIENTS AND METHODS

Taking advantage of a population of 608 patients, we identified the strongest prognostic markers of survival and, subsequently, in a cohort of 212 patients we integrated data of cytogenetic lesions, IGHV mutational status, and CD38 expression in a new and easy scoring system we called the integrated CLL scoring system (ICSS). ICSS defines 3 groups of risk: (1) low risk (patients with 13q(-) or normal fluorescence in-situ hybridization analysis results, mutated IGHV, and CD38) (2) high risk (all 11q(-) or 17p(-) patients and/or all unmutated IGHV and CD38(+) patients); and (3) intermediate risk (all remaining patients).

RESULTS

Using only these 3 already available prognostic factors, we were able to properly redefine patients and better predict the clinical course of the disease.

CONCLUSION

ICSS could become a useful tool for CLL patients' management.

Prognosis and therapy of chronic lymphocytic leukemia and small lymphocytic lymphoma

Chronic lymphocytic leukemia (CLL) is characterized by a highly variable clinical course that has guided treatment principles in as much as anti-leukemic therapy is reserved for patients with active disease. This heterogeneity is somewhat dissected by prognostic markers, many of which represent pathogenic mechanisms. Recently, the introduction of highly active targeted agents and maturing data on predictive markers may lead to more individualized therapeutic approaches. In this chapter, we review key prognostic markers, current and emerging therapy, and will attempt to outline a future "where the two may connect".

Mutation status and immunoglobulin gene rearrangements in patients from northwest and central region of Spain with chronic lymphocytic leukemia

The aim of this study was to investigate the frequency and mutation status of the immunoglobulin heavy variable chain (IGHV) in a cohort of 224 patients from northwest and central region of Spain diagnosed with chronic lymphocytic leukemia (CLL), and to correlate it with cytogenetic abnormalities, overall survival (OS) and time to first treatment (TTFT). 125 patients had mutated IGHV, while 99 had unmutated IGHV. The most frequently used IGHV family was IGHV3, followed by IGHV1 and IGHV4. The regions IGHV3-30, IGHV1-69, IGHV3-23, and IGHV4-34 were the most commonly used. Only 3.1% of the patients belonged to the subfamily IGHV3-21 and we failed to demonstrate a worse clinical outcome in this subgroup. The IGHV4 family appeared more frequently with mutated pattern, similar to IGHV3-23 and IGHV3-74. By contrast, IGHV1-69 was expressed at a higher frequency in unmutated CLL patients. All the cases from IGHV3-11 and almost all from IGHV5-51 subfamily belonged to the group of unmutated CLL.

Hematopoietic stem cell transplantation for chronic lymphocytic leukemia

PURPOSE OF REVIEW

Although hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many aggressive hematologic malignancies, the role of HSCT in chronic lymphocytic leukemia (CLL) has remained controversial. Now in the era of improved conventional treatment and better prognostication of long-term outcome, a review of autologous and allogeneic HSCT in CLL treatment is warranted.

RECENT FINDINGS

Despite an improved disease-free survival in some patients, multiple, prospective, randomized autologous HSCT CLL trials fail to demonstrate an overall survival benefit as compared to conventional therapy. Allogeneic bone marrow transplantation, although limited by donor availability, can successfully eradicate CLL with adverse prognostic features. In the older CLL patients, nonmyeloablative allogeneic transplants are better tolerated than myeloablative transplants. Nonmyeloablative allogeneic transplants are less effective in heavily diseased burdened patients.

SUMMARY

Outside of a clinical protocol, autologous HSCT for CLL cannot be justified. Nonmyeloablative allogeneic transplantation should be considered in high-risk populations early in the disease process, when disease burden is most easily controlled. Alternative donor selection using haploidentical donors and posttransplantation cyclophosphamide has the potential to vastly increase the availability of curative therapy in CLL while retaining a low treatment-related toxicity.