The pathogenic relevance of the prognostic markers CD38 and CD49d in chronic lymphocytic leukemia

Empirical Study on Exploring the Role of CD180 and MD-1 Prognostic Indicators for the Chronic Lymphocytic Leukaemia (CLL) Disease

<b>Background and Objective:</b> Chronic Lymphocytic Leukaemia (CLL) is a frequent type of leukaemia disease. This study was focused on investigating the role of prognostic indicators, such as CD180 and MD-1 for Chronic Lymphocytic Leukaemia (CLL) pathogenesis because they involve cell signalling and proliferation. <b>Materials and Methods:</b> A total of 12 normal controls and 52 patients were taken to determine the expressions of CD180 and MD-1 with different variations in comparison with the IgVH (Immunoglobulin Heavy Chain variable region gene) mutational status, FISH (fluorescence <i>in situ</i> hybridization) and Rai staging. <b>Results:</b> The quantitative data findings were evident that CD180 and MD-1 expressions showed insignificant differences among CLL patients at the protein level based on SPSS results. On the contrary, they resulted in significant differences for subgroups of established biomarkers like Rai staging (stages 0, I, II and III), FISH (13q and non-13q deletions) and IgVH (mutated and unmutated). <b>Conclusion:</b> The CD180 and MD-1 have been used as prognostic indicators to evaluate the outcomes relevant to the cell cycle and survival rate of CLL cells.

Implementation of International Prognostic Index with flow cytometry immunophenotyping for better risk stratification of chronic lymphocytic leukemia

BACKGROUND

Current chronic lymphocytic leukemia (CLL) International Prognostic Index (IPI) stratifies patients based on clinical, molecular, and biochemical features; however, B-cell markers also influence CLL outcomes. Here, prognostic roles of CD11c, CD38, and CD49d were first evaluated, and then an immunophenotypic score was combined with CLL-IPI for risk stratification of CLL patients.

METHODS

A total of 171 CLL subjects were included, and surface marker expression was assessed by flow cytometry. Levels ≥30% were chosen as cut-off of positivity to a marker; then values of 1 (for CD11c and CD38) or 3 (for CD49d) were assigned and scores determined for each patient's clone immunophenotype.

RESULTS

CD49d positivity was significantly associated with simultaneous expression of CD11c and/or CD38, unmutated IGHV status, and higher β2-microglobulin levels compared to those with CD49d negativity. Moreover, CD49d⁺ patients experienced a shorter progression-free survival and time to treatment. When the immunophenotypic score was combined with CLL-IPI, patients with high-risk immunophenotype had a significantly lower time-to-treatment regardless CLL-IPI.

CONCLUSIONS

Our results suggested clinical utility of an integrated prognostic score for better risk stratification of CLL patients. These results require further validation in prospective larger studies.

Low CD49d expression in newly diagnosed chronic lymphocytic leukaemia may be associated with high-risk features and reduced treatment-free-intervals

This study was carried out to assess the prognostic power of low CD49d expression (≥10%) in newly diagnosed CLL patients using a previously described cohort. Eighty-five patients were included. Median age at diagnosis; 70 years (43-88); CD49d was expressed in 33/85 (38.8%); 23/33 (69.7%) at ≥30% referred to as 'HiCD49d' and 10/33 (30.3%) between 10 and 30% with a bimodal pattern on scatterplot analysis referred to as 'LoCD49d'. Eleven patients (12.9%) presented as Binet stage B, of whom 8 (72.7%) were CD49d+ (HiCD49d 7/8; LoCD49d 1/8). Seven of 81 patients (8.6%) were NOTCH1 mutated and all were CD49d+ (p ≤ .01). IgVH analysis was performed on 29 (87.8%) of the CD49d+ cases, of whom 21 (72.4%) were unmutated and 8 (27.6%) were mutated. CD38+/CD49d+ accounted for 11/20 (55%) (CD38+/HiCD49D: 9/11; CD38+/LoCD49D: 2/11). At 42 months, treatment had been initiated in 18/85 (21%) patients, of these 10/33 (30.3%) were CD49d+ versus 8/52 (15.4%) of the CD49d- group. The median treatment free interval for the CD49d+ group was 11 months (HiCD49d; 14.5 months, LoCD49d; 11 months) compared to 21.5 months for the CD49d- group. These findings suggest that the predictive value of CD49d expression is retained at expression levels down to 10%.

Identification of CD105 (endoglin) as novel risk marker in CLL

Several genetic and clinical markers are established as prognostic factors in chronic lymphocytic leukemia (CLL). However, additional markers are needed for risk stratification. Flow cytometric analysis is a mainstay of CLL diagnostics, thus identification of novel prognostic surface markers can improve risk assessment without increasing burden for patients and physicians. Furthermore, surface molecules preferentially expressed in high-risk cases could serve as therapeutic targets for immunotherapy. CD105 (endoglin) is a TGF-beta coreceptor and activates endothelial cells in healthy tissues and cancer. In addition, it is expressed on healthy hematopoietic precursors as well as lymphoid and myeloid leukemias. In acute myeloid leukemia (AML), a CD105 antibody is successfully applied in clinical studies. In CLL, mRNA expression of the CD105 gene ENG reportedly correlates with other risk factors but failed to show significant correlation with overall survival. However, CD105 protein expression in CLL has never been studied. We here analyzed CD105 surface expression on CLL cells from 71 patients by flow cytometry and report for the first time that substantial levels of CD105 are detectable on CLL cells in 70.4% of patients. Using receiver operating characteristics, we established a cutoff of 5.99% positive cells to distinguish between low and high CD105 levels, the latter correlating with decreased time to first treatment and overall survival. High CD105 expression further correlates with CD38 expression. Our study identified membrane expression of CD105 as a potential risk marker and therapeutic target in high-risk CLL. However, multivariant analyses of large cohorts should be performed in confirmatory studies.

Extrinsic interactions in the microenvironment in vivo activate an antiapoptotic multidrug-resistant phenotype in CLL

The Bcl-2 inhibitor venetoclax has yielded exceptional clinical responses in chronic lymphocytic leukemia (CLL). However, de novo resistance can result in failure to achieve negative minimal residual disease and predicts poor treatment outcomes. Consequently, additional proapoptotic drugs, such as inhibitors of Mcl-1 and Bcl-xL, are in development. By profiling antiapoptotic proteins using flow cytometry, we find that leukemic B cells that recently emigrated from the lymph node (CD69+/CXCR4Low) in vivo are enriched for cell clusters simultaneously overexpressing multiple antiapoptotic proteins (Mcl-1High/Bcl-xLHigh/Bcl-2High) in both treated and treatment-naive CLL patients. These cells exhibited antiapoptotic resistance to multiple BH-domain antagonists, including inhibitors of Bcl-2, Mcl-1, and Bcl-xL, when tested as single agents in a flow cytometry-based functional assay. Antiapoptotic multidrug resistance declines ex vivo, consistent with resistance being generated in vivo by extrinsic microenvironmental interactions. Surviving "persister" cells in patients undergoing venetoclax treatment are enriched for CLL cells displaying the functional and molecular properties of microenvironmentally induced multidrug resistance. Overcoming this resistance required simultaneous inhibition of multiple antiapoptotic proteins, with potential for unwanted toxicities. Using a drug screen performed using patient peripheral blood mononuclear cells cultured in an ex vivo microenvironment model, we identify novel venetoclax drug combinations that induce selective cytotoxicity in multidrug-resistant CLL cells. Thus, we demonstrate that antiapoptotic multidrug-resistant CLL cells exist in patients de novo and show that these cells persist during proapoptotic treatment, such as venetoclax. We validate clinically actionable approaches to selectively deplete this reservoir in patients.

Targeting CD38 is lethal to Breg-like chronic lymphocytic leukemia cells and Tregs, but restores CD8+ T-cell responses

Patients with chronic lymphocytic leukemia (CLL) are characterized by monoclonal expansion of CD5+CD23+CD27+CD19+κ/λ+ B lymphocytes and are clinically noted to have profound immune suppression. In these patients, it has been recently shown that a subset of B cells possesses regulatory functions and secretes high levels of interleukin 10 (IL-10). Our investigation identified that CLL cells with a CD19+CD24+CD38hi immunophenotype (B regulatory cell [Breg]-like CLL cells) produce high amounts of IL-10 and transforming growth factor β (TGF-β) and are capable of transforming naive T helper cells into CD4+CD25+FoxP3+ T regulatory cells (Tregs) in an IL-10/TGF-β-dependent manner. A strong correlation between the percentage of CD38+ CLL cells and Tregs was observed. CD38hi Tregs comprised more than 50% of Tregs in peripheral blood mononuclear cells (PBMCs) in patients with CLL. Anti-CD38 targeting agents resulted in lethality of both Breg-like CLL and Treg cells via apoptosis. Ex vivo, use of anti-CD38 monoclonal antibody (mAb) therapy was associated with a reduction in IL-10 and CLL patient-derived Tregs, but an increase in interferon-γ and proliferation of cytotoxic CD8+ T cells with an activated phenotype, which showed an improved ability to lyse patient-autologous CLL cells. Finally, effects of anti-CD38 mAb therapy were validated in a CLL-patient-derived xenograft model in vivo, which showed decreased percentage of Bregs, Tregs, and PD1+CD38hiCD8+ T cells, but increased Th17 and CD8+ T cells (vs vehicle). Altogether, our results demonstrate that targeting CD38 in CLL can modulate the tumor microenvironment; skewing T-cell populations from an immunosuppressive to immune-reactive milieu, thus promoting immune reconstitution for enhanced anti-CLL response.

Evaluation of prognostic variables in chronic lymphocytic leukemia and association with disease stage

The aim of the present study was to investigate different biological prognostic markers to identify high-risk patients with chronic lymphocytic leukemia (CLL) with a higher tumor burden, in order to ensure appropriate management. A total of 81 Egyptian patients with CLL were enrolled in the present study, with 75 healthy subjects serving as the control group. The expression of CD49d, CD38 and ZAP-70 in CLL cells was assessed using flow cytometry. The fluorescence in situ hybridization technique was employed to evaluate TP53 (del17p), ataxia-telangiectasia (del11q) and 13q14 (del13q14) genes and the presence of trisomy 12. The serological markers β2 microglobulin (B2M) and sCD23 were measured by ELISA. The CD49d gene was highly expressed in 25.9% and cytogenetic aberrations were observed in 66.6% of all recruited CLL patients. The patients were categorized according to the Binet staging system and a significant increase in the expression of sCD23, CD49d and ZAP-70 was detected in group C (P=0.008, 0.034 and 0.017, respectively) when compared to groups A and B. CD49d⁺ patients exhibited significantly higher expression of CD38 (P=0.002) and trisomy 12 (P=0.015) and lower expression of del13q14 (P=0.001). Patients who were CD49d⁺ with B2M>3.5 µg/ml exhibited higher total leukocyte count (P=0.048), higher absolute lymphocyte count (P=0.036), higher expression of CD38 (P=0.002) and trisomy 12 (P=0.034) and lower expression of del13q14 (P=0.002). Therefore, sCD23, CD49d and ZAP-70 may be considered as an optimal prognostic marker combination to be evaluated in the early stages of CLL and throughout disease management. Integrating both serological markers and CD49d expression by flow cytometry may add to the prognostic value of each marker alone and help identify high-risk patients with a higher tumor burden.

Therapeutic Options for Patients with TP53 Deficient Chronic Lymphocytic Leukemia: Narrative Review

Chronic lymphocytic leukemia (CLL), which is the most common type of leukemia in western countries in adults, is characterized by heterogeneity in clinical course, prognosis and response to the treatment. Although, in recent years a number of factors with probable prognostic value in CLL have been identified (eg NOTCH1, SF3B1 and BIRC-3 mutations, or evaluation of microRNA expression), TP53 aberrations are still the most important single factors of poor prognosis. It was found that approximately 30% of all TP53 defects are mutations lacking 17p13 deletion, whereas sole 17p13 deletion with the absence of TP53 mutation consists of 10% of all TP53 defects. The detection of del(17)(p13) and/or TP53 mutation is not a criterion itself for starting antileukemic therapy, but it is associated with an aggressive course of the disease and poor response to the standard chemoimmunotherapy. Treatment of patients with CLL harbouring TP53-deficiency requires drugs that promote cell death independently of TP53. Novel and smarter therapies revolutionize the treatment of del(17p) and/or aberrant TP53 CLL, but development of alternative therapeutic approaches still remains an issue of critical importance.

Cardiotoxicity of Novel Targeted Hematological Therapies

Chemotherapy-related cardiac dysfunction, also known as cardiotoxicity, is a group of drug-related adverse events negatively affecting myocardial structure and functions in patients who received chemotherapy for cancer treatment. Clinical manifestations can vary from life-threatening arrythmias to chronic conditions, such as heart failure or hypertension, which dramatically reduce quality of life of cancer survivors. Standard chemotherapy exerts its toxic effect mainly by inducing oxidative stress and genomic instability, while new targeted therapies work by interfering with signaling pathways important not only in cancer cells but also in myocytes. For example, Bruton’s tyrosine kinase (BTK) inhibitors interfere with class I phosphoinositide 3-kinase isoforms involved in cardiac hypertrophy, contractility, and regulation of various channel forming proteins; thus, off-target effects of BTK inhibitors are associated with increased frequency of arrhythmias, such as atrial fibrillation, compared to standard chemotherapy. In this review, we summarize current knowledge of cardiotoxic effects of targeted therapies used in hematology.

CD49d promotes disease progression in chronic lymphocytic leukemia: new insights from CD49d bimodal expression

CD49d is a remarkable prognostic biomarker of chronic lymphocytic leukemia (CLL). The cutoff value for the extensively validated 30% of positive CLL cells is able to separate CLL patients into 2 subgroups with different prognoses, but it does not consider the pattern of CD49d expression. In the present study, we analyzed a cohort of 1630 CLL samples and identified the presence of ∼20% of CLL cases (n = 313) characterized by a bimodal expression of CD49d, that is, concomitant presence of a CD49d+ subpopulation and a CD49d- subpopulation. At variance with the highly stable CD49d expression observed in CLL patients with a homogeneous pattern of CD49d expression, CD49d bimodal CLL showed a higher level of variability in sequential samples, and an increase in the CD49d+ subpopulation over time after therapy. The CD49d+ subpopulation from CD49d bimodal CLL displayed higher levels of proliferation compared with the CD49d- cells; and was more highly represented in the bone marrow compared with peripheral blood (PB), and in PB CLL subsets expressing the CXCR4dim/CD5bright phenotype, known to be enriched in proliferative cells. From a clinical standpoint, CLL patients with CD49d bimodal expression, regardless of whether the CD49d+ subpopulation exceeded the 30% cutoff or not, experienced clinical behavior similar to CD49d+ CLL, both in chemoimmunotherapy (n = 1522) and in ibrutinib (n = 158) settings. Altogether, these results suggest that CD49d can drive disease progression in CLL, and that the pattern of CD49d expression should also be considered to improve the prognostic impact of this biomarker in CLL.

Isatuximab Acts Through Fc-Dependent, Independent, and Direct Pathways to Kill Multiple Myeloma Cells

Isatuximab is a monoclonal antibody targeting the transmembrane receptor and ectoenzyme CD38, a protein highly expressed on hematological malignant cells, including those in multiple myeloma (MM). Upon binding to CD38-expressing MM cells, isatuximab is thought to induce tumor cell killing via fragment crystallizable (Fc)-dependent mechanisms, including antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement-dependent cytotoxicity (CDC), as well as via direct Fc-independent mechanisms. Here, these mechanisms of action were investigated in MM and diffuse large B-cell lymphoma (DLBCL) cell lines, as well as in peripheral blood mononuclear cells derived from healthy donors, and in MM patient-derived samples. Our findings show that isatuximab-mediated cytotoxicity occurred primarily via ADCC and ADCP in MM cell lines and via ADCC and apoptosis in DLBCL cell lines expressing high levels of CD38. We identified the programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) pathway and MM cell-secreted transforming growth factor-beta (TGF-β) as tumor cell-related features that could suppress CD38-mediated ADCC. Furthermore, we established that isatuximab can directly activate natural killer (NK) cells and promote NK cell-mediated cytotoxicity via crosslinking of CD38 and CD16. Finally, isatuximab-induced CDC was observed in cell lines with high CD38 receptor density (>250,000 molecules/cell) and limited expression of inhibitory complement regulatory proteins (CD46, CD55, and CD59; <50,000 molecules/cell). Taken together, our findings highlight mechanistic insights for isatuximab and provide support for a range of combination therapy approaches that could be tested for isatuximab in the future.

Chemokine Receptors CCR1 and CCR2 on Peripheral Blood Mononuclear Cells of Newly Diagnosed Patients with the CD38-Positive Chronic Lymphocytic Leukemia

Chemokines and their receptors direct migration and infiltration of immune cells. CCR1 and CCR2 maintain sequence similarity and respond to a number of the same chemokines secreted in lymphoid organs. Expression of CD38 on leukemic cells has been associated with poor clinical outcomes in patients with chronic lymphocytic leukemia (CLL) and is considered as the negative predictor of progression. In our study of newly diagnosed CLL patients, which included 39 CD38-positive and 22 CD38-negative patients, CCR1 and/or CCR2 were always detected, using flow cytometry, on the peripheral blood (PB) CD19+CD5+ lymphocytes in patients with >30% of the CD38+ CD19+CD5+ lymphocytes (n = 16). Spearman's rank correlation analysis determined correlations between the frequency of the CCR1- and CCR2-expressing PB CD19+CD5+ lymphocytes and the frequency of the CD38-positive CD19+CD5+ lymphocytes (rs = 0.50 and rs = 0.38, respectively). No significant correlations were observed between ZAP70 mRNA expression levels in PB mononuclear cells and the frequency of the circulating CCR1+ or CCR2+ CD19+CD5+ lymphocytes. Further association studies are needed to verify prognostic relevance of the CCR1/CCR2 expression on leukemic cells in CLL patients at diagnosis. We suggest that CCR1/CCR2 signaling pathways could represent attractive targets for development of CLL anti-progression therapeutics.

Aptamers and Antisense Oligonucleotides for Diagnosis and Treatment of Hematological Diseases

Aptamers or chemical antibodies are single-stranded DNA or RNA oligonucleotides that bind proteins and small molecules with high affinity and specificity by recognizing tertiary or quaternary structures as antibodies. Aptamers can be easily produced in vitro through a process known as systemic evolution of ligands by exponential enrichment (SELEX) or a cell-based SELEX procedure. Aptamers and modified aptamers, such as slow, off-rate, modified aptamers (SOMAmers), can bind to target molecules with less polar and more hydrophobic interactions showing slower dissociation rates, higher stability, and resistance to nuclease degradation. Aptamers and SOMAmers are largely employed for multiplex high-throughput proteomics analysis with high reproducibility and reliability, for tumor cell detection by flow cytometry or microscopy for research and clinical purposes. In addition, aptamers are increasingly used for novel drug delivery systems specifically targeting tumor cells, and as new anticancer molecules. In this review, we summarize current preclinical and clinical applications of aptamers in malignant and non-malignant hematological diseases.

An Updated Perspective on Current Prognostic and Predictive Biomarkers in Chronic Lymphocytic Leukemia in the Context of Chemoimmunotherapy and Novel Targeted Therapy

Chronic lymphocytic leukemia (CLL) is a heterogeneous disease with a variable clinical course. Novel biomarkers discovered over the past 20 years have revolutionized the way clinicians approach prognostication and treatment especially in the chemotherapy-free era. Herein, we review the best established prognostic and predictive biomarkers in the setting of chemoimmunotherapy (CIT) and novel targeted therapy. We propose that TP53 disruption (defined as either TP53 mutation or chromosome 17p deletion), unmutated immunoglobulin heavy chain variable region gene status (UM IGHV), NOTCH1 mutation, and CD49d expression are the strongest prognosticators of disease progression and overall survival in the field of novel biomarkers including recurrent gene mutations. We also highlight the predictive role of TP53 disruption, UM IGHV, and NOTCH1 mutation in the setting of CIT and TP53 disruption and CD49d expression in the setting of novel targeted therapy employing B-cell receptor (BCR) and B-cell lymphoma-2 (BCL2) inhibition. Finally, we discuss future directions in the field of biomarker development to identify those with relapsed/refractory disease at risk for progression despite treatment with novel therapies.

Integrative analysis of spontaneous CLL regression highlights genetic and microenvironmental interdependency in CLL

Spontaneous regression is a recognized phenomenon in chronic lymphocytic leukemia (CLL) but its biological basis remains unknown. We undertook a detailed investigation of the biological and clinical features of 20 spontaneous CLL regression cases incorporating phenotypic, functional, transcriptomic, and genomic studies at sequential time points. All spontaneously regressed tumors were IGHV-mutated with no restricted IGHV usage or B-cell receptor (BCR) stereotypy. They exhibited shortened telomeres similar to nonregressing CLL, indicating prior proliferation. They also displayed low Ki-67, CD49d, cell-surface immunoglobulin M (IgM) expression and IgM-signaling response but high CXCR4 expression, indicating low proliferative activity associated with poor migration to proliferation centers, with these features becoming increasingly marked during regression. Spontaneously regressed CLL displayed a transcriptome profile characterized by downregulation of metabolic processes as well as MYC and its downstream targets compared with nonregressing CLL. Moreover, spontaneous regression was associated with reversal of T-cell exhaustion features including reduced programmed cell death 1 expression and increased T-cell proliferation. Interestingly, archetypal CLL genomic aberrations including HIST1H1B and TP53 mutations and del(13q14) were found in some spontaneously regressing tumors, but genetic composition remained stable during regression. Conversely, a single case of CLL relapse following spontaneous regression was associated with increased BCR signaling, CLL proliferation, and clonal evolution. These observations indicate that spontaneously regressing CLL appear to undergo a period of proliferation before entering a more quiescent state, and that a complex interaction between genomic alterations and the microenvironment determines disease course. Together, the findings provide novel insight into the biological processes underpinning spontaneous CLL regression, with implications for CLL treatment.

Expression and function of phosphoinositide 3-kinase delta in mesenchymal stromal cells from normal and leukaemic bone marrow

Within lymphoid tissues, chronic lymphocytic leukaemia (CLL) cells interact with mesenchymal stromal cells (MSC). Inhibitors of phosphoinositide 3-kinase delta (PI3Kδ) cause release of CLL cells from lymphoid tissues into blood. PI3Kδ inhibitors are thought to target only CLL and other immune cells because PI3Kδ expression is restricted to haematopoietic cells. We found that PI3Kδ is unexpectedly expressed in primary MSC derived from CLL patients and healthy donors. PI3Kδ inhibition in MSC using idelalisib or duvelisib significantly reduced their ability to support CLL migration and adhesion. These observations provide the first evidence that PI3Kδ is expressed and functional in CLL MSC.

Molecular Players in Hematologic Tumor Cell Trafficking

The trafficking of neoplastic cells represents a key process that contributes to progression of hematologic malignancies. Diapedesis of neoplastic cells across endothelium and perivascular cells is facilitated by adhesion molecules and chemokines, which act in concert to tightly regulate directional motility. Intravital microscopy provides spatio-temporal views of neoplastic cell trafficking, and is crucial for testing and developing therapies against hematologic cancers. Multiple myeloma (MM), chronic lymphocytic leukemia (CLL), and acute lymphoblastic leukemia (ALL) are hematologic malignancies characterized by continuous neoplastic cell trafficking during disease progression. A common feature of these neoplasias is the homing and infiltration of blood cancer cells into the bone marrow (BM), which favors growth and survival of the malignant cells. MM cells traffic between different BM niches and egress from BM at late disease stages. Besides the BM, CLL cells commonly home to lymph nodes (LNs) and spleen. Likewise, ALL cells also infiltrate extramedullary organs, such as the central nervous system, spleen, liver, and testicles. The α4β1 integrin and the chemokine receptor CXCR4 are key molecules for MM, ALL, and CLL cell trafficking into and out of the BM. In addition, the chemokine receptor CCR7 controls CLL cell homing to LNs, and CXCR4, CCR7, and CXCR3 contribute to ALL cell migration across endothelia and the blood brain barrier. Some of these receptors are used as diagnostic markers for relapse and survival in ALL patients, and their level of expression allows clinicians to choose the appropriate treatments. In CLL, elevated α4β1 expression is an established adverse prognostic marker, reinforcing its role in the disease expansion. Combining current chemotherapies with inhibitors of malignant cell trafficking could represent a useful therapy against these neoplasias. Moreover, immunotherapy using humanized antibodies, CAR-T cells, or immune check-point inhibitors together with agents targeting the migration of tumor cells could also restrict their survival. In this review, we provide a view of the molecular players that regulate the trafficking of neoplastic cells during development and progression of MM, CLL, and ALL, together with current therapies that target the malignant cells.

In contrast to high CD49d, low CXCR4 expression indicates the dependency of chronic lymphocytic leukemia (CLL) cells on the microenvironment

CD49d and CXCR4 are key determinants of interactions between chronic lymphocytic leukemia (CLL) tumor cells and their microenvironment. In this study, we investigated the effect of CD49d and CXCR4 expressions on survival of CLL cells. Primary CLL cells were cultured with CD49d ligand, VCAM-1, or bone marrow stromal cells (BMSCs); then, apoptosis and immunophenotype analyses were performed. VCAM-1 treatment could not induce direct apoptosis protection or immunophenotype change on the CD49d-expressing CLL cells, but resulted in actin reorganization. The BMSC-induced apoptosis protection was independent from the presence of CD49d expression of CLL cells, but showed an inverse correlation with their CXCR4 expression level. We suppose that CD49d contributes to enhanced survival of leukemic cells by mediating migration to the protective microenvironment, not by direct prevention of apoptosis. Moreover, CLL cells with low CXCR4 expression represent a subpopulation that is more dependent on the microenvironmental stimuli for survival, and show increased "death by neglect" when separated from the supportive niche.

Morphological, immunophenotypic, and genetic features of chronic lymphocytic leukemia with trisomy 12: a comprehensive review

Chronic lymphocytic leukemia is an extremely heterogeneous disease and prognostic factors such as chromosomal abnormalities are important predictors of time to first treatment and survival. Trisomy 12 is the second most frequent aberration detected by fluorescence in situ hybridization at the time of diagnosis (10–25%), and it confers an intermediate prognostic risk, with a median time to first treatment of 33 months and a median overall survival of 114 months. Here, we review the unique morphological, immunophenotypic, and genetic characteristics of patients with chronic lymphocytic leukemia and trisomy 12. These patients carry a significantly higher expression of CD19, CD22, CD20, CD79b, CD24, CD27, CD38, CD49d, sIgM, sIgk, and sIgλ and lower expression of CD43 compared with patients with normal karyotype. Circulating cells show increased expression of the integrins CD11b, CD18, CD29, and ITGB7, and of the adhesion molecule CD323. Patients with chronic lymphocytic leukemia and trisomy 12 frequently have unmutated IGHV, ZAP-70 positivity, and closely homologous stereotyped B-cell receptors. They rarely show TP53 mutations but frequently have NOTCH1 mutations, which can be identified in up to 40% of those with a rapidly progressive clinical course.

Subclones in B-lymphoma cell lines: isogenic models for the study of gene regulation

Genetic heterogeneity though common in tumors has been rarely documented in cell lines. To examine how often B-lymphoma cell lines are comprised of subclones, we performed immunoglobulin (IG) heavy chain hypermutation analysis. Revealing that subclones are not rare in B-cell lymphoma cell lines, 6/49 IG hypermutated cell lines (12%) consisted of subclones with individual IG mutations. Subclones were also identified in 2/284 leukemia/lymphoma cell lines exhibiting bimodal CD marker expression. We successfully isolated 10 subclones from four cell lines (HG3, SU-DHL-5, TMD-8, U-2932). Whole exome sequencing was performed to molecularly characterize these subclones. We describe in detail the clonal structure of cell line HG3, derived from chronic lymphocytic leukemia. HG3 consists of three subclones each bearing clone-specific aberrations, gene expression and DNA methylation patterns. While donor patient leukemic cells were CD5+, two of three HG3 subclones had independently lost this marker. CD5 on HG3 cells was regulated by epigenetic/transcriptional mechanisms rather than by alternative splicing as reported hitherto. In conclusion, we show that the presence of subclones in cell lines carrying individual mutations and characterized by sets of differentially expressed genes is not uncommon. We show also that these subclones can be useful isogenic models for regulatory and functional studies.

Composite Lymphoma as Co-occurrence of Advanced Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma Carrying Trisomy 12 and t(14;18) and Peripheral T-cell Lymphoma

Composite lymphoma is defined as the co-occurrence of two types of lymphoma, comprising 1-4% of lymphomas, and the association of B-cell-type chronic lymphocytic leukemia (B-CLL)/small lymphocytic lymphoma and peripheral T-cell lymphoma (PTCL) is rare. Here, we report a case (77-year-old woman) of advanced B-CLL complicated by newly appearing PTCL. Two years after the onset of B-CLL, CLL cells acquired CD38 antigen expression and the disease entity became CLL/prolymphocytic leukemia. Trisomy 12 and t(14;18) karyotypes were observed. Five years after the onset of B-CLL, large abnormal cells with convoluted nuclei appeared in the peripheral blood and rapidly increased in number. These cells were positive for CD3, CD4, CD5, CD30 (partially), CD56, and αβ-type T-cell receptor (TCR), in which PCR demonstrated monoclonal TCR-γ gene rearrangement. An additional diagnosis of PTCL, not otherwise specified was made. We treated her with an R-CHOP regimen, resulting in the marked reduction of B-CLL cells but progressive PTCL. Brentuximab vedotin had a transient effect, but the patient died of sepsis due to residual PTCL and pancytopenia. This case is highly informative for tumor biology of B-CLL in terms of emergence of both chromosomal abnormalities and PTCL with progression of this leukemia.

Blockade of CD38 diminishes lipopolysaccharide-induced macrophage classical activation and acute kidney injury involving NF-κB signaling suppression

The CD38, possessing ADP-ribosyl cyclase (ADPR-cyclase) and cyclic ADP-ribose hydrolase (cADPR-hydrolase), is able to regulate a variety of cellular activities. However, the role and mechanisms for CD38 in macrophage activation and sepsis-induced acute kidney injury (AKI) remain to be determined. Here we report that in cultured macrophages, Lipopolysaccharide (LPS) could upregulate CD38 expression in time and dose dependent manner. Knocking down or blockade of CD38 in macrophages could inhibit LPS-induced macrophage M1 polarization accompanied by diminished NF-κB signaling activation. In mouse model with LPS-induced acute kidney injury, blocking CD38 with quercetin could significantly relieve kidney dysfunction, kidney pathological changes as well as inflammatory cell accumulation. Similar to those in the cultured cells, quercetin could inhibit macrophage M1 polarization and NF-κB signaling activation in macrophages from kidneys and spleens in mice after LPS injection. Together, these results demonstrate that CD38 mediates LPS-induced macrophage activation and AKI, which may be treated as a therapeutic target for sepsis-induced AKI in patients.

CD38 enhances the proliferation and inhibits the apoptosis of cervical cancer cells by affecting the mitochondria functions

Cervical cancer is one of the most common malignant tumors in women all over the world. The exact mechanism of occurrence and development of cervical cancer has not been fully elucidated. CD38 is a type II transmembrane glycoprotein, which was found to mediate diverse activities, including signal transduction, cell adhesion, and cyclic ADP-ribose synthesis. Here, we reported that CD38 promoted cell proliferation and inhibited cell apoptosis in cervical cancer cells by affecting the mitochondria functions. We established stable cervical cancer cell lines with CD38 over-expressed. CCK8 assay and colony formation assay indicated that CD38 promoted cervical cancer cell proliferation. Nude mouse tumorigenicity assay showed that CD38 significantly promotes tumor growth in vivo. CD38 also induced S phase accumulation in cell cycle analysis and suppressed cell apoptosis in cervical cancer cells. Meanwhile, flow cytometry analysis of mitochondria functions suggested that CD38 decreased intracellular Ca²⁺ levels in cervical cancer cells and CD38 was involved in down-regulation of ROS levels and prevented mitochondrial apoptosis in cervical cancer cells. The percentage of cells with loss of mitochondrial membrane potential (Δψm) in CD38-overexpressed cervical cancer cells was less than control groups. Furthermore, we found an up-regulation of MDM2, cyclinA1, CDK4, cyclinD1, NF-kB P65, c-rel, and a downregulation of P53, P21, and P38 by Western blot analysis. These results indicated that CD38 enhanced the proliferation and inhibited the apoptosis of cervical cancer cells by affecting the mitochondria functions.

Diagnosis of chronic lymphoproliferative disorders by flow cytometry using four-color combinations for immunophenotyping: A proposal of the brazilian group of flow cytometry (GBCFLUX)

BACKGROUND

Multiparametric flow cytometry (MFC) is a powerful tool for the diagnosis of hematological malignancies and has been useful for the classification of chronic lymphoproliferative disorders (CLPD) according to the WHO criteria. Following the purposes of the Brazilian Group of Flow Cytometry (GBCFLUX), the aim of this report was to standardize the minimum requirements to achieve an accurate diagnosis in CLPDs, considering the different economic possibilities of the laboratories in our country. Most laboratories in Brazil work with 4-fluorescence flow cytometers, which is why the GBCFLUX CLPD Committee has proposed 4-color monoclonal antibody (MoAb) panels.

METHODS/RESULTS

Panels for screening and diagnosis in B, T and NK lymphoproliferative disorders were developed based on the normal differentiation pathways of these cells and the most frequent phenotypic aberrations. Important markers for prognosis and for minimal residual disease (MRD) evaluation were also included. The MoAb panels presented here were designed based on the diagnostic expertise of the participating laboratories and an extensive literature review.

CONCLUSION

The 4-color panels presented to aid in the diagnosis of lymphoproliferative neoplasms by GBCFLUX aim to provide clinical laboratories with a systematic, step-wise, cost-effective, and reproducible approach to obtain an accurate immunophenotypic diagnosis of the most frequent of these disorders. © 2016 International Clinical Cytometry Society.

Hyaluronic Acid in Vascular and Immune Homeostasis during Normal Pregnancy and Preeclampsia

Preeclampsia (PE) is a multisystem pathologic state that clinically manifests itself after the 20th week of pregnancy. It is characterized by high maternal and perinatal morbidity and mortality. According to modern concepts, the impairment of trophoblast invasion into maternal spiral arteries, leading to the development of ischemia in placenta, is considered to be the major pathogenetic factor of PE development. Ischemic lesions initiate the development of a systemic inflammatory response (SIR) and endothelial dysfunction, which is the main cause of the multiple organ failure in PE. Some data has appear indicating the importance of a glycans-forming endothelial glycocalyx and extracellular matrix (ECM) for placenta morphogenesis, as well as their role in the regulation of vascular permeability and vascular tone in hypertension disorders and, in particular, PE. Since intact glycocalyx and ECM are considered to be the major factors that maintain the physiological vascular tone and adequate intercellular interactions, their value in PE pathogenesis is underestimated. This review is focused on hyaluronic acid (HA) as the key glycan providing the organization and stabilization of the ECM and glycocalyx, its distribution in tissues in the case of presence or absence of placental pathology, as well as on the regulatory function of hyaluronic acids of various molecular weights in different physiological and pathophysiological processes. The summarized data will provide a better understanding of the PE pathogenesis, with the main focus on glycopathology.

CD49d shows superior performance characteristics for flow cytometric prognostic testing in chronic lymphocytic leukemia/small lymphocytic lymphoma

BACKGROUND

CD49d is emerging as a powerful adverse prognostic marker in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). However, flow cytometric testing for CD49d has not yet been widely adopted in the United States, in part due to the lack of establishment of its performance characteristics in the clinical setting, especially in comparison with the more common CLL/SLL prognostic markers CD38 and ZAP-70.

METHODS

CD49d expression levels in 124 CLL/SLL cases were assessed among peripheral blood (PB), bone marrow (BM), and lymph node (LN) specimens and correlated with available CD38 and ZAP-70 expression and cytogenetic findings. For 10 PB/BM specimens, the stability of CD49d, CD38, and ZAP-70 expression was assessed at <24 hours, 48 hours, 72 hours, and 96 hours.

RESULTS

39% (28 of 71) PB, 56% (18 of 32) BM, and 71% (15 of 21) LN involved by CLL/SLL were CD49d+, using a ≥30% threshold. The mean for the CD49d+ cases was 2.8 standard deviations (SD) above the cutoff for positivity, compared with 1.7 SD for CD38 and 1.1 SD for ZAP-70. CD49d demonstrated the lowest mean SD (0.91) and coefficient of variation (CV) (8.0%) compared with CD38 (SD = 2.1, CV = 10.4%) and ZAP-70 (SD = 9.8, CV = 40.5%) in stability studies over a 96-hours time period. CD49d+ CLL/SLL correlated with trisomy 12 (P = 0.025) and lack of isolated deletion (13q) (P = 0.005). CD38+ CLL/SLL correlated with deletion (11q) (P = 0.025). ZAP-70 did not correlate with any underlying cytogenetic abnormality.

CONCLUSIONS

CD49d is a robust adverse prognostic marker in CLL/SLL with superior performance characteristics. © 2016 International Clinical Cytometry Society.

Adhesion molecules expression in CLL: Potential impact on clinical and hematological parameters

BACKGROUND

B-cell chronic lymphocytic leukemia (CLL) is marked by the accumulation of CD5+ B lymphocytes within the blood, bone marrow (BM), and secondary lymphoid tissues. Abnormalities in the expression and function of cell adhesion molecules may account for the patterns of intra-nodal growth and hematogenous spread of the malignant cells. Chemokines and integrin-mediated adhesion and trans-endothelial migration (TEM) are central aspects in trafficking and retention of hematopoietic cells in the BM and lymphoid organs.

AIM OF THE WORK

This work was conducted to study adhesion molecules status in CLL and its potential impact on both hematological and clinical parameters.

PATIENTS AND METHODS

The study included 78 newly diagnosed CLL patients. Immunophenotyping was performed on peripheral blood using the chronic lymphoid panel. Adhesion molecules (CD11a, CD11b, CD49d, CD49C, CD29 and CD38) were tested using monoclonal antibodies and analyzed by Flow Cytometry.

RESULTS

Positive correlation was encountered between adhesion molecules: CD38 with CD49d (r=0.25, p=0.028), CD11a with CD11b, CD49d and CD29 (r=0.394, p=0.001; r=0.441, p=<0.01 and r=0.446, p<0.01 respectively) and CD29 with CD49c and CD49d (r=0.437, p<0.01; r=0.674, p<0.01 respectively). CD49c showed negative correlation with Rai staging (r=-0.269, p=0.033). CD11a and CD29 showed a significant relation with splenomegaly (p=0.04 and 0.03 respectively) and CD49d showed a significant relation with lymphadenopathy (p=0.02).

CONCLUSION

The level of different adhesion molecules expression in CLL is apparently reflected on the potential migratory behavior of the leukemic cells to different organs.

The Role of CD44 in the Pathophysiology of Chronic Lymphocytic Leukemia

CD44 interactions with hyaluronan (HA) play a key role in various malignancies, supporting tumor cell migration, adhesion, and survival. In contrast to solid tumors, the expression of CD44 standard and variant forms and their functional interplay with HA is less understood in hematological malignancies. Chronic lymphocytic leukemia (CLL) is a highly abundant B-cell malignancy with a well coordinated balance between cell cycle-arrest and proliferation of tumor subpopulations. The long-term survival and proliferation of CLL cells requires their dynamic interactions with stromal and immune cells in lymphoid organs. Interactions of HA with CD44 and HA-mediated motility receptor (RHAMM) contribute to CLL cell localization, and hence CLL pathophysiology, by shaping homing, interstitial migration, and adhesion of the tumor cells. CD44 can complex with key prognostic factors of CLL, particularly CD38 and CD49d, bridging the gap between prognosis and cellular function. Here, we review the current evidence for the individual and associated contributions of CD44 to CLL pathophysiology, the dynamic functional regulation of CD44 upon CLL cell activation, and possible therapeutic strategies targeting CD44 in CLL.

Mucosal-associated invariant T cell is a potential marker to distinguish fibromyalgia syndrome from arthritis

BACKGROUND

Fibromyalgia (FM) is defined as a widely distributed pain. While many rheumatologists and pain physicians have considered it to be a pain disorder, psychiatry, psychology, and general medicine have deemed it to be a syndrome (FMS) or psychosomatic disorder. The lack of concrete structural and/or pathological evidence has made patients suffer prejudice that FMS is a medically unexplained symptom, implying inauthenticity. Furthermore, FMS often exhibits comorbidity with rheumatoid arthritis (RA) or spondyloarthritis (SpA), both of which show similar indications. In this study, disease specific biomarkers were sought in blood samples from patients to facilitate objective diagnoses of FMS, and distinguish it from RA and SpA.

METHODS

Peripheral blood mononuclear cells (PBMCs) from patients and healthy donors (HD) were subjected to multicolor flow cytometric analysis. The percentage of mucosal-associated invariant T (MAIT) cells in PBMCs and the mean fluorescent intensity (MFI) of cell surface antigen expression in MAIT cells were analyzed.

RESULTS

There was a decrease in the MAIT cell population in FMS, RA, and SpA compared with HD. Among the cell surface antigens in MAIT cells, three chemokine receptors, CCR4, CCR7, and CXCR1, a natural killer (NK) receptor, NKp80, a signaling lymphocyte associated molecule (SLAM) family, CD150, a degrunulation marker, CD107a, and a coreceptor, CD8β emerged as potential biomarkers for FMS to distinguish from HD. Additionally, a memory marker, CD44 and an inflammatory chemokine receptor, CXCR1 appeared possible markers for RA, while a homeostatic chemokine receptor, CXCR4 deserved for SpA to differentiate from FMS. Furthermore, the drug treatment interruption resulted in alternation of the expression of CCR4, CCR5, CXCR4, CD27, CD28, inducible costimulatory molecule (ICOS), CD127 (IL-7 receptor α), CD94, NKp80, an activation marker, CD69, an integrin family member, CD49d, and a dipeptidase, CD26, in FMS.

CONCLUSIONS

Combined with the currently available diagnostic procedures and criteria, analysis of MAIT cells offers a more objective standard for the diagnosis of FMS, RA, and SpA, which exhibit multifaceted and confusingly similar clinical manifestations.

Second cancers and Richter transformation are the leading causes of death in patients with trisomy 12 chronic lymphocytic leukemia

BACKGROUND

Trisomy 12 (+12) is detected by fluorescence in-situ hybridization (FISH) analysis in up to 20% of patients with chronic lymphocytic leukemia (CLL). Patients with +12 are known to have unique features and to carry an intermediate prognosis.

PATIENTS AND METHODS

In order to better define this large group, we reviewed the characteristics of 250 untreated patients with +12.

RESULTS

When compared to 516 untreated patients negative for +12 by FISH, patients with +12 showed a higher incidence of thrombocytopenia, Richter transformation, and second malignant neoplasms (SMN), in addition to the expected increased rate of CD38 positivity and atypical immunophenotype. At a median follow-up of 51 months, 57% of patients needed first-line treatment; median time to first treatment was 38 months, and on multivariate analysis (MVA), it was found to be shorter in patients with advanced Rai stage, palpable splenomegaly, and deletion of 14q by conventional cytogenetic analysis. The overall response rate with first-line treatment was 94%. The median failure-free survival has not been reached, but on MVA, it was found to be shorter in patients whose disease responded in a manner other than complete remission or with FISH negativity for deletion 13q. The median overall survival for the entire group has not been reached, but MVA revealed it to be shorter in patients with an absolute lymphocyte count of > 30 × 10(9)/L or who developed SMN. Eighteen deaths have been observed so far, and Richter transformation and SMN were the leading causes of death (3 and 6, respectively).

CONCLUSION

Patients with +12 CLL show characteristic clinical and biologic features, and may benefit from increased surveillance for second cancers.

Trisomy 12 chronic lymphocytic leukemia cells exhibit upregulation of integrin signaling that is modulated by NOTCH1 mutations

The leukocyte adhesion cascade is important in chronic lymphocytic leukemia (CLL), as it controls migration of malignant cells into the pro-survival lymph node microenvironment. Circulating trisomy 12 CLL cells have increased expression of the integrins CD11a and CD49d, as well as CD38, but the tissue expression of these and other molecules, and the functional and clinical sequelae of these changes have not been described. Here, we demonstrate that circulating trisomy 12 CLL cells also have increased expression of the integrins CD11b, CD18, CD29, and ITGB7, and the adhesion molecule CD323. Notably, there was reduced expression of CD11a, CD11b, and CD18 in trisomy 12 cases with NOTCH1 mutations compared with wild type. Trisomy 12 cells also exhibit upregulation of intracellular integrin signaling molecules CALDAG-GEFI, RAP1B, and Ras-related protein ligand, resulting in enhanced very late antigen-4 [VLA-4] directed adhesion and motility. CD38 expression in CLL has prognostic significance, but the increased CD38 expression in trisomy 12 CLL cells must be taken into account in this subgroup, and the threshold of CD38 positivity should be raised to 40% for this marker to retain its prognostic value. In conclusion, trisomy 12 CLL cells exhibit functional upregulation of integrin signaling, with β2-integrin expression being modulated by NOTCH1 mutation status.