Clinico-Biological Implications of Modified Levels of Cytokines in Chronic Lymphocytic Leukemia: A Possible Therapeutic Role

Increased Frequency of Circulating Activated FOXP3+ Regulatory T Cell Subset in Patients with Chronic Lymphocytic Leukemia Is Associated with the Estimate of the Size of the Tumor Mass, STAT5 Signaling and Disease Course during Follow-Up of Patients on Therapy

INTRODUCTION

Advanced chronic lymphocytic leukemia (CLL) is accompanied by increased circulating regulatory T cells (Tregs) and increased susceptibility to severe infections, which were also shown to entail a striking induction of FOXP3 expression in Tregs. As homeostasis of the most suppressive CD45RA-FOXP3high activated Treg (aTreg) subset differs, it is critical to analyse homeostatic signalling in Treg subsets.

MATERIALS AND METHODS

In this study, by using conventional and imaging flow cytometry, we monitored STAT5 signalling/phosphorylation (pSTAT5) and investigated Treg subsets in relation to the Binet stage, the total tumor mass score (TTM) and the disease course during a follow-up of 37 patients with CLL.

RESULTS

The aTreg percentage was significantly increased among CD4+ T cells from patients with advanced disease and significantly correlated with the TTM. A subgroup of patients with higher aTreg percentages among CD4+FOXP3+ T cells at the start of therapy was characterised by more frequent episodes of severe infections during follow-up.

CONCLUSIONS

The results suggesting that an aTreg fraction could represent a possible marker of a severe disease course with infectious complications. Augmented homeostatic STAT5 signalling could support aTreg expansion, as higher pSTAT5 levels were significantly correlated with an increased aTreg frequency among CD4+FOXP3+ T cells during the follow-up of patients on therapy, as well as following SARS-CoV-2 antigen-specific stimulation in vitro.

Rewiring the T cell-suppressive cytokine landscape of the tumor microenvironment: a new frontier for precision anti-cancer therapy

T lymphocytes that infiltrate the tumor microenvironment (TME) often fail to function as effective anti-cancer agents. Within the TME, cell-to-cell inhibitory interactions play significant roles in dampening their anti-tumor activities. Recent studies have revealed that soluble factors released in the TME by immune and non-immune cells, as well as by tumor cells themselves, contribute to the exacerbation of T cell exhaustion. Our understanding of the cytokine landscape of the TME, their interrelationships, and their impact on cancer development is still at its early stages. In this review, we aim to shed light on Interleukin (IL) -6, IL-9, and IL-10, a small group of JAK/STAT signaling-dependent cytokines harboring T cell-suppressive effects in the TME and summarize their mechanisms of action. Additionally, we will explore how advancements in scientific research can help us overcoming the obstacles posed by cytokines that suppress T cells in tumors, with the ultimate objective of stimulating further investigations for the development of novel therapeutic strategies to counteract their tumor-promoting activities.

Tuning the B-CLL microenvironment: evidence for BAG3 protein- mediated regulation of stromal fibroblasts activity

The Bcl2-associated athanogene-3 (BAG3) protein, a critical regulator of cellular survival, has been identified as a potential therapeutic target in various malignancies. This study investigates the role of BAG3 within stromal fibroblasts and its interaction with B-cell chronic lymphocytic leukemia (B-CLL) cells. Previous research demonstrated that BAG3 maintains the active state of pancreatic stellate cells (PSCs) and aids pancreatic ductal adenocarcinoma (PDAC) spread via cytokine release. To explore BAG3's role in bone marrow-derived stromal fibroblasts, BAG3 was silenced in HS-5 cells using siRNA. In co-culture experiments with PBMCs from B-CLL patients, BAG3 silencing in HS-5 cells increased apoptosis and decreased phosphorylation of BTK, AKT, and ERK in B-CLL cells, thus disrupting their pro-survival key signaling pathways. The observation of fibroblast-activated protein (FAP) positive cells in infiltrated bone marrow specimens co-expressing BAG3 further support the involvement of the protein in fibroblast-mediated tumor survival. Additionally, BAG3 appears to support B-CLL survival by modulating cytokine networks, including IL-10 and CXCL12, which are essential for leukemic cell survival and proliferation. A robust correlation between BAG3 expression and the levels of CXCL12 and IL-10 was observed in both co-cultures and patient specimens. These findings point out the need for a more in-depth comprehension of the intricate network of interactions within the tumor microenvironment and provide valuable insights for the selection of new potential therapeutic targets in the medical treatment of CLL.

Immune responses during COVID-19 breakthrough cases in vaccinated children and adolescents

Background

Vaccine effectiveness against SARS-CoV-2 infection has been somewhat limited due to the widespread dissemination of the Omicron variant, its subvariants, and the immune response dynamics of the naturally infected with the virus.

Methods

Twelve subjects between 3-17 years old (yo), vaccinated with two doses of CoronaVac®, were followed and diagnosed as breakthrough cases starting 14 days after receiving the second dose. Total IgGs against different SARS-CoV-2 proteins and the neutralizing capacity of these antibodies after infection were measured in plasma. The activation of CD4+ and CD8+ T cells was evaluated in peripheral blood mononuclear cells stimulated with peptides derived from the proteins from the wild-type (WT) virus and Omicron subvariants by flow cytometry, as well as different cytokines secretion by a Multiplex assay.

Results

2 to 8 weeks post-infection, compared to 4 weeks after 2nd dose of vaccine, there was a 146.5-fold increase in neutralizing antibody titers against Omicron and a 38.7-fold increase against WT SARS-CoV-2. Subjects showed an increase in total IgG levels against the S1, N, M, and NSP8 proteins of the WT virus. Activated CD4+ T cells showed a significant increase in response to the BA.2 subvariant (p<0.001). Finally, the secretion of IL-2 and IFN-γ cytokines showed a discreet decrease trend after infection in some subjects.

Conclusion

SARS-CoV-2 infection in the pediatric population vaccinated with an inactivated SARS-CoV-2 vaccine produced an increase in neutralizing antibodies against Omicron and increased specific IgG antibodies for different SARS-CoV-2 proteins. CD4+ T cell activation was also increased, suggesting a conserved cellular response against the Omicron subvariants, whereas Th1-type cytokine secretion tended to decrease.

Clinical Trial Registration

clinicaltrials.gov #NCT04992260.

Leukemic cell-secreted interleukin-9 suppresses cytotoxic T cell-mediated killing in chronic lymphocytic leukemia

The tumor microenvironment (TME) plays a central role in the pathogenesis of chronic lymphocytic leukemia (CLL), contributing to disease progression and chemoresistance. Leukemic cells shape the TME into a pro-survival and immunosuppressive niche through contact-dependent and contact-independent interactions with the cellular components of the TME. Immune synapse (IS) formation is defective in CLL. Here we asked whether soluble factors released by CLL cells contribute to their protection from cytotoxic T cell (CTL)-mediated killing by interfering with this process. We found that healthy CTLs cultured in media conditioned by leukemic cells from CLL patients or Eμ-TCL1 mice upregulate the exhaustion marker PD-1 and become unable to form functional ISs and kill target cells. These defects were more pronounced when media were conditioned by leukemic cells lacking p66Shc, a proapoptotic adapter whose deficiency has been implicated in disease aggressiveness both in CLL and in the Eμ-TCL1 mouse model. Multiplex ELISA assays showed that leukemic cells from Eμ-TCL1 mice secrete abnormally elevated amounts of CCL22, CCL24, IL-9 and IL-10, which are further upregulated in the absence of p66Shc. Among these, IL-9 and IL-10 were also overexpressed in leukemic cells from CLL patients, where they inversely correlated with residual p66Shc. Using neutralizing antibodies or the recombinant cytokines we show that IL-9, but not IL-10, mediates both the enhancement in PD-1 expression and the suppression of effector functions in healthy CTLs. Our results demonstrate that IL-9 secreted by leukemic cells negatively modulates the anti-tumor immune abilities of CTLs, highlighting a new suppressive mechanism and a novel potential therapeutical target in CLL.

p66Shc deficiency in CLL cells enhances PD-L1 expression and suppresses immune synapse formation

Introduction: Escape from immunosurveillance is a hallmark of chronic lymphocytic leukemia (CLL) cells. In the protective niche of lymphoid organs, leukemic cells suppress the ability of T lymphocytes to form the immune synapse (IS), thereby hampering T-cell mediated anti-tumoral activities. By binding its cognate receptor PD-1 at the surface of T lymphocytes, the inhibitory ligand PD-L1, which is overexpressed in CLL cells, mediates the T-cell suppressive activities of CLL cells. However, the molecular mechanism underlying PD-L1 overexpression in CLL cells remains unknown. We have previously reported a defective expression of the pro-apoptotic and pro-oxidant adaptor p66Shc in CLL cells, which is causally related to an impairment in intracellular reactive oxygen species (ROS) production and to the activation of the ROS-sensitive transcription factor NF-κB. The fact that PD-L1 expression is regulated by NF-κB suggests a mechanistic relationship between p66Shc deficiency and PD-L1 overexpression in CLL cells. Methods: 62 treatment-naive CLL patients and 43 healthy donors were included in this study. PD-L1 and p66Shc expression was quantified in B cells by flow cytometry and qRT-PCR. IS architecture and local signaling was assessed by flow cytometry and confocal microscopy. CD8+ cell killing activity was assessed by flow cytometry. Results: Here we show that residual p66Shc expression in leukemic cells isolated both from CLL patients and from the CLL mouse model Eμ-TCL1 inversely correlated with PD-L1 expression. We also show that the PD-L1 increase prevented leukemic cells from forming ISs with T lymphocytes. Reconstitution of p66Shc, but not of a ROS-defective mutant, in both CLL cells and the CLL-derived cell line MEC-1, enhanced intracellular ROS and decreased PD-L1 expression. Similar results were obtained following treatment of CLL cells with H2O2 as exogenous source of ROS, that normalized PD-L1 expression and recovered IS formation. Discussion: Our data provide direct evidence that the p66Shc-deficiency-related ROS depletion in CLL cells concurs to enhance PD-L1 expression and provides a mechanistic basis for the suppression of T cell-mediated anti-tumoral functions in the immunosuppressive lymphoid niche.

Association of CYP1A1 T3801C (rs4646903) variant with the susceptibility and progression of B-chronic lymphocytic Leukemia (B-CLL) in the Egyptian population

BACKGROUND

The frequency of hematological malignancies is increasing universally, and over the last few decades, a significant increase in the incidence of B-chronic lymphocytic leukemia (B-CLL) has been observed. Many studies have revealed the involvement of genetic predisposition along with environmental exposure to genotoxic xenobiotics in the leukemogenesis process of B-CLL. CYP1A1 is a vital member of the cytochromes P450 (CYPs) superfamily, which is involved in pro-carcinogens activation into reactive intermediates during phase I xenobiotic biotransformation.

AIM

This study aimed to determine the possible role of the CYP1A1*2A (T3801C, rs4646903) single nucleotide polymorphism (SNP) as a risk factor for developing B-CLL, as well as the impact of this SNP on the disease progression and the clinical outcome.

PATIENTS AND METHODS

The study was conducted on 100 patients newly diagnosed with B-CLL, and 100 healthy individuals with matched ages and sex, served as the control group. CYP1A1 (T3801C) genotyping of all patient and control samples was performed using the PCR-based Restriction Fragment Length Polymorphism (RFLP-PCR) method. In addition, serum levels of both IL-6 and TNF-α were estimated by the ELISA technique.

RESULTS

Higher frequencies of the heterozygous carrier (TC) and homozygous variant (CC) genotypes of the CYP1A1 (T3801C) variant were observed in B-CLL patients compared to the controls (P < 0.001 for both). The frequencies of the CYP1A1 (T3801C) variant indicated a significant elevated risk of B-CLL under various genetic models, including allelic (OR = 8.8, P < 0.001) and dominant (OR = 9.3, P < 0.001) models. In addition, the median IL-6 level was significantly higher in patients with (TC) and (CC) genotypes than in patients with (TT) genotype (P = 0.001 and P < 0.001, respectively). Also, the median TNF-α level was significantly higher in patients with (TC) and (CC) genotypes than in patients with (TT) genotype (P < 0.001 for both).

CONCLUSION

Our results showed that the CYP1A1*2A (T3801C, rs4646903) SNP increases the susceptibility to B-CLL incidence and is associated with poor disease progression.

Evaluation the -174G>C Genetic Polymorphism of Interleukin-6 in Iranian Patients with Chronic Lymphocytic Leukemia

Background & Objective

Interleukin-6 (IL-6) is involved in inflammation and has a significant role in chronic lymphocytic leukemia (CLL) progression. Accordingly, IL-6 level may increase in CLL-affected patients compared to healthy individuals. The -174G>C single nucleotide polymorphism (SNP) in IL-6 promoter region has been related to differences in IL-6 transcription. Therefore, we investigated the possible association of IL-6 polymorphism with CLL.

Methods

We examined the -174G>C SNP in IL-6 gene and studied its possible relationship with CLL in affected patients and in healthy controls using Amplification Refractory Mutation System- polymerase chain reaction genotyping method. IL-6 plasma level was measured in both studied groups.

Results

According to the results, IL-6 mean plasma concentration was increased significantly in the CLL patients compared to the controls. However, 174G>C genotype of the IL-6 gene was not associated with CLL. Furthermore, there were no significant differences in the distribution of allele and genotype frequencies between the CLL-affected patients and the controls (P>0.05).

Conclusion

Our study showed that -174G>C SNP in promotor of IL-6 gene could not be considered a risk factor for CLL. Larger prospective studies should be performed to confirm our results.

Molecular Evaluation of the Impact of Polymorphic Variants in Apoptotic (Bcl-2/Bax) and Proinflammatory Cytokine (TNF-α/IL-8) Genes on the Susceptibility and Progression of Myeloproliferative Neoplasms: A Case-Control Biomarker Study

The regulation of apoptosis (the programmed cell death) is dependent on the crucial involvement of BCL2 and BAX. The Bax-248G>A and Bcl-2-938 C>A polymorphic variations in the promoter sequences of the Bax and Bcl-2 gene have been recently associated with low Bax expression, progression to advanced stages, treatment resistance, and shortened overall survival rate in some hematological malignancies, including chronic myeloid leukemia (CML) and other myeloproliferative neoplasms. Chronic inflammation has been linked to various stages of carcinogenesis wherein pro-inflammatory cytokines play diverse roles in influencing cancer microenvironment leading to cell invasion and cancer progression. Cytokines such as TNF-α and IL-8 have been implicated in cancer growth in both solid and hematological malignancies with studies showing their elevated levels in patients. Genomic approaches have in recent years provided significant knowledge with the regard to the association of certain SNPs (single nucleotide polymerphisms) either in a gene or its promoter that can influence its expression, with the risk and susceptibility to human diseases including cancer. This study has investigated the consequences of promoter SNPs in apoptosis genes Bax-248G>A (rs4645878)/Bcl-2-938C>A (rs2279115) and pro-inflammatory cytokines TNF-α rs1800629 G>A/IL-8 rs4073 T>A on the risk and susceptibility towards hematological cancers. The study design has 235 individuals both male and female enrolled as subjects that had 113 cases of MPDs (myeloproliferative disorders) and 122 healthy individuals as controls. The genotyping studies were conducted through ARMS PCR (amplification-refractory mutation system PCR). The Bcl-2-938 C>A polymorphism showed up in 22% of patients in the study, while it was observed in only 10% of normal controls. This difference in genotype and allele frequency between the two groups was significant (p = 0.025). Similarly, the Bax-248G>A polymorphism was detected in 6.48% of the patients and 4.54% of the normal controls, with a significant difference in genotype and allele frequency between the groups (p = 0.048). The results suggest that the Bcl-2-938 C>A variant is linked to an elevated risk of MPDs in the codominant, dominant, and recessive inheritance models. Moreover, the study indicated allele A as risk allele which can significantly increase the risk of MPDs unlike the C allele. In case of Bax gene covariants, these were associated with an increased risk of MPDs in the codominant inheritance model and dominant inheritance model. It was found that the allele A significantly enhanced the risk of MPDs unlike the G allele. The frequencies of IL-8 rs4073 T>A in patients was found to be TT (16.39%), AT (36.88%) and AA (46.72%), compared to controls who were more likely to have frequencies of TT (39.34%), AT (37.70%) and AA (22.95%) as such, respectively. There was a notable overrepresentation of the AA genotype and GG homozygotes among patients compared to controls in TNF-α polymorphic variants, with 6.55% of patients having the AA genotype and 84% of patients being GG homozygotes, compared to 1.63% and 69%, respectively in controls. The data from the current study provide partial but important evidence that polymorphisms in apoptotic genes Bcl-2-938C>A and Bax-248G>A and pro-inflammatory cytokines IL-8 rs4073 T>A and TNF-α G>A may help predict the clinical outcomes of patients and determine the significance of such polymorphic variations in the risk of myeloproliferative diseases and their role as prognostic markers in disease management using a case-control study approach.

Assessment of Impact of Human Leukocyte Antigen-Type and Cytokine-Type Responses on Outcomes after Targeted Therapy Currently Used to Treat Chronic Lymphocytic Leukemia

Tumor growth and metastasis are reliant on intricate interactions between the host immune system and various counter-regulatory immune escape mechanisms employed by the tumor. Tumors can resist immune surveillance by modifying the expression of human leukocyte antigen (HLA) molecules, which results in the impaired presentation of tumor-associated antigens, subsequently evading detection and destruction by the immune system. The management of chronic lymphocytic leukemia (CLL) is based on symptom severity and includes various types of targeted therapies, including rituximab, obinutuzumab, ibrutinib, acalabrutinib, zanubrutinib, idelalisib, and venetoclax. These therapies rely on the recognition of specific peptides presented by HLAs on the surface of tumor cells by T cells, leading to an immune response. HLA class I molecules are found in most human cell types and interact with T-cell receptors (TCRs) to activate T cells, which play a vital role in inducing adaptive immune responses. However, tumor cells may evade T-cell attack by downregulating HLA expression, limiting the efficacy of HLA-dependent immunotherapy. The prognosis of CLL largely depends on the presence or absence of genetic abnormalities, such as del(17p), TP53 point mutations, and IGHV somatic hypermutation status. These oral targeted therapies alone or in combination with anti-CD20 antibodies have replaced chemoimmunotherapy as the primary treatment for CLL. In this review, we summarize the current clinical evidence on the impact of HLA- and cytokine-type responses on outcomes after targeted therapies currently used to treat CLL.

Systematic Evaluation of Antigenic Stimulation in Chronic Lymphocytic Leukemia: Humoral Immunity as Biomarkers for Disease Evolution

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world. Studies of CLL antibody reactivity have shown differential targets to autoantigens and antimicrobial molecular motifs that support the current hypothesis of CLL pathogenesis.

METHODS

In this study, we conducted a quantitative serum analysis of 7 immunoglobulins in CLL and monoclonal B-cell lymphocytosis (MBL) patients (bead-suspension protein arrays) and a serological profile (IgG and IgM) study of autoantibodies and antimicrobial antigens (protein microarrays).

RESULTS

Significant differences in the IgA levels were observed according to disease progression and evolution as well as significant alterations in IgG1 according to IGHV mutational status. More representative IgG autoantibodies in the cohort were against nonmutagenic proteins and IgM autoantibodies were against vesicle proteins. Antimicrobial IgG and IgM were detected against microbes associated with respiratory tract infections.

CONCLUSIONS

Quantitative differences in immunoglobulin serum levels could be potential biomarkers for disease progression. In the top 5 tumoral antigens, we detected autoantibodies (IgM and IgG) against proteins related to cell homeostasis and metabolism in the studied cohort. The top 5 microbial antigens were associated with respiratory and gastrointestinal infections; moreover, the subsets with better prognostics were characterized by a reactivation of Cytomegalovirus. The viral humoral response could be a potential prognosis biomarker for disease progression.

An Impact of COVID-19 on Cancer Care: An Update

The world has been affected socioeconomically for the last two years due to the emergence of different variants of the COVID-19 virus. Vaccination is the major and most efficient way to prevent the widening of this pandemic. Those who are having comorbidities are more vulnerable to serious infections due to their immunocompromised state. Additionally, cancer patients could be at significant risk for COVID-19. In this pandemic era, the diagnosis and treatment of cancer were significantly affected. Clinical trials at the initial stage were performed on healthy or COVID-19 infected patients. This produces a greater level of hesitancy in cancer patients. This review article provide an update regarding the vaccination and treatment for COVID-19 in patients with cancer and future directions.

The Impact of COVID-19 Infection in Cancer 2020-2021

This Editorial summarizes the findings of the articles submitted in 2020 and 2021 to the Special Issue "The Impact of COVID-19 in Cancer".

Unravelling soluble immune checkpoints in chronic lymphocytic leukemia: Physiological immunomodulators or immune dysfunction

Chronic lymphocytic leukemia (CLL) is a lymphoid neoplasm characterized by the accumulation of mature B cells. The diagnosis is established by the detection of monoclonal B lymphocytes in peripheral blood, even in early stages [monoclonal B-cell lymphocytosis (MBL^hi)], and its clinical course is highly heterogeneous. In fact, there are well-characterized multiple prognostic factors that are also related to the observed genetic heterogenicity, such as immunoglobulin heavy chain variable region (IGHV) mutational status, del17p, and TP53 mutations, among others. Moreover, a dysregulation of the immune system (innate and adaptive immunity) has been observed in CLL patients, with strong impact on immune surveillance and consequently on the onset, evolution, and therapy response. In addition, the tumor microenvironment is highly complex and heterogeneous (i.e., matrix, fibroblast, endothelial cells, and immune cells), playing a critical role in the evolution of CLL. In this study, a quantitative profile of 103 proteins (cytokines, chemokines, growth/regulatory factors, immune checkpoints, and soluble receptors) in 67 serum samples (57 CLL and 10 MBL^hi) has been systematically evaluated. Also, differential profiles of soluble immune factors that discriminate between MBL^hi and CLL (sCD47, sCD27, sTIMD-4, sIL-2R, and sULBP-1), disease progression (sCD48, sCD27, sArginase-1, sLAG-3, IL-4, and sIL-2R), or among profiles correlated with other prognostic factors, such as IGHV mutational status (CXCL11/I-TAC, CXCL10/IP-10, sHEVM, and sLAG-3), were deciphered. These results pave the way to explore the role of soluble immune checkpoints as a promising source of biomarkers in CLL, to provide novel insights into the immune suppression process and/or dysfunction, mostly on T cells, in combination with cellular balance disruption and microenvironment polarization leading to tumor escape.

Interleukin-10-1082A>G (rs1800896) Single Nucleotide Polymorphism is Not a Risk Factor of Chronic Lymphocytic Leukemia in Sudanese Population

OBJECTIVE

The present study was conducted to examine the association between the IL-10-1082A>G (rs 1800896) polymorphism and risk of Chronic Lymphocytic Leukemia and to assess the correlation between this polymorphism and clinicopathological characters.

METHODS

A case-control study was conducted in Khartoum state, Sudan, during the period from April 2017 to April 2018, involved 110 CLL patients and 80 healthy volunteers as a control group. Physical examination, complete blood count, and immunophenotype were performed in all patients to confirm the diagnosis. Clinical staging such as Rai and Binet were studied. CD38 and ZAP70 were performed by flow cytometry. Blood samples were collected from all participants; DNA was extracted by using ANALYTIKJENA Blood DNA Extraction Kit and analyzed IL-10-1082A>G polymorphism by using Allele Specific-Polymerase Chain Reaction. The statistical analysis was performed using statistical  package  for  social  sciences  version 23.0 software.

RESULTS

Frequency of AA, AG, and GG genotypes was 32.7%, 55.5%, and 11.8% for the patient group and 31.25%, 51.25%, and 17.5% in the control group, respectively. The genotype of IL-10 (-1082A>G) did not associate with susceptibility of CLL in our population. The study showed that the G allele of the IL-10 gene (-1082A>G) is associated with the male sex. However, no significant association was found between -1082A>G genotype and clinicopathological characters.

CONCLUSION

Our results do not support the involvement of the IL-10 -1082A>G promoter gene polymorphism in the increased CLL susceptibility. IL-10-1082G allele (IL-10-1082AG or IL-10-1082GG) was found more frequently in males. Furthermore, no association was observed between the IL-10-1082A>G polymorphism and clinical stages systems as well as established poor prognostic markers. Finally, within the group of patients with CLL, there was no difference in the age at diagnosis and hematological parameters according to genotype distributions.

Interleukin (IL)-9 Supports the Tumor-Promoting Environment of Chronic Lymphocytic Leukemia

Simple Summary

Interleukin 9 (IL-9), a soluble factor secreted by immune cells, has been found in several tumor niches where, depending on the specific tumor type, it either promotes or counteracts tumor development. Recently, IL-9 has been implicated in the development of chronic lymphocytic leukemia, although the underlying molecular mechanism remains unknown. Here, we summarize the current knowledge concerning the roles of IL-9 in disease, with a focus on its implication in the pathogenesis of chronic lymphocytic leukemia.

Abstract

Interleukin (IL)-9 is a soluble factor secreted by immune cells into the microenvironment. Originally identified as a mediator of allergic responses, IL-9 has been detected in recent years in several tumor niches. In solid tumors, it mainly promotes anti-tumor immune responses, while in hematologic malignancies, it sustains the growth and survival of neoplastic cells. IL-9 has been recently implicated in the pathogenesis of chronic lymphocytic leukemia; however, the molecular mechanisms underlying its contribution to this complex neoplasia are still unclear. Here, we summarize the current knowledge of IL-9 in the tumor microenvironment, with a focus on its role in the pathogenesis of chronic lymphocytic leukemia.

Advances in the application of Let-7 microRNAs in the diagnosis, treatment and prognosis of leukemia

The lethal-7 (Let-7) family of microRNAs (miRNAs) controls the process of development and differentiation, but is also related to the occurrence of tumors and a poor prognosis of patients with tumors. Thus, a more comprehensive exploration of its functions will provide further insights into these processes, and may promote the diagnosis and treatment of tumors. Leukemia is a type of progressive malignant disease, and its pathogenesis involves a variety of epigenetic factors. Amongst the several related epigenetic factors, the Let-7 miRNAs are an important family of molecules that play a crucial role in maintaining a variety of critical biological processes, including development, differentiation and proliferation. In the present study, the role of Let-7 as a tumor suppressor gene and oncogene is reviewed, and the complex regulatory functions of several Let-7 family members in different subtypes of leukemia are described. The current body of knowledge thus far indicates that Let-7 is not only a potential diagnostic and prognostic marker of leukemia, but also a potential therapeutic target for the treatment of affected patients, with particular potential when targeted by adjuvant treatments alongside traditional treatment to improve their survival rate.

Impact of active cancer on COVID-19 survival: a matched-analysis on 557 consecutive patients at an Academic Hospital in Lombardy, Italy

BACKGROUND

The impact of active cancer in COVID-19 patients is poorly defined; however, most studies showed a poorer outcome in cancer patients compared to the general population.

METHODS

We analysed clinical data from 557 consecutive COVID-19 patients. Uni-multivariable analysis was performed to identify prognostic factors of COVID-19 survival; propensity score matching was used to estimate the impact of cancer.

RESULTS

Of 557 consecutive COVID-19 patients, 46 had active cancer (8%). Comorbidities included diabetes (n = 137, 25%), hypertension (n = 284, 51%), coronary artery disease (n = 114, 20%) and dyslipidaemia (n = 122, 22%). Oncologic patients were older (mean age 71 vs 65, p = 0.012), more often smokers (20% vs 8%, p = 0.009), with higher neutrophil-to-lymphocyte ratio (13.3 vs 8.2, p = 0.046). Fatality rate was 50% (CI 95%: 34.9;65.1) in cancer patients and 20.2% (CI 95%: 16.8;23.9) in the non-oncologic population. Multivariable analysis showed active cancer (HR_active: 2.26, p = 0.001), age (HR_age>65years: 1.08, p < 0.001), as well as lactate dehydrogenase (HR_LDH>248mU/mL: 2.42, p = 0.007), PaO2/FiO2 (HR_continuous: 1.00, p < 0.001), procalcitonin (HR_PCT>0.5ng/mL: 2.21, p < 0.001), coronary artery disease (HR_yes: 1.67, p = 0.010), cigarette smoking (HR_yes: 1.65, p = 0.041) to be independent statistically significant predictors of outcome. Propensity score matching showed a 1.92× risk of death in active cancer patients compared to non-oncologic patients (p = 0.013), adjusted for ICU-related bias. We observed a median OS of 14 days for cancer patients vs 35 days for other patients.

CONCLUSION

A near-doubled death rate between cancer and non-cancer COVID-19 patients was reported. Active cancer has a negative impact on clinical outcome regardless of pre-existing clinical comorbidities.

Impact of Immune Parameters and Immune Dysfunctions on the Prognosis of Patients with Chronic Lymphocytic Leukemia

Simple Summary

In chronic lymphocytic leukemia (CLL), immune alterations—affecting both the innate and adaptive immunity—are very common. As a clinical consequence, patients with CLL frequently present with autoimmune phenomena, increased risk of infections and second malignancies. The aim of this review article is to present available data on CLL-associated alterations of immune parameters that correlate with known prognostic markers and with clinical outcome. Also, data on the impact of immune-related clinical manifestations on the prognosis of patients with CLL will be discussed.

Abstract

Chronic lymphocytic leukemia (CLL) is characterized by a wide spectrum of immune alterations, affecting both the innate and adaptive immunity. These immune dysfunctions strongly impact the immune surveillance, facilitate tumor progression and eventually affect the disease course. Quantitative and functional alterations involving conventional T cells, γδ T cells, regulatory T cells, NK and NKT cells, and myeloid cells, together with hypogammaglobulinemia, aberrations in the complement pathways and altered cytokine signature have been reported in patients with CLL. Some of these immune parameters have been shown to associate with other CLL-related characteristics with a known prognostic relevance or to correlate with disease prognosis. Also, in CLL, the complex immune response dysfunctions eventually translate in clinical manifestations, including autoimmune phenomena, increased risk of infections and second malignancies. These clinical issues are overall the most common complications that affect the course and management of CLL, and they also may impact overall disease prognosis.

Rapid improvement in symptoms and physical function following ibrutinib initiation in chronic lymphocytic leukemia and the associated changes in plasma cytokines

A prospective pilot study was carried out on 34 CLL patients treated with ibrutinib, evaluating the effects on symptoms and physical function with changes in plasma exosomes (EXs), β2-microglobulin (β2M) and 26 plasma cytokines. The revised Edmonton Symptom Assessment Scale (ESAS-R) demonstrated moderate fatigue, shortness of breath and a sense of unwellness before treatment, which significantly improved within 2 weeks of starting ibrutinib. These changes were associated with a rapid improvement in sit-to-stand and 4 m walking speeds. The plasma levels of CCL11, IL-7, -8 and -10 dropped initially while the levels of TNF-α/-β, CCL3, CCL4, CCL17, and IL-16 continued to decline for 12 months. Despite the initial lymphocytosis, plasma β2M levels fell but no consistent change in plasma EXs occurred. Thus, ibrutinib can produce a rapid and sustained improvement in symptoms and physical function in CLL, associated with a decline in multiple plasma cytokines.

Macrophage Polarization in Chronic Lymphocytic Leukemia: Nurse-Like Cells Are the Caretakers of Leukemic Cells

Macrophages are terminally differentiated innate immune cells. Through their activation, they can be polarized towards the pro-inflammatory M1 type or the wound healing-associated, anti-inflammatory M2 type macrophages. In the tumor microenvironment (TME), M2 is the dominant phenotype and these cells are referred to as tumor-associated macrophages (TAMs). TAMs secrete cytokines and chemokines, exerting an antiapoptotic, proliferative and pro-metastatic effect on the tumor cells. TAMs can be found in many cancers, including chronic lymphocytic leukemia (CLL), where they are called nurse-like cells (NLCs). Despite the generally indolent behavior of CLL, the proportion of treatment-refractory patients is significant. As with the majority of cancers, despite significant recent progress, CLL pathogenesis is poorly understood. The emerging role of the TME in nurturing the neoplastic process warrants the investigation of macrophages as a significant pathogenetic element of tumors. In this paper, we review the current knowledge on the role of stromal macrophages in CLL.

Relevant Cytokines in the B Cell Lymphoma Micro-Environment

Cytokines are soluble protein factors with importance in intercellular communication and, as such, play pivotal roles in the pathogenesis of B cell malignancies. Evidence from in vitro cultures permitted us to choose example cytokines that bind to different biochemical receptor types. Activated malignant B cells or stromal fibroblasts and macrophages prominently secrete the chemokines CCL3 or CXCL12 and CXCL13, respectively. Apart from helper T cells, various cell types of the B cell lymphoma microenvironment are capable of producing the cytokines IL-4, IL-6, IL-10 and TNFα. Owing to its impact on the development of myeloid cells, CSF-1 is among important soluble factors in the B cell lymphoma microenvironment. Inhibitors of B cell receptor-associated kinases often act via the blockade of cytokine production, but also prevent cytokine effects, e.g., chemotaxis. Increments in blood levels in chronic lymphocytic leukemia patients compared to healthy donors and normalization upon treatment with ibrutinib can be explained by producing cell types and modulation of cytokine production observed in vitro.

Low Humoral Immune Response and Ineffective Clearance of SARS-Cov-2 in a COVID-19 Patient With CLL During a 69-Day Follow-Up

Background: A recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), which began in Wuhan, China, with a high level of human-to-human transmission has been reported. There are limited data available on Coronavirus Disease 2019 (COVID-19) patients with hematological malignancies with more than 60 days of follow-up. This study describes the clinical characteristics, including multiple recurrences of COVID-19, in a patient with chronic lymphocytic leukemia (CLL) during 69 days of follow-up.

Case Presentation: A 72-year-old female was admitted to hospital isolation after being infected with COVID-19 as part of a family cluster on January 30, 2020. Apart from SARS-Cov-2 virus infection, laboratory results revealed lymphocytosis of uncertain etiology and abnormal distribution of T lymphocytes. On blood smears, small blue lymphocytes with scant cytoplasm were observed, and the presence of high levels of circulating clonal B cells was also demonstrated by flow cytometry. The patient was diagnosed with COVID-19 and CLL. Among her family members, she had the highest viral loads and the fastest progression on lung injury and developed severe pneumonia. Serological results showed she had both 2019-nCoV-specific IgM and IgG antibodies; however, only IgG antibodies were detected in her husband's plasma.

Results: A combination regimen of antiviral therapy and high-dose intravenous immunoglobulin (IVIG) in the early stage seemed to be effective for treating CLL and SARS-Cov-2 infection. Because of the low humoral immune response, the CLL patient could not effectively clear the SARS-Cov-2 infection and suffered from recurrence twice during the 69-day follow-up.

Conclusion: In CLL, a neoplastic antigen-specific B-cell clone proliferates, and the progeny cells accumulate and outgrow other B cells, leading to immune deficiency. Considering the low humoral immune response and ineffective clearance of SARS-Cov-2 in CLL patients, the follow-up and home quarantine period should be extended. We need further studies to clarify suspending or continuing CLL therapy during COVID infection. For those patients who are prone to progression to severe disease, administering humoral immunity therapies can help to prevent disease progression and quickly meet the cure criteria.