Hematological Malignancies in Sickle Cell Disease Patients: Report of Four Cases in Togo and Literature Review

Background: Hemopathies were rarely observed in major sickle cell disease patients some thirty years ago, probably due to the high mortality rate among the latter as a result of progressive complications. Thanks to advances in the management of sickle cell disease, patients' life expectancy has increased considerably, exposing them more frequently to neoplasia, including hematological malignancies. The increased risk of leukemogenesis is multifactorial and linked to the pathophysiological mechanisms of the clinical manifestations of sickle cell disease. Study Setting: The clinical haematology department of campus teaching hospital and the paediatric onco-haematology unit of Sylvanus Olympio teaching hospital in Lomé were used as study settings. Observations: Four hematologic malignancies were collected in a cohort of 5847 major sickle cell syndromes. The median age of the patients was 31.25 years (extremes: 14 and 58 years) and they were predominantly female (sex ratio M/F = 0.25). Two were on background therapy with hydroxyurea. Among the four patients, there were two cases of acute lymphocytic leukemia, including ALL3 in a 58-year-old SS woman and T-ALL2 in a 12-year-old SC. Then, a case of lymphocytic lymphoma in a 20-year-old SS man was reported and finally a case of chronic myelocytic leukemia in a 33-year-old woman of Sβ+ thalassaemia phenotype. Conclusion: To further report this coexistence, it is therefore essential to systematically consider hematological malignancies during major sickle cell syndromes even if there are similarities in the symptomatology of these two serious pathological situations.

Predictive value of co-expression patterns of immune checkpoint molecules for clinical outcomes of hematological malignancies

Co-expression of immune checkpoint(IC)molecules can exacerbate T cell exhaustion in patients with hematological malignancies(HMs)and contribute to the immune escape of tumor cells,which is related to poor clinical outcome.It is worth establishing and optimizing an ideal prediction model based on the co-expression patterns of IC molecules to evaluate the immune status of HM patients and predict their clinical outcome.In this perspective,we summarize the co-expression patterns of IC molecules and their importance as biomarkers that predict the prognosis of patients with different HMs,providing new insights for designing dual IC blockades(ICBs).

Recent progresson nuclear export protein XPO1 inhibitor in the treatment of hematological malignancies

Most tumor suppressor and growth-regulating proteins are transported via the plasmic nuclear transporter exportin 1(XPO1).Many malignancies have excessive XPO1 expression,which is associated with disease progression and resistance to therapy.A novel class of anticancer medication called selective inhibitor of nuclear export(SINE)can down-regulate the levels of a number of antigenic proteins in the cytoplasm,activate tumor suppressor and other growth regulating proteins,and promote the nuclear retention and apoptosis of tumor cells.This article discusses the function of XPO1 in drug resistance and tumor development as well as the advancement of XPO1 inhibitor research for the treatment of hematological cancers.

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies treated with anticancer therapy

Hepatitis due to hepatitis B virus(HBV) reactivation can be severe and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving cancer chemotherapy, especially rituximabcontaining therapy for hematological malignancies and those receiving stem cell transplantation. All patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen(HBs Ag) and antibody to hepatitis B core antigen(antiHBc). Patients found to be positive for HBs Ag should be given prophylactic antiviral therapy to prevent HBV reactivation. For patients with resolved HBV infection, no standard strategy has yet been established to prevent HBV reactivation. There are usually two options. One is pre-emptive therapy guided by serial HBV DNA monitoring, whereby antiviral therapy is given as soon as HBV DNA becomes detectable. However, there is little evidence regarding the optimal interval and period of monitoring. An alternative approach is prophylactic antiviral therapy, especially for patients receiving highrisk therapy such as rituximab, newer generation of anti-CD20 monoclonal antibody, obinutuzumab or hematopoietic stem cell transplantation. This strategy may effectively prevent HBV reactivation and avoid the inconvenience of repeated HBV DNA monitoring. Entecavir or tenofovir are preferred over lamivudine as prophylactic therapy. Although there is no well-defined guideline on the optimal duration of prophylactic therapy, there is growing evidence to recommend continuing prophylactic antiviral therapy for at least 12 mo after cessation of chemotherapy, and even longer for those who receive rituximab or who had high serum HBV DNA levels before the start of immunosuppressive therapy. Many novel agents have recently become available for the treatment of hematological malignancies, and these agents may be associated with HBV reactivation. Although there is currently limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBs Ag-positive patients receiving novel treatments, especially the Bruton tyrosine kinase inhibitors and the phosphatidylinositol 3-kinase inhibitors, which are B-cell receptor signaling modulators and reduce proliferation of malignant B-cells. Further studies are needed to clarify the risk of HBV reactivation with these agents and the best prophylactic strategy in the era of targeted therapy for hematological malignancies.

TMTP1, a Novel Tumor-homing Peptide, Specifically Targets Hematological Malignancies and Their Metastases

TMTP1, a 5-amino acid peptide NVVRQ, obtained by using the flagella peptide library screening in our previous studies, can be used for the labeling of malignant in situ and metastatic lesions, and even micro-metastases. In this study, TMTP1 was assessed for its ability to specifically target the malignant hematopoietic cells and metastatic lesions of hematological malignancies. FITC-TMTP1 was chemically synthesized. Immunofluorescence assay and competitive test were carried out to determine the specific binding capacity of TMTPl to hematological malignant cell lines, including HL60, k562, SHI-1, Jurkat, Raji, El-4 and umbilical cord blood mononuclear cells. Mononuclear cells were isolated from the bone marrow of healthy subjects and patients with chronic myeloid leukemia. Then the cells were co-clutured with TMTP1 or scrambled peptides and the binding and affinity of TMTP1 peptide to the primary cells of hematological malignancies were flow cytometrically analyzed. The binding speci-ficity of TMTP1 to target hematological malignancies was measured in vivo by intravenous injection of FITC-conjugated TMTP1 into El-4 lymphoma-bearing mice. The results showed that TMTP1 specifi-cally bound to the cells of a series of hematological malignancies, including HL60, k562, Jurkat, Raji , El-4 and chronic myeloid leukemia primary cells but not to bone marrow mononuclear cells from healthy subjects. By contrast, TMTP1 could bind to the metastatic foci of lymphoma originating from the EL-4 cell line while the scrambled peptide failed to do so. Moreover, the occult metastases could be identified, with high specificity, by detecting FITC-TMTP1. We are led to conclude that TMTP1, as a novel tumor-homing peptide, can serve as a marker for primary malignant and metastatic lesions for the early diagnosis of hematological malignances and a carrier of anticancer drugs for cancer treatment.

CAR T Cell Therapy for Hematological Malignancies

As a rapidly progressing field in oncology,the adoptive transfer of T cells that have been genetically modified with chimeric antigen receptors(CARs)has shown striking efficacy in the management of hematological malignancies and has been reported in a number of clinical trials.of note,CAR T cell therapy has shown extraordinary potential,especially in relapsed/refractory patients.However,there are still challenges regarding the further development of this strategy,spanning from engineering and manufacturing issues,to limited applications,to accompanying toxicities.In this review,we will summarize the general knowledge of this novel method,including receptor composition,applications,adverse events and challenges.Additionally,we will propose several comprehensive recommendations.

Characteristics of escape mutations from occult hepatitis B virus infected patients with hematological malignancies in South Egypt

AIM To investigate the prevalence and virological characteristics of occult hepatitis B virus(HBV) infections in patients with hematological malignancies in South Egypt.METHODS Serum samples were collected from 165 patients with hematological malignancies to monitor titers of HBV DNA, hepatitis B surface antigen(HBs Ag), and antibodies to HBV core(anti-HBc) and surface antigens. Serum samples negative for HBs Ag and positive for anti-HBc were subjected to nucleic acid extraction and HBV DNA detection by real-time polymerase chain reaction. DNA sequences spanning the S region were analyzed in cases with occult HBV infection. In vitro comparative study of constructed 1.24-fold wild type and S protein mutant HBV genotype D clones was further performed. RESULTS HBV DNA was detected in 23(42.6%) of 54 patients with hematological malignancies who were HBsA g negative, but anti-HBc positive, suggesting the presence of occult HBV infection. The complete HBV genome was retrieved from 6 occult HBV patients, and P120 T and S143 L were detected in 3 and 2 cases, respectively. Site directed mutagenesis was done to produce 1.24-fold genotype D clones with amino acid mutations T120 and L143. The in vitro analyses revealed that a lower level of extracellular HBsA g was detected by chemiluminescence enzyme immunoassay(CLEIA) with the clone containing T120 mutation, compared with the wild type or the clone with S143 L mutation despite the similar levels of extracellular and intracellular HBs Ag detected by Western blot. Southern blot experiments showed that the levels of intracellular HBV DNA were not different between these clones. CONCLUSION Occult HBV infection is common in patients with hematological malignancies and associated with P120 T and S143 L mutations. 120 T mutation impairs the detection of HBsA g by CLEIA.

Garenoxacin Prophylaxis for Febrile Neutropenia after Chemotherapy in Hematological Malignancies

Background: Febrile neutropenia is one of the most serious adverse events in patients with hematological malignancies and chemotherapy. The routine use of fluoroquinolone prophylaxis in patients with hematological malignancies is controversial. Therefore, we prospectively evaluated the efficacy and safety of prophylactic use of garenoxacin for febrile neutropenia. Patients and Methods: Consecutive adult patients with hematological malignancies who were at risk for chemotherapy-induced neutropenia lasting more than seven days were eligible for present study. They received oral garenoxacin (400 mg daily) from the neutrophil count decreased to less than 1000/μl and continued until the neutropenia had resolved. The primary endpoint was incidence of febrile neutropenia, and the secondary endpoints were the type and incidence of adverse events. Results: We enrolled 46 consecutive patients (median age, 59 years). The underlying diseases comprised acute myeloid leukemia (n = 17), acute lymphoblastic leukemia (n = 3), malignant lymphoma (n = 23), and multiple myeloma (n = 3). There were 23 febrile neutropenia episodes and 2 episodes of bacteremia. There were no grade 3 or 4 adverse events;however serum creatinine levels were significantly elevated after garenoxacin administration. The overall prophylactic efficacy of garenoxacin was 50%, and there were no infection-related deaths. Conclusions: Prophylactic use of garenoxacin is effective and safe in patients with hematological malignancies. (Clinical trial registration number: UMIN000004979).

Combination of CRISPR/Cas9 System and CAR-T Cell Therapy:A New Era for Refractory and Relapsed Hematological Malignancies

Chimeric antigen receptor T(CAR-T)cell therapy is the novel treatment strategy for hematological malignancies such as acute lymphoblastic leukemia(ALL),lymphoma and multiple myeloma.However,treatment-related toxicities such as cytokine release syndrome(CRS)and immune effector cell-associated neurotoxicity syndrome(ICANS)have become significant hurdles to CAR-T treatment.Multiple strategies were established to alter the CAR structure on the genomic level to improve efficacy and reduce toxicities.Recently,the innovative gene-editing technology-clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated nuclease9(Cas9)system,which particularly exhibits preponderance in knock-in and knockout at specific sites,is widely utilized to manufacture CAR-T products.The application of CRISPR/Cas9 to CAR-T cell therapy has shown promising clinical results with minimal toxicity.In this review,we summarized the past achievements of CRISPR/Cas9 in CAR-T therapy and focused on the potential CAR-T targets.

Long non-coding RNA MALAT1 in hematological malignancies and its clinical applications

Metastasis-associated lung adenocarcinoma transcript 1(MALAT1)is a well-established oncogenic long non-coding RNA,the higher expression of which is strongly correlated with cancer events such as tumorigenesis,progression,metastasis,drug resistance,and treatment outcome in solid cancers.Recently,a series of studies has highlighted its potential role in hematological malignancies in terms of these events.Similar to solid cancers,MALAT1 can regulate various target genes via sponging and epigenetic mechanisms,but the miRNAs sponged by MALAT1 differ from those identified in solid cancers.In this review,we systematically describe the role and underlying mechanisms of MALAT1 in multiple types of hematological malignancies,including regulation of cell proliferation,metastasis,stress response,and glycolysis.Clinically,MALAT1 expression is related to poor treatment outcome and drug resistance,therefore exhibiting potential prognostic value in multiple myeloma,lymphoma,and leukemia.Finally,we discuss the evaluation of MALAT1 as a novel therapeutic target against cancer in preclinical studies.

Advances and clinical applications of immune checkpoint inhibitors in hematological malignancies

Immune checkpoints are differentially expressed on various immune cells to regulate immune responses in tumor microenvironment.Tumor cells can activate the immune checkpoint pathway to establish an immunosuppressive tumor microenvironment and inhibit the anti-tumor immune response,which may lead to tumor progression by evading immune surveillance.Interrupting coinhibitory signaling pathways with immune checkpoint inhibitors(ICIs)could reinvigorate the anti-tumor immune response and promote immune-mediated eradication of tumor cells.As a milestone in tumor treatment,ICIs have been firstly used in solid tumors and subsequently expanded to hematological malignancies,which are in their infancy.Currently,immune checkpoints have been investigated as promising biomarkers and therapeutic targets in hematological malignancies,and novel immune checkpoints,such as signal regulatory proteinα(SIRPα)and tumor necrosis factor-alpha-inducible protein 8-like 2(TIPE2),are constantly being discovered.Numerous ICIs have received clinical approval for clinical application in the treatment of hematological malignancies,especially when used in combination with other strategies,including oncolytic viruses(OVs),neoantigen vaccines,bispecific antibodies(bsAb),bio-nanomaterials,tumor vaccines,and cytokine-induced killer(CIK)cells.Moreover,the proportion of individuals with hematological malignancies benefiting from ICIs remains lower than expected due to multiple mechanisms of drug resistance and immune-related adverse events(irAEs).Close monitoring and appropriate intervention are needed to mitigate irAEs while using ICIs.This review provided a comprehensive overview of immune checkpoints on different immune cells,the latest advances of ICIs and highlighted the clinical applications of immune checkpoints in hematological malignancies,including biomarkers,targets,combination of ICIs with other therapies,mechanisms of resistance to ICIs,and irAEs,which can provide novel insight into the future exploration of ICIs in tumor treatment.

Incidence rate and risk factors of second primary neoplasms among older patients with hematological malignancies:Insights from a Chinese single-center experience(1997-2021)

Background:Patients with hematological malignancies face an increased risk of developing second primary neoplasms due to various factors,including immune system compromise and chemotherapy-related effects.However,the incidence and associated risk factors in older patients remain poorly understood.This study aimed to assess the incidence,identify risk factors,and evaluate their impact on survival outcomes among older patients with hematological malignancies.Methods:This retrospective single-center study analyzed data from 163 patients,focusing on the occurrence of second primary neoplasms.Cumulative incidence rates were calculated,and risk factor analysis was conducted using a competing risk model.Results:Among 124 eligible patients with a total follow-up duration of 572.57 person-years,the incidence rate of second primary neoplasms was 15.72/1000 person-years.The standardized incidence ratio(SIR)was 0.81(95%confidence interval[CI][0.39–1.48],P=0.518).History of radiotherapy emerged as a significant risk factor(subdistribution hazard ratio[SHR]=21.61[2.81–166.14],P=0.003),whereas regular natural killer(NK)cell infusion was associated with reduced risk(SHR=3.25 e8[9.81 e9–1.08 e7],P<0.001).Conclusions:These findings underscore the importance of informing older patients with hematological malignancies about the long-term risks of second primary neoplasms.Healthcare providers should carefully weigh risk factors when formulating treatment strategies.The results are valuable for investigating the fundamental principles underlying the occurrence and progression of second primary neoplasms.

Targeting SAMHD1: To overcome multiple anti-cancer drugs resistance in hematological malignancies

Sterile α motif and histidine/aspartic acid domain containing protein 1 (SAMHD1) is a deoxynucleoside triphosphate (dNTPs) triphosphohydrolase that can hydrolyze dNTPs into deoxynucleosides and triphosphates to keep the balance of the intracellular dNTPs pool. Moreover, it has been reported that SAMHD1 plays a role in regulating cell proliferation and the cell cycle, maintaining genome stability and inhibiting innate immune responses. SAMHD1 activity is regulated by phosphorylation, oxidation, SUMOylation, and O-GlcNAcylation. SAMHD1 mutations have been reported to cause diseases, including chronic lymphocytic leukemia and mantle cell lymphoma. SAMHD1 expression in acute myeloid leukemia predicts inferior prognosis. Recently, it has been revealed that SAMHD1 mediates the resistance to anti-cancer drugs. This review will focus on SAMHD1 function and regulation, the association between SAMHD1 and hematological malignancies and will provide updated information on SAMHD1 mediating resistance to nucleoside analogue antimetabolites, topoisomerase inhibitors, platinum-derived agents and DNA hypomethylating agents. Furthermore, histone deacetylase inhibitors and tyrosine kinase inhibitors indirectly increase anti-cancer drug resistance by increasing SAMDH1 activity. We herein highlight the importance of the development of novel agents targeting SAMHD1 to overcome treatment resistance of hematological malignancies, which would be an opportunity to improve the outcome of patients with refractory hematological malignancies.

Challenges and optimal strategies of CAR T therapy for hematological malignancies

Remarkable improvement relative to traditional approaches in the treatment of hematological malignancies by chimeric antigen receptor (CAR) T-cell therapy has promoted sequential approvals of eight commercial CAR T products within last 5 years. Although CAR T cells’ productization is now rapidly boosting their extensive clinical application in real-world patients, the limitation of their clinical efficacy and related toxicities inspire further optimization of CAR structure and substantial development of innovative trials in various scenarios. Herein, we first summarized the current status and major progress in CAR T therapy for hematological malignancies, then described crucial factors which possibly compromise the clinical efficacies of CAR T cells, such as CAR T cell exhaustion and loss of antigen, and finally, we discussed the potential optimization strategies to tackle the challenges in the field of CAR T therapy.

Clinical development of chimeric antigen receptor-T cell therapy for hematological malignancies

Cellular therapies have revolutionized the treatment of hematological malignancies since their conception and rapid development.Chimeric antigen receptor(CAR)-T cell therapy is the most widely applied cellular therapy.Since the Food and Drug Administration approved two CD19-CAR-T products for clinical treatment of relapsed/refractory acute lymphoblastic leukemia and diffuse large B cell lymphoma in 2017,five more CAR-T cell products were subsequently approved for treating multiple myeloma or B cell malignancies.Moreover,clinical trials of CAR-T cell therapy for treating other hematological malignancies are ongoing.Both China and the United States have contributed significantly to the development of clinical trials.However,CAR-T cell therapy has many limitations such as a high relapse rate,adverse side effects,and restricted availability.Various methods are being implemented in clinical trials to address these issues,some of which have demonstrated promising breakthroughs.This review summarizes developments in CAR-T cell trials and advances in CAR-T cell therapy.

Blockade of CD300A enhances the ability of human NK cells to lyse hematologic malignancies

Objective: The human cluster of differentiation(CD)300A, a type-I transmembrane protein with immunoreceptor tyrosine-based inhibitory motifs, was investigated as a potential immune checkpoint for human natural killer(NK) cells targeting hematologic malignancies(HMs).Methods: We implemented a stimulation system involving the CD300A ligand, phosphatidylserine(PS), exposed to the outer surface of malignant cells. Additionally, we utilized CD300A overexpression, a CD300A blocking system, and a xenotransplantation model to evaluate the impact of CD300A on NK cell efficacy against HMs in in vitro and in vivo settings. Furthermore, we explored the association between CD300A and HM progression in patients.Results: Our findings indicated that PS hampers the function of NK cells. Increased CD300A expression inhibited HM lysis by NK cells. CD300A overexpression shortened the survival of HM-xenografted mice by impairing transplanted NK cells. Blocking PS–CD300A signals with antibodies significantly amplified the expression of lysis function-related proteins and effector cytokines in NK cells, thereby augmenting the ability to lyse HMs. Clinically, heightened CD300A expression correlated with shorter survival and an “exhausted” phenotype of intratumoral NK cells in patients with HMs or solid tumors.Conclusions: These results propose CD300A as a potential target for invigorating NK cell-based treatments against HMs.

Prevention of hepatitis B reactivation in patients with hematologic malignancies treated with novel systemic therapies:Who and Why?

The risk of reactivation in patients with chronic or past/resolved hepatitis B virus(HBV)infection receiving chemotherapy or immunosuppressive drugs is a wellknown possibility.The indication of antiviral prophylaxis with nucleo(t)side analogue is given according to the risk of HBV reactivation of the prescribed therapy.Though the advent of new drugs is occurring in all the field of medicine,in the setting of hematologic malignancies the last few years have been characterized by several drug classes and innovative cellular treatment.As novel therapies,there are few data about the rate of HBV reactivation and the decision of starting or not an antiviral prophylaxis could be challenging.Moreover,patients are often treated with a combination of different drugs,so evaluating the actual role of these new therapies in increasing the risk of HBV reactivation is difficult.First results are now available,but further studies are still needed.Patients with chronic HBV infection[hepatitis B surface antigen(HBsAg)positive]are reasonably all treated.Past/resolved HBV patients(HBsAg negative)are the actual area of uncertainty where it could be difficult choosing between prophylaxis and pre-emptive strategy.

Risk of hepatic decompensation from hepatitis B virus reactivation in hematological malignancy treatments

In this editorial,we discussed the apparent discrepancy between the findings described by Colapietro et al,in their case report and data found in the literature.Colapietro et al reported a case of hepatitis B virus(HBV)-related hepatic decompensation in a patient with chronic myeloid leukemia and a previously resolved HBV infection who was receiving Bruton’s tyrosine kinase(BTK)inhibitor therapy.First of all,we recapitulated the main aspects of the immune system involved in the response to HBV infection in order to underline the role of the innate and adaptive response,focusing our attention on the protective role of anti-HBs.We then carefully analyzed literature data on the risk of HBV reactivation(HBVr)in patients with previous HBV infection who were treated with either tyrosine kinase inhibitors or BTK inhibitors for their hematologic malignancies.Based on literature data,we suggested that several factors may contribute to the different risks of HBVr:The type of hematologic malignancy;the type of therapy(BTK inhibitors,especially second-generation,seem to be at a higher risk of HBVr than those with tyrosine kinase inhibitors);previous exposure to an anti-CD20 as first-line therapy;and ethnicity and HBV genotype.Therefore,the warning regarding HBVr in the specific setting of patients with hematologic malignancies requires further investigation.

Preclinical evaluation of cyclophosphamide and fludarabine combined with CD19 CAR-T in the treatment of B-cell hematologic malignancies in vivo

Background:Chimeric antigen receptor T(CAR-T)cell therapy has achieved marked therapeutic success in ameliorating hematological malignancies.However,there is an extant void in the clinical guidelines concerning the most effective chemotherapy regimen prior to chimeric antigen receptor T(CAR-T)cell therapy,as well as the optimal timing for CAR-T cell infusion post-chemotherapy.Materials and Methods:We employed cell-derived tumor xenograft(CDX)murine models to delineate the optimal pre-conditioning chemotherapy regimen and timing for CAR-T cell treatment.Furthermore,transcriptome sequencing was implemented to identify the therapeutic targets and elucidate the underlying mechanisms governing the treatment regimen.Results:Our preclinical in vivo evaluation determined that a combination of cyclophosphamide and fludarabine,followed by the infusion of CD19 CAR-T cells five days subsequent to the chemotherapy,exerts the most efficacious therapeutic effect in B-cell hematological malignancies.Concurrently,RNA-seq data indicated that the therapeutic efficacy predominantly perturbs tumor cell metabolism,primarily through the inhibition of key mitochondrial targets,such as C-Jun Kinase enzyme(C-JUN).Conclusion:In summary,the present study offers critical clinical guidance and serves as an authoritative reference for the deployment of CD19 CAR-T cell therapy in the treatment of B-cell hematological malignancies.

Natural products against hematological malignancies and identification of their targets

Naturally occurring molecules derived from higher plants, animals, microorganisms and minerals play an important role in the discovery and development of novel therapeutic agents. The identification of molecular targets is of interest to elucidate the mode of action of these compounds, and it may be employed to set up target-based assays and allow structure-activity relationship studies to guide medicinal chemistry efforts toward lead optimization. In recent years, plant-derived natural compounds possessing potential anti-tumor activities have been garnering much interest and efforts are underway to identify their molecular targets. Here, we attempt to summarize the discoveries of several natural compounds with activities against hematological malignancies, such as adenanthin, oridonin, gambogic acid and wogonoside, the identification of their targets, and their modes of actions.