Combined flow cytometry natural killer immunophenotyping and KIR/HLA-C genotyping reveal remarkable differences in acute myeloid leukemia patients, but suggest an overall impairment of the natural killer response.

Introduction: Natural killer (NK) cells are key anti-tumor effectors of the innate immunity. Phenotypic differences allow us to discriminate in between three functional stages of maturation, named immature, mature and hypermature that are distinctive in terms of receptor expression, cytokine secretion, cytotoxic properties and organ trafficking. NKs display an impressive repertoire of highly polymorphic germline encoded receptors that can be either activating, triggering the effector's function, or inhibitory, limiting the immune response. In our study, we have investigated peripheral blood NK cells of acute myeloid leukemia (AML) patients. Methods: The Killer Immunoglobulin-like receptors (KIRs) and the HLA-C genotypes were assessed, as HLA-C molecules are cognate antigens for inhibitory KIRs. Results: The AA mainly inhibitory KIR haplotype was found in a higher proportion in AML, while a striking low frequency of the 2DS3 characterized the mainly activating Bx haplotype. Flow cytometry immunophenotyping evidenced a lower overall count of NK cells in AML versus healthy controls, with lower percentages of the immature and mature subpopulations, but with a markedly increase of the hypermature NKs. The analysis of the KIR2DL1, KIR2DL2, KIR2DL3, KIR3DL1, and NKG2A inhibitory receptors surface expression revealed a remarkable heterogeneity. However, an overall trend for a higher expression in AML patients could be noticed in all maturation subpopulations. Some of the AML patients with complex karyotypes or displaying a FLT3 gene mutation proved to be extreme outliers in terms of NK cells percentages or inhibitory receptors expression. Discussion: We conclude that while the genetic background investigation in AML offers important pieces of information regarding susceptibility to disease or prognosis, it is flow cytometry that is able to offer details of finesse in terms of NK numbers and phenotypes, necessary for an adequate individual evaluation of these patients.

Prognostic Value of Association of Copy Number Alterations and Cell-Surface Expression Markers in Newly Diagnosed Multiple Myeloma Patients.

Multiple myeloma results from the clonal proliferation of abnormal plasma cells (PCs) in the bone marrow (BM). In this study, the cell surface expression markers (CD) on atypical PCs (detected by multiparametric flow cytometry (MFC)) were correlated with copy number alterations (CNAs) in the genome (detected by multiplex ligation-dependent probe amplification (MLPA)) to assess their impact on prognosis in newly diagnosed MM patients. Statistically significant results were obtained when different stages of PC maturation (classified based on CD19 and CD81 expression) were associated with CD117 expression and identified CNAs. In the intermediately differentiated PC group (CD19(-) CD81(+)), patients who didn't express CD117 had a lower median progression free survival (PFS) (p = 0.024). Moreover, within this group, patients with less than three adverse CNAs, which harbor CD117, had a better outcome with a PFS of more than 48 months compared with 19 months (p = 0.008). Considering all the results, our study suggested the need to integrate both the CD markers and copy number alterations to evaluate the prognosis of newly diagnosed multiple myeloma patients.

Ibrutinib Monotherapy as Bridge-to-Transplant for Relapsed/Refractory Primary Oculo-Cerebral Lymphoma.

INTRODUCTION: Primary central nervous system lymphoma is an uncommon form of extranodal non-Hodgkin's lymphoma, with increasing incidence, a relatively aggressive course and a poor 5-year survival. Because of its localization, the therapeutic compounds used in this disease must be able to pass through the blood-brain barrier. Chemotherapy regimens based on high-dose methotrexate are currently the standard of care for all patients who can tolerate such drugs. Autologous stem cell transplantation is indicated for malignant lymphomas in the relapsed/refractory setting. METHODS: Three patients, with a median age of 60 years, range 53-64, were diagnosed with primary CNS lymphoma, and treated with ibrutinib monotherapy in the Department of Hematology, Ion Chiricuta Clinical Cancer Center, Cluj-Napoca, Romania, between September 2018 and November 2020 All the patients were relapsed-refractory following high-dose methotrexate chemotherapy. We present our experience using ibrutinib monotherapy-based treatment as a bridge-to-transplant option on a single-center case series and a review of the literature in this field. RESULTS: Two of the patients were given ibrutinib as a second line therapy, both achieving complete remission and being eligible for an autologous stem cell transplantation. The third patient achieved a short remission using six cycles of systemic chemotherapy, but was started on ibrutinib monotherapy, with limited results. CONCLUSION: Our data is limited, and these results should be confirmed by multicentric clinical trials and should be regarded as a single-center case series, with all its limitations. Still, it brings forward a new therapeutic option for this rare subtype of malignant lymphomas, which if left untreated has a dismal prognosis.

The MHC-II antigen presentation machinery and B7 checkpoint ligands display distinctive patterns correlated with acute myeloid leukaemias blast cells HLA-DR expression.

Acute Myeloid Leukaemia (AML) is a neoplasia characterised by rapid proliferation and an increased rate of relapses. The AML blasts display features of antigen-presenting cells (APC), and thus can directly modulate the anti-tumour T cell responses. The bone marrow of a group consisting of 30 newly diagnosed patients and four healthy donors (HD) was investigated for the expression of HLA-DR, several molecules involved in MHC-II antigen-presentation and MHC-II groove editing, like HLA-DM, CD74 and CLIP, as well as a set of immune checkpoint ligands, like ICOS-L, B7.2, PD-L2 and B7-H3. The patients were further characterised for their genetic anomalies and distributed to favourable, intermediate and adverse ELN risk categories. We were able to show that while 23% of our patients displayed a low level of HLA-DR surface expression, all patients displayed higher HLA-DM and CD74 expression compared to HD. However, a higher CLIP expression was noticed only in the HLA-DR low patients. The co-inhibitory PD-L2 and B7-H3 molecules were increased in the cases with normal HLA-DR expression; oppositely, the co-stimulatory ICOS-L and the dual function B7.2 were significantly increased in the cases with HLA-DR low expression. Furthermore, no favourable ELN risk cases were found within the HLA-DR low group. All in all, these data show that the AML with low versus normal HLA-DR expression display different profiles of MHC class II machinery molecules and B7 ligands, which are correlated with distinct ELN stratification. Furthermore, as our study included healthy individuals, it offers valuable information about the expression levels that should be considered as normal for these markers known to cause differences in peptide repertoires, reflected further in distinct T-cells polarisation pathways.

A very rare case of FLT3-D835 positive blastic plasmacytoid dendritic cell neoplasm.

Blastic plasmacytoid dendritic cell neoplasms (BPDCNs) are extremely rare and aggressive hematological malignancies that derive from precursors of plasmacytoid dendritic cells (pDC) and frequently involve skin lesions and bone marrow infiltration. They mostly affect the elderly population and the prognosis is poor with the therapeutic choices currently available. Diagnosis is made with the help of tools such as immunohistochemistry and flow cytometry. Here, we present a particular case of BPDCN with a positive FLT3-D835 mutation and we discuss the possible impact this may have on the evolution of the disease and response to treatment.

ABL1 tyrosine kinase domain mutations in chronic myeloid leukemia treatment resistance.

The development of mutations in the BCR-ABL1 fusion gene transcript causes resistance to tyrosine kinase inhibitors (TKIs) based therapy in chronic myeloid leukemia (CML). Thereby, screening for BCR-ABL1 mutations is advised especially in patients undergoing poor response to treatment. In the current study the authors investigated 43 patients with CML that failed or had suboptimal response to TKIs treatment. Blood samples were collected from patients that were treated with TKIs. The analysis of genetic mutations was performed using a semi-nested PCR assay, followed by Sanger sequencing. The analysis revealed 15 mutations (32.55%): 14 point mutations and an exon 7 deletion. In roughly 30% of cases, mutations in the BCR-ABL1 fusion gene are common causes for treatment resistance.

Let's Talk About BiTEs and Other Drugs in the Real-Life Setting for B-Cell Acute Lymphoblastic Leukemia.

Background: Therapy for acute lymphoblastic leukemia (ALL) are currently initially efficient, but even if a high percentage of patients have an initial complete remission (CR), most of them relapse. Recent data shows that immunotherapy with either bispecific T-cell engagers (BiTEs) of chimeric antigen receptor (CAR) T cells can eliminate residual chemotherapy-resistant B-ALL cells. Objective: The objective of the manuscript is to present improvements in the clinical outcome for chemotherapy-resistant ALL in the real-life setting, by describing Romania's experience with bispecific antibodies for B-cell ALL. Methods: We present the role of novel therapies for relapsed B-cell ALL, including the drugs under investigation in phase I-III clinical trials, as a potential bridge to transplant. Blinatumomab is presented in a critical review, presenting both the advantages of this drug, as well as its limitations. Results: Bispecific antibodies are discussed, describing the clinical trials that resulted in its approval by the FDA and EMA. The real-life setting for relapsed B-cell ALL is described and we present the patients treated with blinatumomab in Romania. Conclusion: In the current manuscript, we present blinatumomab as a therapeutic alternative in the bridge-to-transplant setting for refractory or relapsed ALL, to gain a better understanding of the available therapies and evidence-based data for these patients in 2019.

Exosome-carried microRNA-based signature as a cellular trigger for the evolution of chronic lymphocytic leukemia into Richter syndrome.

Even if considered a cumulative and not a proliferative CD5+ B-cell neoplasm, chronic lymphocytic leukemia (CLL) has a proliferation rate higher than that recognized earlier, especially in the lymphoid tissues. Some patients with CLL develop a clinical syndrome entitled Richter syndrome (RS). Understanding CLL genetics and epigenetics may help to elucidate the molecular basics of the clinical heterogeneity of this type of malignancy. In the present project we aimed to identify a microRNA species that can predict the evolution of therapy-resistant CLL towards RS. In the first phase of our study, microRNA-19b was identified as a possible target, and in the second phase, we transfected three different CLL cell lines with microRNA-19b mimic and inhibitor and assessed the potential role on leukemia cells in vitro. The mechanism by which miR-19b acts were identified as the upregulation of Ki67 and downregulation of p53. This was further supported through RT-PCR and western blotting on CLL cell lines, as well as by next generation sequencing on two patients diagnosed with CLL that evolved into RS.

Efficacy and safety of frontline rituximab, cyclophosphamide, doxorubicin and prednisone plus bortezomib (VR-CAP) or vincristine (R-CHOP) in a subset of newly diagnosed mantle cell lymphoma patients medically eligible for transplantation in the randomized, phase 3 LYM-3002 study.

This post-hoc subanalysis of the LYM-3002 phase 3 study assessed the efficacy and safety of substituting vincristine in rituximab, cyclophosphamide, doxorubicin and prednisone (R-CHOP; n = 42) for bortezomib (VR-CAP; n = 38) in a subgroup of 80 mantle cell lymphoma (MCL) patients aged <60 years who did not receive stem cell transplantation (SCT) despite medical eligibility. Complete response (CR)/unconfirmed CR (CRu) rates were 67 vs. 39% (odds ratio 3.69 [95% CI(confidence interval): 1.31, 10.41]; p = .012). After 40 months median follow-up, median progression-free survival by independent radiology committee with VR-CAP vs. R-CHOP was 32.6 vs. 12.0 months (hazard ratio (HR) 0.59 [95% CI: 0.31, 1.13]; p = .108); median overall survival was not reached vs. 47.3 months (HR 0.81 [95% CI: 0.33, 1.96]; p = .634). Adverse events included neutropenia (92/76%), thrombocytopenia (70/10%) and leukopenia (65/50%). VR-CAP represents a potential alternative to R-CHOP in combined and/or alternating regimens for younger, SCT-eligible MCL patients.

Pact with the devil: alemtuzumab therapy, immune suppression and infectious complications in chronic lymphocytic leukemia.

Infectious complications are an important cause of hospitalization in patients diagnosed with chronic lymphocytic leukemia. The pathogenesis of infection is complex, involving both disease-induced and treatment-related immune depression. During the last decade, the management of chronic lymphocytic leukemia (CLL) has been redefined by the approval of monoclonal antibody-based treatment, which resulted in improved therapeutic responses. Nonetheless, the profound lymphopenia induced by monoclonal agents was accompanied by increased incidence of infections caused by a new spectrum of opportunistic microorganisms. We report the case of a patient with hypercellular CLL who received Alemtuzumab as first line therapy and obtained a satisfactory therapeutic response, but developed subsequent atypical infectious complications.

[Prognostic significance of leukemia-associated phenotype in correlation with other biologic markers in acute myeloid leukemia patients]. / Identificarea semnificatiei prognostice a fenotipului asociat leucemiei in corelatie cu alti markeri biologici la pacientii cu leucemie acuta mieloblastica.

UNLABELLED: Leukemic cells have unique aberrant phenotypes, which permit identification of this cells at diagnose and in evolution of the disease. Signaling molecules with other cells and bone marrow stroma are part of the leukemic cells phenotype. Genetic and molecular abnormalities have the main prognostic significance and confer the leukemic cell status. The main aim of the current study is to identify correlation between recognized prognostic factors in acute myeloid leukemia (AML) patients and other phenotypic markers. MATERIAL AND METHOD: Imunophenotypic analysis (BDFACS CantoII, FACSDiva Software) was performed on peripheral blood/bone marrow aspirate samples of 56 patients diagnosed with AML (9 M0, 3 M1, 10 M2, 4 M3, 28 M4/M5, 1 M6, 1 M7) between 2007-2009 in Hematology Department of "Sf. Spiridon" Hospital Iasi. We used an extended panel of monoclonal antibodies and we determined the level of expression of cytokines receptors (IL3Ra, IL7R) and chemokines (CXCR4, CKR5). RESULTS: In our study, IL7R expression on AML blasts was significant correlate with low WBC count at diagnosis (p = 0.04) and with multilinear displasia (p = 0.01), high CXCR4 expression was correlate (p = 0.05) with lack of response at first induction therapy and CD123 (IL3Ra) expression was correlate with M4 FAB phenotype. Survival was negative influenced by presence of IL3R on AML blasts, but flt3 mutations, CXCR4, IL7R expression on leukemic cells, other phenotypic aberrancies did not influenced treatment response and survival in our patients population. CONCLUSION: Complete investigation of leukemic cells phenotype extended with cytokines/chemokines receptors at diagnostic is useful for correct characterization of the disease, for discover new prognostic categories and for better identification of minimal residual disease.