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Characterization of the novel HLA-C*15:228 and HLA-C*04:434 alleles in two Greek individuals of Cretan origin.

Characterization of HLA-DQB1*03:439 allele in a Greek individual of Cretan origin.

Introduction: Pomalidomide (POM) plus low-dose dexamethasone (POM/LoDex) is a standard of care for patients with relapsed/refractory multiple myeloma (RRMM), who have received ≥2 prior therapies, including lenalidomide (LEN) and bortezomib (BORT). In view of the limited real-world evidence on POM/LoDex effectiveness, this study aimed to provide insight into progression-free survival (PFS), response to treatment and drug utilization patterns in the routine clinical practice in Greece. Methods: 'POWERFUL' (NCT03353545) was a non-interventional, multicenter, retrospective and prospective study of adult RRMM patients, initiated on POM/LoDex between 01-Jan-2016 and 28-Feb-2019 per the approved label. Patients who had received up to one POM/LoDex cycle were consecutively enrolled between 16-Nov-2017 and 21-Feb-2019 (prospective recruitment phase). One month prior to completion of this phase, aiming to facilitate recruitment of the target size, patients, whose treatment with POM/LoDex was ongoing but >1 cycles had been received or for whom treatment was discontinued, were consecutively enrolled in reverse chronological order, based on POM/LoDex start date (retrospective recruitment). Patients were observed until the earliest point of disease progression (PD), death, informed consent (IC) withdrawal, treatment discontinuation for reason other than PD or start of next antimyeloma therapy, physician's decision, or last patient enrolled plus up to 12 months of treatment. IC or consent waiver for deceased subjects was obtained. Safety data were collected prospectively. Results: Eligible patients (N=99; 75 with prospective and 24 with a purely retrospective follow-up) were recruited by 18 hematology departments. The median (IQR) observation period was 8.8 (4.2-15.4) months. Baseline patient characteristics are presented in Table 1. Fifty patients (50.5%) started POM/LoDex as third-line treatment. POM was initiated at 4 mg/day on days 1-21 every 28 days in 75.8% of the patients. A median of 8 (range: 1-38) cycles were received at a median POM dose of 4 mg/day (range: 1-4), over 8.3 (range: 0.3-47.6) months. The POM dose reduction and interruption rates were 28.3% and 59.6%, respectively. Of the patients, 37.4% were treated for ≥ one year. Treatment was discontinued in 81.8%, due to PD (56.8%), safety reasons (22.2%), death (6.2%), other reasons (9.9%), and due to loss of follow-up (4.9%). The investigator-assessed overall response rate (≥partial response [PR]) was 32.3%; best response rates were: stringent complete or complete response (7.1%), very good PR (8.1%), PR (17.2%), minimal response (11.1%), stable disease (21.2%), PD (12.1%), and non-evaluable response (23.2%). Median time to response and duration of response in patients achieving ≥PR was 3.2 [95% confidence interval (CI): 2.6-3.6] and 15.8 (95%CI: 11.3-not reached) months, respectively. Over a Kaplan-Meier estimated median follow-up of 13.8 months, the median PFS was 10.5 months (95%CI: 7.4-14.4) [13.0 vs. 8.8 months for patients treated in the third vs. the fourth- and beyond line (log-rank p=0.494), and 13.0 vs. 8.8 months for patients treated with POM/LoDex only vs. those co-administered other antimyeloma agents (log-rank p=0.411)]. The estimated 6-, 12-, 24- and 36-month PFS rates were 70.3%, 48.3%, 20.1% and 12.0%, respectively. Multivariate Cox regression analysis of the impact of baseline characteristics on PFS indicated male sex [hazard ratio (HR)=2.08; 95%CI: 1.12-3.89; p=0.021] and higher than normal serum lactate dehydrogenase levels (HR=2.84; 95%CI: 1.39-5.81; p=0.004) as negative predictors of PFS. Over a median safety data collection period of 7.6 months (range: 0.4-18.6), the POM-related adverse events (ADR) incidence rate in the safety-evaluable population (i.e., 75 patients with prospective follow-up) was 42.7% (73 events). Only neutropenia (13.3%) was reported at a frequency ≥10%. The serious ADR rate was 18.7%, whereas grade ≥ 3 hematological and non-hematological ADR rates were 8.0%, and 5.3%, respectively. Conclusion: In this Real-World dataset from Greek centers, POM/LoDex, administered in the third-line and beyond setting of RRMM, displayed a longer PFS than in controlled clinical trials, which was not impacted by the treatment line and concurrent receipt of other antimyeloma agents. About one-third of patients achieved at least PR with an about 16-month response duration. Disclosures Terpos: Amgen: Honoraria, Research Funding; Sanofi: Honoraria; Celgene: Honoraria; Takeda: Honoraria, Other: travel expenses , Research Funding; Janssen: Honoraria, Research Funding; Genesis pharma SA: Honoraria, Other: travel expenses , Research Funding; BMS: Honoraria. Repousis:Genesis pharma SA: Membership on an entity's Board of Directors or advisory committees, Research Funding. Hatjiharissi:Roche: Honoraria; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis pharma SA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Honoraria; Gilead: Membership on an entity's Board of Directors or advisory committees. Assimakopoulou:Genesis pharma SA: Research Funding. Vassilopoulos:Abbvie: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Genesis pharma SA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Gilead: Research Funding. Pouli:Genesis pharma SA: Research Funding. Spanoudakis:Genesis pharma SA: Research Funding. Michali:Takeda: Research Funding; Genesis pharma SA: Research Funding. Pangalis:Genesis pharma SA: Research Funding. Poziopoulos:Genesis pharma SA: Research Funding. Kyrtsonis:Genesis pharma SA: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Pappa:Genesis pharma SA: Research Funding. Symeonidis:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GenesisPharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck Sharp & Dohme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; WinMedica: Research Funding; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Honoraria, Research Funding; Astellas: Research Funding; Abbvie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi/Genzyme: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Georgopoulos:Genesis pharma SA: Research Funding. Zikos:Genesis pharma SA: Membership on an entity's Board of Directors or advisory committees, Research Funding. Papadaki:Genesis pharma SA: Membership on an entity's Board of Directors or advisory committees, Research Funding. Dadakaridou:Genesis pharma SA: Research Funding. Karvounis-Marolachakis:Genesis pharma SA: Current Employment. Patos:Genesis pharma SA: Current Employment. Katodritou:Janssen-Cilag: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Theagenion Cancer Hospital: Current Employment; Takeda: Honoraria, Other: Expenses, Research Funding; Genesis Pharma: Honoraria, Other: Expenses, Research Funding; Abbvie: Research Funding; Karyopharm: Research Funding.

Introduction Invasive candidiasis (IC) can be a life-threatening infection in immunocompromised patients, particularly those with cancer, hematologic diseases and/or hematopoietic stem cell transplantation (HSCT) recipients. The objective of this study was to evaluate the effectiveness of micafungin in patients with hematologic malignancies or HSCT recipients, relevant to clinical presentation of IC, in real-life practice in Greece. Methods ASPIRE was a phase IV, multicenter, non-interventional, prospective cohort study, conducted at ten tertiary hospitals in Greece, in adults with hematologic disease. Micafungin treatment for IC or prophylaxis for Candida infection was administered per standard clinical practice until a clinical outcome (success or failure) was reached. Treatment success was defined by the EORTC/MSG criteria for invasive fungal infections (IFI) and was assessed by the investigator. Treatment discontinuation and safety were also evaluated. Results One hundred forty-three patients were enrolled. Median age was 62; 85 (59.4%) patients were male, and 133 (93.0%) had Greek ethnicity. One hundred twenty-six (88.1%) patients had hematologic malignancies, and 21 (14.7%) had received HSCT. Prophylaxis was administered to 74 (51.7%) patients [median (range) dose: 50 (50–150) mg/day] with no signs of IFI. Overall, 52 (36.4%) patients with possible IFI at baseline received micafungin treatment [100 (50–125) mg/day] versus 12 (17.2%) with probable [100 (75–150) mg/day] and 5 (3.5%) with confirmed [125 (100–150) mg/day] IFI. Treatment success was 91.6% (95% CI 85.80–95.59; n = 131) overall and 90.5% (n = 67) in patients receiving prophylaxis. Median time on treatment was 13 days. Treatment discontinuation (n = 26; 18.2%) was not related to adverse events. No treatment-related serious adverse events were reported. Conclusion Micafungin treatment for IC or prophylaxis for Candida infection was effective and well tolerated in patients with hematologic disorders in clinical practice in Greece. These results demonstrate that micafungin could be used more widely for prophylaxis. Further work is required to determine the efficacy and safety of micafungin for the management of IFIs in hematologic settings. Funding Astellas Pharma Inc.

Purpose To estimate the second cancer risk associated with Hodgkin Lymphoma (HL) radiotherapy at supradiaphragmatic or infradiaphragmatic region, using the involved field (IFRT) and the involved site radiotherapy (ISRT). Materials and methods IFRT and ISRT treatment plans were created for twenty HL patients. Three dimensional plans (3DRT) were employed for all patients. The organ equivalent dose (OED) and lifetime attributable risk (LAR) for organs at risk were estimated with mechanistic, plateau and bell-shaped model. Estimated risk values were compared with nominal risk of unexposed population. Results For supradiaphragmatic radiotherapy, the mean OED range was 0.63–8.53 Gy and 0.63–7.26 Gy for IFRT and ISRT, respectively. The corresponding range for infradiaphragmatic radiotherapy was 0.18–7.64 Gy and 0.80–4.95 Gy. The LAR for cancer induction in the partially in field organs at risk after IFRT was 0.5%–8.0% and 0.2%–9.3% at supradiaphragmatic and infradiaphragmatic regions, respectively. The corresponding risk after ISRT method was 0.5%–5.2% and 0.9%–6.0%. Estimated cancer risk for breast, lung, thyroid, colon and rectal with ISRT was found significantly reduced compared to IFRT. The risk of secondary malignancies for lung, mouth, pharynx, rectum and colon was assessed more than 1.2 times higher than nominal risk for IFRT. The respective risk using ISRT was above nominal only for pharyngeal cancer. Conclusion ISRT compared with IFRT, results in decreased second cancer risk in most organs considered. Second cancer probability with IFRT was higher than the nominal risk for certain organs, while for ISRT remains higher only for pharyngeal cancer.

© Springer-Verlag GmbH Germany, part of Springer Nature 2018, Mounting evidence has accumulated on the critical role of the different myeloid cells in the regulation of the cancerous process, and in particular in the modulation of the immune reaction to cancer. Myeloid cells are a major component of host cells infiltrating tumors, interacting with each other, with tumor cells and other stromal cells, and demonstrating a prominent plasticity. We describe here various myeloid regulatory cells (MRCs) in mice and human as well as their relevant therapeutic targets. We first address the role of the monocytes and macrophages that can contribute to angiogenesis, immunosuppression and metastatic dissemination. Next, we discuss the differential role of neutrophil subsets in tumor development, enhancing the dual and sometimes contradicting role of these cells. A heterogeneous population of immature myeloid cells, MDSCs, was shown to be generated and accumulated during tumor progression as well as to be an important player in cancer-related immune suppression. Lastly, we discuss the role of myeloid DCs, which can either contribute to effective anti-tumor responses or play a more regulatory role. We believe that MRCs play a critical role in cancer-related immune regulation and suggest that future anti-cancer therapies will focus on these abundant cells., This work was supported by COST (European Cooperation in Science and Technology) and the COST Action BM1404 Mye-EUNITER (http://www.mye-eunit er.eu). COST is part of the EU Framework Programme Horizon 2020. This work was also supported by Grants from the Cooperation between German Cancer Research Center (DKFZ) and Ministry of Science, Technology and Space of Israel (MOST) in Cancer Research (CA181 to V. Umansky and Z.G. Fridlender).

Myeloid-derived suppressor cells (MDSCs) are immature cells of myeloid origin that have gained researchers’ attention, as they constitute promising biomarkers and targets for novel therapeutic strategies (i.e., blockage of development, differentiation, depletion, and deactivation) in several conditions, including neoplastic, autoimmune, infective, and inflammatory diseases, as well as pregnancy, obesity, and graft rejection. They are characterised in humans by the typical immunophenotype of CD11b+CD33+HLA-DR–/low and immune-modulating properties leading to decreased T-cell proliferation, induction of T-regulatory cells (T-regs), hindering of natural killer (NK) cell functionality, and macrophage M2-polarisation. The research in the field is challenging, as there are still difficulties in defining cell-surface markers and gating strategies that uniquely identify the different populations of MDSCs, and the currently available functional assays are highly demanding. There is evidence that MDSCs display altered frequency and/or functionality and could be targeted in immune-mediated and malignant haematologic diseases, although there is a large variability of techniques and results between different laboratories. This review presents the current literature concerning MDSCs in a clinical point of view in an attempt to trigger future investigation by serving as a guide to the clinical haematologist in order to apply them in the context of precision medicine as well as the researcher in the field of experimental haematology.

Background aims The high genetic diversity of HLA across populations significantly confines the effectiveness of a donor or umbilical cord blood search for allogeneic hematopoietic stem cell transplantation (HSCT). This study aims to probe the HLA immunogenetic profile of the population of Crete, a Greek region with specific geographic and historical characteristics, and to investigate potential patterns in HLA distribution following comparison with the Deutsche Knochenmarkspenderdatei (DKMS) donor registry. It also aims to highlight the importance of regional public cord blood banks (PCBBs) in fulfilling HSCT needs, especially in countries with significant genetic diversity. Methods A cohort of 1835 samples representative of the Cretan population was typed for HLA class I (HLA-A, HLA-B, HLA-C) and class II (HLA-DRB1, HLA-DQB1, HLA-DPB1) loci by high-resolution second field next-generation sequencing. Data were compared with the respective HLA profiles of 12 DKMS populations (n = 20 032). Advanced statistical and bioinformatics methods were employed to assess specific intra- and inter-population genetic indexes associated with the regional and geographic distribution of HLA alleles and haplotypes. Results A considerable HLA allelic and haplotypic diversity was identified among the Cretan samples and between the latter and the pooled DKMS cohort. Even though the HLA allele and haplotype frequency distribution was similar to regions of close geographic proximity to Crete, a clinal distribution pattern from the northern to southern regions was identified. Significant differences were also observed between Crete and the Greek population of DKMS. Conclusions This study provides an in-depth characterization of the HLA immunogenetic profile in Crete and reveals the importance of demographic history in HLA heterogeneity and donor selection. The novel HLA allele and haplotype frequency comparative data between the Cretan and other European populations signify the importance of regional PCBBs in prioritizing HLA diversity to efficiently promote the HSCT program at the national level and beyond.

The “POWERFUL” multicenter, retrospective, and prospective study investigated the effectiveness of pomalidomide plus low-dose dexamethasone (POM/LoDex) therapy in relapsed/refractory multiple myeloma in routine care in Greece. Ninety-nine eligible adult patients treated with POM/LoDex according to the approved label after having received ≥2 prior therapies, including lenalidomide and bortezomib, were consecutively enrolled between 16 November 2017 and 21 February 2019 in 18 hematology departments. Fifty patients (50.5%) started POM/LoDex as third-line treatment. During the treatment period (median: 8.3 months, range: 0.3–47.6 months), the median POM dose was 4 mg/day, and 31.3% of the patients received additional antimyeloma agents. The overall response rate was 32.3%. During a median follow-up period of 13.8 months (Kaplan–Meier estimate), the median progression-free survival (PFS) was 10.5 months (95% CI: 7.4–14.4). The PFS was not significantly different between patients receiving POM/LoDex in the third versus later line of therapy, nor between patients receiving concomitant antimyeloma therapy versus POM/LoDEx doublet. During the prospective safety data collection period (median: 7.6 months) among patients with prospective follow-up (N = 75), POM-related adverse event incidence rate was 42.7% (serious: 18.7%, grade ≥ 3 hematological POM-related adverse events: 8.0%). Only neutropenia (13.3%) was reported at a frequency ≥10%. In conclusion, in this real-world study, POM/LoDex displayed a long PFS with no new safety signals emerging.

End-of-treatment (EoT) PET/CT is used as a guide to omit radiotherapy (RT) patients with primary mediastinal large B-cell lymphoma (PMBCL). We present the mature and extended results of a retrospective study evaluating the prognostic significance of EoT-PET/CT after adequate response to R-CHOP. Among 231 consecutive PMLBCL patients, 182 underwent EoT-PET/CT and were evaluated according to the Deauville 5-point scale (D5PS) criteria. Freedom from progression (FFP) was measured from the time of PET/CT examination. Among 182 patients, 72 (40%) had D5PS score 1 (D5PSS-1), 33 (18%) had 2, 28 (15%) had 3, 29 (16%) had 4, and 20 (11%) had 5. The 5-year FFP was 97, 94, 92, 82, and 44% for D5PSS-1, D5PSS-2, D5PSS-3, D5PSS-4, and D5PSS-5, respectively. Among 105 patients with unequivocally negative PET/CT (D5PSS-1/D5PSS-2), 49 (47%) received RT (median dose 3420 cGy) and 56 (53%) did not with relapses in 0/49 vs. 4/56 patients (2 mediastinum and 2 isolated CNS relapses).The 5-year FFP for those who received RT or not was 100% versus 96%, when isolated CNS relapses were censored (p = 0.159). Among D5PSS-3 patients (27/28 irradiated-median dose 3600 cGy), the 5-year FFP was 92%. The 5-year FFP for D5PSS-4 and D5PSS-5 was 82 and 44%; 44/49 patients received RT (median dose 4000 and 4400 cGy for D5PSS-4 and D5PSS-5). Our study supports the omission of RT in a sizeable fraction of PET/CT-negative patients and definitely discourages salvage chemotherapy and ASCT in patients with PMLBCL who conventionally respond to R-CHOP, solely based on PET/CT positivity in the absence of documented progressive or multifocal disease. The persistence of positive PET/CT with D5PSS < 5 after consolidative RT should not trigger the initiation of further salvage chemotherapy in the absence of conventionally defined PD.

Characterization of two novel HLA-A alleles in two Greek individuals of Cretan origin.

Characterization of the HLA-B*51:232:02 allele in a Greek individual of Cretan origin.

Immune deregulation has a critical role in the pathogenesis of lower risk myelodysplastic syndromes (MDS). The cells of the macrophage/monocyte lineage have been reported to contribute to the inflammatory process in MDS through impaired phagocytosis of the apoptotic hemopoietic cells and abnormal production of cytokines. In the present study we assessed the number of peripheral blood (PB) monocyte subsets, namely the classical CD14bright/CD16−, intermediate CD14bright/CD16+ and non-classical CD14dim/CD16+ cells, in patients with lower risk (low/intermediate-I) MDS (n = 32). We also assessed the production of tumor necrosis factor (TNF)α by patient PB monocytes in response to immune stimulus as well as their transcriptome profile. Compared to age- and sex-matched healthy individuals (n = 19), MDS patients had significantly lower number of classical and increased number of intermediate monocytes. Patient intermediate monocytes displayed increased production of TNFα following stimulation with lipopolysaccharide, compared to healthy individuals. Transcriptional profiling comparison of CD16+ monocytes from patients and controls revealed 43 differentially expressed genes mostly associated with biological pathways/processes relevant to hemopoiesis, immune signaling and cell adhesion. These data provide evidence for the first-time that distinct monocyte subsets display abnormal quantitative and functional characteristics in lower risk MDS substantiating their role in the immune deregulation associated with the disease.

Background R-CHOP can cure approximately 75% of patients with primary mediastinal large B-cell lymphoma (PMLBCL), but prognostic factors have not been sufficiently evaluated yet. R-da- EPOCH is potentially more effective but also more toxic than R-CHOP. Reliable prognostic classification is needed to guide treatment decisions. Materials and Methods We analyzed the impact of clinical prognostic factors on the outcome of 332 PMLBCL patients ≤65 years treated with R-CHOP ± radiotherapy in a multicenter setting in Greece and Cyprus. Results With a median follow-up of 69 months, 5-year freedom from progression (FFP) was 78% and 5-year lymphoma specific survival (LSS) was 89%. On multivariate analysis, extranodal involvement (E/IV) and lactate dehydrogenase (LDH) ≥2 times upper limit of normal (model A) were significantly associated with FFP; E/IV and bulky disease (model B) were associated with LSS. Both models performed better than the International Prognostic Index (IPI) and the age-adjusted IPI by Harrel's C rank parameter and Akaike information criterion. Both models A and B defined high-risk subgroups (13%–27% of patients [pts]) with approximately 19%–23% lymphoma-related mortality. They also defined subgroups composing approximately one-fourth or one-half of the patients, with 11% risk of failure and only 1% or 4% 5-year lymphoma-related mortality. Conclusion The combination of E/IV with either bulky disease or LDH ≥2 times upper limit of normal defined high-risk but not very-high-risk subgroups. More importantly, their absence defined subgroups comprising approximately one-fourth or one-half of the pts, with 11% risk of failure and minimal lymphoma-related mortality, who may not need more intensive treatment such as R-da-EPOCH. Implications for Practice By analyzing the impact of baseline clinical characteristics on outcomes of a large cohort of patients with primary mediastinal large B-cell lymphoma homogeneously treated with R-CHOP with or without radiotherapy, we developed novel prognostic indices which can aid in deciding which patients can be adequately treated with R-CHOP and do not need more intensive regimens such as R-da-EPOCH. The new indices consist of objectively determined characteristics (extranodal disease or stage IV, bulky disease, and markedly elevated serum lactate dehydrogenase), which are readily available from standard initial staging procedures and offer better discrimination compared with established risk scores (International Prognostic Index [IPI] and age-adjusted IPI).

Higher-risk Myelodysplastic syndromes (MDS) patients undergoing treatment with 5-azacytidine (AZA) are typically elderly with several comorbidities. However, the effect of comorbidities on the effectiveness and safety of AZA in real-world settings remains unclear. We analyzed data from 536 AZA-treated patients with higher-risk MDS, Myelodysplastic/Myeloproliferative neoplasms and low blast count Acute Myeloid Leukemia enrolled to the Hellenic National Registry of Myelodysplastic and Hypoplastic Syndromes. Multivariate analysis adjusted also for the International Prognostic Scoring System (IPSS), its revised version (IPSS-R) and the French Prognostic Scoring System (FPSS), demonstrated independent associations of overall and leukemia-free survival with estimated glomerular filtration rate (eGFR) 2 mg/dL, can be utilized as a more precise indicator of renal comorbidity during AZA therapy. Incorporation of eGFR in the prognostic assessment of AZA-treated MDS patients may prove useful not only in routine practice, but also for the appropriate patient stratification in clinical trials with AZA combinations.

Mesenchymal stem cells (MSCs) represent a heterogeneous cellular population responsible for the support, maintenance, and regulation of normal hematopoietic stem cells (HSCs). In many hematological malignancies, however, MSCs are deregulated and may create an inhibitory microenvironment able to induce the disease initiation and/or progression. MSCs secrete soluble factors including extracellular vesicles (EVs), which may influence the bone marrow (BM) microenvironment via paracrine mechanisms. MSC-derived EVs (MSC-EVs) may even mimic the effects of MSCs from which they originate. Therefore, MSC-EVs contribute to the BM homeostasis but may also display multiple roles in the induction and maintenance of abnormal hematopoiesis. Compared to MSCs, MSC-EVs have been considered a more promising tool for therapeutic purposes including the prevention and treatment of Graft Versus Host Disease (GVHD) following allogenic HSC transplantation (HSCT). There are, however, still unanswered questions such as the molecular and cellular mechanisms associated with the supportive effect of MSC-EVs, the impact of the isolation, purification, large-scale production, storage conditions, MSC source, and donor characteristics on MSC-EV biological effects as well as the optimal dose and safety for clinical usage. This review summarizes the role of MSC-EVs in normal and malignant hematopoiesis and their potential contribution in treating GVHD.

Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous population of myeloid cells that suppress immune responses in cancer, infection, and trauma. They mainly act by inhibiting T-cells, natural-killer cells, and dendritic cells, and also by inducing T-regulatory cells, and modulating macrophages. Although they are mostly associated with adverse prognosis of the underlying disease entity, they may display positive effects in specific situations, such as in allogeneic hematopoietic stem cell transplantation (HSCT), where they suppress graft-versus-host disease (GVHD). They also contribute to the feto-maternal tolerance, and in the fetus growth process, whereas several pregnancy complications have been associated with their defects. Human umbilical cord blood (UCB) is a source rich in MDSCs and their myeloid progenitor cells. Recently, a number of studies have investigated the generation, isolation, and expansion of UCB-MDSCs for potential clinical application associated with their immunosuppressive properties, such as GVHD, and autoimmune and inflammatory diseases. Given that a significant proportion of UCB units in cord blood banks are not suitable for clinical use in HSCT, they might be used as a significant source of MDSCs for research and clinical purposes. The current review summarizes the roles of MDSCs in the UCB, as well as their promising applications.

TO THE EDITOR: Treatment of splenic marginal zone lymphoma (SMZL) is not standardized due to the lack of prospective randomized trials.[1][1][⇓][2][⇓][3][⇓][4][⇓][5][⇓][6][⇓][7][⇓][8][⇓][9][⇓][10][⇓][11][⇓][12]-[13][13] After our initial 2007 paper, we now present updated data

Introduction-Aim: Chronic idiopathic neutropenia (CIN) is a neutrophil disorder characterized by the prolonged and unexplained reduction in the number of peripheral blood (PB) absolute neutrophil counts (ANC). The underlying pathogenesis in CIN implicates the production of proinflammatory cytokines by activated lymphocytes and monocytes that induce excessive apoptotic death of the bone marrow (BM) granulocytic progenitor cells. Clonal hematopoiesis identified by next generation sequencing (NGS) of myeloid genes is found in 11% of CIN patients conferring an increased risk for MDS/AML transformation whereas the non-clonal patients display usually a benign course. The basis for the immune cell activation and proinflammatory cytokine production in CIN remains obscure. Based on previously reported data showing increased frequency of mutations of the MEFV gene encoding pyrin in patients with idiopathic inflammatory conditions other than typical Familial Mediterranean Fever (FMF), we sought to investigate the common MEFV mutations in a cohort of well characterized CIN patients. Patients-Methods: We have studied 50 patients fulfilling the previously reported diagnostic criteria of CIN (median ANC 1.5x10 9/L, range 0.2-1.7 x10 9/L), 44 females and 6 males with a median age of 56 years (range 25-87 years) and a long-follow-up (median 132 months, range 8-336 months) in the Department of Hematology of the University Hospital of Heraklion, Crete, Greece. Nonisotopic RNase cleavage assay (NIRCA) analysis was used as first screening method to detect MEFV exons 10 and 2 mutations in DNA extracted from PB or BM samples from CIN patients, confirmed by direct NGS analysis. These sequences contain the main disease-related mutations and polymorphisms. Results: Genetics alterations of MEFV were detected in 22 out of 50 CIN patients (44%). Pathogenic mutations (variants associated with typical or "atypical" FMF phenotype in Greek population) were identified in 10/50 CIN patients (20%). The 20% frequency of MEFV mutations in exon 10 and/or exon 2 in CIN patients is significantly higher compared to the carrier rate of common MEFV mutations in the healthy Greek population (0.7%) according to our previously reported data (PATG; Ile>Met), two patients with heterozygous A744S (GCC>TCC; Ala>Ser) and one with homozygosity, one patient with heterozygous M694V (ATG>GTG; Met>Val), one with heterozygous K695R (AAG>AGG; Lys>Arg) and one with heterozygous M680I (ATG>ATC; Met>Ile), all in exon 10, and (b) four patients with homozygous R202Q mutation in exon 2 (one patient with homozygous A744S co-mutation in exon 10) and two patients with R202Q heterozygosity combined with heterozygosity of I720M and A744S of exons 10, respectively. None of the patients displayed any symptoms/signs of FMF or other systemic inflammatory disease. No statistically significant differences were identified between MEFV mutated and non-mutated CIN patients in the severity of neutropenia or in lymphocyte, monocyte, hemoglobin and platelet counts. A significant difference was identified between the two patient groups in serum IgG (1440±264 vs 1133±245 mg/dl; P = 0.0023, Mann-Whitney test) but not IgA or IgM levels. Discussion: This study reports for the first time that 20% of unselected, consecutive patients with CIN carry mutations of the MEFV gene without clinical manifestations of FMF. Whether these patients represent atypical cases of FMF or the identified MEFV genetic alterations have a pathogenetic/modifying effect in the inflammatory responses associated with CIN is an open/novel field of research. As a first step we are currently investigating the neutrophil autophagic status, IL-1β production and the neutrophil extracellular trap (NET) formation in CIN patients with mutations in MEFV to clarify their potential effect in the immune deregulation known to characterize CIN. Disclosures No relevant conflicts of interest to declare.

Background: We have previously performed NGS analysis of genes that are recurrently mutated in myeloid malignancies in a cohort of patients with the diagnosis of chronic idiopathic neutropenia (CIN) according to previously reported criteria that largely overlap with those proposed for idiopathic cytopenia/neutropenia of undetermined significance (ICUS-N). We have thus estimated for the first time the frequency of clonal hematopoiesis in patients with CIN/ICUS-N (11.54%) and found that clonal CIN patients have a significantly higher risk of developing a myeloid neoplasm than those with no evidence of clonality (non-clonal). 1 However more longitudinal follow-up NGS studies are required for the tracking of clonal evolution and delineation of clonal CIN natural history. Aims: To conduct longitudinal follow-up NGS analyses in order to assess clonal evolution and associate the clinical significance of detected clonal aberrations with the risk of transforming to myeloid malignancy in clonal CIN clinical outcome. Methods: Genomic DNA was extracted from patients' BM or PB samples, sequencing libraries were prepared and subjected to targeted next generation sequencing (NGS) on an Ion S5 Prime Sequencer (Thermo Fisher Scientific) using a panel of 38 genes recurrently mutated in myeloid malignancies. Results: Follow-up analysis by NGS was performed in 16 clonal CIN patients (Figure 1). (Out of these 16 patients, follow-up NGS data has already been published in 9 patients, however additional timepoints were tested in 3 of them). 1 The median time between the first and subsequent analysis was 28.5 months (range 8-164 months). Ten of these patients carried the initial somatic mutations with only subtle changes in the size of clone as estimated by the variant allele frequency (VAF); the patients displayed absence of additional mutations and did not develop myeloid malignancy (Figure 1A-C, E-G, I, K, L, P). Two patients acquired a second mutation at follow-up. One of them still displayed stable disease course (Figure 1D) whereas the second eventually progressed to CMML (Figure 1H). The analysis also revealed that one patient lost the initial detected mutation at follow-up after 98 months (Figure 1J). Two patients who progressed to MDS/MPN and AML respectively, displayed a notable clonal expansion with additional mutations at the time of progression (Figure 1M and Figure 1N, respectively). Specifically, the patient who progressed to MDS/MPN acquired a mutation in JAK2 and ASXL1 while the patient who progressed to AML acquired the typical NPM1 p.L287fs mutation. The patient who developed MDS with multilineage dysplasia, carrying three mutations in DNMT3A and IDH1, showed a moderate increase in the VAF of these mutations at first follow-up (Figure 1O). The patient progressed to acute lymphoblastic leukemia (2 nd follow-up) with acquisition of additional truncating mutation in ETV6. Following treatment (3 rd and 4 th follow-up) mutation in ETV6 was lost, however the three mutations in DNMT3A and IDH1 persisted and their clone size increased. Conclusions: In the majority of patients tested for clonal evolution over time, most mutant clones appeared to be remarkably stable, with minimal VAF change, no acquisition of new molecular alterations and no progression to overt myeloid malignancy. Two CIN patients who transformed to a myeloid malignancy displayed a clonal expansion as was reflected by the increase of VAF and the development of additional mutations whereas in the third patient only a modest VAF increase was identified before malignant transformation. Finally in the patient bearing 4 mutations no progression to overt malignancy was observed after 12 months of follow-up. This ongoing study of sequential NGS analysis of CIN patients is anticipated to contribute to the better understanding and enrich further the knowledge on the natural history of this rare disease. References: Tsaknakis G, Galli A, Papadakis S et al. Incidence and Prognosis of Clonal Hematopoiesis in patients with Chronic Idiopathic Neutropenia. Blood. 2021 Jun 24:blood.2021010815. doi: 10.1182/blood.2021010815. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.

Introduction: Less than 5% of patients with MDS present with thrombocytopenia as an isolated abnormality (MDS-IT). There have been few systematic studies on MDS-IT and data regarding its course and prognosis are conflicting. Previous studies have defined MDS-IT based on the IPSS thresholds (Hb ≥10 g/dL; ANC ≥1.8×10 9/L; PLT Methods: We identified patients who had PLT 13 g/dL (men) or >12 g/dL (women), and ANC ≥1.8 ×10 9/L, registered in the Hellenic National Registry of Myelodysplastic and Hypoplastic Syndromes which includes 2792 patients (analysis cut-off date; July 7, 2016). Patients were divided into 4 groups: group 1 had PLT 149-100 ×10 9/L; group 2, 99-50 ×10 9/L; group 3, Results: A total of 77 patients (45 men; 32 women) with MDS-IT were identified (2.9% of total MDS cohort). Of these, 28.6% were classified in group 1; 49.4% in group 2; 14.3% in group 3; and 7.8% in group 4. Median PLT count was 87 ×10 9/L (12-139 ×10 9/L), WBC count 4.6 ×10 9/L, and Hb 13.6 g/dL. Bone marrow (BM) blasts ranged from 0-9% (median, 2%). Median follow-up was 51.0 months (41.6-60.4), during which 15 (19.5%) patients died. AML developed in 9 patients (11.7%). Histologically, MDS with multilineage dysplasia (MLD) was seen in 77.6% whereas MDS with excess blasts (EB) and MDS with single lineage dysplasia (SLD) comprised 10.7% and 11.9% of cases, respectively. Most patients (73.5%) had lower-risk MDS on the IPSS-R (i.e. IPSS-R ≤3.5). Of the 59 patients with cytogenetic data, 83.1% had favorable, 13.5% intermediate, and 3.4% poor risk cytogenetics. Most (40) had a normal karyotype followed by isolated del(20q) (6). All patients with del(20q) showed a characteristic set of clinical features: age >60 years, blasts 0-3%, bilineage (erythroid/megakaryocytic) dysplasia, and increased reticulin fibrosis. There were no significant differences between any of the 4 PLT groups regarding age, sex, IPSS-R, cytogenetics, BM blasts, and histology. Median OS was 109 months (95% CI 103-115) and LFS 108 months (101-115). Our results showed no significant difference in OS (P=0.891) and LFS (P=0.871) between the 4 PLT groups. As compared with total MDS cohort, MDS-IT occurred at younger age (64.7 vs. 72.4 years, P In comparing MDS-IT with ITP, the median age at diagnosis was 66.0 years for MDS-IT and 49.0 years for ITP (P80 years. Its incidence reached a peak between the ages of 70-79 years, whereas ITP occurred at a more constant level over time (Figure 1B). Women predominated in ITP and men in MDS-IT (P=0.007). Overall, ITP was associated with more marked thrombocytopenia than MDS-IT (15.0 ×10 9/L vs. 87.0 ×10 9/L) (P Conclusions: In one of the largest reported series, we conclude that MDS-IT is associated with MDS-MLD, favorable cytogenetics, lower-risk IPSS-R, high survival rate, and a low risk of AML evolution. Our data suggest that the superior prognosis in MDS-IT than general MDS may have intrinsic genomic underpinnings as survival curves remained unchanged after correcting for age, sex, blasts and IPSS-R. Importantly, no significant differences in OS and LFS were noted between the 4 PLT subgroups, suggesting that the degree of thrombocytopenia does not correlate with mortality in MDS-IT. From the diagnostic standpoint, age 80 years and PLT Figure 1 Figure 1. Disclosures Viniou: Sandoz: Research Funding; Takeda: Research Funding; Novartis: Honoraria, Research Funding; Sanofi: Research Funding; Janssen: Honoraria, Research Funding; Pfizer: Research Funding; Abbvie: Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding; Roche: Research Funding; Astellas: Research Funding; Celgene: Research Funding. Vassilakopoulos: Dr. Reddy's: Research Funding; Amgen: Honoraria, Research Funding; GlaxoSmithKline: Honoraria, Other: Travel; AbbVie: Consultancy, Honoraria; Integris: Honoraria; Pfizer: Research Funding; Roche: Consultancy, Honoraria, Other: Travel; Takeda: Consultancy, Honoraria, Other: Travel, Research Funding; Genesis Pharma: Consultancy, Honoraria, Other: Travel; Merck: Honoraria, Research Funding; Novartis: Consultancy, Honoraria; Karyopharm: Research Funding; AstraZeneca: Honoraria. Hatzimichael: Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; MSD: Consultancy, Honoraria; Gilead: Honoraria; Janssen Cilag: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria; Pharmathen- Innovis: Honoraria; GSK: Honoraria; Bristol Myersr Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees. Symeonidis: Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi/Genzyme: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Demo: Research Funding; MSD: Consultancy, Research Funding; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; WinMedica: Research Funding; Astellas: Consultancy, Research Funding; Gilead: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Sanofi: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GSK: Research Funding; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; GenesisPharma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Background-Aim: Infection from SARS-CoV-2 has emerged as new pathological entity within the global medical community. One of the earliest questions was in relation to the ability of the immunocompromised patients to clear the infection. In COST EuNet-INNOCHRON we were interested in the impact of SARS-CoV-2 infection in patients with different types of chronic neutropenia (CNP). The aim of the current study is to understand the impact of SARS-CoV-2 infection and to identify any possible characteristic patterns of the clinical course in patients with CNP. Patients and Methods: The COST EuNet-INNOCHRON Action in collaboration with the European Haematology Association - Scientific Working Group (EHA-SWG) on Granulocytes and Constitutional Marrow Failure Syndromes has conducted an online survey on SARS-CoV-2 infection in patients with CNP. The EuNet-INNOCHRON participants from different countries got access to an on-line platform fulfilling the General Data Protection Regulation (GDPR) and could register adult and paediatric CNP patients who had been infected by SARS-CoV-2 from March 2020 to June 2021. Data on demographic characteristics, type of CNP, patients' background and SARS-CoV-2 infection history (symptoms, laboratory features, radiological appearance, therapeutic approach and outcome) were collected. Results: Twenty-six patients with diagnosis of CNP, 7 males and 19 females were registered. Patient age distribution as follows: 16 patients >18 years old (y.o.)5 patients 5-18 y.o, 4 patients < 5 y.o whereas age was not available for one of the patients. Nine of the patients were diagnosed with idiopathic CNP, 7 patients with congenital neutropenia (6 of them with severe congenital neutropenia), 3 with secondary CNP, 2 with suspected autoimmune neutropenia of infancy (although antineutrophil Ab were negative), one with autoimmune neutropenia, one with drug induced neutropenia and 3 with other types of CNP. Twelve patients were on treatment with G-CSF and 6 patients had a history of previous viral or bacterial infections. Clonal Cytopenia(s) of Undetermined Significance (CCUS) was excluded in the eight patients who were investigated. Twenty-four out of 26 patients had positive PCR and one was found incidentally with positive antibodies for SARS-CoV-2. One more patient was symptomatic with history of close contact with SARS-CoV-2 infected family members. The commonest observed symptoms were fever >38 oC (19 patients), cough (10 patients), rhinorrhoea (10 patients), sore throat (6 patients), musculoskeletal pains (7 patients), taste/smell loss (5 patients), headache (5 patients), dyspnoea (4 patients), chest pain (one patient) and none of them had gastrointestinal symptoms. No other associated respiratory viral or bacterial infections were reported. Four patients who had one or more underlying conditions (immune deficiency, heart/respiratory/kidney disease) were admitted in hospital and needed anti SARS-CoV-2 treatment. Two of them had non-invasive ventilation and one of them needed admission in intensive care unit (ICU); both recovered. Another patient with Fallot's tetralogy needed mechanical ventilation in ICU and sadly passed away. No other deaths were observed. Deterioration of the pre-existing neutropenia was seen in two patients, two patients developed thrombocytopenia, one patient developed worsening lymphopenia and one anaemia. Twelve patients had chest X-ray and consolidation was found in two of them. All three patients who had chest CT scans were found with ground-glass changes. During the observation period (up to two months), no re-infection from SARS-CoV-2 was found. The Stockholm, Sweden experience is similar to the above data. One hundred fifty-four patients with CNP were followed up, for 10 months (March 1 to December 31, 2020) for SARS-CoV-2. Seventeen of these (i.e. 11 %) were infected. None needed hospitalization and there were no fatalities. Conclusion: Although the relative susceptibility of neutropenic patients to contract SARS-CoV-2 needs to be assessed with further studies, the clinical course and severity of SARS-CoV-2 infection doesn't seem to be worse in CNP patients (regardless the type of neutropenia and the need for GCSF treatment) compared to the general population. Also, like what has been observed in non-neutropenic patients, underlying comorbidities is a significant risk factor for severe disease and adverse outcome. Disclosures Dale: X4 Pharmaceuticals: Consultancy, Honoraria, Research Funding. Palmblad: Chiesi Ltd Sweden: Honoraria; Roche Sweden: Speakers Bureau; Chiesi Ltd Candada,: Honoraria.

Chronic idiopathic neutropenia (CIN) is a granulocytic disorder associated with presence of activated, myelosuppressive T-lymphocytes. In the present study we have evaluated constituents of humoral immunity in CIN patients (n=48) compared to healthy controls (n=52). CIN patients displayed lower serum IgG levels due to a reduction in IgG1, IgG3, IgG4 but not IgG2, lower IgA and increased IgM levels compared to controls. The proportion of CD19+ cells did not differ between patients and controls; however the proportion of the naive IgD+/CD27- B-cells was increased and the proportion of class-switched memory IgD-/CD27+ B-cells was decreased in the patients. The percentage of CD40+ B-cells did not differ between patients and controls and no aberrations in the CD40-meadiated signal transduction pathway or in CD40-gene polymorphisms were identified. These data provide further evidence that immune disturbances are associated with the pathophysiology of CIN and point out for the first time the implication of the B-cell system.

Myeloid-derived suppressor cells (MDSCs) are myeloid cells with immunoregulatory properties characterized mainly by suppression of T-cell responses (Bizymi et al, HemaSphere 2019). They are divided in HLA-DRlow/-/CD11b+/CD33+/CD15+ polymorphonuclear (PMN-MDSCs) and HLA-DRlow/-/CD11b+/CD33+/CD14+ monocytic (M-MDSCs) subsets and they are implicated in inflammatory and malignant diseases. Chronic idiopathic neutropenia (CIN), is a (usually benign) neutrophil disorder characterized by persistent and unexplained neutropenia following a detailed clinical/laboratory investigation including anti-neutrophil antibody testing, bone marrow (BM) biopsy and karyotype (Dale & Bolyard, Curr Opin Hematol 2017). Previous studies have shown that neutropenia in CIN is associated with increased apoptosis of BM granulocytic progenitor cells due to an inflammatory BM microenvironment consisting of oligoclonal T-lymphocytes, proinflammatory monocytes and proapoptotic cytokines. The aim of the present study is to explore the possible involvement of the MDSCs in the pathophysiology of CIN by investigating their number in peripheral blood (PB) and BM in association with their functional characteristics. We have studied 100 CIN patients and 49 age- and sex-matched healthy controls. The patients fulfilled the previously described diagnostic criteria for CIN (Papadaki et al, Blood 2003) and had mean neutrophil counts 1095.67 ± 479.52 (median 1215, range 100-1700). MDSC subsets were quantitated by flow cytometry in the PB mononuclear cell (PBMC) fraction using the combination of CD33PC7/CD15PC5/HLA-DRECD/CD14PE/CD11bFITC monoclonal antibodies and the Kaluza analysis software. MDSC subsets were also studied in the BMMC fraction of 24 CIN patients and 8 healthy controls from the study population. The T-cell suppression function of patient MDSCs was evaluated in coculture experiments of immunomagnetically sorted, CFSE stained, normal CD3+ cells with immunomagnetically sorted M-MDSCs and PMN-MDSCs from 4 patients and 4 healthy donors using recombinant human IL-2 as activating factor. CFSE staining was detected in the CD3+ cells on day 0 and day 3 of coculture and analysis was performed with the Fcs Express 7 software. Statistical analysis was performed with the Statistica software. We found that the proportion of PB M-MDSCs was statistically significant lower in CIN patients (1.45% ± 1.82%) compared to controls (3.68% ± 3.12%, Mann-Whitney test, p < 0.0001) (Figure a) whereas the proportion of PB PMN-MDSCs, although lower in patients, did not differ significantly from the controls. The proportion of BM M-MDSCs did not differ significantly between CIN patients and controls whereas the proportion of BM PMN-MDSCs was statistically significant lower in patients (13.27% ± 11.27%) compared to controls (19.49% ± 4.46%; Mann-Whitney test, p = 0.0291) (Figure b). Paired analysis showed that the proportion of PMN-MDSCs were higher in the BMMC compared to PBMC fraction in both CIN patients (13.27% ± 11.27% vs 1.14% ± 1.64%, respectively; Wilcoxon test, p = 0.005) (Figure c) and healthy controls (19.49% ± 4.46% vs 9.92% ± 9.08%, respectively; Wilcoxon test, p = 0.0118). Interestingly, the proportion of increase of PMN-MDSCs (in BMMC vs PBMC fraction) was significantly higher in patients (86.71% ± 21.26%) compared to controls (55.95% ± 38.59%; Mann-Whitney test, p = 0.0357) (Figure d). The above data indicate low production of PMN-MDSCs in CIN patients compared to controls but a trend for accumulation of these cells in patients' BM. No statistically significant difference was documented in paired analysis of M-MDSCs between BMMC and PBMC fractions in either CIN patients or healthy controls. Patient PMN-MDSCs and M-MDSCs displayed normal capacity to suppress T-cell proliferation as was indicated by the T-cell generations in coculture experiments of normal CD3+ cells in the presence or absence of patient MDSCs (Figure e). In conclusion, CIN patients display low proportion of MDSCs in the PB and lower proportion of PMN-MDSC in the BM compared to normal individuals. Patient MDSCs display normal capacity to suppress T-cell activation. The low proportions of MDSCs may sustain the inflammatory process associated with CIN whereas the accumulation of PMN-MDSCs in the BM represents probably a compensatory mechanism to suppress the inflammatory processes within patients' BM microenvironment. Figure Disclosures Papadaki: Genesis pharma SA: Membership on an entity's Board of Directors or advisory committees, Research Funding.

International audience; Myeloid-derived suppressor cells (MDSC) are a heterogeneous group of immature myeloid cells that exist at very low numbers in healthy subjects but can expand significantly in malignant, infectious, and chronic inflammatory diseases. These cells are characterized as early-MDSCs, monocytic-MDSCs, and polymorphonuclear-MDSCs and can be studied on the basis of their immunophenotypic characteristics and their functional properties to suppress T-cell activation and proliferation. MDSCs have emerged as important contributors to tumor expansion and chronic inflammation progression by inducing immunosuppressive mechanisms, angiogenesis and drug resistance. Most experimental and clinical studies concerning MDSCs have been mainly focused on solid tumors. In recent years, however, the implication of MDSCs in the immune dysregulation associated with hematologic malignancies, immune-mediated cytopenias and allogeneic hemopoietic stem cell transplantation has been documented and the potential role of these cells as biomarkers and therapeutic targets has started to attract a particular interest in hematology. The elucidation of the molecular and signaling pathways associated with the generation, expansion and function of MDSCs in malignant and immune-mediated hematologic diseases and the clarification of mechanisms related to the circulation and the crosstalk of MDSCs with malignant cells and other components of the immune system are anticipated to lead to novel therapeutic strategies. This review summarizes all available evidence on the implication of MDSCs in hematologic diseases highlighting the challenges and perspectives arising from this novel field of research.

The association of Non-Hodgkin lymphomas and Hepatitis C virus is well documented and antiviral treatments facilitate a virological and hematological response in the majority of HCV related Non-Hodgkin lymphomas. The recent years, direct acting antivirals have made cure possible almost for every HCV patient. Some concerns were raised as regards the frequency and the pattern of recurrence in HCV patients with HCC, treated with these agents. We present a patient with DLBCL, in remission after appropriate treatment, HCV cirrhosis that was cured with the new antivirals and shortly after SVR, he experienced a lethal lymphoma recurrence.

Clonal B-cell lymphocytosis of marginal zone origin (CBL-MZ) is a recently described entity characterized by the presence of clonal B cells in the blood and/or bone marrow (BM) with morphologic and immunophenotypic features consistent with marginal zone derivation in otherwise healthy individuals. CBL-MZ is commonly associated with paraproteinemia, usually immunoglobulin M (IgM), raising diagnostic difficulties from Waldenstrom macroglobulinemia (WM). The aim of the present study was to determine the presence of MYD-88 L265P mutation in a well-characterized series of CBL-MZ to identify cases that may in fact represent WM. Fifty-three CBL-MZ cases were retrospectively evaluated. MYD-88 L265P mutation was determined by allele-specific polymerase chain reaction in blood and/or BM mononuclear cells. Almost half of the CBL-MZ cases (49%) were associated with paraproteinemia mainly of the IgM type (65%). MYD-88 L265P mutation was identified in 10 cases (19%). These cases may truly represent WM, whereas 43 cases (81%) are still classified as CBL-MZ. Mutated cases were all associated with paraproteinemia compared with 37% of the nonmutated ones (P

Objective Romiplostim has maintained long-term platelet counts in patients with immune thrombocytopenia (ITP) for up to 5 years in clinical studies. This prospective observational study aimed to describe romiplostim utilisation and outcomes in European clinical practice. Methods Adults with primary ITP who received romiplostim in routine care were eligible. Results Three-hundred and forty patients were eligible for analysis, of whom 299 (88%) completed the two-year observation period. The median age was 62 years, with 43% of patients aged ≥65 years, and two-thirds of patients initiated romiplostim before splenectomy. The median average weekly dose of romiplostim was 2.8 μg/kg. The median baseline platelet count was 20 × 109/L, which increased after 2 weeks of romiplostim treatment and remained >50 × 109/L thereafter. After romiplostim initiation, there was a decrease in rates of grade ≥3 bleeding events (from 12 to 2 per 100 patient-years) and ITP-related hospitalisations (from 87 to 33 per 100 patient-years). The rate of thrombotic events was 2 per 100 patient-years and bone marrow fibrosis occurred in two patients. Conclusions Romiplostim dosing, effectiveness, and safety in an unselected real-world ITP population seemed comparable with that observed in clinical studies. This article is protected by copyright. All rights reserved.

Chronic idiopathic neutropenia (CIN) is an acquired disorder of granulopoiesis characterized by increased apoptosis of the bone marrow (BM) granulocytic progenitor cells under the influence of pro-inflammatory mediators and oligoclonal/monoclonal T-lymphocytes. Because patients with immune-mediated BM failure display frequently paroxysmal nocturnal hemoglobinuria (PNH)-type cells in the peripheral blood (PB), we investigated the possible existence of PNH-type cells in 91 patients with CIN using flow cytometry. The patients displayed increased proportions of PNH-type glycophorin A+ /CD59dim and glycophorin A+ /CD59- red blood cells (RBCs), FLAER- /CD24- granulocytes, and FLAER- /CD14- monocytes, compared to controls (n = 55). A positive correlation was found between the proportions of PNH-type RBCs, granulocytes, and monocytes and an inverse correlation between the number of PB neutrophils and the proportions of PNH-type cell populations. The number of patients, displaying percentages of PNH-type cells above the highest percentage observed in the control group, was significantly increased among patients with skewed compared to those with normal T-cell receptor repertoire suggesting that T-cell-mediated immune processes underlie the emergence of PNH-type cells in CIN. Our findings suggest that patients with CIN display PNH-type cells in the PB at a high frequency corroborating the hypothesis that CIN belongs to the immune-mediated BM failure syndromes.

Splenic marginal zone lymphoma (SMZL) is an indolent B-cell lymphoproliferative disorder characterized by blood and bone marrow (BM) involvement associated with splenomegaly, while lymphadenopathy ...

Purpose: Azacitidine is the mainstay of high-risk myelodysplastic syndromes (MDS) therapy, but molecular predictors of response and the mechanisms of resistance to azacitidine remain largely unidentified. Deregulation of signaling via Stat3 and Stat5 in acute myeloid leukemia (AML) is associated with aggressive disease. Numerous genes involved in cell signaling are aberrantly methylated in MDS, yet the alterations and the effect of azacitidine treatment on Stat3/5 signaling in high-risk MDS have not been explored. Experimental Design: We assessed longitudinally constitutive and ligand-induced phospho-Stat3/5 signaling responses by multiparametric flow cytometry in 74 patients with MDS and low blast count AML undergoing azacitidine therapy. Pretreatment Stat3/5 signaling profiles in CD34+ cells were grouped by unsupervised clustering. The differentiation stage and the molecular properties of the CD34+ G-CSF–inducible Stat3/5 double-positive subpopulation were performed by flow cytometry and quantitative real-time PCR in isolated MDS progenitors. Results: The pretreatment Stat3/5 signaling profiles in CD34+ cells correlated strongly with response and cytogenetics and independently predicted event-free survival. We further identified a CD34+ G-CSF–inducible Stat3/5 double-positive subpopulation (DP subset) whose pretreatment levels were inversely associated with treatment response and cytogenetics. The kinetics of the DP subset followed the response to azacitidine and the disease course, whereas its molecular characteristics and cellular hierarchy were consistent with a leukemia propagating cell phenotype. Conclusions: Our findings provide a novel link among Stat3/5 signaling and MDS pathobiology and suggest that the Stat3/5 signaling biosignature may serve as both a response biomarker and treatment target. Clin Cancer Res; 22(8); 1958–68. ©2015 AACR.

Neutropenias (NPs), being acute and often transient, or chronic, range from life-threatening conditions with very low absolute neutrophil blood counts (ANC) to disorders characterized by only mild NP and of no obvious significance for health. Many are caused by genetic variations/mutations, e.g. the benign familial NP and the chronic severe NPs (e.g. Kostmann disease). Some of the latter are associated with various bodily malformations. Many of the mild-to-moderate NPs are signs of underlying disorders that need specialized treatments (e.g. HIV, hepatitis, autoimmune disorders, the large granular lymphocyte syndrome). We provide here means for the evaluation of a previously unknown NP, suggest a triage and treatments.

Background: 5-azacytidine (5-AZA) improves survival of patients with higher-risk myelodysplastic syndromes (MDSs) and oligoblastic acute myeloid leukemia (AML); however, predictive factors for response and outcome have not been consistently studied. Methods: This study of the Hellenic MDS Study Group included 687 consecutive patients with higher-risk MDS and oligoblastic AML treated with 5-AZA. Results: The International Prognostic Scoring System (IPSS) revised version (IPSS-R), Eastern Cooperative Oncology Group Performance Status (ECOG PS) (0 or 1 versus ⩾2) and baseline serum ferritin (SF) levels > 520 ng/ml were shown to independently predict response to 5-AZA. In the survival analysis, the IPSS and IPSS-R risk classification systems along with the ECOG PS and SF levels > 520 ng/ml proved to be independent prognosticators for overall survival (OS), as well as for leukemia-free survival (LFS). Next, we built new multivariate models for OS and LFS, incorporating only ECOG PS and SF levels besides IPSS or IPSS-R risk classification systems. Thereby, the new modified IPSS and IPSS-R risk classification systems (H-PSS, H-PSS-R) could each discriminate a low, an intermediate and a high-risk patient group regarding OS and LFS. The H-PSS and H-PSS-R proved to be better predictors of OS than their previous counterparts as well as the French prognostic score, while the most powerful OS predictor was the new, H-PSS-R system. Conclusions: ECOG PS and SF levels > 520 ng/ml independently predict response to 5-AZA, OS and LFS. Their incorporation in the IPSS and IPSS-R scores enhances these scores’ predictive power in 5-AZA-treated higher-risk MDS and oligoblastic AML patients.

Hypomethylating agents are widely used in chronic myelomonocytic leukemia (CMML). We analyzed the characteristics of 88 patients with CMML homogeneously treated with 5-azacytidine (Hellenic 5-Azacytidine Registry). The overall response rate was 48.9% and the median overall survival (OS) 29.7 months. Out of the seven most widely used prognostic scoring systems for CMML, the Dusseldorf score (DUSS) showed the best prognostic capability (HR, 2.27

Mucormycosis is a life-threatening respiratory fungal infection predominantly caused by Rhizopus species. Mucormycosis has incompletely understood pathogenesis, particularly how abnormalities in iron metabolism compromise immune responses. Here we show how, as opposed to other filamentous fungi, Rhizopus spp. establish intracellular persistence inside alveolar macrophages (AMs). Mechanistically, lack of intracellular swelling of Rhizopus conidia results in surface retention of melanin, which induces phagosome maturation arrest through inhibition of LC3-associated phagocytosis. Intracellular inhibition of Rhizopus is an important effector mechanism, as infection of immunocompetent mice with swollen conidia, which evade phagocytosis, results in acute lethality. Concordantly, AM depletion markedly increases susceptibility to mucormycosis. Host and pathogen transcriptomics, iron supplementation studies, and genetic manipulation of iron assimilation of fungal pathways demonstrate that iron restriction inside macrophages regulates immunity against Rhizopus. Our findings shed light on the pathogenetic mechanisms of mucormycosis and reveal the role of macrophage-mediated nutritional immunity against filamentous fungi., Mucormycosis is a life-threatening respiratory fungal infection that typically occurs in patients with abnormalities in iron metabolism. Here the authors show that iron restriction inside the phagosome of macrophages is an essential component of the host defense against Rhizopus, the main species causing mucormycosis.

The demethylating factor 5-azacytidine (5-AZA) improves survival in intermediate-2 and high-risk myelodysplastic syndrome (MDS) patients [according to the International Prognostic Score System (IPSS)] responding to treatment. However, the outcome of patients achieving stable disease (SD) is unclear. This retrospective study of the Hellenic MDS Study Group included 353 intermediate-2 or high IPSS risk patients treated with 5-AZA. Forty-four out of 86 (51.6%) patients achieving SD and continuing treatment with 5-AZA showed a lower risk of transformation of MDS to acute myeloid leukemia (AML) and increased overall survival (OS), compared to SD patients who discontinued the treatment (estimated median AML-free survival = 38 months, 95% CI = 10.7-65.3 vs 15 months, 95% CI = 10.4-19.6, P < .001; estimated median OS = 20 months, 95% CI = 5.5-34.5 vs 11 months, 95% CI = 5.8-16.2, P < .001). Moreover, SD patients continuing treatment with 5-AZA had no differences in AML-free survival compared to patients showing response to 5-AZA (estimated median AML-free survival = 38 months, 95% CI = 10.7-65.3 vs 31 months, 95% CI = 23.6-38.4, P = .45; estimated median OS 20 months, 95% CI = 5.5-34.5 vs 25 months, 95% CI = 21.3-28.7, P = .50). In conclusion, MDS patients achieving SD in the first 6 months of treatment with 5-AZA as best response should continue receiving 5-AZA as they may benefit from prolonged treatment.

Previous studies have shown that bone marrow mesenchymal stem/stromal cells (BM-MSCs) are involved in the pathogenesis and disease progression of some B-cell lymphomas, including chronic lymphocyti...

In this study, we investigated the incidence and prognostic impact of monosomal karyotype (MK) in 405 higher-risk Myelodysplastic Syndromes (MDS) patients treated with 5-AZA. The MK was present in 66 out of 405 (16.3%) patients, most of whom had complex karyotype (CK). MK was strongly associated with CK and the cytogenetic risk defined according to IPSS-R, as well as with high-risk disease, according to IPSS (P = .029), IPSS-R (P < .001), and WPSS (P < .001) classification systems. The overall response rate (ORR) was not different between MK+ and MK- patients (46.6% vs. 46.2%). At 28 months median follow-up, the median duration of response was 11 months in the entire cohort, 9.5 months in MK+ patients and 11 months in MK-patients (P = .024). The estimated median time to transformation to acute myeloid leukemia for MK+ patients was 17 months vs. 23 months for MK- patients (P = .025). The estimated median OS for MK+ patients was 12 months vs. 18 months for MK- patients (P < .001). Multivariate Cox regression analysis revealed that performance status (P < .001), IPSS-R (P < .001), and MK (P = .002) were independently associated with overall survival (OS). In a subgroup consisting of high and very-high risk patients according to IPSS-R, MK- patients showed better OS rates compared to MK+ patients (estimated median OS: 17 months vs. 12 months, P = .002). In conclusion, we found that MK is associated with reduced OS in patients with higher-risk MDS treated with 5-AZA. Furthermore, we showed that in MDS with high or very-high IPSS-R risk score, MK can further distinguish patients with worse outcome.

Aims Endothelial progenitor cells (EPCs) are bone marrow-derived cells that are mobilized into the circulation to migrate and differentiate into mature endothelial cells contributing to post-natal physiological and pathological neovascularization. In this study, we evaluated circulating EPCs in patients with hypertrophic cardiomyopathy (HCM) and examined a potential association with clinical parameters of the disease. Methods and results We included 40 HCM patients and 23 healthy individuals. Using flow cytometry we measured EPCs in peripheral blood as two subpopulations of CD45–/CD34+/VEGFR2+ and CD45–/CD34+/CD133+ cells. Circulating CD45–/CD34+/VEGFR2+ cells were significantly increased in HCM patients in comparison with the controls (0.000238 ± 0.0003136 vs. 0.000057 ± 0.0001316, respectively, P = 0.002). However, there was no significant difference in the number of circulating CD45–/CD34+/CD133+ cells (0.003079 ± 0.0033288 vs. 0.002065 ± 0.0022173, respectively, P = 0.153). The CD45–/CD34+/VEGFR2+ subpopulation revealed a moderate correlation with LV mass index (r = 0.35, P = 0.026), while both EPC subpopulation levels showed strong positive correlations with th E/e' ratio (r = 0.423, P = 0.007 for CD45–/CD34+/VEGFR2+ and r = 0.572, P

PET/CT in primary mediastinal large B-cell lymphoma responding to rituximab-CHOP: An analysis of 106 patients regarding prognostic significance and implications for subsequent radiotherapy

This study examines the mobilization of mesenchymal stem cells (MSCs) in patients with hypertrophic cardiomyopathy (HCM) compared to healthy individuals. The pathogenesis of myocardial hypertrophy in HCM is not fully understood. MSCs are involved in the process of neovascularization, fibrosis, and ventricular wall remodeling.We included 40 patients with HCM and 23 healthy individuals. Using flow cytometry, we measured MSCs in peripheral blood, as a population of CD45-/CD34-/CD90+ cells and also as a population of CD45-/CD34-/CD105+ cells. The resulting MSC counts were expressed as percentages of the total cells. Patients with HCM were found to have a greater percentage of circulating CD45-/CD34-CD34-/CD90+ cells compared to controls (0.0041±0.005% vs. 0.0007±0.001%, respectively, P.001). No significant difference in circulating CD45-/CD34-/CD105+ cells in the peripheral blood was found between HCM patients and controls (0.016±0.018% vs. 0.012±0.014%, respectively, P=.4). Notably, circulating CD45-/CD34-/CD90+ cells were positively correlated with left ventricular mass index (r=0.54, P.001).Patients with HCM reveal an increased mobilization of MSCs compared to healthy individuals. Although further research is needed to reveal the clinical significance of our findings, our data open a new dimension in the pathophysiology of the disease and may indicate new future therapeutic possibilities.

Engineering biomaterial scaffolds that promote attachment and growth of mesenchymal stem cells in three dimensions is a crucial parameter for successful bone tissue engineering. Towards this direction, a lot of research effort has focused recently into the development of three-dimensional porous scaffolds, aiming to elicit positive cellular behavior. However, the fabrication of three-dimensional tissue scaffolds with a precise geometry and complex micro- and nano-features, supporting cell in-growth remains a challenge. In this study we report on a positive cellular response of human bone marrow-derived (BM) mesenchymal stem cells (MSCs) onto hybrid material scaffolds consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide, and 2-(dimethylamino)ethyl methacrylate (DMAEMA). First, we use Direct fs Laser Writing, a 3D scaffolding technology to fabricate the complex structures. Subsequently, we investigate the morphology, viability and proliferation of BM-MSCs onto the hybrid scaffolds and examine the cellular response from different donors. Finally, we explore the effect of the materials' chemical composition on cell proliferation, employing three different material surfaces: (i) a hybrid consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide and 50mol% DMAEMA, (ii) a hybrid material comprising methacryloxypropyl trimethoxysilane and zirconium propoxide, and (iii) a purely organic polyDMAEMA. Our results show a strong adhesion of BM-MSCs onto the hybrid material containing 50% DMAEMA from the first 2h after seeding, and up to several days, and a proliferation increase after 14 and 21days, similar to the polystyrene control, independent of cell donor. These findings support the potential use of our proposed cell-material combination in bone tissue engineering.