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Introduction: In patients with primary immune thrombocytopenia (ITP), a short course of steroids is routinely given as first-line therapy. However, the response is often transient and additional therapy is usually needed. Thrombopoietin receptor agonists (TPO-RAs) are frequently used as second-line therapy, although there is little clinical guidance on the timing of their administration and on tapering/discontinuation of the drug. To provide clinical recommendations, we used the Delphi technique to obtain consensus for statements regarding administration and on tapering/discontinuation of second-line TPO-RAs among a group of Italian clinicians with expertise in management of ITP. Methods: The Delphi process was used to obtain agreement on five statements regarding initiation and on tapering/discontinuation of second-line TPO-RAs. Agreement was considered when 75% of participants approved the statement. Eleven experts participated in the voting. Results: Full consensus was reached for three of the five statements. The experts held that an early switch from corticosteroids to a TPO-RA has the dual advantage of sparing patients from corticosteroid abuse and improve long-term clinical outcomes. All felt that dose reduction of TPO-RAs can be considered in patients with a stable response and platelet count >100 × 109/L that is maintained for at least 6 months in the absence of concomitant treatments, although there was less agreement in patients with a platelet count >50 × 109/L. Near consensus was reached regarding the statement that early treatment with a TPO-RA is associated with an increase in clinically significant partial or complete response. The experts also agreed that optimization of tapering and discontinuation of TPO-RA therapy in selected patients can improve the quality of life. Conclusion: The present consensus can help to provide guidance on use of TPO-RAs in daily practice in patients with ITP. Plain language summary Second-line administration of thrombopoietin receptor agonists in immune thrombocytopenia There is little guidance on the timing of administration and tapering/discontinuation of thrombopoietin receptor agonists (TPO-RAs) in patients with primary immune thrombocytopenia (ITP). The Delphi technique was used to obtain consensus for five statements. The present consensus among Italian clinicians aims to provide guidance on second-line use of TPO-RAs for patients with ITP in daily practice.

The efficacy and safety of thrombopoietin receptor agonists (TRAs) in older patients with primary immune thrombocytopenia (ITP) are unknown. We investigated TRA response and switch, thrombotic/hemorrhagic risk, and sustained responses off-treatment (SROTs) in 384 patients with ITP aged ≥60 years. After 3 months, 82.5% and 74.3% of eltrombopag- and romiplostim-treated patients, respectively, achieved a response; 66.7% maintained the response (median follow-up, 2.7 years). Eighty-five (22.2%) patients switched to the alternative TRA; although no cross-toxicity was observed, 83.3% of resistant patients had a response after the switch. Thirty-four major thromboses (3 fatal) and 14 major hemorrhages (none fatal) occurred in 18 and 10 patients, respectively, while on TRAs and were associated with thrombosis history (subdistribution hazard ratio, 2.04, P = .05) and platelet count

Summary Background There is no evidence that phlebotomy alone is sufficient to steadily maintain haematocrit on target level in low-risk patients with polycythaemia vera. This study aimed to compare the efficacy and safety of ropeginterferon alfa-2b on top of the standard phlebotomy regimen with phlebotomy alone. Methods In 2017, we launched the Low-PV study, a multicentre, open-label, two-arm, parallel-group, investigator-initiated, phase 2 randomised trial with a group-sequential adaptive design. The study involved 21 haematological centres across Italy. Participants were recruited in a consecutive order. Participants enrolled in the study were patients, aged 18–60 years, with a diagnosis of polycythaemia vera according to 2008–16 WHO criteria. Eligible patients were randomly allocated (1:1) to receive either phlebotomy and low-dose aspirin (standard group) or ropeginterferon alfa-2b on top of the standard treatment (experimental group). Randomisation sequence was generated using five blocks of variable sizes proportional to elements of Pascal's triangle. Allocation was stratified by age and time from diagnosis. No masking was done. Patients randomly allocated to the standard group were treated with phlebotomy (300 mL for each phlebotomy to maintain the haematocrit values of lower than 45%) and low-dose aspirin (100 mg daily), if not contraindicated. Patients randomly allocated to the experimental group received ropeginterferon alfa-2b subcutaneously every 2 weeks in a fixed dose of 100 μg on top of the phlebotomy-only regimen. The primary endpoint was treatment response, defined as maintenance of the median haematocrit values of 45% or lower without progressive disease during a 12-month period. Analyses were done by intention-to-treat principle. The study was powered assuming a higher percentage of responders in the experimental group (75%) than in the standard group (50%). Here we report results from the second planned interim analysis when 50 patients had been recruited to each group. The trial is ongoing, and registered with ClinicalTrials.gov , NCT03003325 . Findings Between Feb 2, 2017, and March 13, 2020, 146 patients were screened, and 127 patients were randomly assigned to the standard group (n=63) or the experimental group (n=64). The median follow-up period was 12·1 months (IQR 12·0–12·6). For the second pre-planned interim analysis, a higher response rate in the experimental group was seen (42 [84%] of 50 patients) than in the standard group (30 [60%] of 50 patients; absolute difference 24%, 95% CI 7–41%, p=0·0075). The observed z value (2·6001) crossed the critical bound of efficacy (2·5262), and the stagewise adjusted p value early showed superiority of experimental treatment. Thus, the data safety monitoring board decided to stop patient accrual for overwhelming efficacy and to continue the follow-up, as per protocol, for 2 years. Under the safety profile, no statistically significant difference between groups in frequency of adverse events of grade 3 or higher was observed; the most frequently reported adverse events were neutropenia (four [8%] of 50 patients) in the experimental group and skin symptoms (two [4%] of 50 patients) in the standard group. No grade 4 or 5 adverse events occurred. Interpretation Supplementing phlebotomy with ropeginterferon alfa-2b seems to be safe and effective in steadily maintaining haematocrit values on target in low-risk patients with polycythaemia vera. Findings from the current study might have implications for changing the current management of low-risk patients with polycythaemia vera. Funding AOP Orphan Pharmaceuticals, Associazione Italiana per la Ricerca sul Cancro

Thrombopoietin receptor agonists (TPO-RAs) are currently indicated for continuous treatment of chronic primary immune thrombocytopenia (ITP). However, there is growing evidence that TPO-RAs can also trigger sustained response in 10-30% of cases after treatment tapering and discontinuation. Therefore, at least for selected responding patients, it might be rational to plan TPO-RA interruption to exploit off-treatment response. Intriguingly, complete or partial responses with TPO-RAs are frequently observed when treatments are initiated early, suggesting that unknown immune-related mechanisms may be involved in this phenomenon. The sustained responses observed after interruption of TPO-RAs may be interpreted as a recovery of immunological tolerance; thus, the re-establishment of immunological equilibrium might be primarily responsible for the observed off-treatment effect. Importantly, these findings may indicate that anticipated TPO-RA usage can lead to improved responses, and that optimized tapering and interruption in selected patients can furthermore improve prognoses. On the base of this rationale, a series of real-life considerations have been generated by a panel of Experts to elucidate possible novel criteria and modalities to identify subgroups of patients who can benefit from tapering and/or discontinuation of TPO-RAs. Towards this aim, the results of a survey of ITP experts are herein reported, reflecting a snapshot of current real-life experience on early discontinuation of TPO-RA-based therapy. The present manuscript also highlights the importance of future translational studies on novel prognostic and predictive biomarkers that can stratify patients and facilitate the clinical choice for second-line treatment of ITP.

BACKGROUND: The incidence of chronic myeloid leukemia (CML) increases with age, but it is unclear how the characteristics of the disease vary with age. In children, where CML is very rare, it presents with more aggressive features, including huge splenomegaly, higher cell count and higher blast cell percentage. PATIENTS AND METHODS: To investigate if after childhood the disease maintains or loses these characteristics of aggressiveness, we analyzed 2784 adult patients, at least 18 years old, registered by GIMEMA CML WP over a 40-year period. RESULTS: Young adults (YAs: 18-29 years old) significantly differed from adults (30-59 years old) and elderly patients (at least 60 years old) particularly for the frequency of splenomegaly (71%, 63% and 55%, P < 0.001), and the greater spleen size (median value: 4.5, 3.0 and 1.0 cm, P < 0.001). According to the EUTOS score, that is age-independent, high-risk patients were more frequent among YAs, than among adult and elderly patients (18%, 9% and 6%, P < 0.001). In tyrosine kinase inhibitors-treated patients, the rates of complete cytogenetic and major molecular response were lower in YAs, and the probability of transformation was higher (16%, 5% and 7%, P = 0.011). CONCLUSIONS: The characteristics of CML or the host response to leukemia differ with age. The knowledge of these differences and of their causes may help to refine the treatment and to improve the outcome. CLINICAL TRIAL NUMBERS: NCT00510926, NCT00514488, NCT00769327, NCT00481052. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

IntroductionExtracellular vesicles (EVs) and particles (EPs) represent reliable biomarkers for disease detection. Their role in the inflammatory microenvironment of severe COVID-19 patients is not well determined. Here, we characterized the immunophenotype, the lipidomic cargo and the functional activity of circulating EPs from severe COVID-19 patients (Co-19-EPs) and healthy controls (HC-EPs) correlating the data with the clinical parameters including the partial pressure of oxygen to fraction of inspired oxygen ratio (PaO2/FiO2) and the sequential organ failure assessment (SOFA) score.MethodsPeripheral blood (PB) was collected from COVID-19 patients (n=10) and HC (n=10). EPs were purified from platelet-poor plasma by size exclusion chromatography (SEC) and ultrafiltration. Plasma cytokines and EPs were characterized by multiplex bead-based assay. Quantitative lipidomic profiling of EPs was performed by liquid chromatography/mass spectrometry combined with quadrupole time-of-flight (LC/MS Q-TOF). Innate lymphoid cells (ILC) were characterized by flow cytometry after co-cultures with HC-EPs or Co-19-EPs.ResultsWe observed that EPs from severe COVID-19 patients: 1) display an altered surface signature as assessed by multiplex protein analysis; 2) are characterized by distinct lipidomic profiling; 3) show correlations between lipidomic profiling and disease aggressiveness scores; 4) fail to dampen type 2 innate lymphoid cells (ILC2) cytokine secretion. As a consequence, ILC2 from severe COVID-19 patients show a more activated phenotype due to the presence of Co-19-EPs.DiscussionIn summary, these data highlight that abnormal circulating EPs promote ILC2-driven inflammatory signals in severe COVID-19 patients and support further exploration to unravel the role of EPs (and EVs) in COVID-19 pathogenesis.

Background. The treatment of choice in steroid-resistant ITP is still controversial, due to the recent advent of new drugs (anti-CD20 and thrombopoietin mimetics) which have encouraged a generalized tendency to delay splenectomy. Consequently, the importance to define the efficacy and safety of splenectomy in the long-term is substantial. Patients and Methods. We retrospectively analyzed the data of 233 ITP patients who underwent splenectomy between 1959 and 2001, in 6 different European hematological Institutions and have now a minimum follow-up of 10 years from surgery. Results. Of the 233 patients, 206 (88%) achieved a response (87% complete). Sixty-eight out of 206 (33%) responsive patients relapsed, mostly (75%) within 4 years from first response. In 92 patients (39.5%), further treatment was required after splenectomy, which was effective in 76 cases (83%). In 138 patients (59%) response was maintained, free of any treatment, at last contact. No significant association between baseline characteristics and likelihood of stable response was found. Overall, 73 (31%) and 58 (25%) patients experienced at least one infectious or hemorrhagic complication. A stable response to splenectomy was associated with a lower rate of infectious (p=0.004) and hemorrhages (p

Variant Philadelphia (Ph) chromosome translocations have been reported in 5%-10% of patients with newly diagnosed chronic myeloid leukemia (CML). Variant translocations may involve one or more chromosomes in addition to 9 and 22, and can be generated by 2 different mechanisms, 1-step and 2-step rearrangements, as revealed by fluorescence in situ hybridization. The prognostic significance of the occurrence of variant translocations has been discussed in previous studies. The European LeukemiaNet recommendations do not provide a “warning” for patients with variant translocations, but there is limited information about their outcome after therapy with tyrosine kinase inhibitors. To identify the role of variant translocations in early chronic phase (CP) CML patients treated with imatinib mesylate, we performed an analysis in a large series of 559 patients enrolled in 3 prospective imatinib trials of the Gruppo Italiano Malattie EMatologiche dell'Adulto (GIMEMA) Working Party on CML. Variant translocations occurred in 30 patients (5%). Our data show that the presence of variant translocations has no impact on the cytogenetic and molecular response or on outcome, regardless of the involvement of different mechanisms, the number of involved chromosomes, or the presence of deletions. Therefore, we suggest that patients with variant translocations do not constitute a “warning” category in the imatinib era. This study is registered at www.clinicaltrials.gov as NCT00514488 and NCT00510926.

Purpose Deletions of the derivative chromosome 9 [der(9)] have been associated with a poor prognosis in chronic myeloid leukemia (CML) across different treatment modalities. In the imatinib era, the prognostic impact of der(9) deletions has been evaluated mainly in patients with late chronic-phase (CP) CML, giving partially conflicting results. Few data are available in the early CP setting. For this reason, in 2006, the European LeukemiaNet recommendations still considered der(9) deletions as a candidate adverse prognostic factor and required a careful monitoring of the patient. Patients and Methods To investigate the prognostic value of der(9) deletions in early CP CML, we performed an analysis of three prospective imatinib trials of the Italian Group for Hematological Malignancies of the Adult (GIMEMA) CML Working Party. Results A fluorescent in situ hybridization (FISH) analysis of bone marrow cells was performed at diagnosis; der(9) deletions were detected in 60 (12%) of 521 evaluable patients. At 60 months, the cumulative incidence of complete cytogenetic response and major molecular response—and the probability of event-free survival, failure-free survival, progression-free survival, and overall survival—in patients with and without deletions were not statistically different. Conclusion Our data strongly support the notion that, when investigated by FISH, der(9) deletions are not a poor prognostic factor in patients with early CP CML treated with imatinib.

Before the introduction of imatinib, interferon alpha-based regimens were the gold standard for treatment of early chronic phase chronic myeloid leukemia patients. The combination of IFN-alpha with imatinib is currently being investigated in at least two large clinical trials, the German CML Study IV and the French SPIRIT trial. We reviewed the cytogenetic and molecular responses of 76 early chronic phase chronic myeloid leukemia patients who were treated with imatinib and interferon-alpha and of 419 early chronic phase chronic myeloid leukemia patients treated with imatinib alone front-line. The complete cytogenetic response rate was higher in the IM+IFN-alpha group than in the imatinib group at six months (60% vs. 42%; P=0.003), but not at 48 months (88% vs. 88%). The durability of the complete cytogenetic response was similar in the two groups with 94% and 91% of complete cytogenetic responders in continuous complete cytogenetic response at 48 months (P=0.56). The major molecular response rate was higher in the IM+IFN-alpha group at six months (58% vs. 34%; P=0.0001) and 12 months (67% vs. 47%; P=0.001) but not later on (65% vs. 57% at 48 months; P=0.25). Overall and progression free survival were comparable in the two groups; a significant trend to a better event free survival was observed in patients treated with PegIFNalpha (91% vs. 78%; P=0.02). These data suggest that the response to the combination treatment is more rapid. It is not yet known how much a rapid reduction will influence the longer-term overall and progression free survival, and the cure rate.

In 816 patients with 2016 World Health Organization-defined polycythemia vera (PV) enrolled in a multicenter retrospective study, we investigated the predictive value of Charlson comorbidity index (CCI) and body mass index (BMI) on thrombosis, progression to post-PV myelofibrosis (PPV-MF) and survival. Patients were subgrouped according to CCI=0 (58.1%, no comorbidities) or CCI≥1 (41.9%) and according to normal/underweight (BMI&nbsp

Imatinib mesylate (IM), 400 mg daily, is the standard treatment of Philadelphia-positive (Ph+) chronic myeloid leukemia (CML). Preclinical data and results of single-arm studies raised the suggestion that better results could be achieved with a higher dose. To investigate whether the systematic use of a higher dose of IM could lead to better results, 216 patients with Ph+ CML at high risk (HR) according to the Sokal index were randomly assigned to receive IM 800 mg or 400 mg daily, as front-line therapy, for at least 1 year. The CCgR rate at 1 year was 64% and 58% for the high-dose arm and for the standard-dose arm, respectively (P = .435). No differences were detectable in the CgR at 3 and 6 months, in the molecular response rate at any time, as well as in the rate of other events. Twenty-four (94%) of 25 patients who could tolerate the full 800-mg dose achieved a CCgR, and only 4 (23%) of 17 patients who could tolerate less than 350 mg achieved a CCgR. This study does not support the extensive use of high-dose IM (800 mg daily) front-line in all CML HR patients. This trial was registered at www.clinicaltrials.gov as #NCT00514488.

Nilotinib has a higher binding affinity and selectivity for BCR-ABL with respect to imatinib and is an effective treatment of chronic myeloid leukemia (CML) after imatinib failure. In a phase 2 study, 73 early chronic-phase, untreated, Ph+ CML patients, received nilotinib at a dose of 400 mg twice daily. The primary endpoint was the complete cytogenetic response (CCgR) rate at 1 year. With a median follow-up of 15 months, the CCgR rate at 1 year was 96%, and the major molecular response rate 85%. Responses were rapid, with 78% CCgR and 52% major molecular response at 3 months. During the first year, the treatment was interrupted at least once in 38 patients (52%). The mean daily dose ranged between 600 and 800 mg in 74% of patients, 400 and 599 mg in 18% of patients, and was less than 400 mg in 8% of patients. Dose interruptions were mainly due to nonhematologic and biochemical side effects. Myelosuppression was irrelevant. One patient progressed to blastic crisis after 6 months; one went off-treatment for lipase increase grade 4 (no pancreatitis). Nilotinib is safe and very active in early chronic-phase CML. These data support a role for nilotinib for the frontline treatment of CML. This study was registered at ClinicalTrials.gov as NCT00481052.

BACKGROUND: Imatinib mesylate is the first line treatment for chronic myeloid leukemia. The advent of imatinib increased survival significantly in patients in an advanced phase of the disease. However, few long-term data on the outcome of these patients based on large, prospective and controlled trials are available. DESIGN AND METHODS: A phase 2 multicenter trial of the use of imatinib 600 mg/daily in patients with accelerated phase chronic myeloid leukemia was sponsored and promoted by the Italian Cooperative Study Group on Chronic Myeloid Leukemia in 2001. RESULTS: One hundred and eleven patients were enrolled; the median follow-up of the 41 living patients is 82 months (range, 73-87). One hundred and seven patients (96%) returned to chronic phase and 79 patients (71%) achieved a complete hematologic response. Cumulative best rates of major cytogenetic response and complete cytogenetic response were 30% and 21%, respectively. All responses were maintained for a minimum of 4 weeks. At last follow-up, four patients were alive in complete remission after allogeneic transplant, 16 patients (14%) had switched to a second generation tyrosine kinase inhibitor and 21 patients (19%) were alive on imatinib therapy. No late toxicities were observed. Progression-free survival and event-free survival rates were 36.5% and 15%, respectively, at 7 years. The median survival time was 37 months, and was significantly associated with the achievement of a complete hematologic response or a complete cytogenetic response. CONCLUSIONS: Imatinib may induce durable responses, associated with prolonged survival, in patients with accelerated phase chronic myeloid leukemia.

To assess the effect of age on response and compliance to treatment in patients with chronic myeloid leukemia (CML) we performed a sub-analysis within a phase II trial of the GIMEMA CML Working Party (CML/002/STI571). Since the WHO cut-off age to define an older patient is 65 years, among the 284 patients considered, we identified 226 (80%) younger patients (below 65 years) and 58 (20%) older patients (above 65 years) before starting imatinib. Response rates (hematologic and cytogenetic) were lower in the older age group but the probabilities of progression-free survival and overall survival (median observation time 3 years) were the same. Moreover, among complete cytogenetic responders, no differences were found in the level of molecular response between the two age groups. As might be expected, older patients experienced more adverse events, both hematologic and non-hematologic: this worsened compliance did not, however, prevent a long-term outcome similar to that of younger patients.

Background Myelofibrosis (MF) is a clonal disorder of hemopoietic stem/progenitor cells (HSPCs) with high prevalence in elderly patients and mutations in three driver genes (JAK2, MPL, or CALR). Around 10–15% of patients are triple-negative (TN) for the three driver mutations and display significantly worse survival. Circulating extracellular vesicles (EVs) play a role in intercellular signaling and are increased in inflammation and cancer. To identify a biomolecular signature of TN patients, we comparatively evaluated the circulating HSPCs and their functional interplay with the microenvironment focusing on EV analysis. Methods Peripheral blood was collected from MF patients (n = 29; JAK2V617F mutation, n = 23; TN, n = 6) and healthy donors (HD, n = 10). Immunomagnetically isolated CD34+ cells were characterized by gene expression profiling analysis (GEP), survival, migration, and clonogenic ability. EVs were purified from platelet-poor plasma by ultracentrifugation, quantified using the Nanosight technology and phenotypically characterized by flow cytometry together with microRNA expression. Migration and survival of CD34+ cells from patients were also analyzed after in vitro treatments with selected inflammatory factors, i.e. (Interleukin (IL)-1β, Tumor Necrosis Factor (TNF)-α, IL6) or after co-culture with EVs from MF patients/HD. Results The absolute numbers of circulating CD34+ cells were massively increased in TN patients. We found that TN CD34+ cells show in vitro defective functions and are unresponsive to the inflammatory microenvironment. Of note, the plasma levels of crucial inflammatory cytokines are mostly within the normal range in TN patients. Compared to JAK2V617F-mutated patients, the GEP of TN CD34+ cells revealed distinct signatures in key pathways such as survival, cell adhesion, and inflammation. Importantly, we observed the presence of mitochondrial components within plasma EVs and a distinct phenotype in TN-derived EVs compared to the JAK2V617F-mutated MF patients and HD counterparts. Notably, TN EVs promoted the survival of TN CD34+ cells. Along with a specific microRNA signature, the circulating EVs from TN patients are enriched with miR-361-5p. Conclusions Distinct EV-driven signals from the microenvironment are capable to promote the TN malignant hemopoiesis and their further investigation paves the way toward novel therapeutic approaches for rare MF.

Deferasirox (DFX) is used for the management of iron overload (IOL) in many haematological malignancies including myelofibrosis (MF). The ‘RUX-IOL’ study retrospectively collected 69 MF patients treated with ruxolitinib (RUX) and DFX for IOL to assess: safety, efficacy in term of iron chelation response (ICR) and erythroid response (ER), and impact on overall survival of the combination therapy. The RUX–DFX therapy was administered for a median time of 12.4months (interquartile range 3.1–71.2). During treatment, 36 (52.2%) and 34 (49.3%) patients required RUX and DFX dose reductions, while eight (11.6%) and nine (13.1%) patients discontinued due to RUX- or DFX-related adverse events; no unexpected toxicity was reported. ICR and ER were achieved by 33 (47.8%) and 32 patients (46.4%) respectively. Thirteen (18.9%) patients became transfusion-independent. Median time to ICR and ER was 6.2 and 2months respectively. Patients achieving an ER were more likely to obtain an ICR also (p=0.04). In multivariable analysis, the absence of leukocytosis at baseline (p=0.02) and achievement of an ICR at any time (p=0.02) predicted improved survival. In many MF patients, the RUX–DFX combination provided ICR and ER responses that correlated with improved outcome in the absence of unexpected toxicities. This strategy deserves further clinical investigation.

Polycythemia Vera (PV) is a myeloproliferative neoplasm with increased risk of thrombosis and progression to myelofibrosis. Chronic inflammation is commonly observed in myeloproliferative neoplasms including PV. The inflammatory network includes the extracellular vesicles (EVs), which play a role in cell-cell communication. Recent evidence points to circulating microbial components/microbes as potential players in hemopoiesis regulation. To address the role of EVs in PV, here we investigated phenotype and microbial DNA cargo of circulating EVs through multidimensional analysis. Peripheral blood and feces were collected from PV patients (n=38) and healthy donors (n=30). Circulating megakaryocyte (MK)- and platelet (PLT)-derived EVs were analyzed by flow cytometry. After microbial DNA extraction from feces and isolated EVs, the 16S rDNA V3-V4 region was sequenced. We found that the proportion of circulating MK-derived EVs was significantly decreased in PV patients as compared with the healthy donors. By contrast, the proportion of the PLT-derived EVs was increased. Interestingly, PV was also associated with a microbial DNA signature of the isolated EVs with higher diversity and distinct microbial composition than the healthy counterparts. Of note, increased proportion of isolated lipopolysaccharide-associated EVs has been demonstrated in PV patients. Conversely, the gut microbiome profile failed to identify a distinct layout between PV patients and healthy donors. In conclusion, PV is associated with circulating EVs harbouring abnormal phenotype and dysbiosis signature with a potential role in the (inflammatory) pathogenesis of the disease.

Simple Summary The present review is meant to provide an updated overview on the progressions in Ph-chromosome negative MPN, with major focus on the histopathological changes identifiable in routine diagnostic practice on bone marrow biopsies. It integrates these issues with clinical parameters that define the risk of progression and the molecular determinants that are potentially involved in the transformation. The fibrotic and accelerated/leukemic types of progression are defined by the Who Classification, but laboratory changes may occur during the course of the disease, such as monocytosis or leukocytosis. These can impact on morphology and challenge the histologic diagnosis with potential risk of reclassification. Molecular investigations are becoming relevant for the management of these patients and profoundly changing and challenging our diagnostic approach, but histology remains a turning point for the diagnosis and classification of Ph-negative MPN and should remain the reference also in the event of unusual or discordant molecular findings. Abstract Progression in Ph-chromosome-negative myeloproliferative neoplasms (MPN) develops with variable incidence and time sequence in essential thrombocythemia, polycythemia vera, and primary myelofibrosis. These diseases show different clinic-pathologic features and outcomes despite sharing deregulated JAK/STAT signaling due to mutations in either the Janus kinase 2 or myeloproliferative leukemia or CALReticulin genes, which are the primary drivers of the diseases, as well as defined diagnostic criteria and biomarkers in most cases. Progression is defined by the development or worsening of marrow fibrosis or the progressive increase in the marrow blast percentage. Progression is often related to additional genetic aberrations, although some can already be detected during the chronic phase. Detailed scoring systems for clinical usage that are mostly applied in patients with primary myelofibrosis have been defined, and the most recent ones include cytogenetic and molecular parameters with prognostic significance. Additional different clinic-pathologic changes have been reported that may occur during the course of the disease and that are, at present, classified as WHO-defined types of progression, although they likely represent such an event. The present review is meant to provide an updated overview on progression in Ph-chromosome-negative MPN, with a major focus on the pathologic side.

ROMEI, a prospective, observational study in patients with myelofibrosis receiving the oral JAK1/2 inhibitor ruxolitinib in real-world practice, assesses treatment adherence based on the 8-item Morisky Medication Adherence Scale (MMAS-8). Here, we present MMAS-8 results at week 24. Overall, 101 of 188 evaluable patients completed the questionnaire at every visit (full completers). Mean (±standard deviation) total MMAS-8 scores remained stable from week 4 to week 24 in the overall population (7.54 ± 0.77 and 7.67 ± 0.70, respectively) and full completers (7.53 ± 0.79 and 7.67 ± 0.73, respectively). Rates of low (MMAS-8 ˂6) or medium (MMAS-8 ≥ 6 to ˂8) adherence were 25–40% and 26–36%, respectively. Fifty-five full completers (54%) reported ≥1 change in adherence category (improvement and/or worsening), most of which were associated with unintentional behavior. The data suggest that one-third of patients receiving ruxolitinib may be undertreated due to non-adherence, potentially undermining disease control, and indicate a need for better interventions addressing noncompliance to oral therapies.

Myeloproliferative Neoplasms (MPN) are acquired clonal disorders of the hematopoietic stem cells and include Essential Thrombocythemia, Polycythemia Vera and Myelofibrosis. MPN are characterized by mutations in three driver genes (JAK2, CALR and MPL) and by a state of chronic inflammation. Notably, MPN patients experience increased risk of thrombosis, disease progression, second neoplasia and evolution to acute leukemia. Extracellular vesicles (EVs) are a heterogeneous population of microparticles with a role in cell-cell communication. The EV-mediated cross-talk occurs via the trafficking of bioactive molecules such as nucleic acids, proteins, metabolites and lipids. Growing interest is focused on EVs and their potential impact on the regulation of blood cancers. Overall, EVs have been suggested to orchestrate the complex interplay between tumor cells and the microenvironment with a pivotal role in “education” and “crafting” of the microenvironment by regulating angiogenesis, coagulation, immune escape and drug resistance of tumors. This review is focused on the role of EVs in MPN. Specifically, we will provide an overview of recent findings on the involvement of EVs in MPN pathogenesis and discuss opportunities for their potential application as diagnostic and prognostic biomarkers.

BACKGROUND: After ruxolitinib discontinuation, the outcome of patients with myelofibrosis (MF) is poor with scarce therapeutic possibilities. METHODS: The authors performed a subanalysis of an observational, retrospective study (RUX-MF) that included 703 MF patients treated with ruxolitinib to investigate 1) the frequency and reasons for ruxolitinib rechallenge, 2) its therapeutic effects, and 3) its impact on overall survival. RESULTS: A total of 219 patients (31.2%) discontinued ruxolitinib for ≥14 days and survived for ≥30 days. In 60 patients (27.4%), ruxolitinib was rechallenged for ≥14 days (RUX-again patients), whereas 159 patients (72.6%) discontinued it permanently (RUX-stop patients). The baseline characteristics of the 2 cohorts were comparable, but discontinuation due to a lack/loss of spleen response was lower in RUX-again patients (P =.004). In comparison with the disease status at the first ruxolitinib stop, at its restart, there was a significant increase in patients with large splenomegaly (P 10 mg twice daily predicted better spleen (P =.05) and symptom improvements (P =.02), the reasons for/duration of ruxolitinib discontinuation and the use of other therapies before rechallenge were not associated with rechallenge efficacy. At 1 and 2 years, 33.3% and 48.3% of RUX-again patients, respectively, had permanently discontinued ruxolitinib. The median overall survival was 27.9 months, and it was significantly longer for RUX-again patients (P =.004). CONCLUSIONS: Ruxolitinib rechallenge was mainly used in intolerant patients; there were clinical improvements and a possible survival advantage in many cases, but there was a substantial rate of permanent discontinuation. Ruxolitinib rechallenge should be balanced against newer therapeutic possibilities.

Recently, treatment of immune‐mediated thrombotic thrombocytopenic purpura (ITTP) has changed with the advent of caplacizumab in clinical practice. The International Working Group (IWG) has recently integrated the ADAMTS‐13 activity/autoantibody monitoring in consensus outcome definitions. We report three ITTP cases during the coronavirus disease 2019 pandemic, that received a systematic evaluation of ADAMTS‐13 activity and autoantibodies. We describe how the introduction of caplacizumab and ADAMTS‐13 monitoring could change the management of ITTP patients and discuss whether therapeutic choices should be based on the clinical response alone. ADAMTS‐13 activity/antibodies were assessed every 5 days. Responses were evaluated according to updated IWG outcome definitions. These kinetics, rather than clinical remission, guided the therapy, allowing early and safe caplacizumab discontinuation and sensible administration of rituximab. Caplacizumab was cautiously discontinued after achieving ADAMTS‐13 complete remission. These cases illustrate that prospective ADAMTS‐13 evaluation and use of updated IWG definitions may improve real‐life patients’ management in the caplacizumab era.

Up to 30% immune thrombocytopenia (ITP) patients achieve a sustained remission off-treatment (SROT) after discontinuation of thrombopoietin receptor agonists (TPO-RAs). Factors predictive of response are lacking. Patients aged ≥18 years with newly diagnosed or persistent ITP were treated with eltrombopag for 24 weeks. Primary end-point was SROT: the proportion of responders that were able to taper and discontinue eltrombopag maintaining the response during a period of observation (PO) of six months. Secondary end-points included the association between some immunological parameters (TPO serum levels, cytokines and lymphocyte subsets) and response. Fifty-one patients were evaluable. Primary end-point was achieved in 13/51 (25%) treated patients and 13/34 (38%) patients who started the tapering. Baseline TPO levels were not associated with response at week 24 nor with SROT. Higher baseline levels of IL-10, IL-4, TNF-α and osteopontin were negative factors predictive of response (P = 0·001, 0·008, 0·02 and 0·03 respectively). This study confirms that SROT is feasible for a proportion of ITP patients treated with eltrombopag. Some biological parameters were predictive of response.

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No abstract available

The impact of ruxolitinib therapy on evolution to blast phase (BP) in patients with myelofibrosis (MF) is still uncertain. In 589 MF patients treated with ruxolitinib, we investigated incidence and risk factors for BP and we described outcome according to disease characteristics and treatment strategy. After a median follow-up from ruxolitinib start of 3 years (range 0.1-7.6), 65 (11%) patients transformed to BP during (93.8%) or after treatment. BP incidence rate was 3.7 per 100 patient-years, comparably in primary and secondary MF (PMF/SMF) but significantly lower in intermediate-1 risk patients (2.3 vs 5.6 per 100 patient-years in intermediate-2/high-risk patients, P

Myelofibrosis (MF) is characterized by chronic inflammation and hyper-activation of the JAK-STAT pathway. Infections are one of the main causes of morbidity/mortality. Therapy with Ruxolitinib (RUX), a JAK1/2 inhibitor, may further increase the infectious risk. Monocytes are critical players in inflammation/immunity through cytokine production and release of bioactive extracellular vesicles. However, the functional behavior of MF monocytes, particularly during RUX therapy, is still unclear. In this study, we found that monocytes from JAK2V617F-mutated MF patients show an altered expression of chemokine (CCR2, CXCR3, CCR5) and cytokine (TNF-α-R, IL10-R, IL1β-R, IL6-R) receptors. Furthermore, their ability to produce and secrete free and extracellular vesicles-linked cytokines (IL1β, TNF-α, IL6, IL10) under lipopolysaccharides (LPS) stimulation is severely impaired. Interestingly, monocytes from RUX-treated patients show normal level of chemokine, IL10, IL1β, and IL6 receptors together with a restored ability to produce intracellular and to secrete extracellular vesicles-linked cytokines after LPS stimulation. Conversely, RUX therapy does not normalize TNF-R1/2 receptors expression and the LPS-driven secretion of free pro/anti-inflammatory cytokines. Accordingly, upon LPS stimulation, in vitro RUX treatment of monocytes from MF patients increases their secretion of extracellular vesicles-linked cytokines but inhibits the secretion of free pro/anti-inflammatory cytokines. In conclusion, we demonstrated that in MF the infection-driven response of circulating monocytes is defective. Importantly, RUX promotes their infection-driven cytokine production suggesting that infections following RUX therapy may not be due to monocyte failure. These findings contribute to better interpreting the immune vulnerability of MF and to envisaging strategies to improve the infection-driven immune response.

In recent times, there has been a growing interest in understanding the impact of gender on disease biology and clinical outcomes in Philadelphia-negative chronic myeloproliferative neoplasms. Among those, polycythemia vera (PV) is characterized by increased thrombotic risk, systemic symptoms, and overall reduced survival. Here, we aim to summarize data on whether and to what extent female sex can affect PV biology and outcome. To this end, we will discuss the latest acquisitions in terms of pathogenesis, diagnosis, epidemiology, clinical presentation and symptoms burden, thrombotic risk and related treatment strategies, and prognosis in female patients affected by PV.

Ruxolitinib (RUX), the first JAK1/JAK2 inhibitor approved for myelofibrosis (MF) therapy, has recently been associated with the occurrence of second primary malignancies (SPMs), mainly lymphomas and non-melanoma skin cancers (NMSCs). We analyzed the incidence, risk factors and outcome of SPMs in 700 MF patients treated with RUX in a real-world context. Median follow-up from starting RUX was 2·9years. Overall, 80 (11·4%) patients developed 87 SPMs after RUX start. NMSCs were the most common SPMs (50·6% of the cases). Multivariate analysis demonstrated that male sex [hazard ratio (HR): 2·37, 95% confidence interval (95%CI): 1·22–4·60, P=0·01] and thrombocytosis>400×109/l at RUX start (HR:1·98, 95%CI: 1·10–4·60, P=0·02) were associated with increased risk for SPMs. Risk factors for NMSC alone were male sex (HR: 3·14, 95%CI: 1·24–7·92, P=0·02) and duration of hydroxycarbamide and RUX therapy>5years (HR: 3·20, 95%CI: 1·17–8·75, P=0·02 and HR: 2·93, 95%CI: 1·39–6·17, P=0·005 respectively). In SPMs excluding NMSCs, male sex (HR: 2·41, 95%CI: 1·11–5·25, P=0·03), platelet>400×109/l (HR: 3·30, 95%CI: 1·67–6·50, P=0·001) and previous arterial thromboses (HR: 3·47, 95%CI: 1·48–8·14, P=0·004) were shown to be associated with higher risk of SPMs. While it is reassuring that no aggressive lymphoma was documented, active skin surveillance is recommended in all patients and particularly after prolonged hydroxycaramide therapy; oncological screening should be triggered by thrombocytosis and arterial thrombosis, particularly in males.

Simple Summary Patients with polycythemia vera, a myeloproliferative neoplasm, are at increased risk of thrombosis and progression to myelofibrosis. However, no disease-specific risk factors have been identified so far. Extracellular vesicles, released from a broad variety of cells, are receiving increasing attention for their effects on cell-to-cell communication. In addition, they play a role in cancer and thrombosis. Interestingly, circulating microbial components/microbes have been recently indicated as potential modifiers of inflammation and coagulation. Here, we identified a signature of thrombosis history and marrow fibrosis by analyzing the phenotype and the microbial DNA cargo of the circulating extracellular vesicles after isolation from the plasma of patients with polycythemia vera. These data may support the role of extracellular vesicles as liquid biomarkers of aggressive disease, thus contributing to refining the prognosis of polycythemia vera. Abstract Polycythemia vera is a myeloproliferative neoplasm with increased risk of thrombosis and progression to myelofibrosis. However, no disease-specific risk factors have been identified so far. Circulating extracellular vesicles (EVs) are mostly of megakaryocyte (MK-EVs) and platelet (PLT-EVs) origin and, along with phosphatidylethanolamine (PE)-EVs, play a role in cancer and thrombosis. Interestingly, circulating microbial components/microbes have been recently indicated as potential modifiers of inflammation and coagulation. Here, we investigated phenotype and microbial DNA cargo of EVs after isolation from the plasma of 38 patients with polycythemia vera. Increased proportion of MK-EVs and reduced proportion of PLT-EVs identify patients with thrombosis history. Interestingly, EVs from patients with thrombosis history were depleted in Staphylococcus DNA but enriched in DNA from Actinobacteria members as well as Anaerococcus. In addition, patients with thrombosis history had also lower levels of lipopolysaccharide-associated EVs. In regard to fibrosis, along with increased proportion of PE-EVs, the EVs of patients with marrow fibrosis were enriched in DNA from Collinsella and Flavobacterium. Here, we identified a polycythemia-vera-specific host/microbial EV-based signature associated to thrombosis history and marrow fibrosis. These data may contribute to refining PV prognosis and to identifying novel druggable targets.

The role of circulating microvesicles (MVs) in Myelofibrosis (MF) and Essential Thrombocythemia (ET) is far to be defined. Here we found that 1) circulating megakaryocyte-MVs were reduced in MF and ET while platelet-MVs were increased; 2) the proportion of circulating megakaryocyte- and platelet-MVs was associated with disease severity in MF; 3) ruxolitinib normalized the profile of circulating megakaryocyte- and platelet-MVs in spleen responders MF patients only. Of note, a cut-off value of 19.95% of circulating megakaryocyte-MVs predicts ruxolitinib spleen response. In light of these findings, circulating megakaryocyte/platelet-MVs may have a tissue specific diagnostic and prognostic role in MF.

Ruxolitinib is the only commercially available JAK1/2 inhibitor approved for the treatment of myelofibrosis-related splenomegaly and symptoms. During treatment, as rare conditions, leukocytosis and/or thrombocytosis could develop and the management of these situations is not well established. We report here 53 myelofibrosis patients that received a combination of hydroxyurea and ruxolitinib because of uncontrolled myeloproliferation. Both drugs were administered outside clinical trials. At 48weeks, a significant reduction in leucocyte and platelet counts was observed (p= 0.02 and p= 0.04, respectively). Additionally, the spleen volume decreased from a median value of 10cm below the left costal margin (range, 0-10) to 6cm (range, 0-15). The rate of spleen response increased from 14% at the start of the combination to 45% after 48weeks. The safety profile of the combination was consistent with that observed with ruxolitinib single agent. These data require further confirmation in large cohorts of patients prospectively assessed.

Blood cancers are a heterogeneous group of disorders including leukemia, multiple myeloma, and lymphoma. They may derive from the clonal evolution of the hemopoietic stem cell compartment or from the transformation of progenitors with immune potential. Extracellular vesicles (EVs) are membrane-bound nanovesicles which are released by cells into body fluids with a role in intercellular communication in physiology and pathology, including cancer. EV cargos are enriched in nucleic acids, proteins, and lipids, and these molecules can be delivered to target cells to influence their biological properties and modify surrounding or distant targets. In this review, we will describe the “smart strategy” on how blood cancer-derived EVs modulate tumor cell development and maintenance. Moreover, we will also depict the function of microenvironment-derived EVs in blood cancers and discuss how the interplay between tumor and microenvironment affects blood cancer cell growth and spreading, immune response, angiogenesis, thrombogenicity, and drug resistance. The potential of EVs as non-invasive biomarkers will be also discussed. Lastly, we discuss the clinical application viewpoint of EVs in blood cancers. Overall, blood cancers apply a ‘vesicular intelligence’ strategy to spread signals over their microenvironment, promoting the development and/or maintenance of the malignant clone.

Growing evidence highlights the endocannabinoid (EC) system involvement in cancer progression. Lipid mediators of this system are secreted by hematopoietic cells, including the ECs 2-arachidonoyl-glycerol (2AG) and arachidonoyl-ethanolamide (AEA), the 2AG metabolite 1AG, and members of N-acylethanolamine (NAE) family&mdash, palmitoyl-ethanolamide (PEA) and oleoyl-ethanolamide (OEA). However, the relevance of the EC system in myeloproliferative neoplasms (MPN) was never investigated. We explored the EC plasma profile in 55 MPN patients, including myelofibrosis (MF, n = 41), polycythemia vera (PV, n = 9), and essential thrombocythemia (ET, n = 5) subclasses and in 10 healthy controls (HC). AEA, PEA, OEA, 2AG, and 1AG plasma levels were measured by LC&ndash, MS/MS. Overall considered, MPN patients displayed similar EC and NAE levels compared to HC. Nonetheless, AEA levels in MPN were directly associated with the platelet count. MF patients showed higher levels of the sum of 2AG and 1AG compared to ET and PV patients, higher OEA/AEA ratios compared to HC and ET patients, and higher OEA/PEA ratios compared to HC. Furthermore, the sum of 2AG and 1AG positively correlated with JAK2V617F variant allele frequency and splenomegaly in MF and was elevated in high-risk PV patients compared to in low-risk PV patients. In conclusion, our work revealed specific alterations of ECs and NAE plasma profile in MPN subclasses and potentially relevant associations with disease severity.

Recently, the myelofibrosis secondary to PV and ET prognostic model (MYSEC-PM) was introduced to assess prognosis in myelofibrosis (MF) secondary to polycythemia vera and essential thrombocythemia (post-PV and post-ET MF), replacing the International Prognostic Scoring System (IPSS) and/or Dynamic IPSS (DIPSS) that was applied for primary MF (PMF). In a cohort of 421 ruxolitinib (RUX)-treated patients (post-PV and post-ET MF: 44.2%), we evaluated the following: (1) disease phenotype, responses, and toxicity to RUX; and (2) performance of the MYSEC-PM in post-PV or post-ET ME. While the IPSS failed to correctly stratify post-PV or post-ET MF patients at diagnosis, the MYSEC-PM identified 4 risk categories projected at significantly different survival probability (P < .001). Additionally, the MYSEC-PM maintained a prognostic value in post-PV and post-ET MF also when used over time, at RUX start. Notably, the MYSEC-PM reclassified 41.8% and 13.6% of patients into a lower and higher risk category, respectively. Finally, patients at intermediate-1 risk had significantly higher spleen responses and lower hematological toxicities compared to higher risk patients. Compared to PMF, post-PV and post-ET MF presented a more hyperproliferative disease, with higher leukocyte and/or platelet count and hemoglobin levels both at diagnosis and at RUX start. Despite comparable response rates, post-PV and post-ET MF had lower rate of RUX-induced anemia and thrombocytopenia at 3 and 6 months. The study validates MYSEC-PM in post-PV and post-ET MF prognostication. Post-PV or post-ET MF represents a separate entity compared to PMF in terms of clinical manifestations and toxicity to RUX. (C) 2018 Elsevier Inc. All rights reserved.

none 18 no We investigated the influence of molecular status on disease characteristics and clinical outcome in young patients (⩽ 40 years) with World Health Organization (WHO)-defined essential thrombocythemia (ET) or early/prefibrotic primary myelofibrosis (early-PMF). Overall, 217 patients with ET (number 197) and early-PMF (number 20) were included in the analysis. Median follow-up time was 10.2 years. The cumulative incidence of thrombosis, hemorrhages and disease evolution into myelofibrosis/acute leukemia were 16.6%, 8.6% and 3% at 15 years, respectively. No differences were detectable between ET and early-PMF patients, although the latter cohort showed a trend for worse combined-event free survival (EFS). Mutation frequency were 61% for JAK2V617F, 25% for CALR and 1% for MPLW515K, and were comparable across WHO diagnosis; however, JAK2V617F allele burden was higher in the early-PMF group. Compared with JAK2V617F-positive patients, CALR-mutated patients displayed higher platelet count and lower hemoglobin level. CALR mutations significantly correlated with lower thrombotic risk (9.1% versus 21.7%, P = 0.04), longer survival (100% versus 96%, P = 0.05) and better combined-EFS (86% versus 71%, P = 0.02). However, non-type 1/type 2 CALR mutations ('minor' mutations) and abnormal karyotype were found to correlate with increased risk of disease evolution. At last contact, six patients had died; in five cases, the causes of death were related to the hematological disease and occurred at a median age of 64 years (range: 53-68 years). Twenty-eight patients (13%) were unmutated for JAK2, CALR and MPL: no event was registered in these 'triple-negative' patients. Palandri, F; Latagliata, R.; Polverelli, N.; Tieghi, A.; Crugnola, M.; Martino, B.; Perricone, M.; Breccia, M.; Ottaviani, E.; Testoni, N.; Merli, F.; Aversa, F.; Alimena, G.; Cavo, M.; Martinelli, G.; Catani, L.; Baccarani, M.; Vianelli, N. Palandri, F; Latagliata, R.; Polverelli, N.; Tieghi, A.; Crugnola, M.; Martino, B.; Perricone, M.; Breccia, M.; Ottaviani, E.; Testoni, N.; Merli, F.; Aversa, F.; Alimena, G.; Cavo, M.; Martinelli, G.; Catani, L.; Baccarani, M.; Vianelli, N.

Objectives To evaluate the efficacy of a salvage treatment with rituximab (RTX) in adults with primary immune thrombocytopenia (ITP), in terms of short-term response and long-term response (LTR, i.e., probability to achieve and maintain response) and to identify biological and clinical predictors of response. Methods We retrospectively evaluated the outcome of patients with primary ITP treated with standard dosage RTX (375 mg/m2 × 4) as salvage therapy in five Italian centers. One hundred and three patients, median age of 46 yr, were included. The median period of observation was 59 months. Results Response (R) and complete response (CR) were documented in 57 (55%) and 37 (36%) patients, respectively. Patients younger than 40 yr had a higher probability to achieve CR (P = 0.025). Younger women (age < 40 yr) had a significantly higher probability to achieve R and CR (P = 0.039 and P = 0.009, respectively). The estimated LTR rate was 36% and 31% after 48 and 72 months, respectively; female sex (P = 0.033) and younger age (P = 0.021) were associated with better LTR. Younger women had the highest LTR rate (P = 0.006). Response duration was associated with the obtainment of CR after RTX (CR vs. partial response, P = 0.002). Conclusions The effect of RTX salvage treatment appears higher in younger women, with LTR rate possibly approaching that of splenectomy.

No abstract is available for this article.

OBJECTIVE: A novel mechanism of platelet destruction involving the CD47/ signal regulatory protein-α (SIRPα) system has recently been suggested in a mouse model of immune thrombocytopenia (ITP). The CD47 molecule serves as ligand for SIRPα receptor and as receptor for thrombospondin acting as antagonistic to phagocyte activity and a regulator of apoptosis, respectively. In this study, we evaluated if the CD47/SIRPα axis may be involved in the apoptosis and clearance of platelets in human ITP. MATERIALS AND METHODS: Using flow cytometry, we characterized whether expression of CD47 on fresh and in vitro-aged platelets- and of SIRPα receptor on CD14-derived dendritic cells (DCs), macrophages, circulating DCs, and monocytes is reduced is ITP; whether the in vitro platelet phagocytic capacity of CD14-derived DCs and macrophages is differentially modulated in the presence or absence of antibodies against CD47 and SIRPα in ITP; and whether platelets are more susceptible to the CD47-induced death signal in ITP. RESULTS: We demonstrated that low platelet count in ITP is not due to increased phagocytosis associated with decreased expression of CD47 on the platelet surface and, despite reduced SIRPα expression, blockage of SIRPα on immature CD14-derived DCs or CD47 on platelets by specific antibodies failed to modify platelet uptake/phagocytosis of DCs. In contrast, targeting platelet CD47 with specific antibody significantly increases platelet phagocytosis of CD14-derived macrophages, and platelets are not healthy because they show increased apoptosis and are resistant to CD47-induced death signal. CONCLUSIONS: Our results demonstrate that the CD47 pathway in ITP patients abnormally modulates platelet homeostasis.

International audience; Established risk factors for thrombosis in essential thrombocythemia (ET) include age (≥60 years) and previous vascular events. Recently, also leukocytosis has been proposed in risk stratification of ET patients. We report a retrospective study on 532 ET patients followed for a median of 7.6 years. Sixty-four patients (12%) developed 95 thrombotic events during follow-up. Together with the high-risk condition, a white blood cell (WBC) value above 11 × 10/L, corresponding to the fourth percentile value, significantly correlated with a higher thrombotic risk ( = 0.033) by Cox proportional hazards. Moreover, the cumulative risk of thrombosis was significantly higher in high-risk patients with WBC >11 × 10/L. JAK2 V617F mutation did not correlate with thrombosis. Overall, 123 (23%) patients died. Three independent parameters were noted as prognostic factors for survival in multivariate analysis: age >60 years, leukocytosis >11 × 10/L, and hemoglobin level below normal values. Based on these parameters, three groups of risk were defined, with significantly different survivals. Baseline leukocytosis correlated with a higher thrombotic risk in high-risk patients and identified a cohort of patients with worse survival.

An increase in the serum concentration of pancreatic enzymes (amylase and lipase) was reported in a proportion of imatinib-resistant and/or intolerant Philadelphia-positive chronic myeloid leukemia patients treated with nilotinib. Acute pancreatitis was very rare, and the relevance of these laboratory alterations remains unknown. We report on 8 chronic myeloid leukemia patients who developed serum lipase/amylase elevation during treatment with nilotinib. After a median follow-up of 26 months, none of these patients developed an acute pancreatitis or clinical signs of pancreatic disease. Pancreatic hyperenzymemia never led to permanent drug discontinuation and required nilotinib temporary interruption in one case only. The median cumulative duration of dose interruptions and response to treatment were comparable in patients with or without pancreatic enzyme elevation. The mechanisms of action of nilotinib on pancreatic enzymes deserves to be investigated: however, in our experience, the relevance of pancreatic hyperenzymemia was clinically very limited.

Chronic myeloid leukemia (CML) is a clonal hematopoietic stem cell disorder characterised by a specific chromosomal translocation, t(9;22)(q34;q11), resulting in the Philadelphia (Ph) chromosome. T...