ALBERT

Description: Introduction. Despite the increasing of number of patients with Sickle Cell Disease (SCD) in Italy, due to multi-ethnic migratory phenomena, a large percentage of Caucasian sickle population is already present in Italy mainly with b-thal/HbS genotype. Red cell transfusion is one effective treatment for both acute and chronic complications of SCD, while hydroxycarbamide (HC) is used to reduce the frequency of painful vaso-occlusive crises (VOCs) and decrease the need for blood transfusion. Through the National Comprehensive Reference Centers for SCD, the Italian Society of Thalassemia and Hemoglobinopathies (SITE), in collaboration with the Society Italian Transfusion Medicine and Immunohematology (SIMTI) and the Italian Association of Hematology and Pediatric Oncology (AIEOP) conducted a national survey to collect information on different therapeutic approaches used for SCD patients. Aim. To assess therapeutic approaches used a large Italian cohort of patients with SCD, accounting for age, genotype and ethnicity. Patients and Methods. Observational Longitudinal Systemic Multicentre Study (https://clinicaltrials.gov/ct2/show/NCT03397017). Data were collected from 2015 to 2018 through a standard web-based application (www.SITE-italia.org) encrypted by the Central Server. All the SCD patients, treated or not treated, were included in order to identify the overall number and all gave written informed consent. The study was approved by Ethics Committee of Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico of Milan, Italy. Results. Thirty-four centers were involved from 14 Italian regions and 1,579 patients were enrolled (802 male and 777 female; median age 23 years - IQR, 25th-75th 10-41 yrs). Genotype, age and ethnicity distribution are shown in Table 1A. As expected, the median age of non-Caucasian patients, mainly HbSS, is significantly lower than Caucasian ones (p

Description: Megakaryocytopoiesis is regulated by extrinsic (interaction of the growth factor thrombopoietin, TPO with its receptor Mpl) and intrinsic (interaction between the trascription factors GATA-1 and Fog-1) factors. The observation that mice impaired for GATA-1 expression (i.e. harbouring the GATA-1low mutation) are defective not only in megakaryocyte maturation but also in mast cell differentiation (Migliaccio et al. J Exp Med197:281, 2003), led us to investigate whether TPO might control mast cell differentiation as well. We first observed that mice genetically unable to responde to TPO (Mplnull mice) express in the connective tissues 5 times more mast cells than their normal littermates. Then, we analysed the effects on mast cell differentiation of in vivo treatment with TPO. Normal mice, and their GATA-1low littermates, were injected i.p. with TPO (100 μg/kg/day per 5 days, kindly provided by Kirin Brewery, Japan) and the number of immature (Toluidinepos) and mature (AlcianBlue/Saphraninepos) mast cells present in the connective tissues of the animals, as well as the frequency of GATA-1pos and TUNELpos mast cells, was evaluated 14 days after treatment. In wild-type animals, TPO reduced the presence of GATA-1 in mast cells (by immuno-histochemistry) and increased the number of immature cells (from 320±28 to 852±60) and of those undergoing apoptosis (from 16±1 to 600±43). In contrast, in GATA-1low animals, TPO-treatment induced the expression of GATA-1 in mast cells while decreased the number of immature cells (from 1100±72 to 427±29) as well as that of apoptotic cells (from 600±45 to 60±2). The role of TPO on mast cell differentiation were further confirmed by the analysis of the effects exerted by the growth factor on in vitro differentiation of bone marrow derived mast cells (BMMC). In these experiments, wild type bone marrow and spleen cells were cultured for 21 days with SCF and IL-3 with or without TPO and BMMC differentiation measured on the basis of the number of cells expressing the phenotype c-kithigh/CD34high and FcεRIpos. In cultures stimulated with SCF and IL-3, all the cells expressed the phenotype c-kithigh/CD34high and FcεRIpos. In contrast, in cultures supplemented also with SCF, IL-3 and TPO, only 25% of the cells were c-kithigh/CD34high and none of them was FcεRIpos. These results establish a role for TPO in the control of mast cell differentiation (possibly by modulating the GATA-1 content of the cells) and unveil further similarities between the mechanism(s) controlling megakaryocyte and mast cell differentiation.

Description: Background Myelofibrosis (MF) is featured by an inflammatory condition that can also drive the progression of disease. Ruxolitinib (RUX) is the-first-in-class Jak1/2 inhibitor approved for treatment for MF. Clinical benefits of RUX are presumably derived from reduction of inflammatory cytokines even if the exact mechanism remains unclear. Recent reports have identified the ratio between absolute neutrophils count (ANC) and absolute lymphocyte count (ALC), called NLR, as a simple parameter that mirrors the inflammatory status and the myeloid associated immune suppression. In various malignancies NLR has been indicated as predictor of progression free survival (PFS) and overall survival (OS). Our preliminary work in a single-center experience showed that patients with NLR〉6 before RUX start had a lower chance to obtain 〉 50% spleen reduction in the first 12 weeks or a complete resolution of splenomegaly at 24 weeks. Objective : We proposed to test NLR=6 as bio-marker in MF to apply into clinical practice as a possible predictor of response to RUX. Methods We used two separate cohorts to validate NLR (as a continuous variable and as a cut off 6) as predictor of response to RUX bases on our preliminary data from healthy volunteers (data not shown). Cohort (#1) including 111 MF patients from MD Anderson Cancer Center treated with RUX on phase 1/2 clinical trial from 2007 to 2010; and cohort (#2) including 367 patients treated at 18 Italian centers between years 2012 - 2018. Spleen responses to RUX treatment, PFS and OS were independently validated in cohorts #1 and 2. As cohort 1 included patients treated on clinical trial, spleen was assessed by MRI before and after 24 weeks of RUX therapy, and by physical examination at week 12. In cohort #2, spleen size was assessed by physical examination before, after 12 and 24 weeks of RUX continuous treatment in a real-life setting. NLR was calculated using data obtained from the complete blood count before RUX start and correlated with driver mutations, early spleen reduction, progression free survival (PFS), defined as time from RUX start to last follow-up or progressive disease (including progression to acute myeloid leukemia, ≥20% blasts in peripheral blood or bone marrow, AML) or death for any reason; and overall survival (OS). Results : Clinical and demographics characteristics of patients in each cohort are summarized in Table 1. In cohort #1 we found that NLR was lower in patients with lower bone marrow fibrosis (grade 0-1: 6.2±0.8 versus grade 2-3: 7.3±0.8, p=0.03). Similarly, in cohort #2, patients with grade 0-1 bone marrow fibrosis had lower NLR than those carrying grade 2-3 bone marrow fibrosis (7.7±0.7 versus 10.6±1.3, p=0.04). NLR was higher in patients carrying JAK2 (V617F) mutation (mean +/- SD, 6.4±0.6 vs 5.3±0.5, p=0.02 in cohort 1 and 9.1±0.6 vs 5.0±0.5, p=0.002 in cohort 2). While in cohort 1 NLR appeared lower in CALR (exon 9 indel) mutated patients, the difference was statistically significant in cohort 2 (5.4±0.8 vs 8.9±0.6, p=0.03). In both cohorts, there were no differences in NLR in either triple negative or MPL (exon 10) patients. In cohort 1, the mean percentage change from baseline in palpable spleen length was −47.7% at week 12 and −53.4% at week 24. NLR=6 was able to identify at baseline early response to RUX with 66.9% sensitivity and 72.3% specificity (HR 1.68, p=0.01). Patients with NLR〉6 before RUX start had a lower chance to obtain a complete resolution of splenomegaly at 24 weeks (p=0.001). These observations were confirmed in cohort 2 where NLR 〉 6 was able to identify at baseline early response to RUX with 50.3% sensitivity and 67.7% specificity (HR 1.56, p=0.01). The mean percentage change from baseline in palpable spleen length was −60.3% at week 12 and −66.7% at week 24. Patients with NLR〉6 before RUX start had a lower chance to obtain a complete resolution of splenomegaly at 24 weeks (p

Description: In this study we investigated the role of CB1 receptor signaling in angiogenesis and the therapeutic exploitation of CB1 inactivation as an antiangiogenic strategy. We started from the observation that CB1 receptor expression is induced during angiogenesis and that the endocannabinoid anandamide stimulated bFGF-induced angiogenesis in the nanomolar physiologic range. To define the functional involvement of CB1 receptor signaling during angiogenesis, 2 different strategies have been carried out: siRNA-mediated knockdown and pharmacologic antagonism of CB1 receptors. CB1 receptors inactivation resulted in the inhibition of bFGF-induced endothelial proliferation, migration, and capillary-like tube formation, through prosurvival and migratory pathways involving ERK, Akt, FAK, JNK, Rho, and MMP-2. To corroborate the potential therapeutic exploitation of CB1 blockade as an antiangiogenic strategy, we performed in vivo assays founding that CB1 blockade was able to inhibit bFGF-induced neovascular growth in the rabbit cornea assay. A relevant finding was the ability to reduce ocular pathologic neo-vascularization in mouse oxygen-induced retinopathy. These results demonstrate that CB1 signaling participates to the proliferative response elicited by proangiogenic growth factors in angiogenesis and that for this reason CB1 receptor could represent a novel target for the treatment of diseases where excessive neoangiogenesis is the underlying pathology.

Description: Background. Minimal residual disease (MRD) is the strongest prognostic factor in both children and adults with acute lymphoblastic leukemia (ALL). Currently, it is most widely monitored by molecular methods based on real-time-quantitative-PCR (RQ-PCR). Digital-droplet-PCR (ddPCR) and next-generation-sequencing (NGS) represent advanced tools that have the potential to overcome some limitations of standard approaches and potentially provide additional benefits. We analyzed adult ALL follow-up (FU) samples by RQ-PCR, ddPCR and NGS in order to better define the discriminating power of these novel methods. Patients and Methods. Thirty adult ALL patients enrolled in the GIMEMA LAL 1913 protocol and their 83 FU bone marrow (BM) samples were studied. All patients received homogeneous induction/early consolidation chemotherapy, with concurrent MRD analysis at four time-points, to optimize risk classification and support risk/MRD-oriented therapy. RQ-PCR analyses followed the EuroMRD Consortium guidelines (van der Velden, 2007), ddPCR was performed as published (Della Starza, 2016; Cavalli, 2017) and NGS, as previously described (Faham, 2012; Kotrova M, 2017). Results. By MRD RQ-PCR analysis, 19/83 samples were positive and quantifiable (Q), 9/83 were positive not-quantifiable (PNQ) and 55/83 were negative (NEG). By MRD ddPCR analysis, 27/83 samples were Q, 1/83 sample was PNQ and 55/83 proved NEG. Comparing the results of the two methods, we observed that MRD detection was concordantly positive or negative in 81% (67/83) of FU samples, while 19% (16/83) samples were classified as discordant. Most of the discordances occurred in samples with low levels of disease, i.e. PNQ or NEG: 9/83 were RQ-PCR PNQ, 4 of which were Q by ddPCR and 5 were ddPCR NEG. In the remaining 7 discordant FU samples, 5 were RQ-PCR NEG/ddPCR Q, 1 sample was RQ-PCR Q /ddPCR NEG and 1 sample was RQ-PCR NEG/ddPCR PNQ. The use of ddPCR significantly reduced the proportion of PNQ samples if compared to RQ-PCR - 1/83 (3%) vs 9/83 (15%) - respectively (p=0.0179), increasing the proportion of Q samples: 27/83 (33%) vs 19/83 (23%). It is worth noting that ddPCR also quantified the levels of disease in 9% (5/55) of samples, that were RQ-PCR NEG (Table 1). MRD analysis was also performed by NGS in 41 samples from 15 patients: 18/41 samples proved Q and 23/41 were NEG. Comparing the MRD detection obtained by both ddPCR and NGS, we observed a concordant result in 98% (40/41) of samples; only 1 sample was ddPCR NEG and NGS Q with a MRD level of 1x10-5. The concordance between RQ-PCR and NGS was 78% (32/41 samples). Moreover, among these 41 samples 9 (from 7 patients) were discordant between RQ-PCR and ddPCR in the first comparative analysis: in 4 RQ-PCR-NEG FU samples, 3 were Q by both ddPCR and NGS, 1 was ddPCR NEG and NGS Q, with a MRD level of 10- 5; 1 subsequent relapse was observed; 4 FU samples that were RQ-PCR-PNQ/ddPCR-Q, were Q also by NGS; 1 subsequent relapse was observed. Finally, 1 RQ-PCR-PNQ sample was negative by both ddPCR and NGS, and no recurrence has so far been observed. Moreover, in the cohort of samples analyzed only by RQ-PCR and ddPCR, in 1 RQ-PCR NEG/ddPCR Q sample a relapse was observed, while the only case that was RQ-PCR Q/ddPCR NEG has so far not relapsed. Notably, 2 of the 3 relapses were documented in patients who were, at decisional treatment TPs, RQ-PCR PNQ or NEG and ddPCR/NGS Q. Conclusions. When MRD levels are very low, it can be difficult to dissect if the not-quantifiable signal observed by PCR is due to few residual leukemic cells or to a non-specific amplification of normal DNA. The superior sensitivity and accuracy of ddPCR and NGS could be instrumental to univocally define these samples, which presently represent a problematic gray area in the clinical practice of MRD-driven protocols and might be associated with clinical relapse: indeed, among 83 FU samples analyzed we observed 3 relapses, whose FU samples were classified as PNQ or NEG by RQ-PCR, but proved Q by ddPCR and/or NGS. At variance, no relapses were recorded in patients whose FU samples were defined RQ-PCR-PNQ, but proved ddPCR/NGS NEG. Moreover, in 2/3 relapsed cases the change of MRD status (PNQ or NEG vs Q) could have led to a switch in risk classification and therefore in a treatment change. Further studies with a larger number of discrepant cases and a longer FU time will allow to conclusively define the clinical application and implication of these new methods. Disclosures Chiaretti: Shire: Consultancy; Pfuzer: Consultancy; Amgen: Consultancy; Incyte: Consultancy. Foà:NOVARTIS: Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau; CELTRION: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; INCYTE: Other: ADVISORY BOARD; AMGEN: Other: ADVISORY BOARD; GILEAD: Speakers Bureau.

Description: In our series of consecutive patients (p) with objectively diagnosed VTE, cancer constitutes the most frequent ethiology (25%) followed by idiopathic (24%), clinical causes (22%), orthopedics and trauma (16%), general surgery (7%), obstetric entities (3%) and others (3%). Among the neoplastic subtypes, HM are the most prevalent ones followed by prostatic, colonic, lung and CNS cancers. A recent publication (Blom et al, JAMA2005; 293:715) shows this previously undisclosed high tendency of HM for provoking VTE. Our current study describes the experience with this association from 1996 to 2005, excluding central vein catheter thrombosis. Out of 531 p with VTE, 138 have cancer and 34 of them, HM, with the following distribution: plasma cells discrasias (PCD) 9 (4 on treatment with thalidomide), diffuse large cell lymphomas (DLCL) 8, indolent lymphomas (IL) 6, CLL 5, mantle cell lymphoma 1, Burkitt lymphoma 1, RAEB 1, AML 1, myelofibrosis 1, P vera 1. In 25/34 p, the HM was previously known at diagnosis of VTE and mostly active or on treatment. In the other 9 p, the clinical presentation was as an idiopathic VTE, and during follow-up the following HM were disclosed: PCD: 3, CLL: 2, DLCL: 1, IL: 1, myelofibrosis: 1, RAEB: 1. Table 1 Comments: PCD and DLCL constitute the two HM more frequently associated with VTE. However, the contribution of less agressive neoplasms such as indolent lymphomas and CLL is not negligible As in solid tumors, recurrences are high, specially when anticoagulated patients are off-therapy In spite of more chemotherapy related-thrombocytopenia and bone marrow involvement, bleeding rates do not differ of those observed in solid tumors Given the frequent association with VTE, and the probable heterogeneity in the thrombophilic potency of these different entities collectively grouped as HM, prospective multicentric studies are clearly needed to identify groups of patients with HM suitable for primary prophylaxis of VTE. Such studies should also be designed to provide further clue about the use of LMWH instead of oral anticoagulants for secondary prophylaxis in HM. Table 1. Main clinical findings in patients able to be evaluated during follow-up Events Hematologic Malignancies Solid Neoplasms Recurrences 6/28 (21.4%) 5 off anticoagulation 15/106 (14.1%) 7 off anticoagulation (p=ns) Major bleeding 2/28 (7.1%) 10/106 (9.4%) (p=ns)

Description: The response of mice genetically unable to up-regulate GATA-1 expression (GATA-1low mice) to acute (phenylhydrazine [PHZ]–induced anemia) and chronic (in vivo treatment for 5 days with 10 U erythropoietin [EPO] per mouse) erythroid stimuli was investigated. Adult GATA-1low mice are profoundly thrombocytopenic (platelet counts [× 109/L] 82.0 ± 28.0 vs 840 ± 170.0 of their control littermates, P 

Description: Backgrounds. Not pegilated liposomal doxorubicin (Myocet®) has a better pharmacokinetic profile with less myelosuppression, much lower gastroenterological and cardiological toxicity than conventional doxorubicin. In order to reduce toxicity of conventional doxorubicin, in our department from 2002 to 2007 we have treated patients with Multiple Myeloma (MM) and Non-Hodgkin’s Lymphoma (NHL) with therapeutical regimens replacing conventional anthracyclines with not pegilated liposomal doxorubicin. Methods. In our department, from 2002 to 2007, 35 patients (17M,18F) with a median age of 68.8±9.6(range 82–33) affected by Multiple Myeloma (MM) received one or more cycles according to chemiotherapic scheme: VCR 1mg iv at day 1 + Myocet® 25mg/sm iv at day 2 + CTX 100mg/sm os days 1–4 + PDN 60mg/sm os days 1–4. Diagnosis concerned patients with IgG Myeloma (n=26), IgA Myeloma (n=7), micromolecular Myeloma (n=1) and PL (n=1). 22 patients (16M,6F) with a median age of 63.6±9.6 (range 45–79) affected by NHL received chemoimmunotherapy COMP21-R (CTX, Myocet®, VCR and PDN plus Rituximab). Four patients were stage I, 7 stage II, 6 stage III and 5 stage IV. According to IPI score: 2 patients were low risk, 6 low-intermediate, 8 intermediate-high and 6 high risk. In all patients, chemoimmunotherapy induced cardiologic evaluation was made considering Left Ventricular Ejection Fraction (LVEF): cardiotoxicity was evaluated testing the null hypothesis that the LVEF delta is more negative than −4% of the baseline value before chemotherapy (which was felt to be a reasonable clinical threshold separating non-clinically-significant cardiac toxicity from clinically significant damage due to chemotherapy). Results. In MM patients evaluation of treatment was made for 31 patients: mean Monoclonal Component (MC) has been reduced from 3048.2±2296.9 to 2353,7±1912.4 and the one sided t-test on the variable delta resulted statistically significant (P = 0.038). Response of treatment was CR 43,3%, PR 23,3%, DP 16,7%, NR 16,7% but no statistically significant correlations were present with both the line of treatment and the diagnosis. For NHL evaluation was made in 20 patients: 17 (77.3%) obtained a Complete Remission (CR), 1 (4.5%) a Partial Remission (PR) and 2 (9.1%) Not Respond (NR) to therapy: no statistically significant correlations were present with both the line of treatment and the diagnosis. In all patients (21 NHL and 30MM, totally 51 subjects), Myocet® cardiotoxicity has been evaluated by LVEF assessment at baseline and monitored along the course of the treatment: baseline mean was 57.8±5.4% and slightly lowered to 55.6±5.2% at the end of treatment. For each sub-population and for the entire population a one-sided t-test was performed in order to determine whether therapy with not pegilated liposomal doxorubicin determines relatively low cardiotoxicity: the tests resulted significant (NHL: P = 0.022, MM: P = 0.0021, All: P = 0.00020), leading to reject the null hypothesis in favour of the alternative hypothesis that cardiotoxicity is actually less severe and that the decrement of LVEF is not as negative as −4%. Conclusion. Myocet® reduce cardiotoxicity and is effective in the treatment of MM and NHL patients.

Description: Patients with paroxysmal nocturnal hemoglobinuria (PNH) have a large clonal population of blood cells deriving from hematopoietic stem cells (HSCs) deficient in glycosylphosphatidylinositol (GPI)-anchored surface molecules. A current model postulates that PNH arises through negative selection against normal HSCs exerted by autoreactive T cells, whereas PNH HSCs escape damage. We have investigated the inhibitory receptor superfamily (IRS) system in 13 patients with PNH. We found a slight increase in the proportion of T cells expressing IRS. In contrast to what applies to healthy donors, the engagement of IRS molecules on T cells from patients with PNH elicited a powerful cytolytic activity in a redirected killing assay, indicating that these IRSs belong to the activating type. This was confirmed by clonal analysis: 50% of IRS+ T-cell clones in patients with PNH were of the activating type, while only 5% were of the activating type in healthy donors. Moreover, the ligation of IRS induces (1) production of tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) and (2) brisk cytolytic activity against cells bearing appropriate IRS counter-ligands. In addition, these IRS+ T cells show natural killer (NK)-like cytolytic activity to which GPI- cells were less sensitive than GPI+ cells. Thus, T cells with NK-like features, expressing the activating isoforms of IRS, may include effector cells involved in the pathogenesis of PNH.

Description: Introduction Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by hematopoietic/stem cell-derived clonal myeloproliferation leading to cytopenia/cytosis, splenomegaly and bone marrow (BM) fibrosis. The alteration of haematopoiesis associted with BM fibrosis is deeply associated with profound modifications of the BM microenvironment, as a consequence of a defective balance between the vascular niche and the endosteal niche, associated to megakaryocytes, endothelial and mesenchymal stromal cells (MSC) dysfunction through the production of a variety of profibrotic, angiogenic, and pro-inflammatory cytokines, including megakaryocyte-derived PDGF, TGF-beta and osteoprotegerin, IL-6, PDGF, RANTSs, BMP-2, and which can trigger auto-immune mechanisms, chronic inflammation and oxidative stress status. It is well-known that oncogenic lesions can switch the bioenergetics of malignant cells from OXPHOS to glycolysis (Warburg effect) with lactate production, a phenomenon clinically relevant, particularly in PMF where the amount of the enzyme lactate dehydrogenase (LDH) is an established biomarker of leucocyte turnover and an independent biomarker of overall and leukemia-free survival. The shuttling of the main LDH metabolite lactate is implicated in the interplay of cancer cells with neighboring stromal cells which become glycolytic and export lactate. In turn, lactate is taken up by cancer cells and used for oxidative metabolism, to drive angiogenesis in endothelial cells and to inhibit T- cell function. Moreover, there are evidences that lactate may be involved in the promotion of the fibrosis increasing the TGF-beta levels. In this work we aimed to investigate the role of lactate in the BM myelofibrosis. Results. From microarray datasets, we selected 34 PMF patients carrying the JAK2V617F mutation, 28 JAK2 wild-type patients and 16 healthy donors (HD). Our analysis showed that SLC16A1 (MCT1), SLC16A3(MCT2) and SLC16A7 (MCT4) genes were upregulated in patients in respect to healthy donors in a JAK2V617F mutation independent manner. Furthermore, we demonstrated a significant increase of lactate concentration in PB sera from PMF patients compared to HD, associated to higher percentage of circulating granulocyte- and monocyte-myeloid derived suppressor cells (Gr- and Mo-MDSCs), and Treg. Moreover, IDO, LAG3, BTLA, PDL-2, TIM-3 and CD152 levels were significantly increased in PMF sera compaterd to HD ones. To demonstrate that lactate could play a role in driving cancer immune evasion in PMF, healthy peripheral blood mononucleated cells (PBMCs) were incubated in presence of lactate. After 3 days we observed a significant increase of the percentage of Mo-MDSCs, Treg, CD4+PD1+ and CD8+PD1+ lymphocytes. The same results were obtained after incubation of PBMCs with sera from PMF patients. No effects were observed using HD sera. Interestingly, the percentages of Treg and Mo-MDSCs increased after exposure to PMF sera were significantly reduced in presence of the inhibitor of lactate transporter AZD3965. To investigate the role of lactate in the PMF microenvironment, we next exposed healthy MSCs to lactate for 48h. Treated MSCs assumed a CAF-like phenotype increasing expression of aSMA, FAP1 and TGF-beta. Moreover, Masson's trichrome staining showed an increase of collagen deposits in BM-MSCs associated to increased release of IL6, TGF-beta, MMP2, MMP9 and RANTES. Also, exposure to PMF sera induced higher collagen deposits in MSCs and this effect was reverted adding AZD3965. As BM fibrosis is frequently accompanied by osteosclerosis, we also investigated the effects of lactate on ostegenic differentiation of BM-MSCs. After 10 days of treatment with lactate, the BM-MSCs showed a morphological change associated to increased osteogenic gene markers such as BMP2, RUNX2 and SPARC (osteonectin), and higher released levels of calcitonin, BMP-2, MCP-1, sRANKL and osteoprotegerin. Conclusion Our results demonstrate that lactate might be involved in the immune impairment and BM fibrosis of PMF. The inhibition of lactate production and shuttles in myelofibrosis may be a strategy not only to inhibit invasive and metastatic behavior of cancer cells, but also to restore the anti-cancer immune response improving the results of therapy in MF patients. Disclosures Romano: Novartis: Honoraria; Takeda: Honoraria. Di Raimondo:Amgen: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; GSK: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Amgen, Takeda, Novartis: Honoraria; Celgene: Consultancy, Honoraria; GILEAD, Incyte: Research Funding. Palumbo:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.