bluuebunny/crossref_metadata_2025 huggingface dataset:
PS1452 GLI‐1, EFFECTOR OF CANONICAL HEDGEHOG SIGNALING PATHWAY, DOES NOT SEEM TO BE DYSREGULATED IN PATIENTS WITH MYELOFIBROSIS
Authors: Lucijanic M. , Livun A. , Stoos‐Veic T. , Pejsa V. , Jonjic Z. , Dzankic A. Fazlic , Ivic M. , Kusec R.
Published: June 2019

Background:

Although activation of Hedgehog signaling pathway was reported to be present in murine bone marrow transplant model of primary myelofibrosis (PMF) and increased expression of Hedgehog target genes was reported in granulocytes isolated from unselected patients with myeloproliferative neoplasms, therapeutic Hedgehog inhibition showed only limited results in myelofibrosis so far. Also, inconsistent effects of such therapy on Gli1 (effector of hedgehog signaling) were observed.

Aims:

We aimed to investigate Gli‐1 expression in bone‐marrow tissues of patients with primary and secondary myelofibrosis (SMF) and to assess its clinical correlations.

Methods:

We retrospectively investigated Gli‐1 mRNA expression in 32 diseased (28 PMF, 4 SMF) and 16 healthy (limited stage agressive Non‐Hodgkin lymphoma) bone marrow samples using real‐time‐polymerase‐chain‐reaction (GLI1 Hs01110766_m1 Thermo Fischer Scientific TaqMan assay). Expression was normalized to Abl and expressed as a ΔCT value. Correlations with clinical parameters were made. Study was approved by the institutional review board. All procedures were in accordance with the Helsinki Declaration. All patients provided written informed consent.

Results:

Median age of our patients was 70 years, there were 21 (66%) males and 11 (34%) females. Gli‐1 expression did not significantly differ between PMF, SMF and controls (median ΔCT 7.2, 7.3 and 6.9 respectively; P = 0.864).

Higher Gli‐1 bone marrow expression was not significantly associated with neither age, gender, JAK2, CALR, MPL mutational status nor degree of bone marrow fibrosis (P>0.05 for all analyses). Only statistically significant associations were present between higher Gli‐1 expression and higher transferrin saturation (P = 0.039; Rho = 0.4) and higher absolute lymphocyte count (P = 0.032; Rho = 0.4).

Gli‐1 expression separated at median (ΔCT 7.25) had neutral effect on overall survival in our cohort of patients (P = 0.651) as shown in a Figure.

Summary/Conclusion:

Our findings indicate Gli‐1 mRNA expression might not be dysregulated in patients with myelofibrosis and has neutral impact on prognosis of these patients. Although limited by small number of patients, retrospective study design and single center experience, our results are in line with previous observations of modest clinical effects of Hedgehog inhibition in patients with myelofibrosis.

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PS1453 CURCUMIN INHIBITS PROLIFERATION AND INDUCES APOPTOSIS IN JAK2 MUTATED CELLS THROUGH THE INHIBITION OF JAK2/STAT AND MTORC1 PATHWAYS
Authors: Petiti J. , Rosso V. , Iacono M. Lo , Panuzzo C. , Fava C. , Cilloni D.
Published: June 2019

Background:

Myeloproliferative neoplasms are chronic myeloid cancers divided in Philadelphia positive and negative. The JAK2 V617F is the most common mutation in Philadelphia negative patients and results in a constitutive activation of the JAK/STAT pathway, conferring a proliferative advantage and apoptosis inhibition. Furthermore, recent studies identified a functional crosstalk between the JAK/STAT and mTOR pathways. Given the heterogeneous clinical needs of MPNs patients, identification of an effective therapy is often difficult. Therefore, the availability of new therapeutic approaches might be very attractive. Curcumin is the active phytochemical component of the Curcuma longa plant. Previous studies showed that curcumin can suppress JAK2/STAT signaling pathways in different type of cancer and injuries.

Aims:

In this study, we investigated the anti‐proliferative and pro‐apoptotic effects of curcumin in JAK2 V617F cell line and in primary cells.

Methods:

HEL cell line and cells from patients affected by myeloproliferative neoplasms have been incubated with increasing concentrations of curcumin for different time. Apoptosis and proliferation were evaluated. Subsequently, JAK2/STAT and AKT/mTOR pathways were investigated at both RNA and protein levels.

Results:

We showed that curcumin strongly inhibited the proliferation and induced apoptosis in a dose and time dependent manner in HEL cells. Furthermore, we found that curcumin markedly reduced JAK2 phosphorylation and, consequently, the activation of its downstream effectors STAT3 and STAT5 in HEL cells. We observed that JAK2/STAT inhibition induced the down regulation of Pim family members in HEL cell line and in patient specimens. Farther, our results in HEL cells showed that curcumin negatively regulated the mTORC1 complex formation. As a consequence, we observed a strong inhibition of mTORC1 downstream effectors 4eBP1 and p70s6K phosphorylation. Our preliminary data on cells from MPNs patients showed that the in vitro curcumin treatment significantly promoted apoptosis and reduced the expression of Pim family members, bringing back their mRNA expressions to comparable levels with healthy subjects ones. Furthermore, the curcumin effect was strengthened by the observation that CD177, an antigen over expressed in neutrophils of the majority of MPNs patients, was down regulated by curcumin.

Summary/Conclusion:

In conclusion, the present study showed that curcumin exerts an antitumor effect on human JAK2 mutated cells by inducing apoptosis and inhibition of proliferation, through the regulation of both JAK2/STAT and mTORC1 pathways. These findings suggest that curcumin seems to be a promising nutraceutical compound that should be further evaluated in different pharmaceutical formulation for the treatment of MPNs.
PS1469 IL28B GENE POLYMORPHISMS INFLUENCE ON THE RESPONSIVENESS AND TOLERABILITY OF IFN‐Α IN PATIENTS WITH MPN
Authors: Olkhovskiy∗ I. , Stolyar M. , Gorbenko A. , Lagutinskaya D. , Dunaeva E. , Mironov K. , Shipulin G. , Olkhovik T. , Mikhalev M. , Vasiliev E. , Smelyanskaya M. , Hazieva A.
Published: June 2019

Background:

Interferon‐α (IFN‐α) provides several benefits to myeloproliferative neoplasms (MPNs) patients and leads 35% of its experienced a good molecular response. Both newly diagnosed and previously treated patients with polycythemia vera (PV) exhibit high hematologic response rates, and some of these patients achieve molecular responses [Kiladjian J‐J., et al., 2016]. Nevertheless, IFN‐α therapy is often accompanied by serious side effects, which forces some patients to refuse treatment. Only one scientific team [Lindgren M., et al., 2012, 2018] previously published data demonstrating the effect of IL28B gene polymorphisms on the success of interferon therapy in MPNs.

Aims:

Evaluate the prognostic impact of IL28B rs12979860 and rs8099917 on IFN‐α treatment response and toxicity in patients with MPNs.

Methods:

35 patients were investigated: 18 with polycythemia vera, 12 with essential thrombocythemia and 5 with primary myelofibrosis. All patients were treated with IFN‐α (three times weekly). DNA from whole blood samples was isolated using «DNAsorb‐B» (Central Research Institute for Epidemiology, Russia). The rs12979860 and rs8099917 SNPs genotyping was determined by pyrosequencing on a PyroMark Q24 instrument. Allele burden JAK2 V617F was determined using «Myeloscreen JAK2» («Formula of gene Ltd», Russia). Hematologic response was evaluated using the European Leukemia Net criteria. The quantitative values are given as a median and 25% and 75% percentiles.

Results:

The JAK2 V617F allele burden after 60 months of IFN‐α therapy was significantly reduced in samples of patients with polycythemia vera in the presence of a “strong” TT/CC variant of the haplotype IL28B (13; 8.4–24.4) compared with other variants of polymorphism of these gene (57; 44,3–67,0). The average duration of therapy to failure due to side effects of IFN‐α was also 2–3 times shorter (p < 0.05) in patients with a TT/CC haplotype. The therapeutic impact of IFN‐α in patients with MPN involve IL28B signaling pathways. This is the second independent confirmation of the data by Lindgren et al.

Summary/Conclusion:

Genotype evaluation of IL28B can be useful for predicting the effectiveness of interferon therapy in MPNs.

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PS1477 PLATELET DISFUNCTION IN NOONAN AND 22Q11.2 DELETION SYNDROMES IN CHILDHOOD
Authors: RUIZ A. , ISOLA I. , GASSIOT S. , CATALÀ A. , DÍAZ‐RICART M. , MARTÍNEZ‐MONSENY A.F. , SERRANO M. , BERRUECO R.
Published: June 2019

Background:

An underlying thrombocytopathy seems to be the responsible for hemorrhagic symptoms in patients diagnosed with 22q11.2 deletion syndrome (22q11DS) and Noonan syndromes (NS). Whereas in 22q11DS it is explained by a defect in the membrane glycoprotein complex Ib‐V‐IX, the cause of thrombocytopathy in NS remains unclear.

Aims:

To study the incidence of thrombocytopathy in pediatric patients diagnosed with 22q11DS or NS assessing the utility of ISTH‐BAT questionnaire and laboratory techniques in this regard.

Methods:

Prospective study between March and December 2018 in children (2 to 18 year‐old) diagnosed with 22q11DS or NS. Hemorrhagic symptoms, total cell blood count, platelet indices, closure time and platelet aggregation were evaluated in all patients. Membrane glycoprotein expression was only performed in 22q11DS patients.

Results:

Among NS patients (n = 22), near 80% had an aggregation defect with adenosine diphosphate (ADP) and epinephrine without thrombocytopenia. A significant correlation (p < 0.05) between closure times and aggregation with arachidonic acid, epinephrine and ADP was found. This correlation was more evident in those patients with hemorrhagic symptoms.

Five out 29 (17%) patients diagnosed with 22q11DS had thrombocytopenia. Impairment in ristocetin‐induced platelet aggregation was found. This defect was correlated with prolonged closure times. Moreover, a significant correlation between thrombocytopenia, closure times and hemorrhagic symptoms was demonstrated.

Summary/Conclusion:

This study shows in a cohort of patients with NS and 22q11DS a significant impairment of platelet aggregation which correlates with hemorrhagic symptoms and closure times. Thus, closures times might be useful as screening test to evaluate the bleeding risk in this group of patients.
PS1496 ANKRD26‐RELATED THROMBOCYTOPENIA: STUDY OF 3 FAMILIES
Authors: Coelho D. Pereira , Azevedo J. , Martinho P. , Nascimento T. , Marini S. , Ribeiro A. Barbosa , Cortesão E. , Luís D. , Rito L. , Sevivas T. , Guilherme R. , Fidalgo T. , Ribeiro L.
Published: June 2019

Background:

ANKRD26‐related thrombocytopenia (ANKRD26‐RT) is a non‐syndromic form of inherited thrombocytopenia with autosomal dominant transmission, caused by mutations in the 5’UTR region of the ANKRD26 gene. About 8–10% of the patients develop myeloid neoplasms. Recently, in the 2016 revision of the WHO, this entity was recognized in the group of myeloid neoplasms with germ line predisposition and preexisting platelet disorders

Aims:

Characterization of 3 portuguese families with ANKRD26‐RT.

Methods:

Study of 3 families with thrombocytopenia and ANKRD26 gene mutation. Initial study on NGS platform (Ion Torrent ™, Thermo Fisher Scientific), subsequent confirmation/family studies by Sanger direct sequencing. Clinical (symptoms, treatment, evolution) and laboratory data (platelets, MPV, Hb, leukocytes, bone marrow) were analyzed for 11 individuals.

Results:

Mutations in the 5’UTR region of the ANKRD26 gene in heterozygosity were found in 11 individuals studied, belonging to 3 families with autosomal dominal familial thrombocytopenia and normal MPV.: c.‐118C>T mutation in family 1 and 2, and the more recently described c.‐140C>G mutation in family 3. Median age at diagnosis of thrombocytopenia was 16 years (0.25–55), with a current median age of 36 years (2–73). In those affected, the median number of platelets is 48x109L (8–203), with persistently normal MPV in 82% of patients (8,2–12,9). In our cohort, the elderly (> 65 years) had lower platelet counts (<15x109L) and 1 family member with the c.‐140C>G mutation had normal platelet count in one determination. About half of the patients had Htc> 45% (max 50.4%). More than half of the patients (54.5%) were initially interpreted as ITP and treated with prednisolone or IV Ig, with no response. Only 5 patients experienced bleeding events, two requiring platelet transfusion. The patient with the most significant hemorrhagic symptoms (45 years old, platelets 15–30x109L) was classified as MDS in 2011.

Summary/Conclusion:

ANKRD26‐RT is associated with a risk of developing myeloid neoplasia, making its diagnosis and monitoring particularly important. The recognition of this entity is recent and probably underdiagnosed. In our center we identified 3 ANKRD26‐RT families, 2 of them had 3 affected generations. Its characterization and follow‐up will allow us to better understand the variability of presentation and evolution and possibly the identification of bio‐clinical risk factors for neoplastic transformation.
PS1515 PREMEDICATION WITH MONTELUKAST AND RUPATADINE DECREASES INFUSION TIME, RATE AND SEVERITY OF REACTIONS AND OVERALL COST OF RITUXIMAB ADMINISTRATION
Authors: Kotchetkov R. , McLean J. , Gerard L. , Nay D. , Hopkins S.
Published: June 2019

Background:

Rituximab is associated with frequent infusion reactions, which carry significant burden to both patients and health care practitioners. Standard pre‐medications (SP) do not prevent reactions sufficiently. Montelukast (M) and Rupatadine (R) are used for treatment of urticarial, allergic rhinitis, and may impact Rituximab infusion

Aims:

We assessed impact of addition of R, M and their combination (R+M) on Rituximab infusion/rate, rate/severity of reactions and administration cost

Methods:

Adult patients with lymphoproliferative disorders treated at our cancer center between Jan 2018 to Jan 2019 were evaluated with Rituximab‐containing regiments. Since the majority of reactions occur during the first infusion, our study was limited to the initial Rituximab treatment. Patients received either SP with diphenhydramine/acetaminophen and additional R, M or R+M combination. Comparative analysis of infusion time/rate, severity of infusion reactions, number of rescue medications and cost of Rituximab infusions among groups was performed using one‐way ANOVA with Tukey post‐hoc or chi‐square. The study was approved by our institutional ethics board

Results:

Patients received either: 1) standard premedications (SP); 2) SP + Rupatadine (R) 10 mg; 3) SP + Montelukast (M) 10 mg; or 4) both (SP+R+M). Patient characteristics and therapy are shown in Table 1. Compared to SP, the R, M and R+M groups had greater improvement in Rituximab delivery. Mean infusion time was 305 [range 235–441] min. in SP, 254 [105–390] in M, 265 [193–350] in R and 238 [196–342] in R+M groups, (p = 0.0001). Infusion reactions occurred in 92% in SP vs. 38, 45, 31% in M, R and R+M groups (p = 0.0001). Median reaction grade was 2 in SP, 1 (M), 0 (R and R+M). Median number of rescue medications was 3 [0–10] in SP vs 0 [0–7] in M, R and R+M groups. Cost of rescue medications (US$) was 41 [0–63] (SP), 11 [0–50] (M), 17 [0–63] (R), 7 [0–58] (R+M) groups (p < 0.0001). Mean nursing cost (US$) per patient infusion was calculated as 269 [207–388] in SP vs 222 [92–343] (M), 233 [170–308] (R), 209 [174–301] (R+M) group.

RCHOP, Rituximab/Cyclophosphamide/Doxorubicin/ Oncovin/Prednisone; BR, Bendamustine/Rituximab; FCR, Fludarabine/Cyclophosphamide/Rituximab

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Summary/Conclusion:

Addition of R, M and particularly R+M combination significantly improved Rituximab delivery, decreased the rate and severity of infusion reactions, and lowered the cost of Rituximab administration
PS1522 CENTRAL PHYSIOLOGIC MECHANISMS WHICH AUGMENT OXYGEN RELEASE (BOHR EFFECT AND 2,3‐DPG BINDING) ARE PRESERVED IN THE PRESENCE OF VOXELOTOR AT THE THERAPEUTIC TARGET OF 30% HB MODIFICATION
Authors: Pochron M. , Siu V. , Oksenberg D. , Dufu K.
Published: June 2019

Background:

Key physiologic mechanisms that drive O2 offloading to tissues in vivo include the Bohr effect and 2,3‐DPG binding. The Bohr effect is the capacity of Hb to offload more O2 in hypoxic peripheral tissues in response to conditions of increased H+ concentrations (or acidosis). Similarly, the binding of 2,3‐DPG to Hb stabilizes the deoxyHb state, reduces the Hb‐O2 affinity and facilitates O2 release to tissues.

Aims:

To investigate oxygen off‐loading dynamics from voxelotor‐modified hemoglobin in vitro under increased acidity or increased DPG content.

Methods:

In this study, the Oxygen Dissociation Assay (ODA) and oxygen equilibrium curves (OECs) were used to determine the effect of voxelotor on Hb‐O2 affinity in response to H+ and 2,3‐DPG (5 mM). The ODA is a spectrophotometric assay that measures the time dependences of O2 release, while Hb‐O2 affinities can be measured using OECs. Studies in the ODA were conducted with purified Hb (3 μM), while OEC determinations were conducted with both purified Hb (25 μM) and whole blood.

Results:

Relative to Hb alone, voxelotor‐modified Hb dose‐dependently increased the proportion of oxygenated Hb (oxyHb) molecules during two hours of deoxygenation consistent with stabilization of hemoglobin in the oxy, or R‐ state. Under deoxygenated conditions, the percentage of oxygenated voxelotor‐modified Hb decreased over time, demonstrating oxygen release (offloading) by voxelotor‐modified Hb. With increased acidity (down to 6.8), there was an acceleration of oxygen release from voxelotor‐modified Hb under deoxygenated conditions. This resulted in an increase in the p50 of voxelotor‐modified blood and thus demonstrates a pH‐dependent decrease in the affinity of Hb for O2 in the presence of voxelotor at the therapeutic target Hb modification of 30% (Figure 1A). Similarly, the response of Hb to 2,3‐DPG effect was not inhibited in the presence of voxelotor at the 30% modification target (Figure 1B).

Summary/Conclusion:

The results of this study indicate that the central physiologic mechanisms which augment oxygen release to metabolically active tissues, such as the Bohr effect and 2,3‐DPG binding, are preserved when voxelotor is bound to Hb.

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PS1537 CO‐TRANSPLANTATION OF MESENCHYMAL STEM CELLS CAN AMELIORATES ACUTE GVHD AND VIREMIA AFTER ALLO‐HSCT FOR APLASTIC ANEMIA: A MULTI‐CENTER RETROSPECTIVE STUDY OF 75PATIENTS
Authors: Chen M. , Zheng Z. , Hu J. , Yang T.
Published: June 2019

Background:

Mesenchymal stem cells (MSCs) are known to exhibit immunomodulatory, anti‐inflammatory, and pro‐angiogenic properties, and therefore have the potential to improve the outcome of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) for severe aplastic anemia (AA).

Aims:

To explore the efficacy and safety of allo‐HSCT by co‐transplantation with MSCs in AA patients

Methods:

We conducted a multi‐center retrospective study to comparing the incidence and severity of acute GvHD, transplant‐related complication and overall survival (OS) of allo‐HSCT with or without co‐injection of MSCs in AA patients. A total of 75 consecutive severe AA patients (43males/32 females) undergoing allo‐HSCT at 4 hospitals from January 2012 to February 2018 were analyzed. 45 patients transplanted with donor HSCs only,and 30 patients transplanted with HSCs and MSCs. MSCs infusion dose was 0.5–3.0 × 106/kg, at day0/+1 following HSCs infusion.

Results:

All patients achieved successful engraftment within one month post transplant. There was no difference in time to leukocyte and platelet engraftment in the two groups. There was a trend to a lower incidence of aGVHD in the MSC group (13.3% versus 26.7%,χ2 = 2.066 P = 0.151). Moreover, a lower incidence of CMV replication in the MSC group was observed (CMV:26.7% vs 64.4 %,P = 0.003). With a median follow‐up time of 615 days (range:29–2315ays),the 2‐yr OS was similar in both groups (76.2% vs 77.3%,P = 0.883). A combination of bone marrow and peripheral blood as the sources of stem cells co‐transplanted with MSCs (n = 9) demonstrated an improved survival benefit (2‐yr OS = 100%).

Summary/Conclusion:

These data support that co‐transplantation with MSCs could ameliorate the challenges of aGVHD and viremia and facilitate survival in allo‐HSCT for AA patients.
PS1567 UNCOUPLING INK PROTEINS FROM CDK4/CDK6 IN HSCS – UNCOUPLING PROLIFERATION FROM SENESCENCE
Authors: Prchal‐Murphy M. , Bellutti F. , Sexl V. , Kollmann K.
Published: June 2019

Background:

Cyclin‐dependent kinase (CDK) 4 and CDK6 are highly related cell‐cycle kinases that regulate progression from G1 to S‐phase. CDK4/6 are activated upon binding of D‐type cyclins and subsequently phosphorylate the retinoblastoma protein (Rb). CDK4/6 inhibitor proteins, the INK4 family (p16INK4a, p15INK4b, p18INK4c, and p19INK4d) as major player, adds another layer of complexity. Hyperactivity of CDK4 or CDK6 is frequently observed in hematopoietic malignancies due to loss of p16INK4a. Besides, CDK6 has also been identified as transcriptional regulator driving complex transcriptional programs. CDK4/6 inhibitors are approved in breast cancer treatment and are currently tested in hematopoietic malignancies.

Aims:

We aimed to unravel the consequences of the loss of these inhibitory INK‐dependent mechanisms for hematopoiesis.

Methods:

We used knock‐in mice expressing a CDK6 (CDK6R31C, Cdk6

R/R
) and/or a CDK4 (CDK4R24C, Cdk4

R/R
) mutant insensitive to INK4‐mediated inhibition and analyzed stem cell populations. Further we tested the self‐renewal capacity of mutant hematopoietic progenitors under conditions of hematopoietic stress.

Results:

Despite comparable bone marrow cellularity, we found a significant reduction in LSK cells and HSC populations in mice harboring Cdk4

R/R
or Cdk6

R/R
mutation. The combination of Cdk4

R/R
/Cdk6

R/R
in double‐knock‐in mice rescued these defects in all progenitor stages. Serially transplanted Cdk4

R/R
/Cdk6

R/R
double‐knock‐in HSCs display enhanced stem cell proliferation. They maintain the ability to give rise to both myeloid and lymphoid lineages. In response to hematopoietic stress (5‐FU, serial and competitive total bone marrow transplantation), CDK4R24C/CDK6R31C prevents stem cell exhaustion and show robust recovery in stem cell numbers. Low‐input RNAseq of long‐term stress‐triggered HSCs will unravel mechanisms uncoupling proliferation from senescence.

Summary/Conclusion:

HSCs with disrupted CDK4/6 – INK4 binding show enhanced proliferation, reduced exhaustion and improved transplant ability. Analysis of the underlying molecular alterations may open novel therapeutic options for CDK4/6 hyperactive hematopoietic malignancies.
PS1572 HEART DISEASE AND PANCREATIC IRON IN THALASSEMIA MAJOR
Authors: Meloni A. , Pistoia L. , Spadola V. , Murgia M. , Quota A. , Carrai V. , Bulgarelli S. , Mattei R. , Pasin M. , Sardella L. , Restaino G. , Preziosi P. , Positano V. , Pepe A.
Published: June 2019

Background:

Some preliminary data have postulated a correlation between pancreatic iron overload and heart iron and function in thalassemia major (TM) patients.

Aims:

In the present multicenter study we explored systematically the link between pancreatic iron and heart disease in a large cohort of TM patients.

Methods:

We considered 880 TM patients (467 M, mean age 37.83 ± 10.05 years) enrolled in the E‐MIOT (Extension‐Myocardial Iron Overload in Thalassemia) project. T2∗ measurements were performed over pancreatic head, body and tail and global value was the mean. Myocardial iron overload (MIO) was quantified using a T2∗ segmental approach. Biventricular function parameters were assessed by cine images. Late gadolinium enhancement (LGE) images were acquired to detect myocardial fibrosis.

Results:

A significant correlation between pancreatic and cardiac iron was reconfirmed in this more numerous population and a normal pancreas T2∗ showed negative predictive value of 100% for cardiac iron.

LGE sequences were acquired in 273 TM patients and 84 (30.77%) of them showed macroscopic myocardial fibrosis. Global pancreas T2∗ values were significantly lower in patients with fibrosis (7.38 ± 6.19 ms vs 11.91 ± 9.79 ms; P < 0.0001).

Sixty‐four patients had at least one cardiac complication (arrhythmias, heart failure, pulmonary hyperthension, vascular disease). Patients with cardiac complications showed a significant lower global pancreas T2∗ (7.83 ± 5.61 ms vs 12.76 ± 10.34 ms; P = 0.024). Specifically, global pancreas T2∗ values were significantly lower in patients with heart failure as well as in patients with arrhythmias and all patients with one of these two diseases had a pathologic global pancreas T2∗ value (see Figure).

Summary/Conclusion:

Pancreatic iron is a strong predictor not only for cardiac iron, but also for cardiac complications supporting a more profound link between pancreatic iron and heart disease in TM.

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PS1577 PLATELET COUNT AND MEAN PLATELET VOLUME IN ACUTE STROKE: A SYSTEMATIC REVIEW AND META‐ANALYSIS
Authors: Shemirani H.A. , Sadeghi F. , Kovács S. , Zsóri K.S. , Bereczky Z. , csiki Z.
Published: June 2019

Background:

Changes of platelet count (PC) and mean platelet volume (MPV) could be a marker or a predictor of acute stroke (AS).

Aims:

We conducted a systematic review and meta‐analysis of the published literature on the reporting of MPV and PC in AS.

Methods:

Medline, EBSCOhost, Web of Science, ScienceDirect, Google Scholar and Scopus were searched for studies. Studies were included in accordance with Patient Population or Problem, Intervention, Comparison, Outcomes, and Setting (PICOS) framework. The PRISMA strategy was used to report findings. Risk of bias was assessed with Newcastle‐Ottawa Scale. The inclusion criteria were case‐control or cross‐sectional studies, individuals suffered an acute stroke, with fatal or non‐fatal stroke outcomes. Standardized mean difference (SMD) was calculated with a confidence interval of 95% (95% CI).

Results:

We included 32 eligible articles retrieved from the literature. PC was significantly lower in AS patients [standardized mean difference (SMD) = 0.30, (95%CI: 0.49–0.11), N = 2492, P = 0.002] compared with controls (N = 3615). The MPV was significantly higher [SMD = 0.51, (95%CI: 0.27–0.74), N = 2413, P < 0.001] compared with controls (N = 3621). Subgroup analyses showed significantly lower PC in both ischemic stroke (Difference SMD = 0.18, 95%CI: 0.35‐0.01) and hemorrhagic stroke (0.94, 1.62–0.25), but only samples by citrate anticoagulant showed significantly lower result for patients compared to controls (0.36, 0.68–0.04). Ischemic stroke patients had higher MPV (0.55, 0.29–0.81), and samples by EDTA anticoagulant showed significantly higher result for patients compared to controls (0.79, 0.49–1.10).

Summary/Conclusion:

PC and MPV appeared to be significantly different between patients with AS and control populations. MPV was significantly higher in ischemic stroke and PC was significantly lower in both ischemic and hemorrhagic strokes. It is advisable to pay attention to the type of anticoagulant for hematology analyses in AS. Our results highlight the potential predictive role of PC and MPV in the occurrence of stroke.
PS1582 DECREASED PLATELET REACTIVITY IS ASSOCIATED WITH AN INFLAMMATORY STATUS IN PATIENTS WITH CANCER
Authors: Riedl J. , Salzmann M. , Pabinger I. , Ay C.
Published: June 2019

Background:

Decreased platelet reactivity was observed in cancer patients at high risk of venous thromboembolism (VTE) and death. Prothrombotic and inflammatory mechanisms have been suggested to cooperate in the development of VTE, representing represent the hallmark of thromboinflammation.

Aims:

To assess whether platelet reactivity is associated with inflammatory parameters in cancer patients.

Methods:

Platelet reactivity was determined by whole blood flow cytometry in 62 newly diagnosed cancer patients (median age [interquartile range, IQR]: 63 [54–70] years, 48 % female) at several time points during the first 6 months of chemotherapy (total number of samples analyzed: 179). We measured platelet surface P‐selectin and activated glycoprotein (GP) IIb/IIIa expression in vivo and upon ex vivo stimulation with agonists of protease‐activated receptor (PAR) −1, −4, and GPVI. C‐reactive protein (CRP) and fibrinogen levels were analyzed in plasma samples from the corresponding blood draws.

Results:

Platelet reactivity, as determined by percentage of platelets expressing activated GPIIb/IIIa on the surface, upon stimulation with different agonists, correlated with significantly lower levels of CRP and fibrinogen (Table 1). Platelet surface P‐selectin expression upon stimulation of the GPVI receptor also showed a significant inverse correlation with CRP and fibrinogen (Table 1). Platelet activation in vivo (i.e. without ex vivo agonist activation) did not correlate with CRP and fibrinogen levels (Table 1).

Summary/Conclusion:

Our data indicate that there is an inverse relationship between platelet reactivity and inflammatory status in cancer patients, whereby platelets of patients with increased inflammatory parameters are less reactive to stimulation with platelet agonists. Further research is needed to better understand underlying pathophysiological mechanisms.

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PS1595 PREVENTING ALLOIMMUNIZATION OF RECIPIENTS WITH SELECTING OF DONORS BY RED BLOOD CELLS ANTIGENS OF THE RHESUS SYSTEM
Authors: Butina E. , Poponina E. , Yovdiy A. , Sherstnev F. , Zaitseva G. , Paramonov I.
Published: June 2019

Background:

In April 2013, the Ministry of Health of the Russian Federation approved an order regulating transfusion therapy in hematology patients only taking into account the compatibility of the donor and recipient for the antigens C, c, E, e, CW.

Aims:

Assess the effectiveness of organizational measures for the prevention of alloimmunization to antigens of red blood cells in patients receiving intensive hemocomponent therapy.

Methods:

The results of immunohematological studies were analyzed in 3697 patients: 1961 patients were first admitted for treatment at a hematological clinic from 2007 to 2014; 1736 patients ‐ from 2015 to 2018. Non‐Hodgkin lymphoma was diagnosed in 767 patients, chronic myeloid leukemia in 220, chronic lymphocytic leukemia in 320, acute leukemia in 612, multiple myeloma in 398, myelodysplastic syndrome in 73, aplastic anemia ‐ in 147, other hematologic diseases ‐ in 1160. The studies were performed using equipment and reagents from BioRad (USA).

Results:

In 2007–2014, antibodies to antigens C, c, E, e, CW of the Rhesus system were detected in hematological patients with a frequency of 0.92%. Due to the phenotypic selection of donors, the level of alloimmunization decreased 2.6 times and amounted to 0.35% in 2015–2018 (χ2 = 3,831; p = 0.05). The frequency of detection of antibodies to antigen C (0.25% and 0.06%, respectively) and to antigen E (0.46% vs 0.12%) decreased four times. The selection for the antigen was carried out in the clinic since 1998, therefore the immunization index for this antigen remained at the same level (0.10% vs 0.12%). The frequency of detection of antibodies to the CW antigen has not changed significantly (0.10% vs 0.06%). Alloantibodies to the antigen e were not detected for the entire observation period.

Table. The frequency of detection of antibodies to antigens C, c, E, e, CW in hematological patients in the periods 2007–2014, 2015‐2018.

Summary/Conclusion:

Phenotypic selection of donors for antigens C, c, E of the Rhesus system is an effective method of preventing aloimmunization of patients receiving intensive hemocomponent therapy. The selection of red blood cells for antigens CW and e has no practical significance.

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PS1596 AUTOIMMUNIZATION AND ALLOIMMUNIZATION IN TRANSFUSION DEPENDANT THALASSEMIA MAJOR PATIENTS:STUDY ON 300 PATIENTS
Authors: Younas A. , Ghias A. , Farhan S.
Published: June 2019

Background:

Thalassemia is the most common genetic disorder worldwide and one of the major public health problems. Thalassemia patients are dependent on blood transfusions for their survival but they may be associated with many complications. Development of anti red blood cell antibodies(bot alloantibodies and autoantibodies) is one of them. There is a paucity of data on the incidence of alloimmunization and autoimmunization in thalassemic patients in Pakistan,as pre transfusion antibody screening is not routinely performed. Autoantibodies can result in clinical hemolysis and difficulty in cross matching blood. We studied the frequency of Red cell alloimmunization and autoimmunization among Thalassemia patients who received regular transfusions at Sundas Foundation and also to determine types of these antibodies among Thalassemia patients.

Aims:

To study the frequency of Red Cell alloimmunization and autoimmunization among multiple transfused Thalassemia patients and to determine the types of these antibodies.

Methods:

A total of 300 multiple transfused Thalassemia patients were included in this study. Clinical and serological records of all the patients were examined. Screening and identification of antibodies was performed on fresh serum of all patients using 3 cell and 11 cell panel respectively. Detection of autoantibodies was done using using polyspecific Coombs(IgG+C3d) gel cards. Approval of this study was taken from the institutional review board. Informed consent was provided.

Results:

We identified alloantibodies in 17 patients,the most common were Anti E followed by Anti D,Anti C,Anti K,Anti Fyb,Anti‐M.4 patients developed autoantibodies.

Summary/Conclusion:

Alloimmunization is an immune respone stimulated by the transfusion of blood products. Overall rate of alloimmunization was 5.66% in our study while it is 30%/190 in Kuwait,4.97%/161 in India,5%/1435 in Italy,3.7%/1200 in Greece,5%/711 in Iran,9.2%/97 and 22.7%/75 in Pakistan.
S1599 RITUXIMAB MAINTENANCE FOR PATIENTS WITH DIFFUSE LARGE B‐CELL LYMPHOMA IN FIRST COMPLETE REMISSION: RESULTS FROM A RANDOMIZED HOVON‐NORDIC LYMPHOMA GROUP PHASE III STUDY
Authors: Lugtenburg P. , Brown P. , van der Holt B. , D’Amore F. , Koene H. , de Jongh E. , Fijnheer R. , Loosveld O. , Böhmer L. , Pruijt H. , Verhoef G. , Hoogendoorn M. , Bilgin Y. , Nijland M. , Lam K. , de Keizer B. , de Jong D. , Zijlstra J.
Published: June 2019

Background:

This randomized phase III trial assessed whether intensification of rituximab (R) during the first 4 cycles of R‐CHOP can improve outcome of diffuse large B‐cell lymphoma (DLBCL) patients compared with standard R‐CHOP. Patients in complete remission (CR) after induction treatment were randomized between rituximab maintenance and observation. Intensification of rituximab was not more effective than standard R‐CHOP, showing same CR‐rates and progression free survival after induction (ASCO 2016 # 7504). Here, we report the results of the second randomization for rituximab maintenance therapy.

Aims:

To assess in a prospective, multicenter, randomized phase III study in patients with DLBCL the efficacy of maintenance treatment with rituximab in comparison to no further treatment on disease free survival.

Methods:

Patients in CR after R‐CHOP were randomized between 24 months of rituximab maintenance 375 mg/m2 intravenous every 8 weeks (n = 199) or observation (n = 199). CT scans were performed at 6, 12, 18 and 24 months in both arms. The primary endpoint was disease free survival (DFS) from maintenance randomization. Secondary endpoints were overall survival (OS) and adverse events (AEs). (www.trialregister.nl NTR1014).

Results:

Median age was 65 years (range 31–80), 48% were 66 years or older and 49% were male. The majority of patients (54%) had a high‐intermediate or high aa‐IPI score. After a median follow‐up of 79.9 months (maximum 125.7 months), the 5‐year DFS rate was 79% for rituximab maintenance versus 74% for observation. This difference was not statistically significant, with a hazard ratio of 0.83 (95% confidence interval 0.57–1.19, p = 0.31, adjusted for age and aa‐IPI). The secondary endpoint OS was also not significantly different (85% versus 83% at 5 years). No clinical subgroup benefited from rituximab maintenance. Toxicity was mild. Among patients who received rituximab maintenance CTCAE grade 3 and 4 AEs were reported in 17% and 6% of patients, respectively. Infection was the most frequent AE, a grade 3 infection occurred in 6% of patients. Neutropenia was seen in 1% (grade 3) and 3% (grade 4) of patients.

Summary/Conclusion:

Rituximab maintenance therapy provides no additional benefit for DLBCL patients in first CR after R‐CHOP.
S1623 INTESTINAL MICROBIOTA CAN PREDICT AGVHD FOLLOWING ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION
Authors: Han L. , Zhang H. , Chen S. , Zhao K. , Huang F. , Fan Z. , Jin H. , Jiang Z. , Liu Q.‐F.
Published: June 2019

Background:

The intestinal microbiome plays an important role in the development of acute graft‐versus‐host disease (aGVHD), and loss of microbiota diversity is associated with aGVHD. However, it has been rarely reported whether the intestinal microbiota at neutrophil engraftment could predict the occurrence and grades of aGVHD.

Aims:

We collected stool and blood samples from 141 patients undergoing allogeneic hematopoietic stem cell transplantation (allo‐HSCT) at pre‐conditioning, day 0 and day 15 post‐transplantation. The microbiota in stool were detected by 16S rRNA gene sequencing; the inflammatory factors in blood were detected by multiplex immunoassays and dynamic turbidimetric methods; and T lymphocyte subsets were tested by flow cytometry.

Methods:

The microbiota diversity was lower in the aGVHD group compared with non‐aGVHD group at day 0 and day 15 ± 1 (P = 0.018 and 0.009, respectively). Diversity was associated with conditioning (P = 0.017, day 0 and P = 0.045, day 15) and β‐lactam antibiotics (P = 0.004, day 15). The Treg/Th17 ratio in blood was positively correlated with microbial diversity (r = 0.216, P = 0.010), while it was negatively correlated with the levels of TNF‐α, IL‐17A, IL‐1β and LPS in plasma (r = −0.226, −0.225, −0.335, −0.291; P = 0.007, 0.010, < 0.001, < 0.001, respectively) at day 15 post‐transplantation. In addition, the accumulated intestinal microbiota (AIM) score at day 15 could be a predictor for the development of aGVHD (II‐IV aGVHD: AUC = 0.75, P < 0.001; III‐IV aGVHD: AUC = 0.84, P < 0.001). The AIM score was also correlated with aGVHD grades (r = 0.481, P < 0.001).

Results:

These findings suggest that intestinal microbiota and conditioning might induce aGVHD by inflammatory factors and influence the Treg/Th17 balance. The constitution of the intestinal microbiota at neutrophil engraftment can predict the subsequent development and grades of aGVHD.

Summary/Conclusion:

These findings suggest that intestinal microbiota and conditioning might induce aGVHD by inflammatory factors and influence the Treg/Th17 balance. The constitution of the intestinal microbiota at neutrophil engraftment can predict the subsequent development and grades of aGVHD.
S1629 ERFE‐A260S ACCOUNTS FOR HEPATIC IRON METABOLISM IMPAIRMENT BY ACTING ON THE BMP‐SMAD PATHWAY
Authors: Andolfo I. , Manna F. , De Rosa G. , Rosato B.E. , Marra R. , Gambale A. , Iolascon A. , Russo R.
Published: June 2019

Background:

Iron overload is a major clinical challenge in the management of hereditary ineffective erythropoiesis ‐related anemia (iron‐loading anemia). To coordinate iron metabolism with hemoglobin (Hb) synthesis, erythropoietin (EPO)‐stimulated erythroid precursors release erythroferrone (ERFE), a soluble protein that suppresses the expression of hepcidin. Hepcidin is a hormone that controls iron entry into the circulation by blocking the iron exporter ferroportin.

Congenital dyserythropoietic anemia type II (CDAII) is a bone marrow failure anemia characterized by mono‐lineage cytopenia and morphological abnormalities of erythroid precursor cells. The marked clinical variability observed in CDAII patients is related to its major complication, the iron overload associated with reduced expression of hepatic hormone hepcidin. We recently analyzed ERFE expression in both CDAII patients and in vitro model, demonstrating that in CDAII patients ERFE is overexpressed and related to abnormal erythropoiesis.

Aims:

To study possible modifier genes affecting the iron overload phenotype in CDAII.

Methods:

t‐NGS custom panel; genotyping; cells culture and transfection assays; qRT‐PCR; immunoblotting.

Results:

We herein identified a recurrent low‐frequency variant, A260S, in ERFE gene in 12.5% of CDAII patients showing severe phenotype by our 81‐genes target custom panel for modifier genes. We demonstrated that ERFE‐A260S variant leads to an increased expression of ERFE. We further characterized the effect of ERFE‐A260S in an in vitro human hepatic model, HuH7 cells, showing a marked impairment of iron regulation pathways by inhibition of phosphorylation of SMAD1/5/8 and consequent downregulation of the expression of BMP/SMADs pathway target genes: HAMP, ID1, ATHO8 and SMAD6.

Summary/Conclusion:

We herein described for the first time an ERFE polymorphism as modifier variant with a mild effect on disease expression under a multifactorial‐like model in a condition of iron‐loading anemia due to ineffective erythropoiesis. This is a novel paradigm that paves the ways to new investigations for evaluating the role of this ERFE variant as a modifier in many other related pathological conditions, as b‐thalassemia intermedia. Moreover, the discovery of the genetic basis of CDAII and its major complication, iron overload, will lead us to expand our understanding of the biology of ineffective erythropoiesis and to provide initiative for further investigation of new therapeutics. Indeed, ERFE is currently a candidate target for therapeutic inhibition, in iron loading anemia.
PB1653 HIGH RASD1 TRANSCRIPT LEVELS AT DIAGNOSIS PREDICTED POOR SURVIVAL IN ADULT B‐CELL ACUTE LYMPHOBLASTIC LEUKEMIA PATIENTS
Authors: Wang S. , Wang C. , Liu Y.
Published: June 2019

Background:

B‐cell acute lymphoblastic leukemia (B‐ALL) in adults remains a highly challenging disease. Identifying new prognostic biomarkers is necessary to help select the best therapeutic schedules and to improve prognosis. We performed bioinformatics analyses of transcriptomic data to identify aberrantly‐expressed mRNA transcripts in B‐ALL and focused on RASD1 (Ras‐related dexamethasone‐induced 1) which is a member of the RAS family and plays important roles in tumor growth and expansion. To date, no reports on RASD1 and B‐ALL have been reported.

Aims:

To examine the expression and clinical significance of RASD1 in adults with B‐ALL; to explore effects of RASD1 on biological function of B‐ALL.

Methods:

Fifty‐three consecutive adults with de novo B‐ALL were enrolled in this study. The RASD1 transcript levels were determined by TaqMan‐based real time quantitative PCR (RQ‐PCR) at the time of diagnosis. RASD1‐over‐expression cell models were constructed to study the biological function of RASD1 in B‐ALL. The cell proliferation was detected by CCK‐8; cell apoptosis and cell cycle were analyzed by flow cytometry.

Results:

Our data suggested that RASD1 was abnormally overexpressed in B‐ALL. High RASD1 transcript levels at diagnosis were associated with lower survival probabilities (44% [20% > 61%] vs. 79% [60% > 97%]; P = 0.037) and were also an independent prognostic factor in adult B‐ALL (HR = 4.9 [1.5‐15.9]; P = 0.008). Functional in vitro analyses indicated that RASD1 promoted cell proliferation, cell cycle progression and chemotherapy resistance and inhibited cell apoptosis. Bioinformatic analyses also showed that high RASD1 expression in cells correlated with positive regulation of cell proliferation as well as nucleosome assembly and telomere organization.

Summary/Conclusion:

These data demonstrated that RASD1 might serve as a novel prognostic biomarker for adult B‐ALL and as a potential therapeutic target in adult B‐ALL patients.
PB1661 CHARACTERIZATION OF A DUX4‐IGH INHIBITOR AS A POSSIBLE TREATMENT FOR ACUTE LYMPHOBLASTIC LEUKEMIA
Authors: Salome’ M. , Caronni C. , Runfola V. , Giambruno R. , Campolungo D. , Ghirardi C. , Gabellini D.
Published: June 2019

Background:

B cell acute lymphoblastic leukemia (B‐ALL) is the most common pediatric cancer and the major cause of cancer‐related death before the age of 20. In up to 7% of cases, the disease is caused by rearrangements of the Double Homeobox 4 (DUX4) transcription factor to the immunoglobulin heavy chain (IGH) locus, giving rise to the oncogenic fusion protein DUX4‐IGH. While ectopic expression of wild type DUX4 induces apoptosis, DUX4‐IGH has transforming ability in cellular and animal models. These opposite biological activities are mirrored by the ability of DUX4 and DUX4‐IGH to drive the transcription of non‐overlapping sets of target genes, despite the two proteins share the same DNA binding domain (dbd).

Aims:

Through proteomics, we identified a specific DUX4‐IGH inhibitor. Preliminary data indicate that the inhibitor directly binds to DUX4‐IGH dbd blocking the activation of target genes. Based on this evidence, I aim to test the antileukemic activity of the inhibitor.

Methods:

Human cell lines and primary murine bone barrow progenitor cells will be lentivirally transduced to induce the expression of DUX4‐IGH alone or in combination with its inhibitor, and the effects on proliferation, transformation, clonogenic potential and self‐renewal ability in B‐cell differentiation conditions will be evaluated.

To test the efficacy of DUX4‐IGH inhibition in leukemia development, I will employ murine bone marrow transplantation assays and patient derived xenografts of DUX4‐IGH B‐ALL and assess disease latency in the presence or absence of the DUX4‐IGH inhibitor.

Results:

Preliminary data indicate that the activity of DUX4‐IGH is restricted to B‐cells, supporting the need of a B‐cell specific co‐factor. Importantly, lentiviral expression of the DUX4‐IGH inhibitor in NALM6 cells that carry a DUX4‐IGH translocation reduce the endogenous levels of DUX4‐IGH targets.

I expect to see a significant inhibition of DUX4‐IGH driven transformation in the presence of its inhibitor, associated with reduced proliferation, clonogenic and self‐renewal potential in cell culture systems. I predict that the inhibitor will rescue differentiation potential and block or significantly delay leukemia development in mice injected with DUX4‐IGH expressing pro‐B cells.

Summary/Conclusion:

Pre‐clinical validation of the DUX4‐IGH inhibitor will help defining effective therapeutic strategies for DUX4‐IGH B‐ALL patients, improving clinical outcome and lowering treatment toxicity.