bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Mutation in MPL (Y252H) Results in Increased Thrombopoietin Sensitivity and Moderate Thrombocytosis in a Pediatric Patient with Essential Thrombocytosis
Authors: Lambert Michele , Jiang Jing , Tong Wei 
Published: October 2019

Abstract
Abstract 2817
Myeproliferative neoplams (MPNs) constitute a group of hematopoietic malignancies that feature enhanced proliferation and/or survival of one or more myeloid lineage cells, including Essential Thrombocythemia (ET). MPN development is rare in children with an estimated annual incidence of ET of 0.09/106 children. The WHO defines ET as persistent platelet count >600 k/mcL in the absence of known cause of reactive/secondary thrombocytosis. The JAK2 V617F mutation is most commonly reported in both children and adults with ET although the reported frequency varies in pediatric populations from 0 to 36% of patients. Mutations in the thrombopoietin receptor (TPO receptor or MPL) intracellular domain, specifically W515K/L, have also been reported in both adult and pediatric ET patients. Here we report a novel mutation in the MPL extracellular domain, Y252H, causing mild thrombocytosis. The patient presented at 2 years of age with a platelet count of 765 k/mcL. During the 3-year follow-up period, she possessed platelet counts between 600–700k/mcL, without any obvious indication of reactive/secondary thrombocytosis. Because of the persistently increased platelet count, her bone marrow was evaluated and it demonstrated increased numbers of megakaryocytes with focal clustering. JAK2 mutation analysis was negative and cytogenetics did not show any clonal abnormalities. Sequencing of the MPL gene showed a missense variant at c.754 T>C resulting in a tyr252his amino acid substitution. To investigate if this Y252H mutation in MPL dysregulates TPO/MPL- mediated cell growth, we introduced it into cytokine-dependent BaF3 cells. Cells stably expressing the mutant MPL allele showed increased proliferation to TPO, in particular at low concentration, in comparison to cells expressing wildtype (WT) MPL. Upon cytokine withdrawal, BaF3 cells expressing the MPL Y252H mutant survived better than that of WT MPL. Primary bone marrow cells from this patient along with the healthy control were subjected to colony forming unit -megakaryocyte (CFU-meg) assays in response to a serial dose of TPO. The Y252H MPL bone marrow showed significantly increased megakaryocyte colonies at low dose of TPO when compared to control bone marrow (17.5 ± 2.5 colonies versus 4.75 ± 1.1 colonies at 15 ng/mL TPO, p<0.001). These results are consistent with the clinically mild thrombocytosis. In summary, our results suggest a novel MPL mutation, Y252H, results in pediatric ET. Further evaluation of the mechanisms of increased TPO sensitivity imparted by this mutation should contribute to our understanding of the molecular pathogenesis of ET.

Disclosures:
Lambert: Cangene: Honoraria.
Immune Thrombocytopenia in Patients with Chronic Lymphocytic Leukemia Is Associated with Stereotyped B-Cell Receptors
Authors: Maura Francesco , Visco Carlo , Novella Elisabetta , Giaretta Ilaria , Tuana Giacomo , Agnelli Luca , Lionetti Marta , Fabris Sonia , Guidotti Francesca , Reda Gianluigi , Gritti Giuseppe , Barcellini Wilma , Baldini Luca , Neri Antonino , Rodeghiero Francesco , Cortelezzi Agostino 
Published: October 2019

Abstract
Abstract 2847
Chronic lymphocytic leukemia (CLL) is frequently complicated by autoimmune disorders, primarily autoimmune hemolytic anemia and immune thrombocytopenia (ITP). In order to investigate biological features related to ITP development, we retrospectively analyzed 463 CLL patients characterized for immunoglobulin heavy-chain variable (IGHV) gene mutational status, cytogenetic features and B-cell receptor (BCR) configuration (HCDR3) at the time of diagnosis. Thirty-six patients (7.7%) had developed ITP, according to our previously reported criteria (Visco et al, Blood 2008): i) an otherwise unexplained rapid (< 2 weeks) and severe fall (at least half of the initial level and below 100*109/L) of the platelet count; ii) normal or augmented number of megakaryocytes in the bone marrow; iii) no or limited (not palpable) splenomegaly and iv) no cytotoxic treatment in the last month. Stereotyped BCR configuration was defined by means of pair-wise alignment with known stereotyped sequences available from different public databases (Stamatopoulos et al, Blood 2007; Bomben et al, Br J Hematol 2009; Murray et al, Blood 2008), specifically excluding pairs of sequences whose length differed more than 3 amino acids and sharing more than 60% identity on alignments showing less than 3 gaps, as described by others and by our group (Stamatopoulos et al, Blood 2007; Maura et al, Plos One, in press). Our results indicated that the occurrence of ITP was strongly associated with unmutated (UM) IGHV (p<0.0001), unfavorable cytogenetic lesions (P =0.005), and interestingly, the occurrence of stereotyped HCDR3 (P =0.006). Additionally, the UM IGHV mutational status, unfavorable cytogenetic lesions, or stereotyped BCR were significantly associated with shorter time to ITP development (P <0.0001, P =0.02 and P =0.005 respectively) compared to other patients. As regards to the most represented HCDR3 subsets, we observed that subsets #1 (IGHV1-5-7/IGHD6-19/IGHJ4; 16/16 UM) and #7 (IGHV1-69 or IGHV3-30/IGHD3-3/IGHJ6; 13/13 UM) were significantly associated with ITP development (P =0.003 and P =0.001, respectively). Moreover, restricting the analysis to UM patients, subset #7 retained a significant association with the occurrence of ITP (P =0.02). Time to ITP development was also significantly shorter in subsets #1 and #7 patients than in all others patients (P =0.0076 and P <0.0001, respectively). Overall, our data suggest that patients with CLL and peculiar BCR conformations are at higher risk of developing secondary ITP, and that stereotyped BCR may be involved in the pathogenesis of this complication.

Disclosures:
No relevant conflicts of interest to declare.
Truncation of NF-KB2 Is Associated with Poor Response to Bortezomib Treatment in Multiple Myeloma
Authors: Ramachandiran Sampath , Guo Xiangxue , Garderet Laurent , Ikhlef Souhila , El-cheikh Jean , Weil Michael R , Young Andrew N , Bagirov Mahir , Lonial Sagar , Chen Zhengjia , Kowalsky Jeanne , Du Yuhong , Khoury Hanna J. , Sunay Susan , Kaufman Jonathan L. , Boise Lawrence H. , Rossi Michael , Bernal-Mizrachi Leon 
Published: October 2019

Abstract
Abstract 2891
The proteasome inhibitor, bortezomib, is a powerful agent for the treatment of Multiple Myeloma (MM). However, many patients fail to achieve an optimal response. To identify biomarkers that could predict an optimal response to bortezomib, we assessed the role of the noncanonical NF-kB pathway in the response to bortezomib. Our in vitro studies identified that NF-kB2/p100 protein levels correlated directly with bortezomib sensitivity. Based on this finding, we measured at diagnosis the mRNA levels of different NF-kB2 regions in 64 patients schedule to receive bortezomib-based regimens. While no difference in expression of the 5'end regions was found between the CD138 (+) and CD138 (-) cells in these patients, half of them demonstrated low or absent 3'end expression levels in the CD138 (+) cells. Among forty-seven patients treated with four cycles of Bortezomib and dexamethasone, we found that low plasma cell NF-kB2 3'end levels were associated with a lower overall response rate (low: 47.8% vs. high: 96%, see table). In contrast, low plasma cell NF-kB2 3'end levels failed predict bortezomib response when lenalidomide or thalidome was added to the therapeutic regimen. To further understand the cause for NF-kB2 truncation, we are currently analyzing RNA sequencing in 3 non-responder patients and whole genome sequencing of 38 MM patients to determine the potential causative mechanisms. Preliminary results suggest that NF-kB2 truncation result from multiple genetic alterations, including: premature stop codons produced by ALU insertions, inversions and splicing variants. Overall, this study substantiates the basis of a more precise therapeutic algorithm according to NF-kB2 3'end plasma cell levels, which include the use of bortezomib and dexamethasone in patients with high NF-kB2 3'end plasma cell levels and immunomodulators or DNA damaging agents in patients with low NF-kB2 3'end plasma cell levels.BD+BTD or BRD++NF-kB2 3' end mRNA (CD 138(+)/CD138(−)LowHighLowHigh> Very Good Partial Response5 (21.7)9 (37.5)1 (11)4 (50)Partial Response6 (26.1)14 (58.3)7 (78)4 (50)Stable Disease4 (17.4)1 (4.2)0 (0)0 (0)Progressive disease8 (34.8)0 (0)1 (12)0 (0)Overall Response11 (47.8)23 (95.8)8 (88)8 (100)*Bortezomib + Dexamethasone**Bortezomib+Lenalidomide/Thalidomide+Dexamethasone

Disclosures:
Kaufman: Millenium, Onxy, Novartis, Keryx: Consultancy; Merck, Celgene: Research Funding.
Survival Outcome of Young Multiple Myeloma (MM) Patients in the Era of Novel Therapies
Authors: Kapoor Prashant , Gertz Morie A , Rajkumar S. Vincent , Lacy Martha Q , Dingli David , Hayman Suzanne R , Russell Stephen J. , Lust John A , Buadi Francis K , Zeldenrust Steven R , Greipp Philip R. , Dispenzieri Angela , Kyle Robert A , Kumar Shaji 
Published: October 2019

Abstract
Abstract 2950

Background:
The median age of patients diagnosed with MM is approximately 70 years, and it is a relatively uncommon disease in the younger population. Both conventional chemotherapy and stem cell transplantation (SCT) have favorably impacted the overall survival (OS) of young MM patients. The median survival of patients < 40 years of age, diagnosed prior to 1993 was reportedly 54 months at our institution. However, the impact of novel agents in this patient population is not well known. We studied the outcome of young patients presenting to our institution over the last decade.

Methods:
Records of 1538 patients presenting between 01/99 to12/08 were reviewed. The demographics, features and therapeutic interventions in patients up to 45 years of age at diagnosis were analyzed using descriptive statistics. The survival outcome of this group was compared with the remainder of the cohort using the Kaplan-Meier method.

Results:
One-hundred (6.5%) out of 1538 newly diagnosed MM patients were ≤ 45 years of age at diagnosis. The median follow-up of this group of young patients was 86 months. The disease and patient characteristics are outlined in table 1. A median of 5 regimens (range 1–14) was administered, and 85% patients had received high-dose therapy. 15 patients underwent allogeneic SCT after at least one prior autologous SCT. Novel agents were used both in the front-line and relapsed setting (lenalidomide 60%, thalidomide 56%, pomalidomide 9% and bortezomib 49%), and 45% of initial regimens were novel agent based. The 5 and 7-year OS from diagnosis was 69% and 59%, respectively and the median OS was 93 months. In contrast, the median OS of patients >45 years diagnosed during this period was 53 months (P=0.001, figure 1).

Conclusion:
A marked improvement in OS of young patients with MM diagnosed in the novel agent era is noted in comparison to the historical control of similar age group. In addition, the age associated survival benefit in the younger patient population prevails in the era of novel therapies.

Disclosures:
Gertz: Celgene: Honoraria. Lacy:Celgene: Research Funding. Dispenzieri:Binding site: Honoraria; Celgene: Research Funding. Kyle:Millennium: Consultancy; Binding Site: Honoraria. Kumar:Millennium Pharmaceuticals, Inc.: Research Funding; Celgene: Consultancy, Research Funding; Genzyme: Research Funding; Novartis: Research Funding; Merck: Consultancy, Honoraria.
Impact of ATG on New HLA Groups for Unrelated Donor Allogeneic Stem Cell Transplantation
Authors: Moon Joon Ho , Lee Yoo Jin , Lee Soo Jung , Do Young-Rok , Suh Jang Soo , Sohn Sang Kyun 
Published: October 2019

Abstract
Abstract 3017

Background:
The outcomes of unrelated donor transplantation have improved with refinements in HLA testing. Recently, grouping of HLA matching for unrelated donor was suggested, defining by well-matched, partially-matched, and mismatched. In the current study, the role of ATG for each group was evaluated.

Methods:
A total of 92 patients diagnosed as hematologic diseases and received allogeneic stem cell transplantation (SCT) from unrelated donor were retrospectively analyzed.

Results:
Nineteen patients were classified as well-matched, 42 as partially-matched, and 31 as mismatched. Among them, 57 patients received anti-thymocyte globulin (ATG) as graft-versus-host disease (GVHD) prophylaxis. The overall survival (OS) rate was higher for well-matched group (83%) compared to partially-matched (54%) and mismatched (34%, p=0.076). For partially-matched group, the OS was significantly improved with ATG (83.3% vs. 38.6%, p=0.018). But, the OS was not different between groups with or without ATG for well-matched (87.5% vs. 66.7%, p=0.487) and mismatched (32.4% vs. 41.7%, p=0.215). ATG decreased the cumulative incidence of grade 3–4 acute GVHD (10% vs. 40.2%, p=0.068) and severe chronic GVHD (21.2% vs. 52.2%, p=0.037). The use of ATG (HR=0.248, p=0.029) was related with favorable OS for partially-matched group. However, the favorable effect of ATG was not observed in well-matched and mismatched groups.

Conclusion:
ATG effectively improved survival rate for partially-matched group in unrelated donor transplantation. However, the positive effect of ATG was not observed in well-matched and mismatched group.

Disclosures:
No relevant conflicts of interest to declare.
Association Between Genetic Variants in Immune Response Genes and Outcomes After Hematopoietic Cell Transplantation
Authors: Thyagarajan Bharat , Jackson Scott , Basu Saonli , Jacobson Pamala A. , Gross Myron D , Weisdorf Daniel J. , Arora Mukta 
Published: October 2019

Abstract
Abstract 3049

Background:
Despite rapid advances in allogeneic hematopoietic cell transplant (HCT) techniques, the procedure continues to be associated with a high morbidity and mortality with transplant related mortality (TRM) ranging from 15% to as high as 50%. Acute graft versus host disease (GvHD) remains a major cause of morbidity and an important cause of early TRM in patients undergoing allogeneic HCT. Though variations in major histocompatibiliy (MHC) genes are well known determinants of acute GvHD, there is increasing evidence that genetic variation in immune/cytokine response pathways also contributes significantly to the pathogenesis of acute GvHD.

Methods:
We evaluated the association of single nucleotide polymorphisms (SNPs) in non-MHC dependent immune/cytokine response pathways (n= 77 SNPs in recipients and donors) with acute GvHD and TRM at one year in a cohort of 425 recipient-donor pairs who underwent allogeneic HCT for treatment of hematologic malignancies at the University of Minnesota between 1998 and 2007. We used a Fine and Gray proportional hazards model adjusted for competing risk to evaluate the association between the genetic variants and time to acute GvHD and time to TRM.

Results:
After adjustment for recipient age at transplant, race, diagnosis, disease status at transplant, gender mismatch, CMV serostatus of recipient and donor, recipient and donor sex, donor type, conditioning regimen (myeloablative or reduced intensity) and year of transplant, one recipient SNP, rs646005 in the TIRAP gene and one donor SNP, rs2232596 in the LBP gene were marginally associated with increased risk for grade II-IV acute GvHD (Hazard ratio (HR) = 1.33 (95% Confidence interval (CI): 1.07 – 1.62) and 1.32 (1.07 – 1.66) respectively; p =0.01). Similar analyses for TRM showed recipient SNP rs5498 in the ICAM1 gene was associated with a decreased risk of TRM (HR: 0.67(95% CI: 0.50 – 0.89); p=0.0006) while recipient SNPs rs1739654 in the LBP gene and rs3804100 in the TLR2 gene were associated with an increased TRM risk (HR: 1.86 (95% CI: 1.16 – 2.97) and 1.66 (95% CI: 1.11 – 2.48) respectively; p =0.01).

Conclusions:
These findings are consistent with previous reports that support a role for genetic variants in the innate immune response pathways among both recipients and donors can influence the risk of acute GvHD and TRM among patients undergoing allogeneic HCT. These findings indicate that a systematic search for genetic variants in the innate immune response pathways may identify novel biomarkers that can be used to identify patients at high risk for acute GvHD and TRM.

Disclosures:
Weisdorf: Genzyme: Consultancy, Research Funding.
Implications of Serial Magnetic Resonance Imaging and Positron Emission Tomography Scanning for Survival of Untreated Myeloma Patients Treated with Total Therapy 3
Authors: Usmani Saad , Mitchell Alan , Sexton Rachael , Panozzo Susan , Nair Bijay , Waheed Sarah , Alsayed Yazan , Crowley John , Barlogie Bart 
Published: October 2019

Abstract
Abstract 3082

Introduction:
We have previously reported on the prognostic implications of state-of-the-art imaging with magnetic resonance imaging (MRI) in Total Therapy 2 and with fluoro-deoxy-glucose positron emission tomography (PET) in Total Therapy 3 (TT3). With both techniques, baseline focal bone lesion number and reduction and resolution of focal lesions (FL) imparted favorable clinical outcomes. Here we are updating both MRI and PET data as they pertain to survival of patients enrolled in TT3A protocol employing VTD (bortezomib, thalidomide, dexamethasone), now with longer follow-up of 6.2 yr compared to 3.6 yr at the time of original publication. The details of the protocol and clinical outcomes have been reported previously. Methods: Analyses were restricted to 239 truly untreated patients in TT3A, as even one cycle of prior therapy pertaining to 64 patients had been shown to alter PET results. Cox regression modeling was employed for overall survival (OS) and progression free survival (PFS). Results: OS and PFS were adversely affected by the presence of FL number at baseline, whether defined by MBS (p<0.0001 and p=0.0009, respectively), MRI (p=0.03 and p=0.03, respectively), or PET (p<0.0001 and p<0.0001, respectively); in addition, extra-medullary disease (EMD) detected by PET especially affected OS (78% vs 43%, p=0.003) and PFS (73% vs 29%, p=0.003) unfavorably. In the context of GEP-defined 70-gene risk model (GEP70), FL number distinguished significantly poorer outcomes in low-risk myeloma whereas, for high-risk disease, only a trend was observed (Figure 1A).Complete FDG suppression prior to first transplant affected subsequent OS and PFS favorably (Figure 1B), especially in the GEP-70-defined high-risk subset so that such patients fared almost as well as the low-risk group (Figure 1C). Earlier FDG suppression by day 7 of induction therapy also favorably affected the OS (84% vs 78%, p=0.05). In multivariate analysis, >3 PET lesions featured with poorer OS (HR=1.98 95%CI, p=0.011) and PFS (HR=1.78, 95%CI, p=0.021). Conclusions: The data presented herein, confirm and extend the previously reported results on the role and utility of MRI and PET imaging in the diagnosis and management of newly diagnosed multiple myeloma. Presence of MM lesions on MRI & PET, presence of EMD and failure of FDG suppression with induction chemotherapy and transplantation carry adverse outcome and can serve as prognostic indicators of long-term survival. FDG suppression after first transplant was especially significant in further distinguishing the poor responders within the GEP70-defined high-risk myeloma.

Disclosures:
Barlogie: Celgene, Genzyme, Novartis, Millennium: Consultancy, Honoraria, Patents & Royalties.
Intermediate Thrombin Activation Is Associated with Reduced Cardiovascular Death Independently of Markers of Lipid Metabolism and Inflammation
Authors: Isermann Berend H. , Schneider Jochen , Kleber Marcus E , Wang Hongjie , Boehm Bernhard O , Grammer Tanja B , Prüller Florian , Nawroth Peter P , März Winfried 
Published: October 2019

Abstract
Abstract 31
Clinical trials showed an increased frequency of cardiovascular death (CVD) in patients receiving direct thrombin inhibitors. Considering the detrimental effect of local coagulation activation during an acute cardiovascular event these observations are deemed unexpected. These observations raise the question whether enhanced thrombin generation may convey protective effects during non-acute disease stages of cardiovascular disease.
To address the question whether increased endogenous thrombin generation may convey beneficial effects in regard to cardiovascular disease we evaluated the association of the ETP and prothrombin fragment 1+2 (F1+2) with cardiovascular death (CVD) in a large prospective study (3156 individuals, median follow up ten years, Ludwigshafen RIsk and Cardiovascular Health (LURIC)-study). Furthermore, we explored the association of ETP with markers of inflammation (CRP, SAA), endothelial dysfunction (sICAM-1, sVCAM-1), and inflammatory cell activation (PAFAH).
An inverse association between ETP and CVD was observed, with the lowest hazard ratio (HR) in the 3rd ETP quartile. This effect remained significant after adjusting for age, gender, DM, BMI, smoking, hypertension, hsCRP, LDL, HDL and triglycerides and after excluding patients receiving anticoagulants (HR for MOR 0.675, CI 0.531–0.858, P=0.001, and HR for CVD 0.667, CI 0.493–0.903, P=0.009). The nadir of sICAM-1 or sVCAM-1 was observed in the 3rd, for PAFAH in the 4th ETP quartile. When stratifying patients according to F1+2 we observed a similar U-shaped association with CVD (lowest HR in the 2nd quartile: 0.718, CI 0,524–0.983, P=0.039). In contrast, the HR for CVD according to fibrinogen strata increased continuously across the quartiles (highest HR in the 4th quartile: 1.828, CI 1.318–2.536, P<0.001).
These results establish that intermediate levels of ETP or PTF1+2 are associated with a reduced HR for CVD and with lower plasma levels of markers of endothelial dysfunction or inflammatory cell activation. Based on these data we propose that low but sustained levels of thrombin generation mediate vasculo-protective effects translating long term into a reduced risk of CVD. These data may provide a rationale for the observed increased frequency of myocardial infarction in clinical studies evaluating direct thrombin inhibitors.

Disclosures:
No relevant conflicts of interest to declare.