bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphoproliferative Disease in Wiskott-Aldrich Syndrome: Analysis of the French National Registry of Primary Immunodeficiencies
Authors: Cheminant Morgane , Mahlaoui Nizar , Canioni Danielle , Desconclois Celine , Hermine Olivier , Pasquet Marlène , Malphettes Marion , Bertrand Yves , Blanche Stephane , Fischer Alain , Suarez Felipe 
Published: October 2019

Abstract

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immune deficiency (PID) characterized by persistent thrombocytopenia, eczema and immunodeficiency. It has been suggested that these patients had an increased risk of lymphoproliferative diseases (LPD).
We conducted a retrospective study in order to describe LPD occurring in patients with WAS/XLT (X Linked Thrombocytopenia with WAS gene mutation) enrolled in the French national registry for PIDs. Post- hematopoietic stem cell transplantation (HSCT) LPD were excluded. Methodology of the French National Registry for PIDs has been previously described (Clin. Immunol, 2010, ASH 2009 abstract#23950).
Eight patients (4%) with LPD were identified among the 197 patients of our cohort. All patients had a WAS and presented first symptoms of WAS before the age of one year. One patient developed a LPD before the clinical diagnosis of WAS.
All patients for whom histological charts were available (6/8) developed a B-cell LPD. Three of them had diffuse large B-cell lymphomas and three patients had polymorphic B-cell LPD associated with EBV and without detection of clonal IGHV rearrangement. The median age of cancer diagnosis was 18.3 years (range: 2.0-50.7). All LPD were disseminated diseases, mostly with a central nervous system involvement (4/6 patients). All patients received intensive chemotherapy, except one patient with an EBV-associated LPD who only received rituximab. Three patients obtained a complete remission (CR), two patients had a stable disease (SD) and the last one progressed on therapy. Four patients, of whom two were in CR and one in SD, received an allogeneic HSCT during the year following the diagnosis of LPD. Two patients received peripheral blood-derived stem cells and the two other patients received bone marrow-derived stem cells. There were three matched unrelated donor (MUD) and one haplotype-mismatched family donor, with no ex vivo graft manipulation. Three of these four patients were long-term survivors after LPD (2.7, 7.7 and 9.8 years).
The median life expectancy for the entire cohort is 19.1 years (range: 7.8-52.0). Three patients, two of which have received an HSCT, are still alive 2.4, 2.7 and 9.8 years after the cancer onset. The median overall survival among the five remaining patients after diagnosis of LPD was 0.5 years (from 0.3 to 7.7 years).
Additional details on genetic, clinical characteristics and a centralized histopathology review are currently being studied and will be presented.
In conclusion, the occurrence of LPD is less frequent than expected, may occur only in patients with WAS phenotype rather than XLT. As it impairs the prognosis of patients, HSCT could be a therapeutic option for these patients, even in partial remission of LPD.

Disclosures
No relevant conflicts of interest to declare.
Regulation of Natural Killer Cell Responses By Dendritic Cells Via Lymphotoxin-Alpha, Interleukin-12, and Tumor Growth Factor-Beta
Authors: Sarhan Dhifaf , Palma Marzia , Mao Yumeng , Adamson Lars , Kiessling Rolf , Mellstedt Håkan , Österborg Anders , Lundqvist Andreas 
Published: October 2019

Abstract
Dendritic cells (DC) induce T-cell responses in cancer patients. However, less is known about the role of DC-vaccines in shaping natural killer (NK) cell responses. In this study, we sought to investigate the activity of NK cells following vaccination with DC. Patients with chronic lymphocytic leukemia (CLL) and melanoma were vaccinated with tumor-antigen loaded monocytes-derived DC and NK cell activity was analyzed before and two weeks after vaccination. Compared with pre-vaccination samples, NK cells expressed reduced levels of several activation markers and produced less IFNγ (p=0.03). To further explore the mechanism of the reduced NK cell responses, DC were differentiated from monocytes in GM-CSF, IL-4 and LPS and thereafter co-cultured with autologous NK cells in vitro. In these experiments, DC-mediated inhibition of NK cells was independent of cell-contact but dependent on the phosphorylation status of STAT3 in DC. Compared with untreated DC, STAT3-inhibited-DC produced higher amounts of lymphotoxin-alpha (LTα, 5.5±5.0 vs. 38.1±25.9 pg/ml; p=0.005) and IL-12 (29.6±39.0 vs. 176.8±96.8 pg/ml; p=0.005) and reduced amounts of tumor growth factor-beta (TGFβ, 495.0±138.7 vs. 300.4±141.8 pg/ml; p=0.03) and did not suppress NK cell proliferation (p=0.03), cytotoxicity (p=0.0003), and IFNγ production (p=0.02). Neutralization of TGFβ resulted in elevated production of LTα (2.25±4.5 vs. 251.5±12.0 pg/ml; p=0.03) and IL-12 (0.25±0.5 vs. 15.0±1.82 pg/ml; p=0.02) by DC and addition of recombinant LTα or IL-12 in co-cultures of DC and NK cells was indispensable to maintain NK cell activity. Compared with LPS, DC matured with a cocktail of R848, poly I:C, and IFNγ showed reduced levels of pSTAT3 and produced higher levels of LTα and IL-12 and did not inhibit NK cell activity. These results show that LTα, IL-12 and TGFβ are involved in the cross-talk between NK cells and DC. Our findings have important implications for the development of DC-based vaccination strategies to potentiate NK-cell responses in patients with cancer.

Disclosures
Österborg: Celgene: DMC memeber of Celgene-initiated phase 3 trials Other.
The Role of CD11b+CX3CR1+ Cells in Neovascularization
Authors: Kim Jeong-A , Kwak Jae-Yong , Noh Kyoungmi , Lee Joon , Park Youngrok , Broxmeyer Hal E. 
Published: October 2019

Abstract
There are growing evidences that myelo-monocytic cells play a key role in mediating tissue repair and stimulating angiogenesis in response to ischemia. However, the subpopulations of myelo-monocytic cells participating in vascularization and their underlying mechanisms have not been well identified. We previously demonstrated that CD11b+CX3CR1+ cells, a type of proangiogenic myelo-monocytic cells, promotes angiogenesis in a C57BL/6 hind-limb ischemic mouse model. We now provide insight into mechanisms of CD11b+CX3CR1+ cells during recovery of blood perfusion after ischemia.
Ischemic injuries were induced by dissecting the femoral artery of C57BL/6 mice. Single-cell suspensions were made from ischemic muscles, and ischemic muscle-derived CD11b+CX3CR1+ cells were isolated with a FACS Sorter. Extracted proteins (50ug) from the cells were loaded on nitrocellulose membranes, containing 53 different capture antibodies in proteome profiler mouse angiogenesis Kits (R&D systems, ARY105). For aortic ring sprouting assay, thoracic aortas were embedded in Matrigel.
Proangiogenic effects of CD11b+CX3CR1+ cells were confirmed by enhanced blood perfusion upon injection of additional CD11b+CX3CR1+ cells into ischemic tissues after femoral artery dissection in C57BL/6 mice. Sprouting effects were specifically confirmed through purified CD11b+CX3CR1+ cells co-cultured with aortic ring sprouting assay. Also, medium conditioned by CD11b+CX3CR1+ cells was as efficient as CD11b+CX3CR1+ cells in supporting sprouting, suggesting that vascular endothelial cells (ECs) are likely activated by the proteins secreted by CD11b+CX3CR1+ cells in a paracrine fashion. To investigate whether muscle-derived CD11b+CX3CR1+ cells could secrete angiogenic proteins, we examined the angiogenic proteins in CD11b+CX3CR1+ cells isolated from ischemic muscles after 4 days of surgery. Contrary to our expectations, VEGF proteins were not detected from CD11b+CX3CR1+ cells. However, MCP-1, MIP-1α, platelet factor-4 (PF-4) and MMP-9 were expressed at a higher level in CD11b+CX3CR1+ cells than those of CD11b+CX3CR1- and CD11b-CX3CR1- cells. MCP-1, MIP-1α and MMP-9 have been reported to promote angiogenesis, while PF-4 is recognized as an angiostatic factor. However, it has recently been reported that PF-4 combined with VEGF is essential for the initial separation of ECs from vessels prior to angiogenic sprouting. It is postulated that, after ischemia, collaboration of VEGF with PF-4 secreted from CD11b+CX3CR1+ cells dissociates the ECs from vessels and promotes vascular branching processes.
In summary, CD11b+CX3CR1+ cells are a newly identified myelo-monocytic subset for vessel formation, capable of vascular sprouting via secreting PF-4.

Disclosures
Broxmeyer: CordUse: Membership on an entity's Board of Directors or advisory committees.
Similar Levels of Complement Activation in Both Patients with Thrombotic Thrombocytopenic Purpura and Atypical Hemolytic Uremic Syndrome: The Report from the Korean TTP Registry
Authors: Oh Doyeun , Huh Ji Young , Chong So Young , Kim In-Ho , Bang Soo-Mee , Jung Chul-Won , Lee Jong-Wook , Lee Hong Ghi , Lee Sun Min , Kim Yeo-Kyeoung , Park Yong , Jang Seongsoo , Kim Jin-Seok , Jo Deog-Yeon , Zang Dae Young , Yoon Hwi-Joong , Yhim Ho-Young , Sohn Sang Kyun , Hong Junshik , Lee Won-Sik , Baker Ross I 
Published: October 2019

Abstract
Background: Uncontrolled complement activation has a major role in the pathogenesis of atypical HUS (aHUS) and the restraint of this process by eculizumab is life saving. However, the evidence of complement dysregulation in the pathogenesis of Thrombotic Thrombocytopenic Purpura (TTP) is still unclear. In this study we examined the presence of complement activation biomarkers in patients with aHUS and TTP and the levels were compared to normal healthy controls .
Patients and Methods: Patients with thrombotic microangiopathic thrombocytopenia diagnosed either as TTP with low ADAMTS13 activity less than 10% or aHUS with impaired renal function, Cr> 2mg/dL and normal ADAMTS13 activity were chosen from the Korean TTP registry from February 2012 to June 2014. Prospective plasma and serum samples prior to intervention were collected from newly diagnosed patients with TTP (n=20), aHUS (n=20), and 20 healthy controls and frozen at -700C. Complement activation products (C3a, Bb as alternative pathway; C4d as classic pathway; C5a, C5b-9; terminal pathway) were measured by ELISA.
Results: Significantly increased levels of Bb and C5b-9 were observed in TTP (median [range], ng/mL; Bb, 1220 [540.0 – 16560], p=0.048; C5b - 9, 390.1 [238.5 - 938.7], p<0.0001) when compared with controls (Bb, 870.0 [630.0 - 2070]; C5b - 9, 190.8 [77.96 - 458.9]). Increased levels of C3a, C5a, C5b - 9, and Factor Bb were observed in HUS (C3a, 231.3 [80.70 - 791.8], p<0.0001; C5a, 21.38 [5.590 - 34.96], p= 0.006; C5b - 9, 0.49 [0.21 - 1.41], p<0.0001; Bb, 1490 [540.0 – 11800], p= 0.0003) as compared with controls (C3a, 108.7 [30.98 - 425.1]; C5a, 8.620 [2.660 - 26.93]; C5b - 9, 0.49 [0.21 - 1.41]; Bb, 870.0 [630.0 - 2070]). These suggested alternative and terminal complement pathways were activated in initial episodes of TTP or HUS. However levels of C4d were not different in HUS and TTP as compared with controls which suggested classic complement pathways were not important in this process. There were no significant differences in complement levels between TTP and HUS although levels of C3a, C4d, C5b - 9 in HUS (C3a, 231.3 [80.70 - 791.8]; C4d, 2140 [10.00 - 960.0]; C5b - 9, 488.4 [212.7 – 1414]) tended to be increased as compared with TTP (C3a, 134.5 [61.97 - 378.4]; C4d, 1330 [2.000 - 699.0]; C5b - 9, 390.1 [238.5 - 938.7]).
Conclusion: Complement biomarkers are activated to a similar level in both newly diagnosed cases of TTP and aHUS. Complement activation product levels did not differentiate aHUS from TTP.

Disclosures
No relevant conflicts of interest to declare.
Activated Protein C Prevents Peritoneal Fibrosis
Authors: Dinarvand Peyman , Hassanian Mehr Seyed Mahdi , Rezaie Alireza R. 
Published: October 2019

Abstract
Patients with chronic kidney disease require dialysis (hemodialysis or peritoneal dialysis) for treatment. Peritoneal dialysis is an alternative to hemodialysis for the treatment of end-stage renal disease and is based on the use of the peritoneum as a permeable membrane where ultrafiltration and diffusion between dialysate and blood can take place across the peritoneum. Peritoneal fibrosis is one of the main complications of peritoneal dialysis and affects up to 20% of patients undergoing continuous ambulatory peritoneal fibrosis. The exact mechanism of this process has yet to be elucidated and no effective therapy for the problem has been established. APC is a natural vitamin-K dependent anticoagulant protease, which also has potent antiinflammatory activity. We hypothesized that the antiinflammatory function of APC may inhibit dialysis-mediated peritoneal fibrosis. To test this hypothesis, we generated a chlorhexidine gluconate (CG)-induced peritoneal fibrosis model by injecting CG to male C57BL/6 mice for 21 days with or without intraperitoneal administration of a low dose of recombinant APC (50 µg/kg/day bodyweight) one hour before injecting CG. At 10 and 21 days after injection, the mice were sacrificed and the parietal peritoneum and omentom were dissected for histological evaluation and for analysis of expression of inflammatory molecules. Strikingly, we discovered that APC inhibits the thickness of peritoneal fibrosis and potently inhibits the mRNA expression of TGF-b1, cytokeratins, a2-integrin, MMP-2 and 9 and also significantly increases the mRNA expression of TIMP-2 in peritoneal tissues of the experimental animals. We also discovered that APC significantly decreases the concentration of TGF-b1 and dramatically increases the concentration of tPA in peritoneal fluids. Taken together, our findings suggest that APC may have therapeutic potential in ameliorating dialysis-mediated peritoneal fibrosis.

Disclosures
No relevant conflicts of interest to declare.
Cancer-Associated Deep Vein Thrombosis: The Role of Residual Vein Thrombosis for Assessing the Duration of Low Molecular Weight Heparin (the EXTENDED Cancer-DACUS)
Authors: Napolitano Mariasanta , Saccullo Giorgia , Raso Simona , Mancuso Salvatrice , Casuccio Alessandra , Siragusa Sergio 
Published: October 2019

Abstract

Introduction. The optimal duration of Low Molecular Weight Heparin (LMWH) after cancer associated deep vein thrombosis (DVT) is unknown; current guidelines suggest to prolong anticoagulation until cancer is active. We have recently demonstrated, in a randomized trial, that detection of Residual Vein Thrombosis (RVT) after 6 months of LMWH identify patients who require or not extension of therapy with anticoagulants (JCO in press). Now we present data of a prospective study evaluating a RVT-based management of patients with cancer-associated DVT, in whom LMWH has been extended up to 2 years in patients considered at high-risk for recurrent DVT because of persistence of RVT.
Material and Methods. Patients were included at the time of a first diagnosis of cancer-associated DVT of the lower limbs. All received LMWH at therapeutic dosage for the first month (approximately 100 UI anti-FXa b.i.d.) then reduced at 75% for the following months. After 6 months of heparin, the presence of RVT was detected: those without RVT (no-RVT group) suspended treatment, while those with RVT (RVT group) continued LMWH for up to 2 years. Recurrent thrombosis and/or bleeding events were recorded during treatment and one year after LMWH withdrawal. Baseline differences between groups were assessed by the chi-square test (Yates’ correction) for categorical variables and ANOVA test or Kruskal-Wallis test for parametric and nonparametric analyses. Relative risks (RRs) and 95% confidence intervals (CIs) were evaluated.
Results. Between January 2009 and April 2011, 211 cancer patients were enrolled; RVT was detected in 129 patients (61.1%). Recurrent VTE occurred in 19 (14.7%); 4 episodes (3.1%) occurred while on heparin. Among patients without RVT (82), 3 (3.6%) developed recurrent VTE (after LMWH therapy). Adjusted HR for RVT vs no-RVT group was 5.8 (95% CI, 1.9 to 19.2; p 0.0003). Three major bleeding events occurred in RVT group and one in no-RVT group (during LMWH administration). The HR for major bleeding (RVT vs no-RVT group) was 2.58 (95% CI, 0.66 to 12.43;p 0.103). Overall, 44 patients (20.8%) died during follow-up as a result of cancer progression.
Conclusions. These results indicate that in patients without RVT, a short period of treatment with a LMWH is sufficient; in those with persistent RVT, treatment extended to 2 years substantially reduces, but does not eliminate, the risk of recurrent thrombosis. However, when still on LMWH, the risk for recurrent VTE is low.

Disclosures
No relevant conflicts of interest to declare.
Protein Tyrosine Phosphatase-Sigma (PTPσ) Regulates Hematopoietic Stem Cell Repopulating Capacity
Authors: Quarmyne Mamle , Doan Phuong L. , Himburg Heather A. , Yan Xiao , Zhao Liman , Chao Nelson J. , Chute John P. 
Published: October 2019

Abstract
Hematopoietic stem cell (HSC) proliferation, differentiation and self-renewal are regulated by signaling through receptor tyrosine kinases (RTKs) such as c-kit, Flt-3 and Tie2. The functions of receptor protein tyrosine phosphatases (RPTPs) in counterbalancing RTK signaling in HSCs remain incompletely understood. Among 9 examined RPTPs, we found that PTP-sigma (PTPσ) was significantly overexpressed in mouse and human HSCs compared to more mature hematopoietic cells. PTPσ-/- mice displayed no difference in mature blood counts or phenotypic HSC frequency compared to PTPσ+/+ mice. However, competitive transplantation of BM cells from PTPσ-/- mice resulted in greater than 8-fold increased multilineage hematopoietic repopulation in primary and secondary recipient mice compared to mice transplanted with BM from PTPσ+/+ mice. While HSCs from PTPσ-/- mice displayed no differences in cell cycle status or homing capability compared to PTPσ+/+ mice, PTPσ-/- HSCs expressed significantly increased levels of activated Rac1, a RhoGTPase which regulates HSC engraftment capacity, compared to PTPσ+/+ BM cells. PTPσ-/- BM cells also displayed significantly increased transendothelial migration capacity and cobblestone area forming cells (CAFCs), consistent with increased Rac1 activation. Furthermore, Rac inhibition abrogated the increased migration capacity of PTPσ-/- BM cells, suggesting that the augmented engraftment capacity of PTPσ-/- BM cells was mediated via Rac activation. Translationally, we demonstrate that negative selection of human cord blood CD34+CD38-CD45RA-Lin- cells for PTPσ expression yielded a 15-fold enrichment for human long-term repopulating HSCs compared to CD34+CD38-CD45RA-Lin- cells or CD34+CD38-CD45RA-lin-PTPσ+ cells. These data suggest that PTPσ regulates HSC repopulating capacity via inhibition of Rac1 and that selection for human PTPσ - negative HSCs is a translatable strategy to significantly enrich human HSCs for transplantation.

Disclosures
No relevant conflicts of interest to declare.
Mitochondrial Activity Determines Hematopoietic Stem Cell Fate Decisions
Authors: Vannini Nicola , Girotra Mukul , Naveiras Olaia M. , Campos Vasco , Williams Evan , Roch Aline , Auwerx Johan , Lutolf Matthias 
Published: October 2019

Abstract
A tight control of hematopoietic stem cell (HSC) quiescence, self-renewal and differentiation is crucial for lifelong blood production. The mechanisms behind this control are still poorly understood. Here we show that mitochondrial activity determines HSC fate decisions. A low mitochondrial membrane potential (Δψm) predicts long-term multi-lineage blood reconstitution capability, as we show for freshly isolated and in vitro-cultured HSCs. However, as in vivo both quiescent and cycling HSCs have comparable Δψm distributions, a low Δψm is not per se related to quiescence but is also found in dividing cells. Indeed, using divisional tracking, we demonstrate that daughter HSCs with a low Δψm maintain stemness, whereas daughter cells with high Δψm have undergone differentiation.
Strikingly, lowering the Δψm by chemical uncoupling of the electron transport chain leads to HSC self-renewal under culture conditions that normally induce rapid differentiation. Taken together, these data show that mitochondrial activity and fate choice are causally related in HSCs, and provides a novel method for identifying HSC potential after in vitro culture.

Disclosures
No relevant conflicts of interest to declare.
Gtpase Immunity-Associated Protein Family Member 4 Contributes to the Enhanced Expansion of HSPCs in RUNX1 Deficient Mice
Authors: Scholl Amanda , Lam Kentson , Muselman Alex , Tang Tingdong , Matsuura Shinobu , Zhang Dong-Er 
Published: October 2019

Abstract
RUNX1 is the transcription factor described as the master regulator of hematopoiesis. Due to its central role during blood development, numerous RUNX1 mutations have been reported in hematologic abnormalities. Mice null for Runx1 die during embryogenesis, lacking definitive HSCs. Conditional Runx1Δ/Δ mice are viable, but exhibit a variety of blood abnormalities. The most salient defect in these Runx1Δ/Δ mice is expansion of the hematopoietic stem and progenitor cell (HSPC) population, measured as an increase in number of lineage negative, Sca1 positive, cKit positive (LSK) cells. A shortened form of RUNX1 (RUNX1SF) lacking the C-terminal and part of the N-terminal domain (41-214) acts as a dominant negative regulator of RUNX1 and hence also models RUNX1 loss-of-function.
A differential gene expression analysis of HSPCs derived from Runx1Δ/Δ compared to wild type mice uncovered GTPase immunity-associated protein family member 4 (GIMAP4) as one of the genes most highly upregulated. Previous studies have focused almost exclusively on the role of GIMAP4 as a pro-apoptotic protein during T-cell development. This study illuminates a novel non-apoptotic role of GIMAP4 in a formerly unstudied HSPC context. Runx1Δ/Δ mice were crossed with Gimap4-/- mice to generate a double knockout (dKO) mouse line. These dKO mice exhibited attenuated HSPC proliferation in comparison to Runx1Δ/Δ mice, suggesting that GIMAP4 functions in this HSPC expansion phenotype. BMT experiments using lethally irradiated C57 mice and RUNX1SF transduced wild type versus Gimap4-/-bone marrow confirmed this result.
GIMAP4 also worked independently and coordinately with RUNX1 to influence individual progenitor populations. Common lymphoid progenitors (CLP) were affected only by GIMAP4. Gimap4-/- mice exhibited an expansion of the CLP population, consistent with its pro-apoptotic role in lymphoid populations. Conversely, both RUNX1 and GIMAP4 coordinately exerted an effect on myeloid progenitor populations. Runx1Δ/Δ mice harbored expanded granulocyte-macrophage progenitor (GMP) and common myeloid progenitor (CMP) populations. This expansion was not observed when GIMAP4 was also ablated. This suggests a pro-proliferative role of GIMAP4 specifically in myeloid populations. These opposing roles of GIMAP4 in lymphoid versus myeloid cells suggest a more contextual, cell-specific role of this GTPase protein. Ultimately, this study provides insight into how RUNX1 and GIMAP4 may coordinate to maintain HSPC homeostasis.

Disclosures
No relevant conflicts of interest to declare.