bluuebunny/crossref_metadata_2025 huggingface dataset:
Innmune-Related Risk Factors for Non-Hodgkin Lymphoma in Twins
Authors: Wang Jun , Mack Thomas M , Hwang Amie , Nathwani Bharat N. , Hamilton Ann , Cozen Wendy
Published: October 2019

Abstract 1588

Acquired or inherited immune deficiency is an established risk factor for non-Hodgkin lymphoma (NHL), but does not account for the majority of cases. Recent epidemiologic evidence from the InterLymph Consortium suggests that subclinical, subtle alterations in immune response may also affect risk. Specifically, atopic conditions have been associated with a protective effect and infections at an early age with risk. Unaffected twins of patients are ideal controls because they are partially (fraternal) or completely (identical) matched on genetic factors. We evaluated these factors in twin pairs in whom one member was diagnosed with NHL. At least one member of 197 twin pairs returned detailed questionnaires; in 75 pairs, both the case and unaffected co-twin returned the questionnaire and in 122 pairs only one twin (usually the unaffected co-twin) returned the questionnaire. NHL diagnosis in the case-twin was confirmed by medical record and pathology review. Multivariable conditional logistic regression adjusted for education was used to estimate the effect of the exposures on risk with odds ratios (ORs) and 95% confidence intervals (CI). Eczema in childhood was associated with a 60% decreased risk of NHL (OR= 0.4, 95% CI= 0.2, 0.9). Allergic asthma (OR= 0.2, 95% CI= 0.1, 0.6), hay fever (OR= 0.4, 95% CI= 0.2, 0.8) and allergies to plants (OR= 0.3, 95% CI= 0.1, 0.9) were protective. Compared to no atopic conditions, the twin with ≥ 3 atopic conditions had a 90% decreased risk of NHL (95% CI= 0.0, 0.5). Tonsillectomy and appendectomy were each associated with a significant, ∼ 2-fold increased risk. The twin with more early childhood exposures (more contact with pets, young children, sucking thumb or pacifier) likely to transmit infection was also at an increased risk of NHL. The study confirms the inverse association between allergy and NHL risk in genetically matched cases and controls and provides further evidence that childhood exposures are important mediators of risk.

Disclosures:

No relevant conflicts of interest to declare.
Prognositc Inpact of Tumor-Infiltrating Cells Especially CD163 Positive Macrophage in DLBCL Treated with R-CHOP
Authors: Goto Naoe , Kanemura Nobuhiro , Tsurumi Hisashi , Nakamura Nobuhiko , Kasahara Senji , Hara Takeshi , Moriwaki Hisataka , Takami Tsuyoshi
Published: October 2019

Abstract 1594

Background:

Tumor-infiltrating immune cells perform important functions in host immune reaction against tumor cells including diffuse large B cell lymphoma (DLBCL). Recently, variable tumor-infiltrating cells were reported to give a influence for prognosis, for example, regulatory T cell (T reg), cytotoxic T cell, macrophage and mast cell etc. Among these microenvironmental cells, we focused on Treg, cytotoxic T and macrophage cell, and we assessed the distribution and prognostic significance of these cells in DLBCL. Patients and Methods: We examined samples from 124 patients with DLBCL (69 men and 55 women; median age, 70 years) at diagnosis who were prospectively enrolled between 2002 and 2008. All patients were treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone). FOXP3 protein expression as Treg cells, CD8 expression as cytotoxic T cells, and CD163 expression as activated macrophage cells were evaluated by using immunohistochemistry in paraffin-embeded tissue samples. Results: The median count of FOXP3+ cells was 15.2/mm2 (×400) (range 1– 350/mm2), the median of CD8+ cells was 72/mm2 (8−402) and the median of CD163+ cells was 24/mm2 (0−114). Patients with high count of FOXP3+ cells (>15/mm2) have better prognosis than those of low count (5 year (5-y) overall survival (OS); 72.1%, 49.7% p=0.024, respectively). No significant difference was observed for progression free survival (PFS) of FoxP3 expression. No significant difference was observed for OS and PFS of CD8 expression. Patients with low count of CD163+ cells (<15/mm2) have better prognoses than those of high count (5-y OS; 80.1%, 52.5% p=0.009, 5-y PFS: 84.3%, 42.9% p=0.0019, respectively). Multivariate analyses employing factors such as poor risk group of revised International Prognostic Index (R-IPI), non-GCB type of subtype and low counts of FoxP3, low count of CD8, and high count of CD163 demonstrated that CD163 and R-IPI for OS and PFS were independent prognostic factors (OS; CD163 odd's ratio: 2.56, p=0.038, R-IPI: 2.66, p=0.015, PFS; CD163: 2.73, p=0.03, R-IPI: 2.56, p= 0.012). Conclusion: The count of tumor-infiltrating cells especially CD163+ macrophage might predict prognosis of DLBCL treated with R-CHOP.

Disclosures:

No relevant conflicts of interest to declare.
Prior Rituximab Exposure Does Not Appear to Affect Time to Treatment Failure After Radioimmunotherapy
Authors: Burnette Brian L. , Wiseman Gregory , Habermann Thomas M. , Ansell Stephen M. , Porrata Luis F. , Inwards David James , Johnston Patrick B. , Micallef Ivana , Macon William R , Witzig Thomas E. , Nowakowski Grzegorz S.
Published: October 2019

Abstract 1640

Background:

The introduction of radioimmunotherapy (RIT) into clinical practice for the treatment of follicular lymphoma (FL) occurred at a time at which many patients did not have prior exposure to rituximab. Clinical trials in the relapsed/refractory setting, as well as consolidation in the upfront setting have included a small number of patients that had been previously treated with rituximab or a rituximab containing treatment regimen. We evaluated the effect of prior rituximab therapy on the efficacy of RIT.

METHODS:

The prospective lymphoma database was queried for all patients having received a single dose of yttrium-90 ibritumomab tiuxetan for relapsed/refractory FL which had previously been treated with systemic therapy (patients receiving only prior external beam radiation therapy were excluded). The database includes all consecutive adult patients diagnosed with lymphoma seen at Mayo Clinic Rochester. The diagnosis of follicular lymphoma was as by WHO classification and centrally reviewed. Patients with evidence of histologic transformation to diffuse large B cell lymphoma prior to RIT were excluded. Time to treatment failure (TTF) was defined as the time from RIT to next anti-lymphoma therapy.

RESULTS:

111 patients were identified. 57 (51%) were male. Median age at time of RIT was 58 (19–88). Median time from diagnosis to RIT was 35 (6–281) months in patients having received prior treatment with rituximab and 47 (12–272) months in those who had not (p=0.19). 63 (57%) of patients received prior treatment with rituximab or rituximab containing chemotherapy. Median number of prior therapies was 2 (1–10), which was not different between the rituximab treated or untreated groups [2(1–6) vs 2(1–10) p=0.12]. Median TTF was 10.0 months in the patients having received prior rituximab and 10.1 months in those that had not (p=0.29). Figure 1. The median overall survival from RIT was not reached, but appeared similar (Kaplan-Meier estimate 125 months without prior rituximab exposure vs 95 months with prior rituximab exposure; p=0.33).

CONCLUSIONS:

Prior rituximab exposure does not seem to adversely impact the time to treatment failure or overall survival in those patients treated with RIT. While the data leading to the approval of RIT were accrued prior to the routine clinical use of rituximab, our data demonstrate similar clinical benefit of RIT in patients with prior exposure to rituximab or rituximab containing therapy.

Disclosures:

No relevant conflicts of interest to declare.
Allogeneic Hematopoeitic Stem Cell Transplantation (AHSCT) Versus Hypomethylating Agents (HMA) in Patients (pts) with Myelodysplastic Syndrome (MDS): A Case-Control Study
Authors: Tanaka Maria F , Jabbour Elias , Kantarjian Hagop M. , Pierce Sherry , Champlin Richard , Lima Marcos De , Garcia-Manero Guillermo
Published: October 2019

Abstract 1707

BACKGROUND:

Treatment of pts with higher-risk MDS revolves around AHSCT and HMA. Although AHSCT is thought to be the only curative approach for pts with MDS, only a small percentage of pts are appropriate candidates and this procedure carries significant morbidity and mortality rates. We wanted to assess outcomes in pts with higher risk MDS treated with AHSCT or HMA. To study this, we performed a retrospective analysis comparing the outcome of pts with previously untreated MDS who received AHSCT or HMA therapy at M.D. Anderson Cancer Center (MDACC).

METHODS:

From a database of pts with MDS who received AHSCT (N=152) at MDACC between 01/1988 and 04/2008, we selected those with untreated MDS prior to receiving the transplant. A total of 53 (29%) pts were identified. We compared them with a control group of 40 pts treated with HMA among 1748 referred to MDACC. All controls were selected to match at least 3 of the following 5 criteria: 1) age, 2) year of diagnosis, 3) percentage of blasts at the time of diagnosis, 4) IPSS cytogenetic risk, and 5) time from diagnosis to treatment. The primary endpoint was survival.

RESULTS:

A total of 53 pts with untreated MDS who received AHSCT and 40 pts treated with HMA were identified (Table 1). Median age was 51 (range 20–62) and 54 (range 38–79) years for pts treated with AHSCT or HMA respectively. There were more pts greater than 60 years old in the HMA group compared to those in the AHSCT group (58% vs. 1% p>0.001). The median follow up time was 64 months. Donors were HLA matched related (n=37), matched unrelated (n=11), 1 antigen mismatched related (n=4) or 1 antigen mismatched unrelated (n=1). Of the 40 pts treated with HMA, 31 were evaluable for response; of those 31, 19 (61%) responded, 16 (52%) achieving a complete response. The median survival was 26 and 25 months for pts receiving AHSCT or HMA, respectively (p=0.41) (Figure 1). The 8-year overall survival rates for pts receiving AHSCT or HMA were 24% and 23% respectively.

CONCLUSION:

AHSCT did not offer a significant survival improvement in a retrospective analysis of pts with MDS. Treatment with a HMA offers an adequate alternative in older patients or those who cannot tolerate or receive an AHSCT and should be used as a bridge in younger pts who are candidates for AHSCT

Disclosures:

No relevant conflicts of interest to declare.
Impact of a Venous Thromboembolism Prophylaxis “Smart Orderset”: Improved Compliance, Fewer Events
Authors: Zeidan Amer M. , Streiff Michael B. , Ahmed Syed-Rafay , Kraus Peggy S , Hobson Deborah , Horn Paula B , Shermock Kenneth , Tinoco Gabriel , Haut Elliott R
Published: October 2019

Abstract 172FN2

Introduction:

Venous Thromboembolism affects 900,000 Americans annually. Prophylaxis reduces the risk of VTE by 60% but many patients do not receive risk-appropriate VTE prophylaxis. We developed mandatory computer decision support “smart ordersets” (i.e. electronic menus with DVT prophylaxis recommendations) to improve our institution's VTE prophylaxis performance. The ordersets require providers to respond to 2 questions that assess VTE risk factors and contraindications to pharmacologic prophylaxis. Using these answers along with known patient demographics, the orderset gives providers an evidence-based risk-appropriate VTE prophylaxis recommendation.

Methods:

To study the impact of Medicine service-specific orderset on compliance with the 2008 American College of Chest Physicians (ACCP) VTE prophylaxis guideline and clinical outcomes, we conducted a retrospective cohort chart review of consecutive patients admitted to the Medicine service during one month immediately prior to (November 2007) and a single month subsequent to (April 2010) orderset launch. Data collection included patient demographics, VTE risk factors, and use and type of VTE prophylaxis. Patient characteristics before and after implementation of the protocol were compared. The primary outcome measures were compliance with thromboprophylaxis guidelines in patients at risk for VTE and the 90-day VTE rate. Secondary outcomes were bleeding events and 30-day mortality. Outcomes were compared by Student's t-test and Fisher's exact test.

Results:

The before and after cohorts contained 1,025 and 1,057 patients, respectively. Demographic characteristics and contraindications to pharmacologic prophylaxis were similar between groups. (Table 1) Some VTE risk factors were more prevalent in the before group. (Table 1) ACCP compliant prophylaxis increased significantly from 68.3% to 85.9% (p <.0001). Provider choices for prophylaxis changed with an increase in mechanical prophylaxis and twice daily heparin in the post-orderset implementation cohort. (Table 2) Radiographically-documented symptomatic VTE by day 90 post-hospital discharge declined from 2.8% to 0.7% after orderset implementation (p=0.001). There was also a trend toward fewer in-hospital VTE (0.8% versus 0.2%, p=0.06). (Figure 1) Major bleeding remained unchanged (0.3% to 0.1%, p=0.47).

Conclusion:

A VTE prophylaxis computerized decision support “smart orderset” improves ACCP-compliant VTE prophylaxis and results in lower risk of symptomatic VTE without an increase in major bleeding.

Disclosures:

Streiff: BristolMyers Squibb: Research Funding; sanofi-aventis: Consultancy; Daiichi-Sankyo: Consultancy; Eisai: Member of study outcome adjudication committee; sanofi-aventis: Honoraria.
Expression of the CAMPATH-1 Antigen (CD52) on CD34+/CD38- Progenitor Cells in Patients with 5q- MDS and in a Subset of AML
Authors: Blatt Katharina , Herrmann Harald , Cerny-Reiterer Sabine , Herndlhofer Susanne , Sperr Wolfgang R. , Valent Peter
Published: October 2019

Abstract 1728

The target antigen CAMPATH-1 (CD52) is widely expressed in various hematopoietic lineages inlcuding lymphocytes, basophils, and blood monocytes. The anti-CD52 antibody Alemtuzumab is used successfully to treat patients with chemotherapy-refractory chronic lymphocytic leukemia. Based on its strong immunosuppressive effects, Alemtuzumab has also been considered for patients with aplastic anemia and hypoplastic myelodysplastic syndromes (MDS). Indeed, more recently, Alemtuzumab was found to induce major hematologic responses in a group of patients with MDS. Although the immunosuppressive effect was considered to play a role, the exact mechanisms underlying this drug effect remained speculative. In the current study, we asked whether CD34+ bone marrow (BM) progenitor cells in MDS and acute myeloid leukemia (AML) express the CAMPATH-1 antigen. Twelve patients with MDS (5 females, 7 males; median age: 70 years), 25 patients with AML (16 females, 9 males; median age: 62 years), and 34 control cases (normal reactive BM, n=12; idiopathic cytopenia of unknown significance, n=11; chronic myeloid leukemia, CML, n=4; chronic myelomonocytic leukemia, CMML, n=3; JAK2 V617F+ myeloproliferative neoplasms, MPN, n=4) were examined. Surface expression of CD52 on CD34+/CD38+ and CD34+/CD38- BM progenitor cells was analyzed by monoclonal antibodies and multicolor flow cytometry. In the group of MDS, CD52 was detectable on CD34+/CD38- stem cells in 3/4 patients with isolated 5q-. In most of the other MDS patients, CD52 was weakly expressed or not detectable on CD34+/CD38- cells. In AML, CD34+/CD38- cells displayed CD52 in 12/25 patients, namely 3 with complex karyotype including 5q-, 2 with inv(3), one with t(8;21), one with inv(16), one with del13q, one with trisomy 8, one with monosomy 7, and 2 with normal karyotype. Expression of CD52 mRNA in CD34+/CD38- AML stem cells was confirmed by qPCR in all patients tested (n=14). In addition, a good correlation was found between surface CD52 expression and CD52 mRNA expression in AML progenitor fractions. In patients with normal hematopoiesis (n=12) or idiopathic cytopenia (n=11), CD34+/CD38- cells stained weakly positive or negative for CD52. Almost in all cases tested, blood monocytes and blood basophils stained positive for CD52. Together, our data suggest that the target antigen CAMPATH-1 (CD52) is expressed on primitive CD34+/CD38- progenitor cells in MDS, preferentially in 5q- patients, and in a subset of patients with AML. These observations may have clinical implications and explain recently described effects of Alemtuzumab in patients with MDS. Our data also suggest that Alemtuzumab may be an interesting targeted drug in patients with refractory or relapsed AML in whom neoplastic stem cells express the target antigen CD52.

Disclosures:

No relevant conflicts of interest to declare.
Alternate Splicing Factor Fox2 Affects Growth and Survival of Multiple Myeloma Cells
Authors: Song Weihua , Hu Yiguo , Yang Guang , Shah Parantu K , Shan Weisong , Tai Yu-Tzu , Li Yi , Minvielle Stephane , Avet-Loiseau Hervé , Anderson Kenneth C. , Li Cheng , Munshi Nikhil C.
Published: October 2019

Abstract 1810

Alternative splicing of pre-mRNA plays a critical role in number of cellular processes including cell growth and survival. We have previously demonstrated significant frequency of alternate splicing in multiple myeloma (MM) that points to the need for evaluation of not only the expression level of genes but also post translational modifications. Our data utilizing exon array profile from 170 uniformly treated newly diagnosed patients with MM confirms clinical relevance of splicing as demonstrated by impact of level and extent of alternate splicing on both progression free and overall survival. We have now further studied the molecular mechanisms that may be involved in differential splicing in myeloma. We have evaluated the expression data from 170 uniformly treated newly diagnosed patients with MM and identified Fox-2, an RNA binding protein that is thought to be a key regulator of alternative exon splicing as one of the most important gene predicting clinical outcome in MM. We have now investigated the molecular effects of Fox2 and its role on myeloma cell growth and survival. Using Fox-2-directed shRNA lentivirus, we knocked-out (KO) the expression of Fox2 in MM1S and RPMI8226 cell lines. Real-time PCR and western blot analysis confirmed KO of over 90% of Fox2 expression in both cell lines. We observed significant inhibition of proliferation of both MM1S and RPMI8226 cell lines in Fox-2- KO compared to control cell lines. Using annexin V and PI staining and flow cytometric analysis we also observed induction of apoptosis in Fox-2-KO-MM1S and RPMI8226 cells. The apoptosis was Caspase 3 and caspase 8-mediated in the Fox-2-KO. A similar effect of Fox-2-KO was observed on cell survival and proliferation in Hela and 293 cells. Fox-2 also plays a crucial role in the maintenance of cytoskeleton of MM cells. We observed that actin was significantly downregulated in both MM1S and RPMI8226 knockdown cell lines compare to controls, whereas GAPDH expressions are equal in all conditions. It's been recognized that actin derangement is associated with cell apoptosis. The RNA binding specificity of Fox-2 in MM cells by CLIP-seq and changes in alternate splicing in Fox-2-KO by exon array is underway to understand the molecular events mediated by this transcriptome modifier affecting MM pathobiology. These results identify Fox-2 as a biologically important intermediate with essential function in myeloma with potential biological and clinical implications.

Disclosures:

No relevant conflicts of interest to declare.
Risk of Second Cancers Among Multiple Myeloma (MM) Patients in the Era of Novel Agents: Analysis Using the Surveillance, Epidemiology and End Results (SEER) Database
Authors: Raghavendra Meghana , Gundrum Jacob D , Go Ronald S.
Published: October 2019

Abstract 1859

Introduction:

Recent data have drawn interest in the potential association of lenalidomide and the risk of developing of second cancers in patients with MM. However, available data are limited. Though there is lack of chemotherapy specification, SEER data segregated into diagnosis periods may be useful as a surrogate to detect changes in the incidence of second cancers corresponding to the introduction of novel agents.

Methods:

Patients who had MM diagnosed as a first cancer from 1973–2008 were identified in the SEER 17 database. We included only patients who survived at least 2 years after diagnosis. Time segments were created based on the era of novel agents approved for MM: before January 2000 (Period 1; control), January 2000-April 2003 (Period 2; off-label thalidomide), May 2003-April 2006 (Period 3; bortezomib approval), May 2006-September 2006 (Period 4; thalidomide approval) and October 2006-December 2008 (Period 5; lenalidomide approval). The primary outcome measure was incidence of second cancer within 2 years of MM diagnosis. All second cancers were included except for myelodysplastic syndrome and in situ cancer that were not of breast and bladder. Odds ratios (ORs) were adjusted and P values < 0.05 were considered statistically significant.

Results:

There were 29,259 eligible patients. Majority were males (53%) and the mean age at MM diagnosis was 65 years (std.+/− 12). The incidence of second cancers was associated with period of diagnosis (P = 0.048), sex (P < 0.001), treatment (P < 0.001), and age (P < 0.001), but not with race (P = 0.108). Multivariate analyses showed that higher risk of second cancers was associated with older age (OR = 1.03; P < 0.001), male sex (OR = 1.41; P < 0.001), radiation and/or surgery as compared to neither treatment (radiation and surgery OR = 1.77, radiation only OR = 0.82, surgery only OR = 2.31; P values: 0.002, 0.040, and <0.001, respectively), and Periods 3 and 4 as compared to Period 1 (Periods 2–5 ORs: 1.11, 1.22, 1.63, and 1.53, respectively; P values: 0.260, 0.033, 0.011, and 0.096, respectively).

Conclusions:

Our population-based study suggests that the risk of developing second cancers in patients with MM may be increased in the recent decade wherein novel agents were introduced. A more specific study linking SEER to Medicare database is recommended in order to further define the risk specific to novel agents.

Disclosures:

No relevant conflicts of interest to declare.
A Plasmin Inhibitor Prevents Lethal Acute Graft-Versus-Host Disease in Mice
Authors: Sato Aki , Tashiro Yoshihiko , Nishida Chiemi , Gritli Ismael , Kusubata Kaori , Takahashi Satoshi , Heissig Beate , Hattori Koichi , Nakauchi Hiromitsu
Published: October 2019

Abstract 1897

Proinflammatory cytokines released upon cell damage can cause excessive tissue destruction in acute graft-versus-host disease (GVHD). Certain key cytokines for GVHD like TNF-α and Fas-ligand, are secreted by ectodomain shedding from matrix metalloproteinases (MMPs). Many MMP inhibitors have been developed and used over the last three or four decades, but its widespread use is hampered by severe side effects. We reported that the fibrinolytic system, above all plasmin formation promotes the activation of several MMPs. Therefore we hypothesized that plasmin inhibition might be a novel means to control acute GVHD in part by suppressing MMP and inflammatory cytokine secretion. We found that the fibrinolytic system is activated during the development of acute GVHD in mice and in humans. Here, we examined a novel plasmin inhibitor (YO-2) that inhibits MMP activation and inflammatory cytokines release for lethal acute GVHD model in mice. Administration of YO-2 into (BALB/c × C57BL/6) F1 that received C57BL/6 spleen cells showed markedly reduced mortality and weight loss in association with minimal signs of GVHD pathology in the liver, intestine, and hematopoietic tissues. Furthermore, our results suggest that administaration of YO-2 blocked the processing of inflammatory cytokines through MMP inhibition in vitro and in vivo. These data have major implications for transplantation medicine, as pharmacological inhibition of plasmin does not require the need for intensive immunosuppression. Our results suggest that YO-2 could be a novel molecular therapeutic agent for GVHD.

Disclosures:

No relevant conflicts of interest to declare.
Stat3 Activation in Donor CD4 T-Cells Is Critical for Acute Gvhd
Authors: Ozaki Katsutoshi , Matsu Haruko , Hatanaka Keiko , Meguro Akiko , Oh Iekuni , Tatara Raine , Suzuki Takahiro , Mori Masaki , Nagai Tadashi , Muroi Kazuo , Ozawa Keiya
Published: October 2019

Abstract 1906

Stat3-deficient (Stat3KO) T-cells reportedly are less proliferative due to accelerated apoptosis in the presence of IL-6, and have suppressed IL-2Ra expression. There are conflicting mouse model results concerning Stat3 in graft-versus-host disease (GVHD). Previously, we demonstrated IL-21 signaling is essential for GVHD. As Stat3 is a downstream signaling molecule, clarifying its role in GVHD T-cells is important.

After co-transplantation of bone marrow and wild-type or Stat3KO CD4+ T-cells, recipients of the latter developed attenuated GVHD with longer survival than recipients of the former, and their splenic CD4+ T-cells exhibited a profound proliferation defect in the mixed lymphocyte reaction (MLR). In contrast to IL-21R-deficient CD4+ T-cells, pre-transplantation Stat3KO CD4+ T-cells showed similar MLR impairment, suggesting an intrinsic defect. Consistently, proliferation in low-dose anti-CD3 stimulation was defective, but MLR apoptosis was not increased. Neutralizing antibody against IL-2, but not IL-6R, suppressed MLR wild-type CD4 T-cell proliferation, suggesting Stat3KO CD4+ T-cells' MLR apoptosis might be attributed to lack of IL-6 contribution.

Pallandre et al. reported Stat3 ablation in CD4 exacerbated GVHD, speculating Stat3 depletion suppressed regulatory T-cell function, leading to accelerated GVHD. Lu et al. analyzed T-cell phosphorylated proteins during allo-activation, demonstrating Stat3 and Erk1/2 are important for this and GVHD. Radojcic et al. showed Stat3KO T-cells cannot induce chronic cutaneous GVHD because of repressed CD4 proliferation and loss of Th17 differentiation. Reasons for differing conclusions are unknown. One possibility is enhanced innate immunity induced by Stat3-siRNA-transduced stem and progenitor cells, consistent with several reports. Our use of Stat3KO T-cells overcame this problem. The latter two reports are consistent with our results. To our knowledge, we report the first direct evidence Stat3 activation in donor CD4+ T-cells is critical for acute GVHD. Durant et al. delineated detailed gene regulation in Stat3KO CD4+ T-cells, and one of their conclusions—Stat3 is important for CD4+ T-cell proliferation—is consistent with our results.

Disclosures:

No relevant conflicts of interest to declare.
Use of the G-CSF Biosimilar Ratiograstim® to Mobilize Peripheral Stem Cells in Healthy Donors for Allogeneic Stem Cell Transplantation
Authors: Schmitt Michael , Lena Diestel , Schneider Catarina , Xu Xun , Borchert Kersten , Gläser Dietrich , Hilgendorf Inken , Scheuerlein Robert , Freund Mathias , Schmitt Anita
Published: October 2019

Abstract 1928

INTRODUCTION:

There is limited experience in the application of the biosimilar Ratiograstim® for mobilization of peripheral stem cells and especially in healthy donors (HD). The G-CSF biosimilar Ratiograstim® was approved by the EMA for mobilization of peripheral stem cells. Here, we investigated on two cohorts the efficacy and safety of peripheral stem cell mobilization by either the biosimilar or the reference G-CSF.

MATERIAL AND METHODS: 22 patients and their related donors were investigated for: 1. leukocyte-count in the peripheral blood of healthy donors, 2. number of collected CD34+ stem cells, 3. number of apheresis procedures, 4. CD34+ cell count per kg body weight of the patients, 5. time till regeneration, 6. side effects.

RESULTS:

In HD receiving subcutaneously Ratiograstim®, WBC counts in the peripheral blood ranged from 29.9 G/L to 64.6 G/L (mean 48.9 G/L) and the CD34 cell counts from 19.3/μl to 114.6/μl (mean 67.6/μl). In a mean of 1.45 apheresis procedures 172.5×106 up to 494×106 CD34+ cells (mean 354.7×106) were collected. This resulted in CD34+ cell numbers of 2.28×106 up to 1×107 (mean 5.17×106) per kg body weight of the patients. In HD receiving subcutaneously the reference G-CSF, WBC counts ranged from 27.1 G/L up to 62.5 G/L (mean 43.3 G/L) and the CD34+ cell counts from 13.55/μl up to 122.4/μl (mean 57.3/μl). A mean of 1.27 apheresis procedures were necessary to collect 181.74×106 up to 598.00×106 CD34+ cells (mean 370.49×106) absolutely. This translates into 2.33×106 up to 7.9×106 (mean 4.95×106) CD34+ cells per kg body weight of the patients. Patients regenerated >0.5 G/L neutrophils/μl within 15 days in the Ratiograstim® cohort versus 17 days in the reference group.

In total we analyzed two cohorts, one cohort of 22 patients and donors receiving the biosimilar Ratiograstim® versus another cohort receiving reference G-CSF. No unexpected side effects and no increased frequencies in side effects as flu-like symptoms, allergic reactions and alterations in kidney and liver function were observed. In comparison to the reference group we did not see significant differences in 1. WBC count in the peripheral blood after mobilisation, 2. CD34+ cell count after mobilisation, 3. CD34+ cell count absolute numbers, 4. CD34+ cells per kg body weight of the patients, 5. engraftment, 6. regeneration of WBC, neutrophils and platelets. All patients engrafted. Therefore, the efficacy of the biosimilar Ratiograstim® when compared to the reference G-CSF was comparable in our cohort of patients in the context of allogeneic stem cell transplantation.

Disclosures:

Schmitt: ratiopharm: Honoraria, Research Funding. Freund:Medac: Honoraria, Research Funding.
Carboxyl-Terminal Thrombospondin-Type 1 (TSP-1) Repeats of ADAMTS13 Inhibits Platelet Adhesion to Collagen-Coated Surface Under Shear Stress, Independent of Proteolytic Activity
Authors: Xiao Juan (Jenny) , Zheng X. Long
Published: October 2019

Abstract 195

ADAMTS13 contains multiple free thiols on its surface, which may form disulfide bonds with surface-exposed free thiols on plasma-derived von Willebrand factor (VWF). This interaction may prevent lateral association of apposed VWF under arterial shear stress. However, the functional consequence of ADAMTS13-VWF interaction without proteolysis is not known. We hypothesize that the interaction between the C-terminus of ADAMTS13 and the C-terminus of VWF inhibits thrombus formation under shear stress. Using a BioFlux microfluidic system, we showed that under arterial shear stress, 10 dyn/cm2, fluorescein-labeled platelets from PPACK (thrombin inhibitor) anti-coagulated human whole blood adhered to collagen (type I)-coated surface in a time-dependent manner. Addition of human recombinant full-length ADAMTS13 (10 nM) into whole blood dramatically reduced the surface coverage of fluorescein-labeled platelets. Conversely, addition of an inhibitory polyclonal anti-ADAMTS13 IgGs (150 ug/ml) to whole blood dramatically accelerated the accumulation of fluorescein-labeled platelets. These results suggest that this microfluidic system is highly sensitive for the assessment of anti-thrombotic function of ADAMTS13. Under the same conditions, we were able to further show that addition of recombinant C-terminal fragment of ADAMTS13 comprising of the 5th to 8th thrombospondin type 1 (TSP1) repeats and two CUB domains (T5C) or the 2nd to 8th TSP1 repeats and two CUB domains (T2C) into whole blood also inhibited the surface coverage of fluorescein-labeled platelets on collagen-coated surface in a concentration-dependent manner. In the presence of 0.1 μM and 0.5 μM of recombinant T2C or T5C, the surface coverage of fluorescein-labeled platelets was reduced by ∼40% and ∼60%, respectively. The inhibitory activity of these recombinant C-terminal fragments was nearly abolished if pre-treated with 40 mM of N-ethylmaleimide which blocked surface-exposed free thiols. Moreover, recombinant CUB domains at the highest concentration tested (1.0 μM) did not appear to alter the surface coverage of fluorecein-labeled platelets under the same conditions. These results suggest that the C-terminal TSP1 repeats of ADAMTS13 inhibit platelet adhesion and aggretion or thrombus formation through thiol-thiol interactions between ADAMTS13 and VWF (or other proteins). We conclude that the C-terminal TSP1 repeats may modulate thrombus formation independent of proteolytic activity.

Disclosures:

No relevant conflicts of interest to declare.
Formation of Procoagulant Platelets in Heparin-Induced Thrombocytopenia (HIT) Follows a Unique Signaling Pathway
Authors: Andre Pierrette , Stolla Moritz , Woulfe Donna , Chavez Massiel , Bergmeier Wolfgang , Rauova Lubica , Cines Douglas B. , Poncz Mortimer , McKenzie Steven
Published: October 2019

Abstract 197

HIT is a drug-induced, immune-mediated thrombocytopenia and thrombosis disorder associated with considerable morbidity and mortality. HIT is associated with generation of procoagulant platelet microparticles (Warkentin et al., Blood 1994; 84:3691), one of the cardinal features of procoagulant platelets, along with a phosphatidylserine-positive (PS+) external plasma membrane and surface retention of procoagulant proteins from plasma or released from platelet γ-granules. Other names for procoagulant platelets include COAT, or coated, platelets (Dale, J Thromb Haemostas 2005; 3:2185). To date, virtually all of the work on procoagulant platelets has used collagen or convulxin signaling via ITAM-associated GPVI, combined with thrombin signaling via GPCRs PAR1/PAR4. Batar and Dale reported the formation of coated platelets as a result of dual platelet FcγRIIa and thrombin stimulation; they used crosslinking of an anti-FcγRIIa antibody or anti-platelet glycoprotein antibodies which also engaged FcγRIIa (J Lab Clin Med 2001; 138:393). We report here the procoagulant activation of human and FcγRIIa transgenic (tg) mouse platelets stimulated by the HIT immune complex (IC) and thrombin (thr). HIT IC consist of ultralarge complexes of heparin and platelet factor 4 (hep/PF4) bound by HIT-like monoclonal antibody KKO. Washed human platelets, wild-type mouse platelets, or FcγRIIa tg mouse platelets were stimulated with the HIT IC + thr. Controls include convulxin (100 ng/ml) + thr, HIT IC alone, or thr alone as the stimulus. Human platelets and FcγRIIa-tg platelets, but not wild-type mouse platelets, develop a 40 to 60% PS+ population in response to HIT IC (100 ug/ml KKO)+ thr (0.5 U/ml), but not to either alone, as assessed by flow cytometry using labeled Annexin V. Unlike cvx + thr, which consistently shows a broad distribution of PS+ platelets in our hands and in the literature, HIT IC-stimulated platelets reproducibly show one discrete PS+ subpopulation (n = 6 per group). Preincubation of platelets with novel specific Syk inhibitor PRT318 (Reilly et al., Blood 2011; 117:2241) completely prevented PS+ platelet formation. FcγRIIa-tg platelets null for Akt2 showed a ∼50% reduction in the formation of PS+ platelets. Studies with FcγRIIa-tg mice null for Cal-DAG GEFI are ongoing. Understanding the unique pattern of procoagulant platelets generated by HIT IC + thr and the signals which produce it may lead to new diagnostic tests and therapeutic interventions.

Disclosures:

No relevant conflicts of interest to declare.
Hepatitis B and Hepatitis C Co-Infection in Patients with Hematological Malignancies
Authors: Garmaeva Tatyana Ts , Kulikov Sergey M. , Michailova Elena A , Sudarikov Andrei B , Filatov Felix P , Savchenko Valeryi G
Published: October 2019

Abstract 2090

BACKGROUND.

Coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) in immunocompromised patients (pts) with hematological malignancies is not well-studied problem. Early recognition of HBV and HCV infectioning incidence in such pts is difficult due to influence of cytostatic and immunosuppressive therapy and possible mutual HBV or HCV inhibitions. Independence of HBV and HCV infection events has to be discussed.

AIM.

To determine the prevalence of HBV and HCV co-infection in pts with hematological malignancies to check the possible correlation between the incidence of the infections.

PATIENTS AND METHODS.

All 265 patients treated in hematology department during 2004–2006 years were prospectively continuously monitored and examined for markers HBV and HCV (HBsAg, anti-HCV, DNA HBV, RNA HCV, HBeAg, anti-HBs, anti-HBc, anti-HBe) in serum, plazma, blood cells, bone marrow, cerebrospinal fluid) and clinico-biochemical symptoms of liver dysfunction were registered approximately every 3 weeks until 2008 year. Liver biopsy was performed on 64 pts in 2004–2006 yy, 23 pts esch with HBV and HCV immunohistology. Approximately 80% of pts were with acute leukemias (AL) and aplastic anemias (AA). Male; 47% (n=125), female; 53% (n=140). The median age was 38 years (range, 15 to 79).

RESULTS.

At the beginning of treatment and monitoring 17 of 265 pts (6.4%) had positive markers of HCV and the number of pts with positive markers of HCV increased up to 70 (26%) to the end of monitoring, and for HBV markers increased from 23 pts (8.7%) to 174 pts (65.3%). We found, that many pts were co-infected with HBV and HCV, and their total number increased from 5 pts (1,9%) äî 37 pts (14%). Positive tests of HBV and HCV co-infection was found in 57 pts of 265, that is 32.8% of 174 HBV-positive pts and 81.4% of 70 HCV-positive pts, odds ratio (OR=2.9) (95%CI =1.5–5.7), xi square significance p=0.0012. More complicate longitude analysis did not show that the incidence rate of second infection is significantly higher than the first. That means that the correlation between first and second infections is still questionable. Coinfection with HBV and HCV resulted in clinical presentation of hepatitis B and/or hepatitis C in most cases and cumulative incidence rate rises up to 100% at 630 day after the first appearance of any positive marker.

CONCLUSION.

The high prevalence of HBV and HCV coinfection of pts with hematological malignancies is attributed to common risk factors for infection transmission after transfusions of blood components and parenteral medical procedures. For pts with hematological malignancies after first detection of positive test for single marker of HBV and/or HCV it is very reasonable to intensify the monitoring of HBV and HCV markers and to follow clinical signs.

Disclosures:

No relevant conflicts of interest to declare.
Efficacy and Safety of VTE Prophylaxis with Oral Rivaroxaban Compared to Fondaparinux or Low-Molecular Weight Heparin In a Large Cohort of Consecutive Patients Undergoing Major Orthopaedic Surgery
Authors: Beyer-Westendorf Jan , Donath Lars , Lützner Jörg , Werth Sebastian , Radke Oliver , Guenther Klaus-Peter , Weiss Norbert
Published: October 2019

Abstract 210

Efficacy and safety of VTE prophylaxis with oral rivaroxaban compared to fondaparinux or low-molecular weight heparin in a large cohort of consecutive patients undergoing major orthopaedic surgery.

Aim:

Patients undergoing major orthopaedic surgery (MOS) have a high risk of postoperative venous thromboembolism (VTE). Several types of pharmacological thromboprophylaxis are approved for this indication. In phase III VTE prevention trials in MOS, the new oral facor Xa inhibitor rivaroxaban proved superior efficacy over LMWH in preventing VTE without increasing bleeding complications. However, study populations consist of selected patients screened for strict exclusion criteria before randomisation. Little is known about efficacy and safety of rivaroxaban prophylaxis in large unselected cohorts of patients undergoing MOS in daily practice.

Method:

We retrospectively evaluated 5346 consecutive patients undergoing MOS at our centre between January 2005 and June 2011 for the rate of VTE events, bleeding complications and surgical revisions by review of patient charts, complication and transfusion databases and autopsy reports. All events were analyzed according to the type of thromboprophylaxis used.

Results:

Of the 5346 patients, 1055 patients received thromboprophylaxis with rivaroxaban (R; hospital standard since 2010), 1683 patients received LMWH (hospital standard 2005–2007), 2069 received fondaparinux (F; hospital standard 2007–2009) and 539 patients received other prophylaxis. Symptomatic VTE event rates for patients receiving R, F or LMWH were 2.5%, 5.5% and 3.9%, respectively (table 1). R was significantly more effective to prevent symptomatic VTE compared to F or LMWH, mostly due to significantly lower rates of distal VTE.

Overall, the safety of VTE prophylaxis with R was superior over F or LMWH with significantly lower rates of surgical revisions (1.1%, 1.8% and 4.7%, respectively) and lower rates of severe bleeding complications (7.4%, 11.1% and 14.9%, respectively, which also was statistically significant.

Conclusion:

VTE prophylaxis with rivaroxaban is superior over prophylaxis with fondaparinux or LMWH with regard to the prevention of symptomatic VTE complications. Furthermore, rivaroxaban prophylaxis was also safer with regard to severe bleeding complications and surgical complications compared to fondaparinux or LMWH, which is in contrast to the results of large phase III trials and the current opinion, that superior efficacy of prophylaxis has the downside of higher bleeding complications. We conclude that real world patients undergoing MOS are different from study populations and may especially benefit from rivaroxaban prophylaxis with regard to both efficacy and safety.

Disclosures:

Beyer-Westendorf: Bayer Healthcare: Research Funding, Speakers Bureau.
Protein Disulfide Isomerase Regulates Sickle Erythrocyte Volume Via ET-1 Dependent Casein Kinase II Mechanism
Authors: Valentin-Berrios Shirley D , Romero Jose R , Rivera Alicia
Published: October 2019

Abstract 2114

Disordered K+ efflux and osmotically induced water loss leads to red blood cell (RBC) dehydration and plays a role in the pathophysiology of Sickle Cell Disease. We previously reported that activation of endothelin-1 (ET-1) receptors in sickle erythrocyte was partially responsible for dense sickle cell formation. However, the mechanism by which ET-1 regulates RBC volume remains unclear. Serine/threonine kinases have been shown to regulate K+ transport in RBC. Casein Kinase II (CK2), a serine/threonine kinase, phosphorylates acidic proteins, regulates calmodulin activity and cytoskeletal proteins and is present in RBC. CK2 activity is blocked by apigenin, emodin, heparin, and ornithine decarboxylase. Previous reports have shown a role for flavonoids such as apigenin as substrates for erythrocyte plasma membrane oxidoreductases. We recently observed a role for Protein Disulfide Isomerase (PDI) in regulating cellular hydration and K+ efflux in human RBC. PDI catalyzes disulfide interchange reactions in the plasma membrane, mediates redox modifications and is up-regulated under hypoxic conditions. However the relationship between CK2 and PDI in the setting of cellular hydration status is un-explored. Our results indicate that erythrocyte membrane CK2 activity increases when sickle cells are incubated with 500 nM ET-1 for 30 min (2.8 ± 0.1 to 4.9 ± 0.01 nmol/min/mL * 106 cell) an event that is blunted by pre-incubation with the ET-1 B receptor blocker, BQ788 (2.5 ± 0.1 nmol/min/mL * 106 cell, n=3, p<0.04) and 20 μM apigenin (2.7 ± 0.4 nmol/min/mL * 106 cell, n=3, p<0.04). We examined the role of CK2 activation on cellular dehydration. We incubated sickle erythrocytes for 3 hours in deoxygenation-oxygenation cycles in the presence or absence of 20μM apigenin or 2μM 4,5,6,7-tetrabromobenzotriazole (TBB), a specific CK2 inhibitor, and measured the changes in erythrocyte density by phthalate oil density analysis. We observed that inhibition of CK2 led to reduced deoxygenation-stimulated cellular dehydration in sickle erythrocytes by apigenin (D50= 1.106 to 1.100 g/mL) or TBB (D50 =1.097 g/mL). We then studied the role of CK2 inhibitors on PDI activity by Insulin Turbidity Assay and observed that apigenin and TBB led to significant reductions in PDI activity in vitro (64% and 42% respectively). We also studied the effects of the flavonoids: naringenin, naringin, apigenin and rutin on PDI activity and observed reductions in PDI activity that were greater with apigenin>rutin>TBB>naringin>naringenin (n=2, P<0.05). Furthermore, we observed that K+ flux via Gardos channel activation is correlated with PDI activity in vitro in sickle erythrocytes. Taken together our results implicate CK2 and PDI as intermediate regulators of ET-1 stimulated cellular volume systems in red blood cells. Supported by NIH R01-HL09632 to AR.

Disclosures:

No relevant conflicts of interest to declare.
Single-Photon Emission CT to Access Outcomes in Children with Moyamoya Syndrome and Sickle Cell Disease Before and After Encephaloduroarteriosynagiosis
Authors: Sarnaik Sharada A. , Lancelot Moira M.
Published: October 2019

Abstract 2143

Background:

About 11% of patients with sickle cell disease (SCD) will develop and ischemic stroke by 20 years. Patients with SCD and Moyamoya Syndrome (MMS) are at an especially high risk for developing stroke. Encephaloduroarteriosynagiosis (EDAS) is emerging as a safe and effective method for the treatment of MMS in Pediatric patients with SCD since it provides improved revascularization. Single-photon emission CT (SPECT) has been used in pediatric MMS patients to demonstrate regions of decreased cerebral perfusion and cerebrovascular reserve. The use of SPECT in SCD patients with MMS undergoing EDAS has not been evaluated.

Methods:

Between 2001 and 2011 we had 45 patients with SCD who developed clinical evidence of cerebrovascular accident (CVA), transient ischemic attack (TIA), or seizure with radiologic evidence (magnetic resonance and or angiography) of MMS. 20 underwent surgical revascularization with EDAS. Vascular reserve and cerebral perfusion was assessed with SPECT before and after EDAS in 9 patients.

Results:

6/9 patients had bilateral EDAS while 3/9 had unilateral EDAS. The postoperative clinical outcome of each patient was assigned to one of the following 3 categories based on the SPECT reports: (1) improved if there was increased perfusion and vascular reserve after EDAS, (2) stable if there were no new areas of decreased perfusion or vascular reserve after EDAS and (3) worsened if there were new areas of decreased perfusion or vascular reserve with increased risk for future infarct after EDAS. 6/9 patients showed improvement, 2/9 patients showed stable cerebral perfusion and vascular reserve and 1 patient showed additional areas at risk for future infarct. SPECT was performed on average 5.7 (range 1.5–16.1) months before EDAS and 16.2 (range 1–47.1) months after EDAS.

Conclusions:

SPECT performed before and after EDAS of the involved cerebral hemispheres can assess effectiveness of revascularization surgery and may predict the further clinical outcomes of pediatric patients with SCD and MMS.

Disclosures:

No relevant conflicts of interest to declare.