bluuebunny/crossref_metadata_2025 huggingface dataset:
Monocytosis As Prognostic Factor in Aggressive, Non-Primary Cutaneous Peripheral T-Cell Lymphoma: A Study of 251 Cases
Authors: Beltran Brady E , Cotacallapa Erick , Castillo Jorge J
Published: October 2019

Abstract 1608

Background:

Peripheral T-cell lymphoma (PTCL) is a heterogeneous family of entities with a worse prognosis, stage by stage, than their B-cell counterparts. We have previously reported that an absolute lymphocyte count (ALC) <1000/uL is associated with a worse prognosis in Peruvian patients with PTCL (Castillo et al. 2010). The goal of this study is to investigate the prognostic value of absolute monocyte count (AMC) in the survival of patients with PTCL.

Methods:

A total of 251 cases of aggressive, non-primary cutaneous PTCL diagnosed at our institution between January 1997 and January 2012 were reviewed, reevaluated according to their morphological, immunological and clinical characteristics, and reclassified according to the 2008 WHO classification of lymphoid neoplasms. Characteristics will be presented descriptively. Kaplan-Meier method was used to estimate overall survival (OS) curves, which were compared using the log-rank test. The multivariate analysis was performed using the Cox proportional-hazard regression test.

Results:

According to the new WHO classification of lymphoid neoplasms, 104 cases (41%) were classified as adult T-cell leukemia/lymphoma (ATLL), 103 cases (41%) as PTCL, unspecified (PTCLU), 27 cases (11%) as analplastic lymphoma kinase (ALK)-negative anaplastic large cell lymphoma (ALCL), 11 cases (4%) as extranodal NK/T-cell lymphoma (NKTCL), nasal type, 4 cases (2%) as angioimmunoblastic lymphoma (AIL), and 2 cases (1%) were diagnosed with ALK+ ALCL. The median age at diagnosis was 57 years (range 14–92 years); 47% of patients were >60 years. The male-to-female ratio was 1:1. ECOG performance status >1 was seen in 51%, LDH was elevated in 67%, advanced stage was seen in 73%, and >1 extranodal sites were seen in 22% of the patients. Bone marrow involvement was reported in 30% and B symptoms in 64% of patients. An International Prognostic Index (IPI) score 3–5 was seen in 55%, and a Prognostic Index for PTCLU (PIT) score of 2–4 in 63%. The median overall survival (OS) for the whole group was 10 months. The IPI score, the PIT score, ALC <1000/uL and AMC >800/uL (Figure) showed statistical significance in the univariate survival analysis (p<0.001, p<0.001, p=0.001 and p=0.001, respectively). In the multivariate analysis, PIT score and AMC >800/uL showed statistical significance (p=0.006, p=0.046, respectively).

Conclusions:

Monocytosis, defined as AMC >800/uL, and the PIT score were independent prognostic factors for OS in patients with aggressive, non-primary cutaneous PTCL.

Disclosures:

No relevant conflicts of interest to declare.
Comparison of Referring and Final Pathology for T-Cell Lymphomas in the NCCN
Authors: Herrera Alex F , Crosby-Thompson Allison , Friedberg Jonathan W. , Abel Gregory A. , Czuczman Myron S. , Gordon Leo I. , Kaminski Mark S. , Millenson Michael , Nademanee Auayporn , Niland Joyce , Rodriguez Maria A. , Zelenetz Andrew D. , LaCasce Ann S.
Published: October 2019

Abstract 1610

Background:

T-cell lymphomas (TCL) are an uncommon group of diseases recently updated in the WHO classification. Accurate diagnosis requires immunophenotyping and molecular techniques. Diagnostic accuracy of TCLs utilizing the WHO classification has not previously been evaluated.

Methods:

The NCCN NHL database prospectively collects clinical, treatment, and outcome data for patients seen at 7 comprehensive cancer centers. Using this unique resource, we evaluated diagnostic concordance between referring and NCCN centers for TCLs, including peripheral T-cell lymphoma, NOS (PTCL NOS), angioimmunoblastic T-cell lymphoma (AITL), ALK-positive anaplastic large cell lymphoma (ALK+ ALCL), and ALK-negative ALCL utilizing pathology reports, immunohistochemical stains, flow cytometry, fluorescence in situ hybridization/cytogenetics, T-cell gene rearrangement, and progress notes.

Results:

Of 98 eligible patients enrolled from April 2007 to March 2011, 38 (39%) cases were concordant and 60 (61%) were non-concordant. Among non-concordant cases, 34 (57%) had a provisional diagnosis before referral, 6 (10%) were discordant with no additional studies performed, 17 (28%) were discordant with additional studies performed, and 3 (5%) required an additional biopsy. Concordance was highest for ALK+ ALCL at 73%, while the remaining subtypes had low concordance: PTCL NOS 28%, AITL 28%, ALK- ALCL 47%. In 13 (13%) discordant cases (referral diagnosis was benign, a B-cell NHL, or ALK status was undefined) patients may have experienced a significant change in treatment with pathologic reclassification.

Conclusions:

In patients with TCL, the likelihood of a concordant final diagnosis at a referring institution was low. Among non-concordant cases, the majority were referred with provisional diagnoses, and many referral diagnoses were discordant. Establishing a precise diagnosis is critical for prognosis and impacts both therapeutic decisions and clinical trial enrollment. As current and future therapies, such as brentuximab vedotin, target subsets of TCLs, our data suggest that all suspected TCLs may benefit from evaluation by an expert hematopathologist.

Disclosures:

Kaminski: Allos: Consultancy, Honoraria.
Combination of ACY1215, a Selective Histone Deacetylase 6 (HDAC6) Inhibitor with the Bruton Tyrosine Kinase (BTK) Inhibitor, Ibrutinib, Represents a Novel Therapeutic Strategy in Mantle Cell Lymphoma (MCL)
Authors: Sahakian Eva , Rock-Klotz Jennifer , Shah Bijal D. , Powers John , Cultrera Jennifer L. , Deng Susan , Woods David M , Nguyen Michael , Cheng Fengdong , Wang Hongwei , Perez-Villarroel Patricio , Lienlaf Maritza , Knox Tesa , Chen-Kiang Selina , Villagra Alejandro , Tao Jianguo , Pinilla-Ibarz Javier , Jones Simon S , Sotomayor Eduardo M.
Published: October 2019

Abstract 1660

Recently, we have found that HDAC6 is overexpressed in MCL cell lines and in primary human MCL cells. Knocking-down HDAC6 in MCL cells with a shRNA lentiviral system resulted in cell cycle arrest and apoptosis induction. Interestingly, MCL cells lacking HDAC6 displayed a significantly decreased STAT3 phosphorylation and abrogation of IL-10 gene transcriptional activity. ACY1215 is a novel, selective, orally bioavailable HDAC6 inhibitor. Treatment of MCL cell lines with this agent resulted in decreased cell viability and proliferation. In addition, ACY1215 inhibits IL-10 production in a dose dependent manner.

Bruton tyrosine kinase (BTK) is a member of Tec family of kinases with a very distinct role in B-cell antigen receptor (BCR) signaling. The selective BTK-inhibitor PCI-32765 has shown promising pre-clinical and clinical activity in MCL. In addition to their direct anti-lymphoma effects, disruption of BTK also induces positive immunological changes such as inhibition of the immunosuppressive STAT3/IL-10 signaling pathway1.

The above observations led us to determine whether the direct antitumor effects and the immunological properties of ACY1215 and PCI-32765 could be potentiated when these agents are used in combination. First, the viability of MCL cells was decreased when they were treated in vitro with either PCI-32765 or ACY1215. However, combination of these two agents resulted in a 3-fold increase in apoptosis induction, pointing to a synergistic effect of BTK and HDAC6 inhibition in MCL. The additional findings that this approach can increase the immunogenicity of MCL cells and anti-MCL immune responses has provided the proper framework for combining the selective HDAC6 inhibitor ACY1215 with BTK inhibition as a novel therapeutic strategy in MCL.

Disclosures:

Chen-Kiang: Bristol Myers Squibb: Consultancy; Pfizer: Research Funding. Jones:Acetylon Pharmaceuticals, Inc: Employment.
Microtransplantation with Decitabine and Cytarabine Improves Patient Outcomes in Myelodysplastic Syndromes
Authors: Ai Huisheng , Hu Kaixun , Sun Qiyun , Li Xiao , Guo Mei , Yu Changlin , Qiao Jianhui , Qiao Junxiao , Liu Guangxian , Dong Zheng , Qiao Zhenhua
Published: October 2019

Abstract 1709

The outcome of myelodysplastic syndromes (MDS) still remains unsatisfactory, with a low complete remission (CR) rate and a poor overall survival rate. Decitabine improved the overall responses of MDS as a hypomethylating agent, but CR rates remain low and prolonged pancytopenia. Our recently study showed that infusion of G-CSF mobilized HLA-mismatched peripheral blood stem cells (G-PBSC) can improve the outcome of chemotherapy for acute myeloid leukemia in elderly patients. However, whether G-PBSC combining decitabine and cytarabine chemotherapy will improve outcomes in MDS patients is unknown.

Material and methods:

Total of 72 patients with MDS, from 16 to 82 years of age, were assigned to receive decitabine 25–30 mg/m2daily for 4 days with cytarabine 150 mg/m2 daily for 7 days by intravenous followed to infusion of G-PBSC on 24 hours after each completion of the cytarabine therapy (Microtransplantation-group, n=28) or decitabine 20 mg/m2 daily for 5days (Decitabine group, n=27) or 15 mg/m2 daily for 5days (low decitabine group, n=17). The infused cells of mononuclear cells and CD34+ cells with HLA-mismatched in 3 loci (n=22) and 2 loci (n=5) and 1 loci (n=1) were 3.33(3.04–10.8)108/kg, 2.26(0.68–5.25)106/kg and no any GVHD prophylactic treatment was used in the Microtransplantation-group.

Results:

Total CR rate of was 42.9%#x2610;#x0025; A14.8% and 29.4% in the three groups, respectively. That of MST-group is significantly higher than that of B group (P=0.02). The CR rate after first course in MST group is 21.5% which was higher the other two groups (10% and 0%, P=0.14#x2610;#x0025; GP=0.04). The complete cytogenetic response rate in the Microtransplantation-group was 90.9% which is highest than the other two groups (10% and 11%, P<0.001,P<0.001). The progress free survival(PFS) of Microtransplantation-group in 12 months is 50.1% which is higher than other two group (9.9%,9.6%, P=0.01#x2610;#x0025; GP=0.008). Median times of neutrophil recovering over 1×109/L in three groups after 1 course therapy was 17,19 and 13 days and median times of platelet recovering over 50×109/L was 17,26 and 28days, respectively. These of MST group recovered more fastly than those of the other groups. The severe infection rate and early phase mortality rate in three groups had no differences. No donor chimerism, no graft-versus-host disease were observed in all of the patients in the MST group.

Conclusion:

Our clinical results suggested that decitabine with cytarabine and microtransplantation may improve clinical response CR rate early, especially on complete cytogenetic response and PFS, no increase infection rate and early phase mortality rate. The MST may provide an new method for MDS treatment. Further studies with much more patients and long-term follow-up should be conducted.

Disclosures:

No relevant conflicts of interest to declare.
CD30/CD123 Expression in Systemic Mastocytosis Does Not Correlate with Aggressive Disease
Authors: Moonim Mufaddel T , Kossier Thibaud , van Der Walt Jon , Wilkins Bridget , Harrison Claire N , Radia Deepti H
Published: October 2019

Abstract 1746

Introduction:

Systemic Mastocytosis (SM) is a myeloproliferative neoplasm (MPN) with heterogeneous clinical manifestations and limited treatment options for patients with aggressive disease. The WHO Classification sub divides SM patients into Indolent (ISM: evidence of clonal mast cells in bone marrow), Smouldering (SSM: Trypstase > 200ng/ml;organomegaly without dysfunction; bone marrow mast cell burden > 30% ), Aggressive (ASM: organomegaly with laboratory evidence of dysfunction), Mast Cell Leukaemia (MCL; > 20% mast cells on aspirate and >10% on blood film) and Associated Haematological Non-Mast Cell Disorders (AHNMD). The c-kit mutation (D816V) is present in > 90% of SM patients. Tryptase levels reflect total mast cell burden. To date there is no discriminatory marker to allow for identification of SM patients with more aggressive disease. CD30 (Ki-I antigen) has been reported as a potential marker for mast cells in high grade mastocytosis (Sotlar et al, 2011).We present preliminary data on 43 SM patients seen at Guys and St Thomas' Hospitals NHS Foundation Trust looking at CD30 and CD123 expression with clinical correlates.

Methodology:

43/58 SM patients who have a full set of clinical records and bone marrow trephine samples have been evaluated. Bone marrow trephine processing: fixation in a neutral buffered formalin < 24hours; EDTA decalcification for 48 hours;Immunochemistry on an automated immunostainer (Leica Bondmax)using standard protocols: CD 30 (Dako dilution 1:75, antigen retrieval ER2). CD123 (BD Sciences, Novacastra, dilution 1:400,antigen retrieval ER2). Bone Marrow trephine samples were reviewed by haematopathologists at diagnostic MDM. Disease bulk was estimated as a percentage of the trephine sample. Immunocytochemistry review of the CD30/CD123 was reviewed by a single haematopathologist for this study. Clinical information was reviewed for laboratory results, tryptase levels, clinical symptoms and SM diagnosis.

Results:

43 patients: M:F(18:25). SM diagnoses: 26 ISM (60%), 2 SSM (5%),3 ASM (7% ), 12 AHNMD (28%). Data on 43 patients for CD30 expression and 40 for CD123 expression.

Tryptase: 20 CD30(+) patients median 74.9ng/ml (range 16.6–285ng/ml): 23 CD 30(−) patients median 43.6ng/ml (range 15.1–386ng/ml).

Conclusions:

Our preliminary data on 43 patients with SM/ CD30/123 expression suggests:

Disclosures:

Harrison: Novartis: Honoraria, Research Funding, Speakers Bureau; YM Bioscience: Consultancy, Honoraria; Sanofi Aventis: Honoraria; Shire: Honoraria, Research Funding.
The PD-1/PD-L1 Axis Contributes to T Cell Dysfunction in Chronic Lymphocytic Leukemia
Authors: Brusa Davide , Serra Sara , Coscia Marta , Rossi Davide , Gaidano Gianluca , Inghirami Giorgio , Vaisitti Tiziana , Deaglio Silvia
Published: October 2019

Abstract 1778

Chronic lymphocytic leukemia (CLL) is characterized by a progressive accumulation of mature B lymphocytes and it is marked by profound defects in T cell function. The mechanisms responsible for T cell dysfunction remain unclear, even if several observations show that T cells from CLL patients express markers of chronic activation. One of this marker is Programmed death-1 (PD-1), a cell surface molecule that inhibits activation of immune cells and it is involved in tumor escape mechanisms through binding of the specific PD-L1 ligand. The aim of this work is to evaluate the expression and function of the PD-1/PD-L1 axis in the CLL context.

Using multiparameter flow cytometry, we showed that CD4+ and CD8+ T lymphocytes from CLL patients (n=117) express significantly higher levels of the PD-1 receptor, as compared to the same cell subpopulations purified from age- and sex-matched normal donors (n=33; 52% vs 34%, p <0.001). In keeping with the notion that PD-1 is a marker of cell exhaustion, CD4+ and CD8+ T lymphocytes from CLL patients displayed increased numbers of effector memory and terminally differentiated cells, respectively, with a concomitant decrease in naïve and central memory cells, when compared to controls. The number of effector memory and terminally differentiated cells positively associated with a more advanced stage of disease, treatment requirements and unfavorable genomic aberrations. Moreover, leukemic lymphocytes expressed higher levels of PD-L1 than circulating B lymphocytes from normal donors. PD-1 and PD-L1 expression significantly increased when T or B lymphocytes were treated with mitogenic signals, suggesting that this interaction might work efficiently in an activated environment. This hypothesis was tested by immunohistochemical analyses determining PD-1 and PD-L1 expression in the proliferation centers of lymph nodes sections from CLL patients. The results obtained indicate that PD-L1+ proliferating CLL cells are in close contact with CD4+/PD-1+ T lymphocytes. Lastly, functional experiments performed using anti-PD-1 antibodies or recombinant soluble PD-L1 clearly indicate that the PD-1/PD-L1 axis contributes to driving IL-4 secretion and to the inhibition of IFN-g production by CD8+ T cells.

In conclusion, these results show that CD4+ and CD8+ T lymphocytes from CLL patients express high levels of the surface marker PD-1 and exhibit an exhausted phenotype, while B leukemic cells express the PD-L1 ligand. Functional data suggest that PD-1/PD-L1 interactions are critical in skewing the T cell compartment towards a Th2 phenotype, by impairing IFN-g secretion by CD8+ cells. Taken together, these observations suggest that pharmacological manipulation of the PD-1/PD-L1 axis might be relevant in restoring T cell functions in the CLL microenvironment.

Disclosures:

Inghirami: OncoEthix SA: Research Funding.
The Broad Kinase Inhibitor Dasatinib in Combination with Fludarabine in Patients with Refractory Chronic Lymphocytic Leukemia: A Multicenter Phase 2 Study
Authors: Kater Arnon P. , Spiering Marjolijn , Liu Rob D , Beckers Marielle M , Tonino Sanne H. , Daenen Simon M. G. J. , Doorduijn Jeanette K , Lankheet Nienke A , Luijks Dieuwertje M , te Raa Doreen , Eldering Eric , Van Oers Marinus H.J.
Published: October 2019

Abstract 1798

Introduction

Development of chemoresistance in chronic lymphocytic leukemia (CLL) is at least partly mediated by protective stimuli within the lymph node (LN) microenvironment. Dasatinib has activity against multiple kinases which have been reported to be activated by the microenvironment, including SRC, c-Abl and BTK. We have recently shown that Dasatinib can effectively inhibit the anti-apoptotic program and as a consequence, restore fludarabine sensitivity in vitro.

Patients and methods

We conducted an open-label phase 2 trial of Dasatinib combined with fludarabine in twenty refractory CLL patients. Patients were treated with Dasatinib 100 mg once daily for 28 days. In patients who did not reach at least a PR, fludarabine was added (40 mg/m2 for 3 consecutive days q28) for at least 2 and a maximum of 6 cycles. Response assessments included CT-scans at baseline, following 4 weeks of Dasatinib monotherapy, after 2 cycles of combination therapy and at the end of protocol. In a subset of patients with high numbers of circulating lymphocytes at baseline, RNA expression profiles of apoptosis regulator genes as well as inflammation genes were analyzed prior and during treatment by MLPA analysis.

Results

Toxicities were comparable to those observed in fludarabine containing regimens and as expected in heavily pre-treated refractory patients.

Three patients (18%) reached a PR. Although most patients did not reach a formal nodal response, most patients showed reduction in lymph node (LN) size with a median of −20% as best response. Subsequent dasatinib fludarabine treatment following dasatinib monotherapy induced additional clinical effects but primarily in patients without del11q or del17p. Patients with a LN reduction of at least 20% had a significant improved PFS (256 days) and OS (510 days) as compared to non-responders (80 days and 158 days respectively). Also, in responding patients PFS was superior to PFS after last prior treatment.

NF-κB expression levels decreased while expression levels of the pro-apoptotic gene NOXA increased both after Dasatinib treatment and combination treatment.

Conclusion

In conclusion, Dasatinib fludarabine combination treatment has clinical efficacy in heavily pretreated refractory patients which correlated with decreased NF-κB and increased NOXA expression. As recently showed with other targeted agents, improvement of PFS and OS is also observed in patients with tumor responses less than 50%. These data do encourage further studies on a broad-spectrum kinase inhibitor like Dasatinib in combination with other classes of drugs in relapsed and refractory CLL.

Disclosures:

No relevant conflicts of interest to declare.
Exposure to Novel Agents Contribute to Extramedullary Spread of Multiple Myeloma Cells and Altered Expression of Adhesion Molecules: A Clinicopathologic Study of 91 Consecutive Autopsy Cases
Authors: Mine Sohtaro , Hagiwara Shotaro , Tagashira Amane , Igari Toru , Miwa Akiyoshi
Published: October 2019

Abstract 1832

Background

Recent development of novel agents such as bortezomib, lenalidomide, and thalidomide improved the remission rate and survival of multiple myeloma. However, the end stage of myeloma is still uncontrollable. The extramedullary disease (EMD) progression of myeloma was frequently observed in heavily treated patients, whereas few data exist about its incidence and predictive factors. It is well known that adhesion molecules play a role in disease progression and drug resistance. We investigated factors associated with the EMD progression based on the autopsy cases. In addition, the effect of the exposure to novel agents on the expression of adhesion molecules on myeloma cells was analyzed.

Methods

We reviewed autopsy reports and medical records of 91 multiple myeloma cases between 1979 and 2012 at the National Medical Center for Global Health and Medicine in Tokyo, Japan. The sites of myeloma cell invasion, infection, hemorrhage and renal complications were studied gross and microscopically. Patient profile, duration of illness, type of monoclonal gammopathy, clinical stage and history of treatment were studied. Durie & Salmon's criteria was used for diagnosis and staging. Factors associated with EMD were statistically analyzed using Student's t-test and the chi-square test. NCAM, VCAM, ICAM, and LFA-1 immunostaining in the bone marrow was performed.

Results

In 91 autopsy cases, 62.6% was male. Mean age and the duration of illness was 63.0 (38–85) years old and 40.6 months (1–156). Eighteen patients (19.8%), 23 (25.3%), and 15 (16.4%) were treated with novel agents, SCT and both respectively. EMD progression of myeloma cells was observed in 65 patients (71.4%). Frequent sites of EMD were spleen (48.9%), liver (37.8%), kidney (31.1%), lymph nodes (28.6%), lung (25.6%), pancreas (20.0%), and gastro-intestinal tract (18.9%).

The incidence of EMD was significantly higher in patients treated with novel agents than in patients without novel agents (94.4% vs. 65.8%, p=0.016). The risk factors of EMD were novel agents, longer duration of illness, and adverse cytogenetic abnormalities.

In the cases with novel agents, the expression of NCAM was significantly low (11.1% vs. 57.4%, p=0.049) compared to the cases without novel agents. However, the expression of VCAM was significantly higher in the cases with novel agents than the cases without novel agents (40.0% vs. 0%, p=0.01).

Conclusion

Multi-organ involvement of myeloma is not rare in autopsy cases of the disease. Exposure to novel agents may contribute to extramedullary spread of myeloma cells and altered expression of adhesion molecules. Further study on other adhesion molecules is needed.

Disclosures:

No relevant conflicts of interest to declare.
Membrane Lipid Biosynthesis As a Potential Therapeutic Target in Multiple Myeloma
Authors: Bardeleben Carolyne , Lichtenstein Alan
Published: October 2019

Abstract 1836

Phosphatidylcholine (PC) is the most prominent phospholipid in mammalian endoplasmic reticulum (ER) membranes. The rate-limiting step in PC synthesis through the Kennedy pathway is the conversion of phosphocholine + cytidine triphosphate (CTP) to cytidine diphosphocholine, (CDP)-choline, via the enzyme CTP:phosphocholine cytidylyltransferase (CCT) (see figure).

Multiple myeloma (MM) cells may be particularly dependent on this biosynthetic reaction because of their high consistent level of ER stress and requirement to continuously replenish ER membranes. Indeed, CCT-null mice have a defect in differentiation of B lymphocytes to plasma cells and deficiencies in Ig synthesis. To test whether this pathway remains critical in survival of malignant MM cells, we exposed MM cell lines to an inhibitor shown to inhibit CCT activity, HexPC. HexPC induced apoptosis in all MM cell lines in a concentration- and time-dependent manner. The addition of lysophosphatidylcholine (LPC), presumably converted to PC independently of the Kennedy pathway, completely rescued MM cell apoptosis. In contrast, similar concentrations of LPC in the same cell lines could not rescue apoptosis induced by bortezomib. An additional intervention to inhibit phosphatidylcholine synthesis, namely inducing pyrimidine starvation, also resulted in MM cell apoptosis and down-regulation of CDP-choline levels. Apoptosis of MM cells induced by HexPC was associated with induction of ER stress as shown by enhanced phosphorylation of IRE1 and eIF-2alpha. This ER stress was also prevented when LPC was added to HexPC although LPC could not prevent similar ER stress induced by bortezomib. These results underscore the importance of this phosphatidylcholine synthesis pathway in MM cells and provide new targets for future therapy.

Disclosures:

No relevant conflicts of interest to declare.
Mef2C Maintains B Cell Homeostasis Through the Regulation of DNA Repair Machinery
Authors: Wang Wenyuan , Montel-Hagen Amelie , Sasidharan Rajkumar , Mikkola Hanna K. A.
Published: October 2019

Abstract 278

B lymphocytes are central mediators of humoral immunity as they are able to bind specifically to an antigen through B cell receptor (BCR) and generate antibodies against the antigen. During aging, specific reduction of bone marrow pre-B cells and defects in BCR rearrangement result in declined B lymphopoiesis and contribute to immunosenescence.

One novel regulator of B cell homeostasis is Mef2C, a MADS-box transcription factor that activates target genes by binding to the MEF2 consensus binding site. Using VavCre+ Mef2Cfl/fl mice that ablate Mef2C in hematopoietic cells, we observed a specific reduction in the bone marrow pre-B cell already in young adults – a phenotype that resembles B cell aging. Loss of Mef2C resulted in higher percentage of late apoptotic and necrotic (AnnexinV+, 7AAD+) pre-B cells, suggesting a requirement for Mef2C in pre-B cell survival.

To investigate the mechanism that Mef2C uses to regulate B lymphoid homeostasis, we performed gene expression study. Gene Ontology analysis of Mef2C dependent genes in pre-B cells showed a significant down-regulation of DNA repair and cell cycle genes. Furthermore, by searching for the MEF2 consensus binding site, we identified critical regulators of cell cycle (Ccnb1&2,E2F2, E2F6) and DNA damage response (Ercc8, H2afx, Mre11a, Rad51ap1, Rad54l, Rpa1) as putative Mef2C direct targets in pre-B cells. To functionally assess the requirement for Mef2C in DNA damage response, we performed radio-sensitivity analysis. Upon 6Gy irradiation, Mef2C deficient mice showed a dramatic ablation of peripheral blood B cells as compared to controls while their T and myeloid cells remained largely unaffected. These data suggest that Mef2C regulates DNA repair machinery to protect B lymphocytes against irradiation induced stress.

Pre-B cell stage is a vulnerable step of B lymphopoiesis as successful BCR rearrangement is required for the pre-B cell receptor (pre-BCR) to support pre-B cell survival and expansion. DNA repair is a critical step during V(D)J recombination. Interestingly, in absence of Mef2C, V(D)J initiators (Rag1&2) and critical DNA repair effectors (Ku70, Xrcc4 & Lig4) failed to be upregulated during pro-B to pre-B transition as they did in controls. Furthermore, loss of Mef2C in both pro- and pre-B cells resulted in decreased expression of surrogate light chain genes (VpreB1&2) and recombined IgH μ chain.

These findings define Mef2C as a lineage specific DNA repair regulator that links the classical DNA repair machinery to B cell factors and guards B lymphoid homeostasis at an inherently precarious developmental stage.

Disclosures:

No relevant conflicts of interest to declare.
Splenectomy for Massive Splenomegaly Associated with Myelofibrosis: Outcomes From 63 Patients At Mayo Clinic.
Authors: Singh Preet Paul , Timucin Taner , Nagorney David M , Tefferi Ayalew
Published: October 2019

Abstract 2848

Background:

Massive splenomegaly (MS) (>1500 grams) is a rare and overtly symptomatic manifestation of myelofibrosis. While splenectomy may provide palliation, the procedure may be technically difficult and lead to high operative risks. We retrospectively analyzed myelofibrosis patients who underwent splenectomy for MS to analyze complications and outcomes.

Methods:

Retrospective chart review of all patients with myelofibrosis at our institution who underwent splenectomy for MS between 1998 and 2006 was performed. MS was defined as post-operative spleen weight measured to be more than 1500 grams. A total of 63 patients with MS had splenectomy for palliation of pressure symptoms or transfusion requiring cytopenias during that time period. Kaplan Meier statistics and log rank test were used for survival analysis.

Results:

Mean age of the study patients was 64.9 ± 9.5 years and 56% of those were males. Commonest pre-splenectomy symptoms were left upper quadrant abdominal discomfort (85.7%), fatigue (81%), early satiety (76.2%), anorexia (54%) and weight loss (39.7%). Packed red blood cell and platelet transfusions were required pre-operatively in 36/63 (57.1%) and 10/63 (15.9%) of patients, respectively. Median spleen weight was 2805 (range 1540 – 13085) grams. Perioperative complications occurred in 15 patients (23.8%) including infection (= 4 patients [6.3 %]), thrombosis (= 6 patients [9.5%]), or bleeding (= 9 patients [14.3%]), 2 of which (3.2% of all patients) were fatal.

Median post-splenectomy survival (PSS) of these patients was 16.4 (0–110) months and 5 year PSS was 20%. Excluding patients lost to follow up, 43/55 (78.2%), 33/55 (60%) and 26/54 (48.1%) patients were alive at 6 months, 1 year and 2 years after splenectomy, respectively. At 1 year, out of 33 alive patients, 24 (72.7%) patients had relief of pressure symptoms. Out of 36 patients who were red cell transfusion dependent pre-splenectomy, 13 were alive and 6/13 (46.2%) patients were transfusion independent at 1 year. Similarly, out for 10 patients requiring platelet transfusions pre-operatively, 5 were alive and 3/5 (60%) were transfusion independent after 1 year follow up.

PSS after splenectomy for MS was decreased in patients that required pre-operative packed red cell transfusions (median 9.3 months vs. 32.1 months, p= 0.033) (Fig 1), but not affected by other factors including age (>64 years), pre-operative thrombocytopenia (<100 × 109/uL), prolonged operative time (>90 minutes) or larger spleen size (>2800 grams).

Conclusions:

Splenectomy is relatively safe and effective palliative treatment for pressure related symptoms and refractory cytopenias related to MS in patients with myelofibrosis. Pre-operative anemia requiring red cell transfusions may predict advanced disease and is associated with inferior PSS.

Disclosures:

No relevant conflicts of interest to declare.
Trial Sequential Analysis in Meta-Analyses of Maintenance Therapies for Multiple Myeloma.
Authors: Miladinovic Branko , Kumar Ambuj , Mhaskar Rahul , Mahoney Helen , Wheatley Keith , Djulbegovic Benjamin
Published: October 2019

Abstract 2975

Background:

Meta-analyses (MAs) with few participants (i.e. small number of primary studies) are at risk of producing random errors and consequently overestimating treatment effects. With insufficient information the risk of obtaining a false positive result (type I error) increases, which may lead to false conclusions. Trial sequential analysis (TSA) has been proposed as a method to ascertain whether results of MAs are conclusive (true vs. false positive, true vs. false negative). It adjusts for the risk of random error by constructing monitoring boundaries under the sample size necessary to conclude significant treatment effect. In TSA, the information size is calculated based on a pre-specified event rate in the control group, a minimum intervention effect (risk ratio reduction), and a desired maximum risk of type I error α and type II error β. Here we apply TSA on MAs of randomized controlled trials of maintenance therapies in the management of multiple myeloma.

Methods:

A comprehensive literature search of MEDLINE (PubMed), the Cochrane Central Register of Controlled Trials (CENTRAL), and meetings abstracts from American Society of Hematology, American Society of Clinical Oncology, European Society for Medical Oncology and European Hematology Association was undertaken to identify all phase III randomized controlled trials (RCTs) of maintenance therapy published until July 2012. We extracted data on overall survival and progression-free survival comparing treatments that could be pooled in random effects meta-analysis. We performed TSA for the apriori diversity-adjusted information size (APDIS) under risk ratio reduction of 20% and 25%. The information size was adjusted for between-study trial diversity, which is defined as the total relative variance expansion changing from a fixed effect into a random effects meta-analysis. We used two-sided α = 5% and 1 – β = 80% power. All analyses were done in Stata 11.2 using metacumbounds command.

Results:

Nine separate meta-analyses (18 randomized controlled trials) met the inclusion criteria (Table 1). The median number of patients was 1193 (range 351–2824) and median diversity 0% (range 0%-91%). Under both risk ratio reductions of 20% and 25%, 4/9 MAs were false negative and 1/9 false positive. The observed power based on the accrued sample size and observed risk ratio reduction was greater than 80% in 5/9 MAs.

Conclusion:

TSA detected one false positive MA of two trials comparing thalidomide with prednisone/dexamethosone for the outcome of overall survival. Future MAs need to consistently undertake TSA to avoid misleading conclusions.

Disclosures:

No relevant conflicts of interest to declare.
Plasmablastic Lymphoma Is Curable The HAART Era. A 10 Year Retrospective By The AIDS Malignancy Consortium (AMC)
Authors: Noy Ariela , Chadburn Amy , Lensing Shelly Y. , Moore Page
Published: October 2019

Background

The highly aggressive plasmablastic lymphoma (PBL), originally described almost exclusively in HIV+ patients, was nearly uniformly fatal in the pre-HAART era. We hypothesized that aggressive chemotherapy and HAART could result in cures.

Methods

We retrospectively analyzed baseline characteristics, treatment patterns and outcomes of patients (pts) with PBL treated at multiple centers within the AIDS Malignancy Consortium (AMC). HIV positivity was not required. 19 confirmed PBLs from 9 national AMC sites diagnosed between 1999 and 2008 were evaluated.

Results

17/19 patients (pts) with confirmed PBL were HIV+. Data was captured at initial diagnosis on 12 pts (all HIV+) and 7 with relapsed/refractory disease (5 HIV+). HAART status at PBL initial diagnosis was 33% on, 58% off, and unknown 8%. Median CD4 count 110 (range 4-658). First line chemotherapy was given to 10/12 (83%) newly diagnosed patients with stage I/II (6) vs III/IV(6) disease. This was CHOP(4), CDE (1), EPOCH (2) and EPOCH with high dose methotrexate and zidovudine (2). Second line therapy was given to 5/7 relapsed/refractory patients with stage I (1) vs Stage III/IV (5) disease and a median CD4 83 (range 10-202): EPOCH alternate HD Mtx+AZT (n=1); Hyper-CVAD (n=2); High dose Mtx + AZT (n=1); VACOP-B(n=1). One pt underwent BEAM based autologous stem cell transplant. For both groups combined, 6 patients experienced grade 3/4 toxicity. Febrile neutropenia was the most common grade 3/4 toxicity (4 patients) followed by thrombocytopenia (3 patients). One patient with refractory disease experienced grade 5 toxicity. For the 12 newly diagnosed patients, 8 patients were alive at last follow-up and 4 had died. Median follow-up for survivors was 73 (range, 40-165) weeks. One-year survival was 66.7% (SE, 13.6). See Figure 1. For the 7 relapsed/refractory patients, 2 patients were alive at 24 and 54 weeks, and 1 was lost to follow-up. One-year survival was 53.6% (SE, 20.1%).

Conclusions

In the HAART era, aggressive treatment of PBL can result in significant survival times.

However, determination of the superior treatment regimen could not be determined from this small patient sample. CTSU 9177 is prospectively studying PBL with EPOCH.

Disclosures:

No relevant conflicts of interest to declare.
The Platelet-Derived Microparticles Related to the Clinical Phenotype Heterogeneity of Hemophlia a
Authors: Qin Fangmei , Huang Shunhua , Li Zhitao , Ye Jieyu , Sun Jing
Published: October 2019

Keywords: Hemophlia A, Phenotype; Heterogeneity; Flowcytometry ; Mircoparticle

Background: The clinical phenotype for hemophlia A are typically recognized sub-clinical, mild, moderate and severe according to the residue FVIII level of the plasma. For recent years, there are evidences indicate that the residue FVIII level is not the only factor relate to the clinical phenotype of patients with severe hemophlia A. Platelets are an important role in hemostasis and platelet-derived microparticles (PMPs) are known to mediate a prothrombotic state in patients, we hypothesized that PMPs contributes to the clinical phenotype heterogeneity of hemophilia A patients.

Methods: Thirty-one patients with severe hemophlia A (FVIII:C<1%, age 18-33 yrs, median 23.5 yrs) treated on demand were enrolled in this study, including 10 patients with mild type(FVIII:C<1%, but annualized bleed rates<6) and 21 patients with severe type (FVIII:C<1% and annualized bleed rates≥24). Seventeen healthy male donors were selected as normal controls. We also compared the baseline PMPs counts from eleven patients on demand treatment to that when they had three months prophylactic treatment. Venous blood was anticoagulated with sodium citrate (1:9). Plasma was isolated (1550g for 20 min at RT) and then cell free supernatant was ultracentrifuged (18,000g for 20 min at 20°C). The supernatant plasma samples were measured for baseline PMPs counts, with phycoerythrin (PE)-conjugated monoclonal antibodies CD41, CD42b, CD61, CD62P, and CD63 specific for PMPs derived from platelets respectively. Analyzed by flow cytometry, Forward scatter was set in scale using fluorescent microspheres of 1.0μm and standard fluorescent microbeads (0-1.0μm) in diameter were used to set the microparticle gate. Statistics were performed using independent-samples T test

Results: There was a trend toward higher the mean level of PMPs counts in mild type patients compared to severe type (mean ± SD: 2.06±1.33 vs 0.95±0.64, p = 0.02), the PMPs counts of normal individuals was significantly higher than severe type(mean ± SD: 1.06±1.20 v s0.95±0.64, p = 0.02), significantly lower than mild type (mean ± SD: 1.06±1.20 vs 2.06±1.33, p = 0.02). The PMPs counts decreased after 3 months low dose (10 iu/kg, 2-3/w) prophylacticlly treatment (mean ± SD: 6.50±0.51 vs 0.45±0.50, p = 0.00).

Conclusion/Discussion: Platelet-derived Microparticles (PMPs) are generated in response to platelet activation, our observations demonstrate that the PMPs counts differs in patients of severe hemophlia A, the mean lever of PMPs in mild clinical phenotype patients was higher than the severe type, prophylacticlly treated patients has a lower PMPs lever, PMPs is likely to play a role in clincal phenotype heterogeneity of sever hemophilia A.

Disclosures

No relevant conflicts of interest to declare.
Value and Implications of the Anti-Xa Activity Monitoring for Prophylactic Dosing Adjustment of LMWH in Pregnancy: A Retrospective Study
Authors: Paulus Samuel , Lambert Catherine M , Boban Ana , Hermans Cedric R.
Published: October 2019

Introduction: Low molecular weight heparins (LMWH) have stable pharmacokinetics. However, physiologic changes during pregnancy can alter pharmacokinetics of LMWH and make the biodisponibility of the drug less predictable. When starting prophylactic treatment with LMWH in pregnant woman, most physicians calculate the initial LMWH dose based on the body weight and adapt the dose according to the weight gain. An alternative method is to monitor the anti-Xa activity and adjust the LMWH dose accordingly. LMWH are for the moment the only anticoagulant available for prophylaxis of venous thrombo-embolism in pregnant women and prevention of severe pregnancy complications. Therefore, we conducted a study addressing the rationality of performing an anti-Xa activity monitoring regularly during pregnancy.

Methods: We retrospectively analyzed data from pregnant women undergoing prophylaxis with LMWH followed at the Hemostasis and Thrombosis Unit of the Saint-Luc University Hospital Unit. All the patients that had anti-Xa activity done at least three times during pregnancy were included in the study. The measurements of anti-Xa were done regularly every 6 weeks and the dose of LMWH was increased in case of anti-Xa activity lower than 0.3 U/ml. Initial LMWH dose was calculated based on the patient body weight and the first measurement of anti-Xa done 10 days afterwards.

Results: Out of 173 women evaluated in the study, 79% needed LMWH dose adjustment. 97 patients (56%) had one dose adjustment, 35 patients (20%) two and 5 patients (3%) three. The first augmentation of LMWH dose was needed before the patient gained body weight in 36,5% of cases. The average increase of the LMWH dose was 49%, 100% and 116% for the one, two and three dose adjustments, respectively. Under-dosing of LMWH, defined as anti-Xa activity <0,2 U/mL, was present in 12% of patients on the first monitoring versus 3,5% on the last monitoring visit. No severe side effects occurred during the treatment. Five patients (3%) had unfavorable outcome of the pregnancy.

Conclusions: This study demonstrates that regular monitoring of anti-Xa activity can help in maintaining the prophylactic levels of LMWH throughout the pregnancy. We also showed that the reduction of the anti-Xa activity is not always directly correlated with the weight gain in pregnant women. Therefore we recommend that LMWH dose adjustment should not be made based solely on the weight gain of the patient during pregnancy.

Disclosures

No relevant conflicts of interest to declare.
The Prognostic Significance of the Absolute Lymphocyte to Monocyte Count Ratio (ALC/AMC-dx) at Diagnosis in Hodgkin´s Lymphoma
Authors: Acosta-Maldonado Brenda Lizeth , Ramirez-Ibarguen Ana , Grimaldo-Gomez Flavio A , Oñate-Ocaña Luis , Rivas-Vera Silvia
Published: October 2019

Background. In Classic Hodgkin's lymphoma (cHL), malignant cells constitute only about 1% of the bulk of tumor tissue, the rest constitutes the microenvironment and is made up of a compound of inflammatory cells. Lymphocytopenia and increased CD68+ tumor-associated macrophages (TAMs) are adverse prognostic factors in cHL. TAMs are derived from circulating monocytes and are possibly related to absolute monocyte count (AMC). We have sought to investigate the relationship of circulating lymphocytes and monocytes with response and survival in patients. Recently, Porrata et al. reported that a low absolute lymphocyte count/absolute monocyte count at diagnosis [ALC/AMC-Dx] (<1.1) is an independent prognostic factor in cHL. Subsequent studies used different cutoffs for ALC/AMC (1.5 and 2.9). Currently, there are no studies that evaluate the usefulness of the index relative to the overall response.

Aim To determine the prognostic value of ALC /AMC at diagnosis in patients with cHL and its impact on treatment response to therapy, progression and overall survival.

Methods: We evaluated 262 consecutive individuals with cHL, referred and treated at the National Cancer Institute in Mexico between 2006 to 2013. The great majority of patients were treated with ABVD with or without radiotherapy, and all had available data for ALC/AMC determined at diagnosis. It was made a multivariate analysis and ROC curves for cutoff point of ALC/AMC.

Results: Median age was 35 y (14-89), 59.2% of patients were male, 77% had B-symptoms, 36.3% had stage IV disease, 85% had advanced stage (IB,IIB,III,IV), 51.5% had IPS ≥3, 46.2% nodular sclerosing histology and 45.4% mixed cellularity. The overall response (CR + PR) was obtained in 188 patients (72%) and failure (stable disease or progressive disease) in 73 patients (28%). A new cutoff point, 1.77 in ALC/AMC-Dx ratio with area under the curve of 0.62. Multivariate analysis showed that the ALC/AMC-Dx index was an independent predictor for response to treatment, progression as well as overall survival (Table 1). Additionally the IPS≥3 showed to be an independent factor for response 68.8% vs 41.7% in low and high risk, respectively (p<0.0000).

Conclusion: In our population ALC/AMC-Dx index was established with a cutoff of 1.77. The group of patient with < 1.77 had a less overall response and overall survival. It proves that ALM/AMC-Dx is an independent predictor of response, progression and overall survival in patients with classical cHL. That differs of other reviews where the cutoff was lower.

Table 1. Multivariate analysis according to ALC/AMC-DX ratio ALC/AMC -Dx index p Low< 1.77 High >1.77 Overall Response 58.1% 79.8% OR 0.25-.0.84p 0.011 Overall Survival8 years 81% 94% p 0.004

Disclosures

No relevant conflicts of interest to declare.
Circulating Plasma Cells in Newly Diagnosed Symptomatic Multiple Myeloma As a Prognostic Marker for Patients with Standard-Risk Cytogenetics
Authors: Vagnoni Davide , Travaglini Fosco , Angelini Stefano , Dalsass Alessia , Mestichelli Francesca , Angelini Mario , Pezzoni Valerio , Natale Annalisa , Ruggieri Miriana , Bigazzi Catia , Troiani Emanuela , Falcioni Sadia , Mazzotta Serena , Galieni Piero
Published: October 2019

Multiple Myeloma (MM) is a clonal B-cell disorder characterized by accumulation of malignant plasma cells (PCs) in the bone marrow (BM). Circulating PCs can be detected in the peripheral blood of a significant proportion of patients with MM and their presence is a well-known prognostic factor. Indeed, the appearance of circulating PCs in the blood could indicate relative indipendence from adhesion to the microenvironment, thus implying more aggressive disease. In this study, we examined the relationship between the number of PCs and citogenetic risk in patients with newly diagnosed MM.

We analyzed peripheral blood from patients with Monoclonal Gammopathy of Undetermined Significance (MGUS; n=15), Smoldering Myeloma (SM; n=28), Solitary Plasmacytomas (SP; n=3) and active Multiple Myeloma (MM; n=105). These patients were followed by the U.O.C. Ematologia at the "Mazzoni" Hospital from January 2006 to December 2013, with a median follow-up of 25 months. We analyzed clinical, laboratory and cytogenetic data of patients with active MM. However, cytogenetic analysis was not evaluable for 15 patients. The number of circulating PCs was detected by flow cytometry using a simple two-colours approach. Cells were stained with fluorescence-labeled CD38 and CD45 antibodies and 50,000 events were acquired and analyzed for each patient. PCs were identified by gating on CD38bright+/CD45- cells.

Using a receiver operating characteristics (ROC) analysis, we assessed that ³41circulating PCs is the optimal cut-off for defining poor prognosis.

The 8-years probability of Overall Survival (OS) and Progression-Free Survival (PFS) in patients with <41 and ³41circulating PCs, was 32% vs 8% (p=0.017) and 29% vs 0% (p=0.0008), respectively. Patients with high-risk cytogenetics (n=24) had poor prognosis, independently of circulating PCs (PC<41 vs PC³41: OS=0% vs OS=16%, p=n.s.; PFS=0% vs 17%, p=n.s.). Patients with standard-risk cytogenetics (n=66) showed a better prognosis associated to a lower number of circulating PCs (PC<41 vs PC³41: OS=36% vs 10%, p=0.026; PFS=37% vs 0%, p=0.0001). These data were confirmed by multivariate analysis (Cox model) for the subgroup with standard-risk cytogenetics, in which the presence of ³41 circulating PCs, older age, DS stage >I and lack of maintenance therapy, adversely affected OS and PFS.

All patients with SP showed no circulating PCs. In all cases of MGUS or SM, circulating PCs, when detected, were <20.

In summary, our results suggest that the quantification of circulating PCs by flow cytometry could provide useful prognostic information in newly diagnosed MM patients with standard-risk cytogenetics.

Figure 1 Figure 1.

Figure 2 Figure 2.

Disclosures

No relevant conflicts of interest to declare.