bluuebunny/crossref_metadata_2025 huggingface dataset:
F8 and HLA-II Haplotypes in the Hispanic Population: Implications for Inhibitor Risk Development in Hispanic Hemophilia A Patients
Authors: Kim Benjamin , Sauna Zuben E. , Carless Melanie A. , Curran Joanne E. , Viel Kevin R. , Cole Shelley S. , Raja Rajalingam , Blangero John , Howard Tom E.
Published: October 2019

Abstract 3365

Background:

A recent study suggested an increased rate of inhibitor development among Hispanic compared to White hemophilia A (HA) patients; however, a possible mechanism was not proposed or explored. In light of findings implicating a role for race-specific distributions of factor VIII (F8) and class-II human-leukocyte antigen (HLA-II) haplotypes on the disparate risk of inhibitor development in the Black HA population, we sought to determine the distributions of F8 and HLA-II haplotypes among Hispanic Americans and compare them to that of Black and White Americans.

Methods:

Using archived genomic DNA samples from the 194 unrelated founders of the San Antonio Family Heart Study (SAFHS), a collection of 1431 people from 41 large Mexican American families, we re-sequenced all exons of F8 to genotype the known nonsynonymous-single nucleotide polymorphisms (ns-SNPs) and identify any novel ns-SNPs. We then performed high-resolution HLA-II genotyping to identify each founders' pair of HLA-DRB1 alleles to compare them against those found in other ethnic groups.

Results:

Among the 291 potentially distinct Mexican American X-chromosomes evaluated, we identified the H2 F8 haplotype, defined by D1241E, in 25.0% of the subjects, which is in between that observed in the White (7.4%) and Black (37.4%) populations. We also found H3 F8, defined by D1241E and M2238V, in two subjects, who represent the first non-Black individuals reported to carry this haplotype. Furthermore, we discovered a previously unreported ns-SNP (H1919N), whose minor allele was found in only one male and defines a ninth wild-type F8 haplotype (H9). Regarding HLA-II alleles, the distribution among Mexican Americans in the present study was quite different from those found in Black and White individuals in the National Marrow Donor Program registry (see Figure). Three of the 4 most common HLA-II alleles in the Mexican Americans (DRB1*0802, DRB1*0407 and DRB1*1406) were seen in < 1% of both Blacks and Whites.

Discussion:

This is the first study to report the haplotypic prevalence of F8 and HLA-II alleles in Mexican Americans, the largest Hispanic ethnic group in the United States. By informing specific wild-type factor VIII (FVIII) peptides for use in HLA-II binding and T-cell stimulation assays, these results may help to identify high risk combinations of FVIII therapeutics and individual HLA-II repertoires that contribute to the higher rate of inhibitor development observed in Mexican versus Caucasian American HA patients.

Disclosures:

Viel: Histonis, Incorporated: Employment. Howard:Haplomics, Inc.: Equity Ownership.
Unique Effects of p53−/− Leukemic Cells On Mesenchymal Stromal Cell Gene Expression Profile in Vitro
Authors: Ling Xiaoyang , Chen Ye , Ruvolo Peter P. , Ruvolo Vivian , Wang Zhiqiang , Zhang Min , Shi Yuexi , Konopleva Marina , Davis Richard E , Andreeff Michael
Published: October 2019

Abstract 3468

Mesenchymal stromal cells (MSC) participate in the generation of the microenvironmental bone marrow niche which protects normal and leukemic stem cells from injuries, including chemotherapy. MSC produce numerous factors that aid in this function; however, little is known about how leukemic cells affect MSC. In this study, paired murine AML cells, MLL/ENL/FIT3-ITD/p53−/− and MLL/ENL/FIT3-ITD/p53wt, originally derived from C57BL/6 mice (Zuber et al. Genes & Dev. 2009), were co-cultured with MSC from the same strain. After 48 hrs, MSC were isolated by FACS sorting using CD45−/PDGFr+ as markers. Total RNA was profiled on Illumina WG6 mouse whole-genome bead arrays by standard procedures. The significance analysis of microarrays (SAM) method identified 429 differentially-expressed genes (DEG) whose expression in MSC differed significantly (false discovery rate, 10%) in co-cultures with p53−/− (C78) vs. p53wt (C147) leukemic cells. Differences in these DEG were highly consistent in replicates (Figure 1). The results demonstrate that: 1) p53 status (p53−/− vs. p53wt) of AML cells affects GEP patterns in co-cultured MSC. Comparison of the GEP in MSC co-cultured with p53−/− (78) or p53wt (147) (Fig 1) identified the following 5 genes that showed the most significant differences (up- or down-regulated): up-regulated: WNT16, WNT5, IGFBp5, GCNT1, ATP1B1; down-regulated: NOS2, DCN, CCL7, CCL2, CAR9, CCL4. These were selected for qPCR validation, and the results confirmed the array data. In addition, immunohistochemical staining showed that WNT16 was up-regulated in MSC co-cultured with p53wt leukemic cells. In addition, CXCL5 was found up-regulated in MSC co-cultured with p53−/− leukemic cells. These results were consistent with the GEP data. 2) Leukemic cells alter MSC Signaling proteins in vitro: Western blotting showed that Stat3, Akt, PTEN, CXCL5 and HIF-1α were up- regulated in MSC co-cultured with p53−/− leukemic cells as compared to p53wt leukemic cells (48 hrs). Additional analyses showed that the downstream targets of HIF-1α, VEGFa and VEGFc, but not VEGFb, were up-regulated. Taken together, these results suggest that 1) leukemic cells with different p53 genetic background co-cultured with normal MSC have profoundly differential effects on GEP of normal MSC; 2) MSC co-cultured with p53−/− leukemic cells resulted in increased levels of onco-proteins such as Akt and HIF-1α when compared to MSC co-cultured with p53wt leukemic cells. Results suggest, for the first time, that the genetics of leukemic cells determines gene expression in co-cultured MSC. In vivo experiments are in progress to provide in vivo evidence for the existence of a novel model of leukemia-stroma interactions where the genetics of the tumor cell impacts stromal cell biology.

Disclosures:

No relevant conflicts of interest to declare.
Expression of Human Leukocyte Antigen B61 Is Associated with Idiopathic Aplastic Anemia, Hepatitis-Associated Aplastic Anemia and Fulminant Hepatic Failure in Children
Authors: Takahashi Yoshiyuki , Ohara Akira , Kobayashi Ryoji , Yabe Hiromasa , Kikuchi Akira , Yagasaki Hiroshi , Morimoto Akira , Watanabe Ken-ichiro , Ito Etsuro , Kudo Kazuko , Fukuda Akinari , Sakamoto Seisuke , Kasahara Mureo , Nakazawa Atsuko , Kojima Seiji
Published: October 2019

Abstract 3487

Introduction:

Increasing evidence supports the notion that aplastic anemia (AA) defined as peripheral blood pancytopenia and bone marrow hypoplasia is an autoimmune disease mediated by T-cells attacking hematopoietic progenitor cells. Around 10% of acquired AA is associated with acute hepatitis, yet a causative virus has not been identified in most patients. Like other autoimmune disorders, adult AA is associated with human leukocyte antigen (HLA)-DR15. However, HLA-DR15 is not significantly associated in children with AA (Fuhrer et al. Pediatric Blood Cancer 2007 and Yoshida et al. Br J Haematol 2008). Human leukocyte antigen associations might differ between children and adults with AA. We therefore investigated the HLA types among patients with idiopathic aplastic anemia, hepatitis-associated aplastic anemia and fulminant hepatic failure who underwent liver transplantation.

Patients and methods:

We investigated data from 321 children (male, n = 202; female, n = 119; median age, 10 [range 0 – 18] years) with severe and very severe AA. All patients were enrolled in the AA-92 or AA-97 study from 1992 to 2010 and received immunosuppressive therapy (IST) using antithymocyte globulin and cyclosporine. Two hundred and sixty nine children had idiopathic AA and 52 had AA associated with hepatitis. The HLA alleles of 25 children with fulminant hepatic failure who underwent liver transplantation between 2006 and 2011 were characterized. Differences in all HLA alleles between the patients and healthy controls in the Japanese population were statistically analyzed at the phenotype level by χ2 and t tests using PRISM software.

Results:

The prevalence of HLA-B61 was significantly higher in idiopathic AA (21.9%, P < 0.0001), hepatitis associated AA (19.2%, P = 0.0089) and fulminant hepatic failure (20%, P = 0.0008) than in healthy Japanese controls (10.7%). No other HLA class I and II alleles including HLA-DR15 significantly differed between children with AA and healthy controls. Furthermore, HLA distribution did not significantly differ between patients who responded completely or partially to immunosuppressive therapy (IST) and non-responders.

Conclusions:

We did not uncover a significant association between AA and HLA-DR15 in children. Associations between HLA and disease might differ between children and adults with AA. HLA-B61 was positively associated with idiopathic aplastic anemia, hepatitis-associated aplastic anemia and fulminant hepatic failure in pediatric patients. These findings suggest that a common autoimmune mechanism is responsible for both hepatic- and bone marrow-related pathologies in children.

Disclosures:

No relevant conflicts of interest to declare.
Notch/HES1 Implicated As a Tumor Suppressor Mechanism in Human AML in Vivo
Authors: Golfman Leonard S , Kannan Sankaranarayanan , Hall Mandy A , Zweidler-McKay Patrick A
Published: October 2019

Abstract 3524

Background:

Although Notch signaling contributes to T cell leukemogenesis, the role of Notch in human AML is unclear. We and others have found that activation of Notch signaling inhibits AML growth and survival, e.g. a tumor suppressor like effect. However it is not known what the consequences of activating or inhibiting Notch signaling are in human AML in vivo.

Approach:

To determine whether Notch signaling would have growth inhibiting effects in vivo, we stably-transduced ML1 human AML cells with the constitutively-active forms of Notch1 and Notch2 (ICN1, ICN2), the common Notch target gene Hairy/Enhancer of Split 1 (HES1) or the pan-Notch inhibitor dominant-negative Mastermind-like (dnMAML) and performed in vivo competitive proliferation assays. Briefly, following transduction, each vector type were sorted to 50% GFP+ (containing the gene of interest) and GFP- (untransduced control cells). Groups of NSG mice were injected with these 50:50 mixtures of ML1 cells, and peripheral blood levels of GFP- and GFP+ cells were measured with flow cytometry for anti-human CD45 and GFP.

Results:

Peripheral blood engraftment of human CD45+ ML1 cells by week 5 was similar (2–5%) for ICN1, ICN2 and HES1 injected mice, but was significantly higher (23%) in dnMAML injected mice (Panel A). Similar to in vitro competitive proliferation assays, ICN1, ICN2 and HES1 all led to decreased relative numbers of GFP%+ cells, with 1%, 4% and 16% respectively (Panel B). Importantly, dnMAML had little effect on AML proliferation in vitro, however led to dramatic increases in GFP% as well as early morbidity and mortality due to increased leukemia burden, with 93% GFP+ (Panel B), demonstrating a selective advantage for dnMAML-expressing ML1 in vivo. When GFP+ (transduced) ML1 peripheral engraftment was directly compared to GFP- (parental CD45+) engraftment, the GFP- control cells had similar engraftment rates (2–5%) across groups of mice, while the GFP+ engraftment rates were significantly lower in ICN1, ICN2, and HES1 groups, but significantly higher in the dnMAML group (Panel C), demonstrating enhanced engraftment/proliferation in dnMAML-expressing cells.

Conclusions:

This suggests a previously unreported concept, namely that endogenous Notch ligands can inhibit human AML growth in vivo. This data supports the hypothesis that Notch behaves as a tumor suppressor in AML, and suggests the potential use of Notch agonists in human AML.

Disclosures:

No relevant conflicts of interest to declare.
Intensified Chemotherapy Regimen for Very High Risk Childhood B-Precursor Acute Lymphoblastic Leukemia (B-ALL): Results From Dana-Farber Cancer Institute (DFCI) ALL Consortium Protocol 05–01
Authors: Vrooman Lynda M. , Stevenson Kristen E. , Harris Marian , Neuberg Donna S. , Sallan Stephen E. , Silverman Lewis B.
Published: October 2019

Abstract 3563

Background:

High levels of minimal residual disease (MRD) at the end of 4-weeks of multiagent induction chemotherapy have been shown to be associated with a high risk of subsequent relapse in pediatric patients (pts) with B-ALL. Published reports indicated that pediatric B-ALL pts with high end-induction MRD had event-free survival (EFS) rates < 50% when treated with standard chemotherapy.[Zhou, Blood 2007; Borowitz Blood 2008] Pts with high-risk (HR) cytogenetic abnormalities, such as low hypodiploidy and MLL gene rearrangements (MLL-R) also have a high relapse risk. On DFCI ALL Consortium Protocol 05–01, we piloted an intensified regimen for B-ALL pts with high end-induction MRD and/or HR cytogenetics.

Methods:

Between 2005–2010, 482 evaluable pts aged 1–18 years with B-ALL were enrolled. Pts were initially classified as standard-risk (SR) or high-risk (HR) based on NCI age/WBC criteria. MRD was prospectively evaluated at the end of the 4-week induction phase via RQ-PCR analysis of IgH or TCR rearrangements. Results were reported as the ratio of copy numbers of target gene:GAPDH; a ratio >0.001 was considered high MRD. Pts with high MRD or HR cytogenetics (hypodiploidy with <45 chromosomes or MLL-R) were reclassified at the end of induction phase as very high risk (VHR), and received 2 additional chemotherapy cycles beginning at week 7 (cycle 1: cyclophosphamide, low-dose cytarabine, 6-MP; cycle 2: high-dose cytarabine, etoposide, dexamethasone, L-asparaginase), followed by the DFCI ALL Consortium HR consolidation phase, including 30 weeks of L-asparaginase and doxorubicin to a cumulative dose of 300 mg/m2. After consolidation, pts received a standard maintenance phase. Total duration of treatment was 25 months.

Results:

51 pts (11%) were classified as VHR, 25 of whom had been initially classified as SR and 26 as HR. 35 VHR pts had high end-induction MRD as the sole VHR criterion; 16 had HR cytogenetics. 9 pts relapsed (all marrow-involved) and 1 pt developed a secondary AML. There were no deaths in first remission. With median follow-up of 4.4 yrs, the 5-yr EFS (95% confidence interval) for all 51 VHR pts was 76% (60,87)[Figure 1] and 5-yr overall survival was 81% (60,92). The 5-yr EFS was 81% (59,90) for the 35 pts with high MRD.

Conclusion:

Intensification of chemotherapy (without stem cell transplant) resulted in a relatively favorable EFS in VHR B-ALL pts (defined by the presence of either high end-induction MRD or HR cytogenetics). More pts and longer follow-up will be necessary to confirm these promising results.

Disclosures:

No relevant conflicts of interest to declare.
Utility of Peripheral Blood BCR-ABL Mutation Analyses in Patients with Unexplained Neutrophilic Leukocytoses. Incidence of a Positive Test and Its Clinical Correlates
Authors: Dao Bao , Dowell Jonathan E , Illum Henrik , Shah Sachin , Sharma Anant
Published: October 2019

Abstract 4444

Background:

In patients with chronic unexplained neutrophilic leukocytoses (UNL), underlying Chronic Myeloid Leukemia (CML) is a concern. In these patients, peripheral blood BCR-ABL mutation analyses using fluorescent in situ hybridization (FISH) is often performed to investigate for CML. Diagnostic yield of this test, in patients presenting UNL and especially in those with mild leukocytoses is uncertain.

Objective:

To establish the overall incidence BCR-ABL mutation in patients with UNL using peripheral blood FISH analyses. To determine the incidence within subgroups based on severity of leukocytoses. To explore the association between a positive test and the presenting clinical and laboratory features.

Patients and Methods:

We performed a retrospective chart review (2000–2010) of adult patients referred to the hematology service at the Dallas Veterans Administration Medical Center for evaluation of UNL. All patients had undergone, peripheral blood BCR-ABL mutation analyses by FISH. Neutrophilic leukocytoses were defined as a white blood count (WBC) above 11 × 109/L along with an absolute neutrophil count (ANC) greater than 7 × 109/L. It was considered unexplained, if it persisted on repeat testing and the referring physician deemed its etiology as uncertain. The primary end point was incidence of BCR-ABL positivity in patients with UNL. Incidence of BCR-ABL positivity within subgroups based on degree of WBC elevation defined as mild (11–20 × 109/L), moderate (>20–50 × 109) or severe (>50 × 109) was also calculated. Univariate and multivariate regression analyses of various laboratory and clinical features was performed to identify any confounding variables.

Results:

The median time from discovery of leukocytoses to the performing the test was 1545 days (n=285). 26 (9.1%) patients were found to be positive for BCR-ABL (n= 286). Majority had mild leukocytoses (n=202). The incidence increased with the severity of leukocytoses. Mild = 4/202 (2%), moderate = 9/62 (14.5%), severe = 13/22 (59.1%). On univariate analyses, a positive test was associated with presence of an elevated LDH (OR=107 CI 14.17–809.99), myeloid left shift (OR=107 CI 14.17–809.99) and hepatosplenomegaly (OR 3.87 CI 1.57–9.54). On multivariate regression, the presence of a myeloid left shift was strongly associated with a positive test (OR=67.20 CI 8.36–540.36). Myeloid left shift was seen in 3/4 (75%) of patients with a mild leukocytoses and positive test for BCR-ABL,

Conclusion:

In patients with UNL, peripheral blood FISH for BCR-ABL mutation should be restricted to those with moderate to severe leukocytoses. Incidence of BCR-ABL is especially low (2%) in patients with mild leukocytoses (<20 × 109/L). In these patients BCR-ABL testing should be limited to those with an unexplained myeloid left shift.

Disclosures:

No relevant conflicts of interest to declare.
Impact of Disease Status On Outcomes of Allogeneic Hematopietic Stem Cell Transplantation for Refractory Acute Myeloid Leukemia
Authors: Zhou Qianlan , Tang XiaoWen , Qiu Huiying , Sun Aining , Ruan Changgeng , Depei Wu
Published: October 2019

Abstract 4470

Objective:

To evaluate the impact of disease status on outcomes of allogeneic hematopietic stem cell transplantation (allo-HSCT) for refractory acute myeloid leukemia (AML).

Methods:

32 patients with refractory AML received allo-HSCT after myeloablative conditioning regimen, including 17 patients not in remission (NR) and 15 patients in complete remission (CR) at the time of transplant. Treatment related adverse events, relapse rate and leukemia free survival (LFS) were compared in two groups.

Results:

There were no difference between two groups regarding patients gender, age, cytogenetic risk, donor type, stem cell resource, conditioning regimen, median number of CD34+ cells. 30 patients engrafted successfully. Only one patient failed to engraftment and another one died from veno-occlusive disease. Compared with CR group, NR group had a higher treatment related mortality (29.4% vs.13.3%,p=0.254), relapse rates (33.3% vs. 20.0% P=0.341),relative higher incidence of aGVHD (35.3% vs. 20.0%, p=0.287) and cGVHD (44.4% vs. 36.4%, p=0.217), but no significant difference was observed. 2-year LFS of the two groups were comparable (35.3% vs.40.0%,p=0.267). For the patient with refractory AML, univariate analysis showed that two factors, such as less than 35 years old and cGVHD, were benefit for overall survival.

Conclusion:

Regarding treatment related mortality, relapse rates, incidence of GVHD, there were no significant difference between the patients who achieved CR or NR prior to transplant. 2-year LFS of patients with CR and NR was comparable. In summary, our results showed that allo-HSCT is an appropriate treatment option for refractory AML patients.

Disclosures:

No relevant conflicts of interest to declare.
Extramedullary Relapse of Acute Leukemia After Allogeneic Hematopoietic Stem Cell Transplantation —Single Center Experience
Authors: Ge Lin , Tang XiaoWen , Ye Fan , Sun Aining , Ruan Changgeng , Depei Wu
Published: October 2019

Abstract 4473

Objective:

To investigate the incidence, risk factors and clinical outcome of extramedullary relapse (EMR) following allogeneic hematopoietic stem cell transplantation (allo- HSCT).

Methods:

We retrospectively studied the patients with AL (n =410) who underwent allo-HSCT at our center between 2001 and 2012 who developed either bone marrow (BM) or extramedullary (EM) relapse.

Results:

1. The incidence of overall relapse was 22% (90/410), with 68 cases of medullary relapse (16.6%), 13 cases of isolated extramedullary relapse (3.2%) and 13 cases of extramedullary relapse with concomitant bone marrow involvement (3.2%); 2. The 3-year overall survival (OS) of EMR and BMR was 14.1% and 13.8% respectively (p=0.027). Not only the 6-month overall survival (OS), but also the 12-month OS, the 24-month OS and the 36-month OS post relapse in patients with EMR was significantly better than that of BMR patients. Acute lymphoblastic leukemia (ALL) subtype (P=0.006) and complete remission status (P=0.047) at transplant yielded better 6-month survival in patients with EMR.; 3.Relapse sites included central nervous system (n=17), testicular (n=4), lymphatic (n=2), skin (n=2), bone (n= 1); 4.CNSL is the most common subtype of EMR. Univariate analysis showed that the factors associated with CNSL included ALL as the underlying diagnosis (relative risk [RR] = 2.727, p= 0.044) and sourse of peripheral blood stem cell (RR= 1.412, P= 0.018).

Conclusion:

CNSL is the most common subtype of EMR. Univariate analysis showed that ALL subtype and source of PBSC were associated with an increased risk of CNSL relapse. Patients with EMR have better overall survival compared with those with BMR.

Disclosures:

No relevant conflicts of interest to declare.
Pretransplant Parathyroid Hormone Level Has No Correlation with Platelet Recovery After Stem Cell
Authors: Kim Soo-Jeong , Kim Yundeok , Hyun Shin-Young , Jang Ji-Eun , Hwang Doh Yu , Cheong June-Won , Kim Jin Seok , Kim Yu Ri , Lee Hye Won , Min Yoo-Hong
Published: October 2019

Abstract 4495

Background

Stem cell fate is influenced by specialized microenvironments called as stem cell niche. Osteoblasts are considerd to play very important role in stem cell niche. They are activated by parathyroid hormone (PTH) or PTH related protein through PTH/PTHrP receptor and produce hematopoietic growth factors. In few large animal studies PTH treatment after hematopoietic stem cell transplantation (HSCT) improved post-transplant platelet count and CD4 lymphocyte count. Effect of PTH on cord blood stem cell transplantation to improve engraftment is under clinical trial. Therefore, authors investigated on correlation between pre-transplant serum PTH level and platelet recovery after allogeneic HSCT.

Methods

From January 2008 to December 2009, we measured pre-transplant serum PTH, ferritin of 28 patients who underwent allogeneic HSCT. Post-transplant platelet was checked at the point of post-transplant 14 days, 30 days, 60 days, 90 days and 180days. Surveillance of cytomegalovirus was done by weekly or biweekly CMV-PCR assay. Acute graft-versus-host disease (GVHD) was graded by IBMTR classification and chronic GVHD by NIH scoring system.

Results

Five patients received graft from partially matched donors and the others from fully matched donors, 15 from unrelated and 13 from related donors. Nineteen patients were in high risk at diagnosis. Nonmyeloablative conditioning was applied to 7 patients. Only 1 patient used bone marrow as stem cell source. Median dose of infused stem cell was 5.7×10∧6/kg (range 1.68 – 12.74). All patients were successfully engrafted. Acute GVHD more than grade 2 occurred in 15, and chronic GVHD more than moderate degree in 7. Five patients relapsed and 15 patients died of relapse or treatment related mortality. Pre-transplant serum PTH had no correlation with platelet count recovery. There was no correlation with pre-HSCT PTH and acute or chronic GVHD. However patient with lower PTH level had tendency to more frequent CMV reactivation (P=0.098).

Conclusion

Our hypothesis was that higher pre-transplant PTH would be related to better platelet recovery but failed to find correlation between two of them. There are various factors which affect engraftment and graft function. Role of PTH for engraftment should be evaluated in larger number of cases.

Disclosures:

No relevant conflicts of interest to declare.
A Retrospective Study to Evaluate the Survival Rates in R-CHOP Chemotherapy Followed by Autologous Stem Cell Transplantation for the Treatment of Diffuse Large B Cell Lymphoma
Authors: Lee Mark H. , Kim Sung-Yong , Kim Inho , Park Seonyang , Kim Yeo-Kyeoung , Kim Yang Soo , Lee Ho Sup , Kim Jeong-A , Park Jinny , Kim Seok Jin , Park Sung Kyu , Park Byeong-Bae , Shim Hyeok , Eom Hyeon Seok , Lee Junglim
Published: October 2019

Abstract 4517

Prognosis in diffuse large B cell lymphoma (DLBCL) is highly associated with the International Prognostic Index (IPI) score, which was proposed to assign prognosis to patients with aggressive non-Hodgkin lymphoma undergoing treatment with doxorubicin-containing chemotherapy. The addition of rituximab to CHOP or CHOP-like regimens has resulted in significant improvements in the overall survival (OS) rate of CD20 positive DLBCL. In addition, the original IPI scoring system has been validated even in patients receiving rituximab-based chemotherapy. However, OS and progression-free survival (PFS) in patients with high-intermediate or high IPI DLBCL were not satisfactory, and the upfront autologous stem cell transplantation (ASCT) was reported to improve the survival rates in these patients subset. Therefore, we retrospectively evaluated the survival rates in patients with DLBCL with CD20+, who were treated with R-CHOP followed by ASCT.

We analyzed 40 DLBCL patients who underwent an ASCT, reported to the Korean Blood and Marrow Transplant Registry between 2005 and 2011 by 12 centers. Patients characteristics at diagnosis: 60% male, 5% stage II with bulky disease, 95% stage III or IV, 42.5% bone marrow involvement, 65% high-intermediate or high risk by IPI score. Patients characteristics at ASCT: median age 47 years (range, 23–66) and 82.5% of patients received ≥6 cycles of R-CHOP. Response to R-CHOP: 62.5% CR and 37.5% PR. 17.5% of patients received involved field radiotherapy prior to ASCT for bulky disease or residual lymphoma. Disease status at ASCT: 72.5% CR and 27.5% PR. Median time from diagnosis to ASCT was 7.85 months (range, 4.4–16.1).

Median follow-up period from diagnosis was 36.2 months (range, 6.3–84.8). 2-year estimates of PFS, OS and relapse from diagnosis were 73.8%, 86.4% and 24.3%, respectively. 5-year estimates of PFS, OS and relapse were 70.8%, 68.3% and 27.4%, respectively. 3-year estimates of PFS and OS according to IPI score were not significantly different among 4 risk groups (P=0.890 and P=0.855, respectively).

The upfront ASCT following R-CHOP induction therapy may improve survival for patients with advanced high risk DLBCL. Prospective evaluation of the treatment outcome of R-CHOP followed by ASCT is needed for high risk DLBCL on a large scale.

Disclosures:

No relevant conflicts of interest to declare.
Autologous Transplantation in Relapsed and Refractory Mantle Cell Lymphoma
Authors: Shah Bijal D. , Little Bryan J , Cultrera Jennifer , Bello Celeste M. , Sokol Lubomir , Sotomayor Eduardo M. , Tomblyn Marcie , Ayala Ernesto
Published: October 2019

Abstract 4542

Introduction:

Consolidation with autologous transplantation (AutoSCT) may extend progression free survival when administered following initial induction. There are limited data to support the role of AutoSCT in the relapsed or refractory setting.

Methods:

We retrospectively evaluated all patients with MCL transplanted at our institution before 2010. We identified 57 patients, among whom 42 were transplanted in first remission (CR1, n=32; PR1 n=10), 11 in second remission (CR2, n=4, PR2, n=7), and 4 with relapsed/refractory disease beyond first remission.

Results:

The median PFS are: CR1 37mo, PR1 24mo, CR2 not reached, and PR2 23mo. No statistically significant difference was observed between patients transplanted CR1 vs PR1 (p one-sided =0.08), CR2 vs PR2 (p one-sided =0.10), or in CR/PR1 vs CR/PR2 (p one-sided =0.39). The median PFS for those with refractory disease, and/or those transplanted beyond second remission was 6mo which is significantly inferior to the cohort of those transplanted in first or second remission (p one-sided =.01).

The median OS calculated from transplant are: CR1 63mo, PR1 50mo, CR2 not reached, PR2 45mo. No statistically significant difference was observed between patients transplanted CR1 vs PR1 (p one-sided =0.47), CR2 vs PR2 (p one-sided =0.46), or in CR/PR1 vs CR/PR2 (p one-sided =0.29). The median OS for those with refractory disease, and/or those transplanted beyond second remission was 16mo which is not statistically significantly inferior to the cohort of those transplanted in first or second remission (p one-sided =.067).

MIPI data collected at diagnosis were available for 30 patients, all transplanted in first or second remission with chemosensitive disease. These data were not predictive of survival or progression from transplantation. Simplified MIPI obtained at the time of transplant were available for 44 patients, all transplanted in first or second remission with chemosensitive disease. These data were similarly uninformative for prediction of progression or survival from transplantation.

Conclusions:

Consolidation with AutoSCT may be similarly effective for patients in first relapse with chemosensitive disease. MIPI at diagnosis and the simplified MIPI at transplant may failed to account for survival among highly selected patients considered eligible for transplantation.

Disclosures:

Sokol: Celgene: Honoraria, Speakers Bureau.
Identification of Differentially Expressed and Spliced Genes with RNA Sequencing Analysis of CLL Specimens
Authors: Liao Wei , Jordaan Gwen , Jaroszewicz Artur , Pellegrini Matteo , Sharma Sanjai
Published: October 2019

Abstract 4582

High throughput sequencing of cellular mRNA provides a comprehensive analysis of the transcriptome. Besides identifying differentially expressed genes in different cell types, it also provides information of mRNA isoforms and splicing alterations. We have analyzed two CLL specimens and a normal peripheral blood B cells mRNA by this approach and performed data analysis to identify differentially expressed and spliced genes. The result showed CLLs specimens express approximately 40% more transcripts compared to normal B cells. The FPKM data (fragment per kilobase of exon per million) revealed a higher transcript expression on chromosome 12 in CLL#1 indicating the presence of trisomy 12, which was confirmed by fluorescent in-situ hybridization assay. With a two-fold change in FPKM as a cutoff and a p value cutoff of 0.05 as compared to the normal B cell control, 415 genes and 174 genes in CLL#1 and 676 and 235 genes in CLL#2 were up and downregulated or differentially expressed. In these two CLL specimens, 45% to 75% of differentially expressed genes are common to both the CLL specimens indicating that genetically disparate CLL specimens have a high percentage of a core set of genes that are potentially important for CLL biology.

Selected differentially expressed genes with increased expression (selectin P ligand, SELPLG, and adhesion molecule interacts with CXADR antigen 1, AMICA) and decreased (Fos, Jun, CD69 and Rhob) expression based on the FPKM from RNA-sequencing data were also analyzed in additional CLL specimens by real time PCR analysis. The expression data from RNA-seq closely matches the fold-change in expression as measured by RT-PCR analysis and confirms the validity of the RNA-seq analysis. Interestingly, Fos was identified as one of the most downregulated gene in CLL. Using the Cufflinks and Cuffdiff software, the splicing patterns of genes in CLL specimens and normal B cells were analyzed. Approximately, 1100 to 1250 genes in the two CLL specimens were significantly differentially spliced as compared to normal B cells. In this analysis as well, there is a core set of 800 common genes which are differentially spliced in the two CLL specimens. The RNA-sequencing analysis accurately identifies differentially expressed novel genes and splicing variations that will help us understand the biology of CLL.

Disclosures:

No relevant conflicts of interest to declare.
Spontaneous Remission of Chronic Lymphocytic Leukemia, Possibly More Rare Then Previously Reported?
Authors: Nakhla Peter , Butera James N , Castillo Jorge J , Treaba Diana O , Quesenberry Peter J
Published: October 2019

Abstract 4589

Introduction:

Spontaneous remission of chronic lymphocytic leukemia (SRCLL) has occassionaly been reported since the 1950s. About 40–50 cases have been reported in the English literature. The often quoted incidence of such a phenomena is estimated to be 1% of all CLL cases (Table 1). However, a review of these reports which have determined this incidence suggests that many patients did not have a true SRCLL. The authors have conducted a systemic search within their own institution database to determine the true incidence of SRCLL.

Methods:

After obtaining appropriate IRB approval, a systemic search was performed within the our institution's hematopathology databases for the diagnosis of chronic lymphocytic leukemia from year 2000 to 2012. Records and laboratory findings were reviewed for all cases. Records for patients with laboratory data suggestive of remission were reviewed to determine if they had received any form of therapy. All cases were included in the review if the diagnosis of CLL was firmly established by flow cytometry. SRCLL was defined as: 1) the patient's elevated lymphocyte number at diagnosis was >5 × 109/L and persisted for >6 months confirming the initial diagnosis of CLL, 2) the lymphocyte number subsequently normalized to <5 × 109/L, the lymphocyte count remained normal for greater than 9 months, 3) resolution of other features of CLL such as lymphadenopathy, and 4) no intervening treatment was given to patients, including radiation therapy or steroids.

Results:

After reviewing 167 cases, only one case met our inclusion criteria, with an estimated incidence of 0.6%.

Conclusion:

Spontaneous remission of CLL is a rare phenomenon. This review suggests that the incidence of SRCLL is less then the previously often quoted incidence of 1% and may more appropriately approximate 0.6%.

Disclosures:

No relevant conflicts of interest to declare.
Plasmacytoid Transformation of Chronic Lymphocytic Leukemia CLL with Multiple Lytic Bony Lesions
Authors: Jajeh Ahmad
Published: October 2019

Abstract 4590

Richter transformattion in patients with Chronic Lymphocytic Leukemia CLL can happen in 3%- 15%. This involve transformation of relatively indolent CLL cells into higher grade and aggressive form of Lymphoma. Plasmcytoid transformation of CLL with paraprotinemia, multiple lytic lesions and hypercalcemia can occur. This abstract will describe six patients with CLL who presented with hypercalcemia and lytic bony lesions in the course of their disease. Mean age is 72 years old. All were males, four whites and two blacks. One patient had solitary bony lesion with solitary small lung lesion that biopsy showed moderately differentiated adenocarcinoma. Bone scan was negative and monoclonal IgG lambda was present. The second patient had multiple lytic lesions with nephrotic range proteinuria of five grams; kappa light chain with bone marrow biopsy showing plasma more than 10%. Two patients has progressive adenopathy with elevated IgM level more than 2 grams with increased LDH. One patient progressed to PLL and developed renal failure that required hemodialysis with lambda light chain in urine. One patient with progressive bony lesion involving the scapula and close vertebrae with IgG spike. All patients expired in a short period less than six months with therapy. Biopsy was available for four patients which showed plasmacytoid or plasmablastic morphology.

In conclusion: Plasmacytoid transformation in patient with CLL should be considered when hypercalcemia, lytic bony lesions and paraproteinemia is present.

Disclosures:

No relevant conflicts of interest to declare.
Assessment of Minimal Residual Disease Levels in B-CLL After Front-Line Treatment with FC-R and Rituximab Maintenance
Authors: Garcia-Vela Jose A. , Lopez Javier , Ferrer Secundino , Giraldo Pilar , González-Barca Eva , Conde Eulogio , González Marcos , Guzman Jose-Luis , De la Serna Javier , Osma Mar , Deben Guillermo , Monzo Encarna , De Paz Raquel , Penalver Francisco-Javier , Jarque Isidro , Martinez Rafael , Burgaleta Carmen , de Oteiza Jaime Perez , Andreu M.Angeles , Carbonell Felix , Garcia-Marco Jose A
Published: October 2019

Abstract 4599

Objective:

To prospectively analyze change over time in minimal residual disease (MRD) in a cohort of 84 untreated patients diagnosed with CD20+ B-CLL who received from October 2007 to December 2010 six cycles of R-FC (Rituximab 375 mg/m2 IV in cycle 1 and 500 mg/m2 in cycles 2–6; F: 25 mg/m2, and C: 250 mg/m2 on days 1–3; every 28 days). Patients who achieved response were treated with rituximab 375 mg/m2 every 2 months for 3 years.

Materials and methods:

EDTA-anticoagulated peripheral blood (PB) and bone marrow (BM) samples were taken at diagnosis, after 3 and 6 cycles of R-FC, and every 6 months during the maintenance phase. MRD was centrally assessed by four-color multiparameter flow cytometry using the following antibody combinations: CD22/CD23/CD19/CD5, CD81/CD22/CD19/CD5, CD20/CD38/CD19/CD5, and CD20/CD79b/CD19/CD5. An acquisition was performed by selection of CD19+ cells/SSC including at least 200,000 events, reaching a sensitivity level of 0.01% (10-4).

Results:

PB/BM samples for assessing MRD were available from 28 of the 84 patients after 3 cycles of R-FC and from 79 patients after the 6 induction cycles, and 43 (58%) of the 74 patients on maintenance reached the interim study at 18 months of maintenance (9 cycles). Correlation between PB and BM was 57%, 68%, and 86% at the three study time points. After three R-FC cycles, 16 patients (56.8%) had a MRD- in PB, but only 4 patients (14%) also had MRD- in BM. After six R-FC cycles, 58 patients (73.3%) had a negative study in PB, and 41.7% also in BM. Among the 24 patients analyzed after the third cycle with BM+, 11 achieved negativization after 6 cycles, and MRD was negative in PB in 10 of 12 patients. After 18 months of maintenance, 11 patients (26.2%) converted to MRD- in PB/BM, and a single patient (2.4%) converted to MRD+.

Conclusion:

Six cycles of R-FC achieved better MRD- rates in PB and BM as compared to 3 cycles. Addition of rituximab as maintenance after R-FC increased the number of MRD-negative in BM, and in consequence the MRD-negative CRs. A good correlation was not found between MRD values in blood and bone marrow in the induction phase. However, these levels improved in the maintenance phase due to an increase in the number of cases with RMD-negative in BM witch were negatives in PB during induction phase.

Disclosures:

Off Label Use: R in Maintenance.
Replication Timing and Pediatric Leukemia
Authors: Gilbert David M , Battaglia Dana , Chang Bill H , Buckley Quinton , Pope Benjamin D , Druker Brian J. , Ryba Tyrone
Published: October 2019

Abstract 4609

Abnormal temporal control of replication (“replication timing”) is a universal hallmark of cancer, but the significance of this relationship is not understood. During normal development, changes in replication timing are regulated in defined chromosomal units (“replication domains”) of 400–800 kb, with late replication generally associated with stable gene silencing. We have performed genome-wide replication timing mapping on pediatric acute leukemias and identified patterns of replication-timing mis-regulation (“leukemia fingerprints”) in common across multiple types of pediatric leukemia (“multi-lineage fingerprints”), as well as those linked to specific subtypes of acute leukemia and patient-specific fingerprints. Most of the mis-regulated regions are not associated with copy number variation or translocations and correspond to many of the same domains whose replication timing is regulated during normal development. The existence of multi-lineage fingerprints suggests an early origin of their mis-regulation while type-specific and patient-specific fingerprints suggest that mis-regulation continues to occur downstream of the initiating event. Our hypothesis is that there exists an hierarchy of replication-timing mis-regulation, initiating with frozen vestiges of normal hematopoiesis that are inappropriately maintained, followed by additional changes that evolve as the tumor differentiates. These changes may then affect the ability of downstream lineages to activate or silence genes. Since chromatin is assembled at the replication fork, and different types of chromatin are assembled at different times during S phase, changes in replication timing likely contribute to domain-wide changes in chromatin structure, similar to those observed in long range epigenetic silencing (LRES). In fact, we find that genes within leukemia fingerprint domains are significantly enriched for those transcribed during hematopoiesis and/or mis-regulated in cancers. Replication timing is an exceptionally stable epigenetic property that is not easily disturbed by loss or mis-expression of single master regulators of cell fate and is not directly related to transcription, but rather to the stability of gene silencing. Hence, events occurring early in hematopoiesis could have profound effects on the activation of transcriptional programs in downstream lineages. Elucidating the genesis and genealogy of leukemia-specific replication timing fingerprints and their relationship to transcriptional control will be fundamental to understanding their link to the development of acute leukemias.

Disclosures:

No relevant conflicts of interest to declare.
Patterns of Clinical Presenations of Thrombotic Thrombocytopenic Purpura in Plasma Exchange Era
Authors: Dawod Muath , Alhyari Mohammad , Kuriakose Philip
Published: October 2019

Abstract 4642

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious disease in which early diagnosis and management has a major impact on outcome. TTP has been historically linked to a pentad of clinical features (mental status changes, fever, acute renal failure, anemia and thrombocytopenia). The frequency of the classical pentand in the pre plasma exchange era has been reported to be as high as 40 percent. With the introduction of plasma exchange and increased awareness of this disease a different pattern of clinical presentation of TTP might be forming based on early diagnosis. We reviewed the clinical presentation of 91 patients with a diagnosis of TTP in terms of pattern and duration of symptoms.

Only 9% of patients (n=8) presented with the pentad. Duration of symptoms in all patients ranged between 1 and 60 days, with a mean of 9.3 days. Statistical analysis showed no correlation between the duration of symptoms prior to diagnosis and the presence of the pentand (mean of symptom duration in the pentad and non-pentad groups were 9.4 and 9.3 days with range of (3–30) and (1–60), respectively).

The most common patterns of clinical presentation were in the form of constitutional symptoms (fatigue, malaise and generalized weakness), which were seen in 67% of patients (n=60), followed by neurological symptoms (mainly headache and confusion) in 51% of pateints (n=46). Gastrointestinal (GI) symptoms (nausea, vomiting or abdominal pain) were seen in 47% of patients (n=42).

The most common triad of symptoms was neurological (headache and confusion), constitutional (fatigue, weakness and anorexia) and GI(nausea, vomiting and abdominal pain), which was present in 14% of patients (n=13).

In terms of clinical outcome, there was also no correlation between the duration of symptoms and the clinical outcome (mean of symptom duration in the alive and dead groups were 9.2 and 10 days, with range of 1–60 and 1–21 days, respectively). There was no association between the presence or absence of the pentad and mortality, (25% (n=2/8) as compared to 11% (n=9/83), P-value of 0.248). On the other hand patients with poor outcome (defined as death) were less likely to present with constitutional and nonspecfic symptoms (27.3% (n=3/11) as compared to 72.5% (n=58/80), P-value of 0.005),

As a conclusion, the pentad is a very rare presentation in TTP and the duration of symptoms prior to diagnosis does not predict its presence. While nonspecific and/or constitutional symptoms are the most common presentation, patients who do not present with such symptoms tend to do worse. Our study highlights the importance of defining the clinical presentation of this disease in a new and pertinent form that could help clinicians in the diagnosis and timely management. It also raises the question of prognsotic value of the clinical presentation in this potentially lethal disease.

Disclosures:

No relevant conflicts of interest to declare.
Patterns of Clinical Presentation of Thrombotic Thromboxytopenic Purpura. Is There a Racial Difference?. A Single Institution Experience.)
Authors: Dawod Muath , Alhyari Mohammad , Kuriakose Philip
Published: October 2019

Abstract 4653

Background:

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious disease that has been reported more frequently in African-Americans (AA). While recent reports have showed an increased incidence of TTP amongs AA patients, there is no data with regards to the patterns of clinical presentation in this racial subgroup and if there is any difference as compared to other racial subgroups.

Patients and methods:

In this retrospective study we reviewed characterstics and clinical presentation of 91 patients with the diagnosis of TTP. Sixty four patients were AAs (70%). The second largest racial subgroup was Caucasians (24 patients, 26%). Demographics, lab values and symptoms were compared between AAs and Caucasians. Continuous variables were compared using two-sided two-sample t-tests. Alternatively, the Wilcoxon rank-sum test was used if the data were not normally distributed. Categorical variables were compared using Chi-square tests.

Results:

AA patients were older [median age of 47.6 years as compared to 40 years, P-value of 0.057] and more likely to be females [68.8%, (n=44/64) as compared to 45.8%, (n=11/24), P-value of 0.048]. As for laboratory evaluation, AA patients were more likely to have positive ANA [44% (n=22/64) as compared to 14.3% (n=2/24), P-value of 0.042] and higher ESR (median of 75.5 as compared to 40.7, P-value 0.03). Other laboratory evaluation including hemoglobin, platelet counts and creatinine were comparable. The most common patterns of clinical presentation in AA patients were in the form of constitutional symptoms (fatigue, malaise and generalized weakness) which were seen in 67% of patients (n=43), followed by neurological symptoms (mainly headache and confusion) in 53% of pateints (n=34). Gastrointestinal (GI) symptoms (nausea, vomiting or abdominal pain) were seen in 44% of patients (n=28). This pattern was comparable to what is seen in Caucasian patients. Skin symptoms were reported less frequently in AA as compared to Caucasians (17.2% vs. 41.7%, p = 0.016).

Conclusion:

While AA patients are more likely to be females, older and have positive ANA, the clinical presentation of TTP is similar among different racial subgroups (African Americans and Caucasians).

Disclosures:

No relevant conflicts of interest to declare.