bluuebunny/crossref_metadata_2025 huggingface dataset:
Confirmation of Safety, Efficacy and Response Duration in Non-Hodgkin Lymphoma Patients Treated with 60 μg/m2/d of BiTE® Antibody Blinatumomab.
Authors: Nagorsen Dirk , Zugmaier Gerhard , Viardot Andreas , Goebeler Mariele , Noppeney Richard , Schmidt Margit , Klappers Petra , Baeuerle Patrick A , Kufer Peter , Bargou Ralf C
Published: October 2019

Abstract 2723

Poster Board II-699

Indolent and mantle cell lymphoma (MCL) are predominantly treated with chemotherapy or a combination of chemotherapy with monoclonal antibodies. Despite high initial response rates, eventually almost all patients however relapse, leaving the disease incurable. Moreover, with increasing numbers of regimens administered, the responsiveness of patients is reduced. Blinatumomab is a single-chain bispecific antibody construct with specificity for CD19 and CD3, belonging to the class of bispecific T cell engager (BiTE®). Here, we report on patients in an ongoing phase 1 trial treated at a dose of 60 μg/m2/d for 4–8-week by continuous i.v. infusion with single-agent blinatumomab. In total, 12 patients with indolent mainly follicular lymphoma or MCL were treated at 60 μg/m2/d during the first treatment cycle. 11/12 patients showed an objective response (7 PR and 4 CR). As of July 2009, median response duration was 12 months with 6 out of 11 responses still ongoing. The single non-responding patient experienced a reversible, neurological adverse event leading to early discontinuation of treatment. Of the 11 responders, one patient developed a port infection and 4 patients showed neurological symptoms, which were all fully reversible. In order to mitigate neurological adverse events during first dosing, which can occur in a defined subset of patients, patients were treated for 1–2 weeks with a lower initial dose (5 and/or 15 μg/m2/d) followed by a maintenance dose of 60 μg/m2/d. A lower starting dose appeared to ameliorate initial adverse events to an extent that treatment could be continued without interruption. Taken together, our data confirm a high single-agent activity of 60 μg/m2/d blinatumomab infused for 4–8 week with long lasting remissions and a favorable risk/benefit profile. The confirmed dose will be considered for further clinical development of blinatumomab in follicular lymphoma and MCL. New data on patients treated with a dose of 90 μg/m2/d will be presented.

Disclosures:

Nagorsen: Micromet: Employment, Equity Ownership. Zugmaier:Micromet: Employment, Equity Ownership. Schmidt:Micromet: Employment, Equity Ownership. Klappers:Micromet: Employment, Equity Ownership. Baeuerle:Micromet: Employment, Equity Ownership. Kufer:Micromet: Employment, Equity Ownership, Patents & Royalties. Bargou:Micromet: Consultancy, Patents & Royalties.
Infectious Complications in Advanced Relapsed/Refractory Multiple Myeloma Patients Treated with Lenalidomide (Revlimid +/- Corticosteroids).
Authors: Kukreti Vishal , Masih-Khan Esther , Dean Saima , Kumar Deepali , Mikhael Joseph R. , Trudel Suzanne , Reece Donna E. , Chen Christine
Published: October 2019

Abstract 2876

Poster Board II-852

Multiple myeloma (MM) patients (pts) are immunosuppressed given the underlying disease, previous treatments and myelosuppression seen on lenalidomide (Revlimid, Rev). We evaluated the infectious complications seen on Celgene's Expanded Access Rev program at Princess Margaret Hospital. We have treated 75 pts who had progressed after at least one prior therapy as part of a national study in Canada. At entry, pts were required to have a neutrophil count of ≥1.0 ×109/L. The median age was 61 yrs (range 35-79); 52% were males. Prior therapy included stem cell transplant in 65, thalidomide in 54 and bortezomib in 24. Number of lines of prior therapy were as follows: 24 (one), 29 (two), 16 (three), 8 (four) and one (five). Neupogen was used liberally (63%) after a patient had a dose delay on trial due to neutropenia. Patients were treated with full dose lenalidomide at entry onto clinical trial and were maintained on full dosing unless platelet counts were <30×109/L or ANC was <1.0×109/L. No other dose adjustments were made for renal dysfunction.

Results:

There were 32 pts (43%) who had a clinically evident infection; the majority (91%) was on prophylactic antibiotics (septra/ciprofloxacin) at the time. There were two deaths due to infection and 23 pts (72%) required hospitalization (range 2-27 days). The majority of infections occurred within the first 4 cycles of treatment (26 pts) and seemed to occur more in pts with several lines of prior therapy – 7/24 (29%) with 1 prior therapy, 14/29 (48%) with 2, 9/16 (56%) with 3 and 2/8 (25%) with 4 prior therapies. Sixteen were neutropenic of which 7 had febrile neutropenia (9%). The types of infections were: respiratory in 14 (1 with pneumocystis pneumonia), cellulitis in 4, herpes simplex and herpes zoster in 2 pts each. These included streptococcus pneumoniae (1), staphylococcus aureus (3), respiratory syncitial virus (1) and mycobacterium chelonae (1). Rev was held during the infection in 23 pts (72%).

Conclusions:

1) Infections are frequent in this patient population (43%) and often lead to hospitalization (72%); respiratory infections accounted for a large majority (43%).

2) Early aggressive growth factor support and broader antibiotic prophylaxis may be of benefit especially in heavily pretreated patients.

3) Dose reduction of Rev in the context of serious infections should be further evaluated.

Disclosures:

Kukreti: Celgene: Honoraria. Trudel:Celgene: Honoraria, Speakers Bureau; Ortho Biotech: Honoraria. Chen:Celgene: Honoraria.
Odds of Venous Thromboembolims (VTE) Associated with Hospitalization, Surgery, and Cancer Among Nursing Home Residents: A Population-Based Study.
Authors: Leibson Cynthia L. , Heit John A. , Bailey Kent R. , Petterson Tanya M. , Ashrani Aneel
Published: October 2019

Abstract 2984

Poster Board II-960

In previous studies of venous thromboembolism (VTE) among all residents of Olmsted County, MN, the odds of VTE associated with surgery, medical hospitalization, or active cancer were extremely high (Univariate odds ratio [OR] =14.6; 4.6, and 8.4 respectively). We also showed that nursing home (NH) residency was an independent risk factor for VTE (OR =5.6).

From a clinical practice perspective, it is important to identify which NH residents are at risk of VTE. While it might be assumed that, similar to estimates for the population generally, surgery, medical hospitalization, and cancer are associated with increased risk of VTE within the NH population, the answer remains unclear.

We took advantage of the previous identification of all Olmsted County, MN residents who met research criteria for incident VTE 1998-2005 (N=1168). We then determined which individuals were resident of a local NH at time of symptom onset, regardless of location of symptom onset (i.e., for purposes of this study, individuals whose VTE occurred in-hospital having been admitted from a NH were considered NH residents). For each such NH VTE case (N=96), we identified 2 same sex Olmsted County residents of similar age and duration-of-medical-history who were resident of a local NH at the time of the case's VTE event (i.e., index date) (N=192). The detailed provider-linked medical records of NH VTE cases and NH non-VTE controls were reviewed for 3 months before index for surgery or medical hospitalization and for 6 months surrounding index for active cancer. Using conditional logistic regression, we tested and estimated the odds ratio associated with each of these potential risk factors.

The proportions of NH VTE cases and NH non-VTE controls with surgery (33%, 28%), medical hospitalization (44%, 46%), and active cancer (12%, 9%) were similar. Univariate odds ratios (95% confidence intervals) and p values for surgery, medical hospitalization, and active cancer were 1.5 (0.7-3.1), p=0.30; 1.1 (0.6-2.1), p=0.74; and 1.4 (0.6-3.2), p=0.46 respectively.

Compared to the entire Olmsted County population, the odds of VTE associated with surgery, hospitalization, and cancer are surprisingly much lower for NH residents. Additional investigation is needed to characterize the subset of NH residents at increased risk of VTE.

Disclosures:

No relevant conflicts of interest to declare.
Hemoglobin Bound Von Willebrand Factor (HbVWF) Multimers Are Hyperactive and More Prevalent in Patients with Sickle Cell Disease.
Authors: Zhou Zhou , Han Hyojeong , Udden Mark M. , Cruz Miguel A. , Dong Jing-fei , Guchhait Prasenjit
Published: October 2019

Abstract 3058

Poster Board II-1034

Elevated levels of von Willebrand factor (VWF), especially the ultra-large multimers, play a significant role in the pathogenesis of vascular occlusion in sickle cell disease (SCD) by promoting cell adhesion to the endothelium. Investigating the pathophysiology of vaso-occlusion and thrombosis in SCD, we have recently observed that excessive extracellular-hemoglobin (Hb) in plasma significantly inhibited ADAMTS-13 proteolysis of VWF by binding directly to the enzyme cleavage-site on VWF. Here, we further show that subpopulations of VWF multimers, which are bound to extracellular-Hb, exist in plasma. We have successfully isolated the Hb-bound VWF (HbVWF) multimers from SCD patients' plasma using the Ni-NTA column and quantified by commercial kit. The HbVWF multimers exist in 5 to 6-times less quantity than the Hb-free multimers as measured in SCD patients. Purified HbVWF multimers are mostly uncleavable by recombinant ADAMTS-13 in vitro. These HbVWF multimers are hyper active in agglutinating platelets as detected by ristocetin cofactor (RCof) activity assay, and also hyper adhesive to collagen type-III compared to the Hb-free multimers. The HbVWF multimers exists in about 2-fold more quantity in SCD patients than normal individuals [mean percent level ± SE, 8.1±1.8 (individual mean 6 – 11) vs. 16.6±3 (12 – 21), P <0.001; n=10]. Using another sandwich-ELISA assay we have reexamined the HbVWF levels, which showed a similar pattern as above. Further, the increased level of HbVWF multimers exists parallely with an elevated RCof activity of plasma VWF [mean percent activity ± SE, 100.4±15.1 (78 – 124) vs. 132.9±11.4, (109 – 149), P <0.001] and high extracellular-Hb levels [mean mg/L ± SE, 59±6.5 (42 – 96) vs. 281.5±71.7 (184 – 410), P <0.001] in plasma of SCD patients compared to normal individuals. Therefore, we believe that these hyperactive HbVWF multimers play a crucial role in cell adhesion, vascular occlusion and thrombosis in SCD. Also, we speculate that this mechanism is not only limited in SCD, but also occurred in other pathophysiological conditions associated with severe intravascular hemolysis.

Disclosures

No relevant conflicts of interest to declare.
Genetic Polymorphism of NAD(P)H:Quinine Oxidoreductase 1 Is Associated with An Increased Treatment-Related Mortality in Patients Undergoing Allogeneic Transplantation.
Authors: Koldehoff Michael , Beelen Dietrich W. , Elmaagacli Ahmet H
Published: October 2019

Abstract 3342

Poster Board III-230

Introduction:

The widely expressed detoxification enzyme NAD(P)H:quinine oxidoreductase 1 (NQO1) is involved in the cellular response to oxidative stress and irradiation and protects cells against the mutagenicity from free radicals and toxic oxygen metabolities. NQO1 is subject to a genetic polymorphism (C609T) leading to a change in its amino acid sequence. Heterozygous individuals C/T have intermediate activity and homozygotes T/T are NQO1 deficient. Never before the influence of genetic polymorphisms of NQO1 on patients who underwent allogeneic transplantation, was evaluated.

Methods:

Here we genotyped in a retrospective study 198 patients (and their donors) for NQO1 expression that underwent allogeneic transplantation for various diseases and analyzed their outcome. Genotyping of NQO1 was performed by real-time PCR using subsequent melting curve analysis.

Results:

145 patients (73.2%) were genotyped as homozygous wild-type gene C/C, 48 patients (24.2%) were genotyped as heterozygous genotype C/T and five patients (2.5%) were genotype as homozygous gene mutation T/T. From the donors 147 donors (74.2%) were C/C, 50 donors (25.3%) were C/T, and one donor (0.5%) had a homozygous gene mutation T/T. Calculated genotype frequencies did not differ from that reported earlier by other studies for Caucasians. Five-year estimate for treatment-related mortality (TRM) was highest in genotype C/T- and T/T-patients with 39% ±11% compared to homozygous wild-type gene C/C-patients (21% ± 3.9% [p<0.045]), whereas the five-year estimate for relapse or overall survival (OS) were not statistically different between the groups. No differences for five-year estimates for TRM, relapse rate, or OS were seen in recipients with either genotype C/C-, C/T- or T/T-donors. No statistic differences were found in the incidence of acute GVHD grade 2-4 within the study groups. NQO1 C/T, T/T genotypes were not associated with elevated bilirubin or creatinin levels regarding on recipient or the donor side, even after stratification based on HLA disparity.

Conclusions:

These results suggest that patients with genetic polymorphism of NQO1 do have an increased TRM after transplantation. Genotyping for NQO1 (C609T) might help to identify patients with higher risk for TRM.

Disclosures:

No relevant conflicts of interest to declare.
Interim Analysis on a Dutch HOVON Multicenter Randomized Open Label Phase II Trial on 3 Rituximab Dosing Schemes In Chronic ITP Patients:
Authors: Zwaginga Jaap Jan , van der Holt Ronnie , Biemond Bart J. , Boekhorst Peter A.W. te , Levin Mark , Vreughdenhil Art , Huijgens P.C. , Brand Anneke , van der Griend Rene , Luten Marleen , Pruijt Hans , Weerdt Okke de , van Pampus Elisabeth , Zweegman Sonja , Hollestein Rene , Koene Harry R.
Published: October 2019

Abstract 2514

The overall short term effectivity of Rituximab in the treatment of ITP is reported to be around 50%. In most studies the traditional CD20 dosing scheme of 4 weekly interspaced 375 mg/m2 doses is used although other single-arm studies suggest comparable effectivity of lower doses. To investigate alternative dosing schemes, we conducted an open label phase II multicenter trial and randomized 156 ITP patients that were refractory for corticosteroid treatment, between three schemes. Questions were: are higher CD20 peak levels of value and is dose saving a feasible approach in early responding patients? The treatment arms were: A) 375 mg/m2 once a week for 4 weeks, B) 750 mg/m2 once a week for 2 weeks and C) 375 mg/m2 once a week for 2 weeks, in early and sustained responding patients (= within 15 days and still responding at 43 days) and another 2 × 375 mg/m2 to patients not fulfilling these criteria. In retrospect, seven of the 156 patients appeared ineligible at randomization and were therefore excluded from all analyses. Here we report on the best response within 71 days as primary end point for the first 105 patients that were included, i.e. 35 per treatment arm

Arm A (n=35) 4 × 375 mg/m2 Arm B (n=35) 2 × 750 mg/m2 Arm C (n=35) 2 or 4 × 375 mg/m2 Patient characteristics Male/female, % 37/63 49/51 43/57 WHO 0/1/2/not reported, % 86/6/–/9. 77/20/3/– 91/9/–/– Age in years, median (range) 56 (19–77) 56 (17–82) 41 (18–80) On stable corticosteroid, % 36 29 46 Splenectomized, % – 15 11 Baseline plt count × 109/l, median (range) 16 (3–31) 15 (1–30) 19 (2–30) Treatment outcome, % Early responses in Arm C 26 All best responses within 71d 46 42 51 CR: >150 × 109 plt/l 20 14 14 GR: >50 × 109 plt/l 20 14 23 MR: >30 × 109 plt/l AND >2 × baseline 6 14 14 No response 54 58 49 Treatment failure at 6 months, % (standard error) 57 (8) 60 (8) 54 (9)

So far, on the basis of the within 71 days overall response data, no superior dosing scheme of CD20 can yet be discerned.

Disclosures:

No relevant conflicts of interest to declare.
Angiopoietin-Like 3 Affects Homing Ability of Hematopoietic Stem Cells.
Authors: Umikawa Masato , Zheng Junke , Huynh HoangDinh , Zhang Chengcheng
Published: October 2019

Abstract 2632

Angiopoietin-like proteins (Angptls) are a seven-member family of secreted glycoproteins that share sequence homology with angiopoietins. It is known that several members of the Angptl family including Angptl3 support ex vivo expansion of hematopoietic stem cells (HSCs). However, the physiological role of Angptls in the hematopoietic system is not well known. Here we show that Angptl3 is expressed by both bone marrow stromal cells and HSCs. To study the intrinsic effect of Angptl3 in mouse HSCs, we isolated the same number of HSCs from wild-type and Angptl3-null mice and performed reconstitution analysis. Adult bone marrow Angptl3-null HSCs showed decreased repopulation compared to wild-type HSCs, suggesting that Angptl3 has cell-autonomous effect on HSC activity. By contrast, HSCs isolated from liver of the null mice had enhanced HSC repopulation activity than their wild-type counterparts. To study whether this effect is caused by difference in homing, we injected CFSE labeled wild-type HSCs and Angptl3 null HSCs into lethally irradiated mice, and checked the homing to bone marrow, spleen, and liver. While homing of these two types of cells to bone marrow or spleen was not significantly different, Angptl3 null HSCs homed better to the liver than the wild-type HSCs. Our result suggests that Angptl3 is important for the retention of HSCs in the bone marrow, and the absence of Angptl3 leads HSCs to move to extramedullary organs such as liver.

Disclosures:

No relevant conflicts of interest to declare.
Evidence That High-Mobility Group A2 (Hmga2) Expression Contributes to the Ontogeny-Dependent Properties of Fetal Hematopoietic Stem Cells.
Authors: Copley Michael R. , Kent David G. , Benz Claudia , Rowe Keegan M. , Woehrer Stefan H. , Eaves Connie J.
Published: October 2019

Abstract 2634

Fetal and early neonatal hematopoietic stem cells (HSCs) are distinct from their adult counterparts by their rapid turnover and expansion rates in vivo. However, the mechanisms underlying the regulation of these properties are poorly understood. In previous studies using serial limiting-dilution competitive repopulating transplant assays, our lab has shown that the rapid expansion phenotype of fetal HSCs is at least partially intrinsically determined since significantly more daughter HSCs are produced from fetal as compared to adult HSCs when similar numbers are transplanted into the same type of irradiated adult host. Additionally, we have observed a conversion of fetal HSCs to the adult regeneration phenotype that occurs within six weeks of transplantation in the primary host. To facilitate a comparison of highly-purified subsets of fetal and adult HSCs identified by an identical phenotype, we adopted the use of the CD45+EPCR+CD150+CD48− (E-SLAM) phenotype which we found gave HSC purities of 20–50% for hematopoietic tissues from early fetal to aged adulthood. We then used comparative gene expression analysis to identify candidate regulators of the fetal HSC high self-renewal program. This gave 20 candidate genes whose transcript levels were measured by quantitative real time PCR in E-SLAM cells isolated from E14.5 fetal liver (FL) and adult bone marrow (ABM). Of these genes only Hmga2 and Smarcc1 showed significant differences (p<.05) in expression between fetal and adult HSCs and only Hmga2 maintained this differential expression when the same cells were stimulated to divide for 48 hrs in vitro. To test the hypothesis that high expression of Hmga2 is a necessary and sufficient factor in determining the fetal HSC self-renewal program, purified adult E-SLAM HSCs were transduced with Hmga2-overexpressing or control lentiviruses and the kinetics of transduced vs untransduced hematopoietic cells in a congenic serial-transplantation model were then analyzed. Interestingly, when BM cells from the primary repopulated mice (transplanted 6-weeks earlier) were injected into secondary animals and the peripheral blood was analyzed for donor-type %Y/GFP chimerism, the Hmga2-overexpressing cells were observed to have a competititve advantage and exhibited an ∼6-fold expansion relative to the untransduced cells. In contrast, the control virus-infected BM cells were found to be equally competitive. These findings support the hypothesis that high expression of Hmga2 may be a critical mediator of the high self-renewal phenotype of fetal HSCs.

Disclosures:

No relevant conflicts of interest to declare.
Recovery of KIR Expression After Allogeneic Stem Cell Transplantation in Multiple Myeloma Patients
Authors: Stuebig Thomas , Lioznov Michael , Fritsche-Friedland Ulrike , Alchalby Haefaa , Wolschke Christine , Ayuk Francis , Bacher Ulrike , Zander Axel R. , Kroeger Nikolaus
Published: October 2019

Abstract 4555

Introduction:

Activating and inhibitory killer immunoglobulin like receptors (KIR) are predominantly expressed on natural killer (NK) cells. KIR mismatch allogeneic stem cell transplantation (alloSCT) has been reported to provide beneficial effects for Multiple Myeloma (MM). However, their recovery in MM patients remains poorly understood. We, therefore, analysed KIR recovery in 90 MM patients after alloSCT.

Methods:

KIR expression (CD158a/h, CD158b/b2, CD158e1/e2) on NK cells and T cell subsets was measured by flow cytometry at different time points after alloSCT.

Results:

During the first 90 days after alloSCT NK cells represent the largest lymphocyte subset. Activating receptors like NKp30 and NKp44 showed a fluctuating expression while members of the KIR family were expressed at a constant rate (20% of NK cells). There was no significant difference in the early post transplantation period (day 0–90) compared to later time points (day 360).

In contrast, T cells showed increased KIR expression during the first 30 days after alloSCT, which was highly significant for CD158e (p=0,0001). After 30 days the expression declined to baseline. Furthermore, T cell activation marker HLA-DR reached its highest expression between days 60 and 90 when KIR receptors were expressed at their lowest level (27% vs. 8%, p < 0,0001).

Conclusions:

We conclude that KIR receptors were differentially expressed on NK and T cells. Because KIR receptors are constantly expressed by NK cells and NK cells are the most frequent lymphocyte populations early after alloSCT, NK cells may be useful for KIR mismatch cellular therapy.

Disclosures:

No relevant conflicts of interest to declare.
The Importance of WT1 in Leukemia
Authors: Pandey Sony , Moazam Mustafa , Eisermann Kurtis , Hord Jeffrey , Fraizer Gail , Kuerbitz Steven J
Published: October 2019

Abstract 4645

Acute leukemias collectively comprise the most common group of malignancies in the pediatric age group. Increasingly, therapeutic approach and prognosis are influenced by leukemia-specific cytogenetic abnormalities and genetic alterations, thus highlighting the importance of identifying novel prognostic markers. The Wilms’ tumor suppressor gene WT1 is expressed in leukemic blasts and is found to be mutated in approximately 10 percent of leukemia cases. Although it is unclear whether WT1 acts as an oncogene or a tumor suppressor gene in leukemia, it is known to regulate genes involved in cancer progression, including the angiogenic and mitogenic factor, VEGF. Previous studies in kidney and prostate cell lines identified potential WT1 binding sites on the VEGF-A gene promoter and demonstrated that WT1 transcriptionally regulated VEGF expression. Thus, we hypothesized that WT1 transcriptionally regulates VEGF expression in leukemia. To examine WT1 and VEGF expression patterns in pediatric Acute Lymphocytic Leukemia (ALL), Acute Myeloid Leukemia (AML) and non-neoplastic bone marrow samples, we performed quantitative real time PCR. It was observed that WT1 and VEGF expression varied depending upon the type and sub-type of leukemia. Furthermore, to understand the significance of WT1 expression, we over-expressed GFP- WT1 in Molt-4 cells (T-ALL), HL-60 (AML) and K562 cells (CML) and then quantified mRNA levels of VEGF and the potential WT1 target genes CCNA1 and JAG. The results showed that WT1 levels induced variable expression of VEGF, CCNA1 and JAG in these different leukemic cell lines. Elevated expression of WT1 genes harboring mutations of the zinc finger (ZF) DNA binding domain has also been described in a subset of leukemias and has been associated with a poor prognosis. We therefore screened pediatric acute leukemia samples for novel ZF mutations that would abrogate its ability to regulate VEGF and other target genes. Conversely, a well described SNP rs16754 (in exon 7 of the WT1 gene) identified as a good prognostic marker in Cytogenetically Normal AML (CN-AML) was observed in our pediatric population as both homozygous and heterozygous variants of the WT1 gene. Our long term goal is to determine the molecular basis of the prognostic impact associated with variant WT1 expression in pediatric and adult leukemias.

Disclosures:

No relevant conflicts of interest to declare.
Founder Effects of a Recurrent Splicing Mutation IVS9-1G>C of the UNC13D Gene in Korean Patients with Familial Hemophagocytic Lymphohistiocytosis
Authors: Song Joon Sup , Kim Hee Jin , Seo Ja Young , Kim Sun Hee , Lee Ki O , Park In Ae , Lee Mee Jeong , Koo Hong Hoe , Ahn Hyo Seop , Lyu Chuhl Joo , Kim Ji Yoon , Park Eun Sil , Jeon In Sang , Lim Young Tak , Kim Bo Eun , Koh Kyung Nam , Im Ho Joon , Seo Jong Jin
Published: October 2019

Abstract 4730

Background:

Familial hemophagocytic lymphohistiocytosis (FHL) is a potentially fatal disease with an autosomal recessive inheritance. Mutations in the UNF13D gene (FHL3) are the major genetic background of Korean patients with FHL (∼90). In particular, a single splicing mutation, IVS9-1G>C, is recurrent and accounts for the majority of mutant alleles (>50%), suggesting a founder effect. In this regard, the authors investigated the signature of founder effect in Korean patients with FHL3.

Methods:

The study patients were 17 pediatric patients with FHL3 recruited from the Korean Registry of HLH between January 2007 and June 2010. Nine patients had 1 (n=8) or 2 (n=1) mutant alleles of IVS9-1G>C. Haplotypes of the genomic region of UNC13D were reconstructed using the genotype information of short tandem repeat (STR) and single nucleotide polymorphism (SNP) markers in a set of 192 control chromosomes of Korean descent. The haplotypes of the 17 patients were assigned and analyzed with respect to the mutation status.

Results:

Fifteen haplotypes (Ht1-Ht15) were reconstructed based on the genotype data from 5 common SNPs of UNC13D (rs7210574, rs2290770, rs7223416, rs3744007, and rs3744010) in the control group. Haplotype analyses in the control group demonstrated that Ht3 was remarkably more prevalent in the patient group than in the control group (55.0% vs. 31.3%), and all 9 patients with IVS9-1G>C had Ht3. In addition, all patients with IVS9-1G>C except one had the 258 allele of a polymorphic STR marker near UNC13D (DS19S1839).

Conclusions:

The results suggested a founder effect in the recurring mutation IVS9-1G>C of UNC13D in Korean patients. This observation may explain the unusually high proportion of FHL3 in Korea.

Disclosures:

No relevant conflicts of interest to declare.
FLT3-ITD Mutations in AML: Structural and Numerical Variation of Mutations and Identification of Subgroup with Poor Prognosis
Authors: Blau Olga , Berenstein Rimma , Sindram Annette , Thiel Eckhard , Blau Igor Wolfgang
Published: October 2019

Abstract 4868

FLT3-ITD occurs with a frequency of 35%–45% in normal karyotype AML and has an adverse impact on prognosis. FLT3-ITD mutations are very variable in length and position of the tandem duplication. We have analyzed 211 AML patients with a median age of 54 years (range, 17–75). For all patients, intensive double-induction and consolidation therapy were intended. Patients with a matched related (MRD) or unrelated donor (MUD) were allocated to allogeneic stem cell transplantation (alloSCT). To investigate ITD insertion site and length, as well as their clinical impact in AML patients, we have performed sequencing analysis in diagnostic samples from 46 FT3- ITD–mutated patients. In 39 (87%) patients a single sequence was found, 6 patients displayed 2 and more different mutations. The median size of the inserted sequences was 63 nucleotides (range, 21–203 nucleotides). ITD integration sites were categorized according to functional regions of the FLT3 receptor: juxtamembrane domain (JMD), n =29 (JMD switch motif, n=3; JMD zipper motif, n=20; and JMD hinge region, n=6) and beta1-sheet of the tyrosine kinase domain-1 (TKD1), n=17. In the majority of the cases insertion sites were localized in JMD between amino acid (AA) 593 and 609 (n=20; 43%) and in TKD1 between AAs 610 and 615 (n=17; 37%). Integration site was strongly correlated with the ITD size (p=0.001) and with white blood cells (WBC) count (p=0.05). The prognostic significance of FLT3-ITD size is discussed controversial. Several studies reported conflicting results. We have found that CR durations was significant better (p=0.05) in patients with bigger ITD size, and there were no statistical differences in OS and DFS. There was no significant association between the number of mutations and OS or DFS. Presence of the any type of mutations was more common in M5 (16 of 54, 29%, P 0.01). It was associated with normal karyotype (72% vs 43%), p=0,0001; higher white blood cells (WBC) count (98×109/l vs 21×109/l), p=0,0001; higher BM blasts (85% vs 71%, p=0,0001), de novo AML (91% vs 69%), p=0,0001); and inferior OS (p=0,008) and DFS (p=0,01), when we excluded AML M3 patients. The prevalence of ITD allele on the DNA level was heterogeneous. Based on quantitative analysis, the mutant/wild-type (wt) ratio ranged from 0,1 to 11,5. Patients with a mutant/wt ratio above 0,3 had significantly shorter CR duration (p=0,02), OS (p=0,03), and DFS (p=0,01). Taken together, our data confirm that FLT3 mutation represent a common aberration in adult AML and associated with inferior outcome. A high mutant/wt ratio appears to have a major impact on the prognostic relevance.

Disclosures:

No relevant conflicts of interest to declare.
Technical Standards and Guidelines for Use of Clinical Genomic Microarray Analysis in Hematopoietic and Other Neoplastic Disorders: A Draft From a Working Group of the American College of Medical Genetics Laboratory Quality Assurance Committee
Authors: Slovak Marilyn L , Wolff Daynna J , Li Marilyn M , Lebo Matthew S , Cooley Linda D
Published: October 2019

Abstract 4906

Interrogation of the genome utilizing microarray technologies (copy number array-CGH with or without single-nucleotide polymorphism (SNP) probes) allows detection of genomic gains and losses with unprecedented resolution. Array findings are increasing our knowledge of the genetic basis of hematologic and other malignancies. However, prior to the clinical use of these new analytic tools, laboratories must extensively validate multiple parameters such as their platform(s), software, methods, detection limits, and quality control metrics. The laboratory must demonstrate expertise in the performance of the test and interpretation of the results by testing numerous samples, different sample types, and samples from patients with different types of diseases; these array results should then be compared with the results obtained using the gold standard methods. A working group of the Laboratory Quality Assurance committee of the American College of Medical Genetics (ACMG), a professional organization of board-certified clinical and laboratory geneticists, has drafted technical standards and guidelines for clinical laboratories that intend to offer clinical testing using these technologies.

The ACMG Technical Standards and Guidelines provide support for clinical laboratory geneticists to help them provide quality laboratory genetic services. The guidelines discuss array design, selection and coverage of the genomic microarray platforms, manufacturer's premarket analytical validation recommendations (assay performance characteristics, quality parameters, and software specifications), laboratory validation recommendations for each neoplastic disorder and tissue type (blood, bone marrow, and formalin-fixed paraffin-embedded tissue), quality control metrics and documentation, and methods for confirmation of the copy number aberrations (e.g., conventional cytogenetics, FISH, PCR, MLPA, or a different microarray). Data analysis, interpretation and reporting recommendations relating to clonal diversity, limitations of the assay, and the assessment of the clinical significance of array findings are included. Quality assurance guidelines address laboratory personnel training and certification, proficiency testing, and clinically appropriate turnaround times.

Clinical laboratory medical professionals with appropriate training and certification will correlate clinical and pathological information with array findings for final reporting. The ACMG Laboratory QA committee welcomes input as the draft guidelines are being formulated.

Disclosures:

No relevant conflicts of interest to declare.
Further Observations on the Effect of Cortisone and Thyroxin on the Blood Picture of Hypophysectomized Rats
Authors: MEINEKE HOWARD A. , CRAFTS ROGER C.
Published: October 2019

Adult female rats of the Wistar strain were hypophysectomized and divided into 3 groups, the first of which received no treatment for 100 days, the other 2 groups receiving no treatment for 50 days followed by daily subcutaneous injections of 0.6 mg. of cortisone alone or in combination with 0.005 mg. of thyroxin for another 50 days. Another group of rats served as normal unoperated controls.

Hypophysectomy induced a decrease in the number of nucleated cells in the bone marrow, the erythroid elements being the cells responsible for this decrease; the myeloid elements remained normal in number. These marrow changes were reflected in a decrease in reticulocyte percentage and subsequent anemia, while the total white cell count remained normal.

A combined thyroxin-cortisone therapy induced a decrease in myeloid elements in the bone marrow, which resulted in a decrease in the peripheral white cell count. It increased the number of erythroid elements in the bone marrow to a level above that of the hypophysectomized animals with no treatment but not to normal levels. This is undoubtedly due to a very rapid production and release of these cells, for the reticulocyte count was 72 per cent above normal and the anemia in these animals completely eliminated. Blood volume studies showed that these changes in the peripheral blood were not due to a hemoconcentration.

Cortisone therapy alone induced changes in the myeloid elements in the bone marrow similar to that following the dual therapy, and produced a similar decrease in peripheral white cell count. This therapy did not, however, eliminate the post-hypophysectomy anemia as did the combined therapy. Although erythropoiesis in the marrows appeared stimulated and the reticulocyte percentage was elevated, the total cellular volume in these animals was not elevated.

A combined thyroxin and cortisone therapy will not only prevent post-hypophysectomy anemia, as was found previously, but will eliminate the anemia once it has become established.
Acquired Hypoprothrombinemia
Authors: LEWIS JESSICA H. , FERGUSON JOHN H. , SPAUGH EARLE , FRESH JAMES W. , ZUCKER MARJORIE B.
Published: October 2019

Hypoprothrombinemia was encountered in 105 patients including cases of vitamin K deficiency, liver disease, newborns, Dicumarol-type drug therapy and a few miscellaneous disorders. The findings stress the association of acquired hypoprothrombinemia with deficiencies proconvertin and PTC and suggest that these three proteins are formed in the liver and that vitamin K is essential to their production.
An Unusual Syndrome of Hemolytic Anemia, Thrombocytopenic Purpura and Renal Disease
Authors: SHUMWAY CLARE N. , MILLER GERALD
Published: October 2019

This paper describes a recurrent illness which occurred in a child and consisted of hemolytic anemia, thrombocytopenia, and a renal disease clinically resembling acute glomerulonephritis. The hemolytic process was characterized by unusual red cell morphology together with evidence of an extracorpuscular hemolytic mechanism. Acute respiratory infections appeared to be related to exacerbations of the disease. Splenectomy failed to prevent recurrence of the hematologic abnormalities, and cortisone did not appear to influence the course of one typical episode of illness.

It is the authors’ opinion that this syndrome represents a form of "hypersensitivity" and may be related to the syndrome of thrombotic thrombocytopenic purpura.
Leukocytic Alkaline Phosphatase
Authors: KENNY JOHN J. , MOLONEY WILLIAM C.
Published: October 2019

1. Evidence of a marked difference in alkaline phosphatase activity in the leukocytes of normal subjects and individuals with chronic myelogenous leukemia has been provided by observations on the behavior of the enzyme following prolonged incubation and during pyogenic infection.

2. Therapy with radiation and radiomimetic drugs in chronic myelogenous leukemia and myeloid metaplasia resulted in a marked fall in leukocyte count but no change was observed in the relative population of alkaline phosphatase positive and negative cells.

3. In our laboratory histochemical and biochemical values for leukocyte alkaline phosphatase have been similar to those reported in the literature for typical cases of chronic myelogenous leukemia and most leukemoid reactions. However, in certain cases parodoxical findings have been noted in which histochemical and biochemical studies were inconsistent with the pathologic diagnosis.

4. The inadequacies of purely morphologic criteria in these atypical cases were noted and the desirability of the further development of cytochemical methods has been pointed out.
Erythrokinetics. IV. The Plasma Iron Turnover as a Measure of Erythropoiesis
Authors: BOTHWELL THOMAS H. , HURTADO ARNOLD V. , DONOHUE DENNIS M. , FINCH CLEMENT A.
Published: October 2019

Experimental and clinical studies have been performed to define more clearly the significance of the plasma iron turnover.

It has been shown that the plasma iron turnover is not affected by the rate of red cell destruction and to only a limited extent by increased body stores. It does, however, reflect the degree of erythroid marrow activity and is a sensitive indicator for measuring changes in such activity.

A series of 85 studies in normal subjects and in patients with various hematologic disorders were carried out to define the range of response with anemia and to assess the clinical value of the plasma iron turnover as an index of erythropoiesis. In states of marrow hyperfunction it is increased from 3 to 6 times normal and may be depressed to approximately half normal with marrow hypofunction. The plasma iron turnover is increased with marrow dyspoiesis. This increase is a measure of total erythropoiesis and does not indicate the production of viable red cells.
A Case of Congenital Afibrinogenemia
Authors: FERNANDO P. B. , DHARMASENA B. D.
Published: October 2019

1. A case of congenital afibrinogenemia of a Sinhalese boy of 22 years is reported.

2. The main features of the reported cases are reviewed.

3. The principal features of this case are total absence of fibrinogen in the blood, complete non-coagulability of blood, history of several episodes of hemorrhage dating from infancy, low erythrocyte sedimentation rate, cosanguinity of the parents and the occurrence of spontaneous hemoperitoneum from which he recovered after operation.

4. Treatment consists of blood or fibrinogen transfusion.
Attempted Passive Transfer of Thrombotic Thrombocytopenic Purpura
Authors: BRITTINGHAM T. E. , CHAPLIN HUGH
Published: October 2019

Transfusion of 300 ml. of plasma from a patient with thrombotic thrombocytopenic purpura produced no hematologic change in a healthy recipient; 10 months after the infusion there has been no evidence of transmission of any disease.
Studies on Abnormal Hemoglobins
Authors: SINGER KARL , JOSEPHSON AARON M. , SINGER LILY , HELLER PAUL , ZIMMERMAN HYMAN J.
Published: October 2019

A family study is reported in which the simultaneous presence of C-thalassemia and S-thalassemia disease is noted. Marked interaction of the genes for the abnormal hemoglobins and for thalassemia is evident.

The value of the accessory hemoglobins for the diagnosis of thalassemia minor is discussed.

The Hb S + F pattern can no longer be assumed to be diagnostic of sickle cell anemia. Evaluation of all hematologic data and the family background of the patient may be necessary to rule out the presence of the thalassemia gene.

A discussion of the genetics of the double heterozygous states for thalassemia and an abnormal hemoglobin is presented.
Quantitative Plasma Amino Acid Values in Leukemic Blood
Authors: KELLEY JOHN J. , WAISMAN HARRY A.
Published: October 2019

1. Quantitative methods for analysis of free amino acids in plasma have been performed on blood from normal and leukemic individuals.

2. An increase in the glutamic acid phenylalanine and "leucine" levels was found in the blood plasma of patients with acute leukemia.

3. Both the chronic myelogenous and the chronic lymphatic leukemia patients had high levels of glutamic acid, phenylalanine, alanine and proline.

4. Lower than normal levels of asparagine and threonine were found in the plasma of patients with acute leukemia.
Studies in Leukemia
Authors: SCHOOLMAN HAROLD M. , SPURRIER WILMA , SCHWARTZ STEVEN O. , SZANTO PAUL B. , YATES LEROY
Published: October 2019

1. A 33 week old Swiss female mouse that had been caged with AKR males exhibited a "spontaneous" lymphoblastoma resembling the spontaneous disease in the AKR strain.

2. Tumor cell suspensions of this animal did not grow when inoculated into AKR mice.

3. Tumor cell suspensions grew progressively in both Swiss and DBA mice, producing a leukemia.

4. Cell-free filtrates of leukemic Swiss or DBA mouse brain induced leukemia in 48 of 106 adult Swiss mice inoculated intracerebrally and 39 of 55 animals inoculated intraperitoneally. The leukemia appeared in the majority of the animals within one to three weeks from the time of inoculation.

5. Cell-free filtrates of the leukemic tumor failed to induce leukemia under the conditions of the experiment.
Serum Vitamin B12 in Leukemias and Malignant Lymphomas
Authors: RACHMILEWITZ M. , IZAK G. , HOCHMAN A. , ARONOVITCH J. , GROSSOWICZ N.
Published: October 2019

High serum vitamin B12 levels were found in chronic myeloid leukemia and in acute leukemia with myeloid differentiation. Following x-ray therapy and repeated blood transfusions, a drop of serum vitamin B12 was found.

In chronic lymphatic leukemia, undifferentiated stem cell leukemia, Hodgkin’s disease, and multiple myeloma, the serum vitamin B12 concentrations were normal.

In polycythemia with marked leukocytosis the serum B12 was normal.

In myelosclerosis high B12 values may be found.

The serum vitamin B12 in chronic myeloid leukemia is in a bound form and the binding capacity for added B12 is increased.

Serum vitamin B12 determination may be of some value in differentiating various types of leukemia and other myelo-proliferative disorders.
The Nature of the Hemorrhagic Disorder Accompanying Hemolytic Transfusion Reactions in Man
Authors: KREVANS JULIUS R. , JACKSON DUDLEY P. , CONLEY C. LOCKARD , HARTMANN ROBERT C.
Published: October 2019

A hemorrhagic diathesis has been observed in 2 patients who received 500 ml. of incompatible whole blood. In both, hypofibrinogenemia, hypoprothrombinemia and thrombocytopenia were observed and there was no evidence of increased fibrinolytic activity. In one, accelerin activity was reduced and there was transient evidence of a low-titered circulating anticoagulant.

The most likely explanation for the observed changes is intravascular coagulation in the recipient, presumably initiated by the thromboplastin-like activity of the hemolyzed red blood cells.
The Impact of Race, Age, and Sex in Follicular Lymphoma (FL): A Comprehensive SEER Analysis in the Pre- and Post-Rituximab Eras
Authors: Nabhan Chadi , Aschebrook-Kilfoy Briseis , Chiu Brian C-H , Kruczek Kimberly , Patel Anand , Smith Sonali M. , Evens Andrew M.
Published: October 2019

Abstract 1576

Background:

While racial disparity has been documented in a number of cancers, the impact of race, sex, and socioeconomic status (SES) on FL outcomes is not well defined. Furthermore, the impact of modern therapeutics on these disparities has not been fully explored.

Methods:

We examined population-based FL overall survival (OS) data from SEER 13 (1993–2008) for race, sex, age, and socioeconomic status (SES) over two consecutive 8-year periods: Era 1 (1993–2000, n=7,409) and Era 2 (2001–2008, n=9,083).

Results:

We identified a total 16,492 FL patients (pts) (white (W): n=13,441 (81.5%); Hispanic (H): n=1,417 (8.5%); Asian/Pacific Islander (A/PI): n=887 (5.3%); and Black (B): n=747 (4.5%)). Median age at diagnosis differed significantly according to race: (in years, yrs) W: 62.1, H: 57.3, A/PI: 60.5, B: 56.6; P<0.01 for each race vs. W. For all pts, OS was superior in Era 2 vs. Era 1 (5-yr OS: 77% vs. 68%, respectively, P<0.0001). Further, OS was significantly improved for all age groups (<50, 50–59, 60–69, and 70–79 yrs) as well as for males (P=0.0019) and females (P<0.0001) across eras. Interestingly, females had superior OS compared with males in Era 1 (P=0.004), but not in Era 2 (P=0.83). We subsequently compared OS within and across races (see Table). All races, except A/PI, had improved 5-yr OS rates (age adjusted) from Era 1 to Era 2 (W: <0.001, H: 0.049, A/PI: 0.15, B: 0.003). Notably, A/PIs had the highest OS in Era 1, while H had the poorest OS in Era 2. These differences were more evident in males compared with females within each race. Finally, pts with higher SES had improved OS compared with low SES in both eras (P=0.02 in era 1 and <0.0001 in era 2), although OS was improved across eras within low and high SES populations (P<0.0001).

Conclusions:

Collectively, we identified improved OS in FL across eras, which was apparent for all ages, both sexes, and all races. However, racial disparities persist, including inferior OS for H and superior OS for A/PIs in the contemporary era. The disproportionate improvement in OS over eras and persistent inequality in outcomes based on race warrants continued examination.

Disclosures:

No relevant conflicts of interest to declare.