Median WBC Research Articles

Phenotypes of JAK2-Mutated Polycythemia Vera and Essential Thrombocythemia with and without Thromboembolic Events: Results of the Hinc-207 (OSHO #91) Study

Thrombosis is the major cause of morbidity and mortality in polycythemia vera (PV) and essential thrombocythemia (ET). Age ≥60 years (y) and/or history of thrombosis labels patients (pts) as high-risk for thrombosis. Yet, thrombosis frequently occurs prior to the diagnosis of PV/ET. In a multicenter study of the East German Study Group (HINC-207; OSHO #091), the interaction between age and time occurrence of the first thrombosis as risk factors for thrombosis after diagnosis was studied. Methods After IRB approvals, JAK2 mutated adults with PV or ET were prospectively enrolled in 9 centers and centrally stratified in a one to two ratio (group A: pts with a history of thrombosis; group B: pts without thrombosis) with a pre-planned minimum of 60:120 pts. Based on a longitudinal and cross-sectional design, clinical and laboratory data at diagnosis, last follow-up, and thrombosis (for group A) were collected. Thrombosis prior to diagnosis was labeled as A1 and thrombosis after diagnosis as A2. Thrombosis risk factors were grouped into age-, previous thrombosis-, thrombosis prior to PV/ET-, cardiovascular (CV)-, thrombophilia-, and disease- (JAK2 allele burden, Hct, and WBC) related. Additionally, therapies [aspirin (ASS), anticoagulation, phlebotomy, and cytoreduction] and data from a study-own patient questionnaire were included. All pts signed informed consent. The primary endpoint was the phenotypic diversity in JAK2-mutated ET and PV pts with or without thrombosis. Results From April to Dec, 2019, 246 pts were recruited. Data on 237 pts (median age 62y; 59% females, 58% PV) are available. At diagnosis, pts in group A (n=71, median age 59.5y) tended to be younger than those in group B (n=166, median age 63y) (p=0.07). Yet, 70.4% thrombotic events (venous: median age 46.5y; arterial: median age 57y) occurred in A1 and correlated with younger age (p=0.03). Only 3 pts developed a second event after diagnosis. These were counted in A2 (n=24, median age at thrombosis: 61y). Overall, thrombosis occurred either prior to or within the first 3y after diagnosis in 63/71 (89%) pts. Age>60y could not be identified as a risk factor for thrombosis or type of thrombosis at any time point. The 5 y probability of no thrombotic event after diagnosis in pts >60y was 90.4% vs. 89.2% for pts <60y (p=0.8) and that of a thrombotic event >3y after diagnosis in pts >60y was 3.7% vs. 4.9% for pts <60y (p=0.7). Similarly, A1 did not correlate with A2 (p=0.3). With 1691 patient-years for the entire cohort, the incidence of thrombosis after PV/ET diagnosis was 0.7 for arterial and 0.6 for venous events per 100 patient-years. Smoking was more prevalent in pts >60y (p=0.003) and was not associated with thrombosis. Irrespective of age, hypertension (65%, p=0.03), hyperlipidemia (19%, p=0.008), and diabetes (16.4%, p=0.05) were frequent and correlated with A2 while atrial fibrillation (p=0.03) and inherited thrombophilia risk factors (p<0.00) with A1. JAK2 allele burden (median 19%) and Hct >45% (median 45%) at diagnosis correlated strongly with age >60y (p=0.005) but not with A, A1, or A2, although Hct >45% at diagnosis correlated with A2 in PV (p=0.001). Surprisingly, a Hct >45% at thrombosis was more frequently present in A1 (55%) vs A2 (30%) (p<0.00). Median WBC at diagnosis was higher in B compared to A (p=0.004), strongly associated with age >60y (p<0.00) but not with A2. WBC >15% at thrombosis did not correlate with A. Age rather than thrombosis was the trigger for cytoreduction [82% hydroxyurea (HU) in B pts >60y vs 53% in A pts <60y] (p<0.00). In PV, ASS did not correlate with thrombosis (25% of pts in B did not receive ASS). Cytoreduction, interval between diagnosis and cytoreduction, nor the duration of exposure correlated with thrombosis. Conclusions: The majority of thrombotic events occurred prior to or within the first 3 years after the diagnosis of JAK2 mutated PV/ET and were associated with CV-risk factors rather than older age. Phenotypic features such as Hct >45%, high WBC, and JAK2 allele burden were associated with age >60y and less with thrombosis. Their value as surrogate markers for therapeutic interventions to reduce thrombosis needs to be critically evaluated in larger series. Whether adequate PV/ET- or CV-risk- treatments account for the low rate of CV events after diagnosis (despite a higher incidence of CV-risk factors) compared to the general population could not be answered due to study design and needs to be addressed prospectively. Disclosures Al-Ali: Novartis: Honoraria, Research Funding; Celgene: Honoraria, Research Funding.

Clinicopathologic Correlates and Natural History of Atypical Chronic Myeloid Leukemia

Clinicopathologic Correlates and Natural History of Atypical Chronic Myeloid Leukemia

Decitabine Versus Hydroxyurea for Advanced Proliferative CMML: Results of the Emsco Randomized Phase 3 Dacota Trial

Decitabine Versus Hydroxyurea for Advanced Proliferative CMML: Results of the Emsco Randomized Phase 3 Dacota Trial

A Phase I/II Trial of CPX-351 + Palbociclib in Patients with Acute Myeloid Leukemia

A Phase I/II Trial of CPX-351 + Palbociclib in Patients with Acute Myeloid Leukemia

Reduced-Intensity Induction with Dasatinib Vs. Hypercvad + 2nd Generation TKIs with MRD-Guided Follow-up Therapy Leads to Comparable Rates of MRD-Negative Remission While Reducing Transfusions and Neutropenia in Ph+ ALL

Reduced-Intensity Induction with Dasatinib Vs. Hypercvad + 2nd Generation TKIs with MRD-Guided Follow-up Therapy Leads to Comparable Rates of MRD-Negative Remission While Reducing Transfusions and Neutropenia in Ph+ ALL

A Simple Quick Method of Draining Red Cells from Granulocyte Concentrates Ex Vivo without the Addition of Hetastarch after Granulocytapheresis

Introduction Granulocytapheresis from healthy volunteer donors are performed regularly at our institution to treat severely neutropenic leukemia/SCT patients with overwhelming bacterial/fungal infections. 500 to 750 mL of Hespan® (6% hetastarch in 0.9% sodium chloride injection) with citrate anticoagulant is administered by aseptic addition to the input line of the centrifugation apparatus at a ratio of 1:13 to venous whole blood. The traditional method of gravity sedimentation of Granulocyte concentrates (GC) is the addition of 50 cc of 6% Hydroxyethyl starch in ACD anticoagulant which results in RBC volume reduction to < 5ml (range acceptable for transfusion to ABO incompatible recipients according to AABB standards). The method is time consuming, tedious and adds additional HES to the product. We streamlined the process by allowing the sedimented red cells to drain via gravity upon completion of the apheresis procedure without the addition of Hetastarch. Method: GCs are obtained from prescreened eligible (meet AABB/FDA guidelines) family/friends of the patients. G-CSF is administered as a fixed dose of 480 mcg (donors < 250 lbs.) or as 2 doses of 300/480 mcg (donors > 250 lbs) plus 8 mg of dexamethasone (without history of cataracts) 12 hours prior to the collection. 30 ml of TriCitrasol Anticoagulant (46.7% Trisodium citrate) is added to 500 ml of 6% Hetastarch in 0.9% Sodium Chloride Injection for IV use only and not more than 1000 ml is used in a single GC apheresis procedure. Our current practice is to test all O blood group donors for Anti-A Isoagglutinin titers. Cut off titers are set at <128. GCs from group O donors with Anti-A titers > 128 are drained of red cells if the recipient is non-O. For pediatric patients, our practice is to drain all GC products regardless of ABO compatibility between donor and recipient. Process: Upon completion of the Granulocytaheresis, the GC collection bag is left undisturbed hanging on the IV pole leaving all slips clamps attached. Red cells collected during the apheresis procedure settle at the base the collection bag. The collection line of the GC collection bag is clamped distal to the attachment of the sterile barrier filter inclusive of the sample bulb assembly. The clamp proximal to the sample bulb assembly needs to be left clamped. The collection bag is then sterile docked to a transfer bag (the plasma bag from the IDL set can be used) to create a closed sterile system. Two hemostats clamps are placed, one close to the inlet port of the collection bag and the other close to the sterile dock of the transfer bag. The clamps are opened slowly and the sedimented red cells are allowed to slowly drain into the transfer bag. Pressure using two fingers may be used to create a funnel to express the sedimented red cells into the port from the GC unit. When the desired amount of red cells are expressed into the transfer bag the process is stopped. The transfer bag is then removed by clamping and a relatively clean GC product is now available for transfusion. The entire process takes approximately 10-15 minutes. The GC bag is then sampled via the incorporated sample bulbs for the bag count, then labelled ready for release for transfusion. Results: We reviewed the results of six drained GCs by this method; the median Bag RBC was 0.8 x10e6/uL (range 0.06 - 0.23), Bag Hgb 0.8 g/dL (range 0.5-1.0) and Bag Hematocrit 0.7% (range 0.6-2.6). The median Bag WBC count was 10.6 x 10e10 (range 5.8 to 15.1), median bag volume 641 mL (range 462-774) and median volume processed 10526 ml (range 8800-12175 mL). We achieved our goal of reducing the red cells to <2 ml, providing a GC with more than the minimum yield (1.0 x 10e10) required according to AABB standards and also the availability of a GC product within 2 hours of completion for transfusion. Discussion: The use of the newer Apheresis machine allows for efficient removal of the targeted component and monitors/adjusts the depth at which the cells are collected within the Buffy coat layer based on the desired hematocrit of the collected product. Our practice is to collect a relatively clean GC product where there is less than 2 mL of red cell contamination in the GC unit. However, this is not always achieved and the GC units do have to be drained. Approximately 10-25 mL of red cells are drained depending on the collection and the GC units drained in this manner are comparable to the GCs drained after the addition of 50 cc of Hetastarch to the GC product. Disclosures No relevant conflicts of interest to declare.

Evaluating Predictors of Immune-Related Adverse Events and Response to Checkpoint Inhibitors in Myeloid Malignancies

Evaluating Predictors of Immune-Related Adverse Events and Response to Checkpoint Inhibitors in Myeloid Malignancies

Implications of RAS Mutational Status in Subsets of Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) across Therapy Groups

Implications of RAS Mutational Status in Subsets of Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) across Therapy Groups

A Personalized Clinical-Decision Tool to Improve the Diagnostic Accuracy of Myelodysplastic Syndromes

Background While histo- and cytomorphological examinations are central to the diagnosis of myelodysplastic syndromes (MDS), significant inter-observer variability exists. The diagnosis can be challenging in pancytopenic patients (pts) without evidence of dysplasia and is contingent on observer expertise. We developed and externally validated a geno-clinical model that uses mutational data and peripheral blood counts/clinical variables to distinguish MDS from other myeloid malignancies. Methods Clinical and genomic data, including commercially available next-generation sequencing panels, were obtained for patients (pts) treated at the Cleveland Clinic (CC; 652 pts), Munich Leukemia Laboratory (MLL; 1509 pts), and the University of Pavia in Italy (UP, 536 pts). All patients had carried a diagnosis of MDS, chronic myelomonocytic leukemia (CMML), MDS/myeloproliferative neoplasm overlap (MDS/MPN), myeloproliferative neoplasm (MPN; either polycythemia vera, essential thrombocythemia, or myelofibrosis), clonal cytopenia of undetermined significance (CCUS), or idiopathic cytopenia of undetermined significance (ICUS). All diagnoses were established with bone marrow aspiration and according to World Health Organization 2017 criteria. The training cohort included data from CC and UP and randomly divided into learner (80%) and test (20%) cohorts. The final model was independently validated in the MLL cohort. A machine learning algorithm was used to build the model; multiple extraction algorithms were used to extract genomic/clinical variables on both the cohort and individual levels. Performance was evaluated according to the area under the curve of the receiver operating characteristic (ROC-AUC) and accuracy matrices. Results Among the 2697 pts included from all sites, the median age was 70 years [36 - 86]. Median hemoglobin (Hb) was 10.4g/dl [6.9 - 15.7], median platelet count (PLT) was 132 k/dL [14 - 722], median WBC count was 5.3 k/dL [1.4 - 49.9], median ANC was 2.8 k/dL [0.3 - 27.7], median monocyte count was 0.3 k/dL [0 - 9.9], and median lymphocyte count (ALC) was 1.1 k/dL [0.1 - 5.4], and median peripheral blast percentage 0% [0 - 8]. The most commonly mutated genes in all patients were (list top 5 genes) and among pts with MDS were SF3B1 (27%), TET2 (25%), ASXL1 (19%), SRSF2 (16%), and DNMT3A (11%); among patients with MDS-MPN/CMML, the most commonly mutated genes were MDS-MPN/CMML (TET2 46%, ASXL1 34%, SRSF2 29%, RUNX1 13%, CBL 12%) ; among patients with MPNs, the most commonly mutated genes were (JAK2 64%, ASXL1 27%, TET2 14%, DNMT3A 8%, U2AF1 7%); among patients with CCUS the most commonly mutated genes were (TET2 41%, DNMT3A 27%, ASXL1 19%, SRSF2 17%, ZRSR2 10%). The most important features for model predictions (ranked from the most to the least important) included: number of mutations detected/sample, peripheral blast percentage, AMC, JAK2 status, Hb, basophil count, age, eosinophil count, ALC, WBC, EZH2 mutation status, ANC, mutation status of KRAS and SF3B1, platelets, and gender. The final model achieved an average AUROC of 0.95 (95% CI 0.93-0.96) when applied to the test cohort and 0.93 (95% CI 0.91 - 0.94) when it was applied to the MLL cohort. The model also provides individual-level explanations for predictions, providing top differential diagnoses and individual-level explanations of how features influence a putative diagnosis (Figure 1b). Conclusions We developed and externally validated a highly accurate and interpretable model that can distinguish MDS from other myeloid malignancies using clinical and mutational data from a large international cohort. The model can provide personalized interpretations of its outcome and can aid physicians and hematopathologists in recognizing MDS with high accuracy when encountering pts with pancytopenia and with a suspected diagnosis of MDS. Disclosures Sekeres: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda/Millenium: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees. Mukherjee:Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Partnership for Health Analytic Research, LLC (PHAR, LLC): Honoraria; Bristol Myers Squib: Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Aplastic Anemia and MDS International Foundation: Honoraria; Celgene/Acceleron: Membership on an entity's Board of Directors or advisory committees; EUSA Pharma: Consultancy. Gerds:Sierra Oncology: Research Funding; Imago Biosciences: Research Funding; Apexx Oncology: Consultancy; Celgene: Consultancy, Research Funding; Incyte Corporation: Consultancy, Research Funding; Roche/Genentech: Research Funding; CTI Biopharma: Consultancy, Research Funding; AstraZeneca/MedImmune: Consultancy; Gilead Sciences: Research Funding; Pfizer: Research Funding. Maciejewski:Alexion, BMS: Speakers Bureau; Novartis, Roche: Consultancy, Honoraria. Nazha:Jazz: Research Funding; Incyte: Speakers Bureau; Novartis: Speakers Bureau; MEI: Other: Data monitoring Committee.

Newly Diagnosed Childhood AML Patients Treated with Bortezomib Show Superior Survival If CD74 Is Expressed: A Report of 991 Patients from the Children's Oncology Group AAML1031 Protocol

Introduction: CD74 is a type II transmembrane protein expressed on antigen-presenting cells and an MHC class II chaperone. It has been associated with tumor progression and metastasis in solid tumors, and its expression has been suggested to serve as a prognostic factor in many cancers, with higher relative expression associated with oncogenesis. As the expression of CD74 has been associated with response to bortezomib in multiple myeloma, we inquired whether such correlation might be seen in pediatric AML. We prospectively evaluated CD74 expression by difference from normal (ΔN) flow cytometry and correlated expression with clinical characteristics and outcome as part of Children's Oncology Group protocol AAML1031 that randomized patients younger than 30 years of age with de novo AML to standard treatment with (Arm B) or without (Arm A) bortezomib. The addition of bortezomib to standard chemotherapy increased toxicity but did not improve survival. Given the association of CD74 with B-lymphoid neoplasms and bortezomib's known efficacy in B-cell neoplasms and multiple myeloma, we hypothesized that within Arm B, the patients with CD74 expression would have a more favorable outcome. Methods: In total, 1,139 newly diagnosed pediatric patients with de novo AML were randomized to standard chemotherapy (n=561, Arm A) or standard chemotherapy with bortezomib (n=578, Arm B). All patients received the identical chemotherapy backbone with either four intensive chemotherapy courses or three courses followed by allogeneic hematopoietic stem cell transplantation for high-risk patients. To qualify for this correlative study, 991 patients satisfied 2 criteria: (1) submitting a bone marrow aspirate for ΔN at diagnosis and (2) providing consent for correlative biology studies. All diagnostic specimens were centrally and prospectively evaluated for the expression of CD74 by ΔN. AML was considered to be CD74-positive if the MFI was more than two times above background autofluorescence and more than 40% of the leukemia was above background autofluorescence. Results: Among 991 patients, 263 were CD74-positive (26.5%) by ΔN, with similar prevalence in Arm A (27.9%) and Arm B (25.2%). Correlation of CD74 expression with clinical characteristics showed that those with CD74 expression had higher median age (p<0.001), lower median WBC (p<0.001), higher prevalence of low risk protocol status (p=0.039), lower frequency of CEBPA mutation (p=0.039), inv(16) (p=0.001), and KMT2A rearrangements (p=0.002), and were enriched for t(8;21) (p<0.001) and t(6;9) (p=0.014) fusions. All these features retained significance when patients were sub analyzed by respective treatment arms. CD74-positive patients had a higher morphologic CR rate (p=0.016), however, measurable residual disease by flow cytometry was not significant in the entire cohort or in the sub analysis of treatment arms (p=0.155). CD74-positive patients showed superior 5-year OS (70.6% vs 61.8%, p=0.003) and EFS survival (51.2% vs 43.1%, p=0.007) compared to those who were CD74-negative. For patients in Arm A (no bortezomib), the differences in OS (66.1% vs 61.0%, p=0.138) and EFS (48.9% vs 41.7% p=0.088) were not significant between those that were CD74-positive and those that were CD74-negative (Figure 1). However, patients in Arm B receiving bortezomib that were CD74-positive showed a significant improvement in OS (75.3% vs 62.5%, p=0.006) and EFS (53.6% vs 44.3%, p=0.028) compared to those who were CD74-negative (Figure 1). Comparison of the outcomes for CD74-positive patients with and without bortezomib exposure showed a difference in OS of 66.1% vs. 75.3% for those in Arm A vs. Arm B but did not reach significance (p=0.155). Multivariable analysis for OS yielded a hazard ratio of 0.67 (95% CI: 0.44 - 1.02) and p=0.061, approaching, but not reaching, statistical significance. Conclusions: These data demonstrate that CD74 expression is associated with more favorable disease characteristics and survival. Patients receiving bortezomib that were CD74-positive showed a superior response to therapy compared to patients who did not express CD74, by both OS and EFS, suggesting that CD74-positive childhood AML patients stand to benefit from bortezomib therapy. Bortezomib may induce a mechanistic response in CD74-positive AMLs similar to that in bortezomib-treated B-cell neoplasms and/or multiple myeloma, where bortezomib has proven to be beneficial. Disclosures Cooper: Celgene: Other: Spouse was an employee of Celgene (through August 2019). Pollard:Syndax Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Systemic Inflammatory Biomarkers in Patients with Fuchs' Uveitis Syndrome: Neutrophil/Lymphocyte Ratio and Platelet/Lymphocyte Ratio.

To evaluate the neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) in patients with Fuchs' uveitis syndrome (FUS). A case-control study. Department of Ophthalmology, Haydarpasa Numune Training and Research Hospital, Turkey, between July 2016 and June 2019. Twenty-eight patients with unilateral FUS and 30 healthy subjects were enrolled in the study. The NLR and PLR were calculated from complete blood counts tests; and compared between the groups. There were 28 patients (14 females, 14 males; median age: 33.5 (30-47.5) in the FUS group; and 30 patients (16 females, 14 males; median age 37.5 (33-41.8) in the healthy group. The NLR (1.7 v.s 1.2, p = 0.036 was found to be significantly higher and PLR was lower (100.27 ±37.13 v.s. 141.68 ±26.50 p <0.001) in the FUS group compared with the healthy controls. The median WBC (p <0.001), neutrophil (p <0.001), lymphocytes (p <0.001), and monocyte (p=0.041) values were found significantly higher in the FUS group compared with controls. The significant correlations were not seen between the number of anterior chamber cells; which are ocular inflammatory parameter and NLRs (r = 0.312, p = 0.106) and PLRs (r = 0.148, p = 0.453). The current study suggests that a slowly progressive immune-mediated process can affect peripheral blood inflammatory biomarkers and there is evidence of benign subclinical systemic inflammation in patients with FUS. Key Words: Fuchs uveitis syndrome, Neutrophil to lymphocyte ratio, Platelet to lymphocyte ratio.

The association between white blood cell count and outcomes in patients with idiopathic pulmonary fibrosis

BackgroundThe course of idiopathic pulmonary fibrosis (IPF) is uncertain with variable patterns of disease progression. We sought to evaluate the prognostic utility of the WBC, a routinely performed lab test, in a well-defined cohort of outpatient IPF subjects. MethodsWe reviewed IPF patient records from two independent ILD centers (Inova Fairfax in Falls Church, VA, USA and Ege University Hospital in Izmir, Turkey) between 2007 and 2018. Demographics, CBC data, and patient outcomes were obtained. Survival differences were analyzed. ResultsThere were 436 IPF outpatients in the cohort with a median WBC of 8.9 × 109 cells per liter. For pragmatic purposes, patients were categorized into two groups, WBC ≥9 or WBC <9. Patients with WBC <9 had a median transplant-free survival of 50.5 months from the time of the CBC, compared to 32.4 months for those with WBC ≥9 (p < 0.0001). The association between WBC and attenuated survival remained significant after adjusting for GAP stage, steroid use, and antifibrotic use when WBC was analyzed both as a continuous (HR: 1.11; 95% CI: 1.05–1.17) and a dichotomized variable (high (WBC ≥9) vs. low (WBC <9), (HR: 1.53; 95% CI:1.09–2.15). WBC and absolute neutrophil count (ANC) were highly correlated suggesting that PMNs account for most of this association (r = 0.92). ConclusionsBaseline WBC may impart important and readily available prognostic information in outpatients with IPF. Further studies are warranted to validate this as a potential biomarker for IPF, as well as to define the biologic basis for the association.

Direk ve indirek inflamatuar belirteçler Brusella epididimo-orşiti non-Brusella epididimo-orşitten ayırabilir mi?

Giriş: Çalışmamızda inflamasyonu gösteren direk ve indirek belirteçlerin Brusella epididimo-orşit (BEO) tanısında ve Brusella dışı epididimo-orşit (NBEO) ayırıcı tanısındaki değerinin araştırılması amaçlanmıştır.

Prospective Evaluation of Feline Sourced Platelet-Rich Plasma Using Centrifuge-Based Systems.

Objective: To evaluate the hematologic components of platelet-rich plasma (PRP) generated using feline blood with two commercially available centrifuge-based systems1,2.Materials and methods: Twenty healthy adult cats were enrolled in this prospective study from November 2018 to January 2019. Feline blood samples were obtained for analysis of whole blood (WB) cellular components and preparation of PRP product. PRP was prepared using two commercial systems and complete blood count (CBC) testing was performed on both WB and PRP samples. The cellular composition of the PRP product was compared to the WB sample for each patient.Results: Both systems showed significant decrease of median RBC concentration in PRP products compared to WB samples (P = 0.002 for both systems). System 1 significantly decreased median WBC concentration (P = 0.002). System 2 decreased WBC concentration, though statistical significance was not reached (P = 0.63). Median platelet concentration was decreased by 3% using System 1, and increased by 187% using System 2. Platelet aggregation presented a challenge with 8/20 (40%) of samples demonstrating platelet aggregation.Clinical relevance: Commercial systems available for generation of PRP may be useful for creating a feline sourced product and in this study showed promise in decreasing RBC and WBC concentration. Neither system tested achieved 2–5 times platelet concentration from baseline. Platelet aggregation presented a significant obstacle to reliable generation of PRP products using feline blood. This treatment modality may be particularly beneficial for feline patients with osteoarthritis and soft tissue injuries, though first characterizing the PRP product made using feline blood is critical to validate its use in further clinical studies.

Clinical Characteristics and Prognostic Influencing Factors of Adult AML Patients with MLL Rearrangement

To investigate the clinical characteristics and prognostic influencing factors of adult AML patients with MLL rearrangement. Clinical data of 184 adult AML patients with MLL rearrangement treated in our hospital from January 2011 to December 2017 were analyzed retrospectively. The clinical features, immunophenotypic characteristics, cytogenetic characteristics, molecular biological characteristics and gene mutation characteristics were recorded, the survival and prognostic influencing factors of patients were analyzed. Among 184 patients, 94 cases were male, 90 cases were female, median age were 36.0 years, median WBC count were 22.0×109/L, 156 cases as 84.78% for FAB typing M5, and 18 cases as 28.13% for MLL/AF9 gene positive. The median total survival time and recurrence-free survival time of 184 patients were 15.7 months and 13.3 months respectively. The cumulative total survival rate and recurrence-free survival rate by followed-up for 2 years were 36.72% and 29.33% respectively. The cumulative overall survival rate and recurrence-free survival rate of transplant recipients were significantly higher than those of non-transplant recipients by follow-up for 2 years (P＜0.05). Univariate analysis showed that age, baseline WBC count, baseline Hb levels, complete remission after one course of treatment and transplantation or no were the influencing factors of overall survival time in adult AML patients with MLL rearrangement (P＜0.05). Cox regression model multivariate analysis showed that baseline WBC count, complete remission after one course of treatment, and transplantation or no were the independent influencing factors for overall survival time in adult AML patients with MLL rearrangement（P＜0.05）. Adult AML patients with MLL rearrangement are mostly belong to acute monocytic leukemia, and MLL/AF9 is the most common associated gene. Patients with AML and MLL rearrangement are prone to recurrence after routine chemotherapy. Allo-HSCT treatment is helpful to improve clinical prognosis of patients.

Positive Microbiological Findings at the Site of Presumed Aseptic Revision Arthroplasty Surgery of the Hip and Knee Joint: Is a Surgical Revision Always Necessary?

Little is known about patients that undergo presumed aseptic revision arthroplasty surgery of the hip and knee joint and having positive microbiological findings of the intraoperatively taken tissue samples. 228 “aseptic” operations were retrospectively analyzed from prospectively collected data with regard to the following parameters: demographic data; reasons for primary and revision surgery, respectively; time between primary and revision surgery; preoperative laboratory findings; microbiological and histopathological findings; type and length of systemic antibiotic therapy; clinical outcome; and follow-up. Identification of microorganisms was present in 8.8% of the cases (9.3% of the hip and 7.8% of the knee cases). Preoperatively, the median CRP value was 8.4 mg/l (normal values 0-5.0 mg/l) and the median WBC count 8,100 × 106/l (normal values 3, 700‐10,100 × 106/l). The most common identified organism was methicillin-resistant Staphylococcus epidermidis in 30%, followed by viridans streptococci in 15% of the cases. In 7 cases, the microbiological findings were interpreted as a contamination, and no antibiotic therapy was administered. In the other cases, a systemic antibiotic therapy was applied for a time period between 2 weeks and 3 months. 68.4% of the patients did not have any infectious complications at a median follow-up of 20 (3-42) months. The present study indicates that more than 2/3 of the cases with positive microbiological findings at the site of presumed aseptic revision arthroplasty surgery of the hip and knee joint can be successfully treated conservatively and they do not require any further surgical therapy.

Non-Steroid Anti-Inflammatory Drug Salsalate Provides Safe and Effective Pain Control during Stem Cell Transplantation

<h3>Intro</h3> NSAIDs are drugs of choice for the treatment musculo-skeletal pain and other inflammatory conditions. Salsalate is a platelet sparing NSAID with less gastric toxicity compared to aspirin. Using NSAIDs during HSCT is challenging as periods of profound pancytopenia and toxicity raise concerns about the safety of these agents. To date, the use of salsalate during HSCT has not been previously reported. <h3>Methods</h3> All HSCT recipients treated with salsalate for at least 7 days during the period of profound neutropenia and thrombocytopenia were included. Patients were monitored for kidney, liver (25% for > 2 days), hearing, emergence of GI/GU or other bleeding disorders, time to engraftment, drug toxicity or discontinuation. The Verbal Rating Scale for Pain (Severe: 7-10, Moderate: 4-6, Mild: 1-3) was used to grade pain before and after treatment. <h3>Results</h3> 44 (28 autologous and 16 allogeneic) stem cell recipients were identified. Female (24/44; 55%), Age -61(32-74); Dx: Myeloma (n=24), NHL (n=8), AML (n=5), Other(n=7). 8 patients were receiving NSAIDS prior to admission. 6 patients were admitted with baseline grade 3 CKD . Median WBC and platelet nadir while receiving salsalate was <0.1 and 8 cells/ml respectively. Median salsalate start date was Day+4(-6-32), median daily dose was 1.5g/day (1-3gm), and number of treatment days was 9(7-41). More than 80% patients experienced mucositis in addition to their treatment-directed pain. Table 1 show pain was improved or eradicated in 27/44 (64%) of patients, and stable in 15/44 (36%)- 9 of which were receiving NSAID PTA. All patients who experienced generalized body pain improved with salsalate. Change in kidney and liver function was infrequent (<10%) and there were no major bleeding episodes or hearing loss. Discontinuation occurred in 4 patients, 2 in patient for possible toxicity, and 2 for lack of effect. Time to engraftment was within normal limits and there was no hospital related mortality. Moderate doses of NSAID salsalate are well tolerated throughout the entire transplantation period in autologous and allogeneic recipients and may benefit patients with a variety of different types of pain, including growth factor, engraftment and cytokine release pain syndromes. Additional studies are needed to confirm these results.

PRMT5 Inhibition Modulates E2F1 Methylation and Gene Regulatory Networks Leading to Therapeutic Efficacy in JAK2VF Mutant MPN

Dysregulation of the protein arginine methyltransferase, PRMT5, occurs in a variety of malignancies and is associated with increased cancer cell proliferation. We investigated the role of PRMT5 in MPN pathogenesis through use of C220, a potent and selective small molecule PRMT5 inhibitor, and aimed to elucidate key PRMT5 targets contributing to the maintenance of MPN cells. We found that PRMT5 is overexpressed in MPN, most highly in PV. C220 dose-dependently reduced the proliferation of MPN cell lines and BaF3 cells expressing JAK2V617F in vitro. Human CD34+ cells from PV/PMF patients showed a high degree of sensitivity to C220 ex vivo. Consistent with the in vitrostudies, C220 treatment of SET2 xenografts in vivoled to a 71% reduction of median tumor volume, greater than that observed with JAK inhibition (59%). We assessed the efficacy of C220 in Jak2V617F- and MPLW515L-driven murine MPN models.In the conditional Jak2V617Fmodel of PV, mice treated with C220 displayed significant lower hematocrits (median 50.1% vs. 77.4 %, p&amp;lt;0.0001), WBC (median 4.5 K/µl vs. 16.9 K/µl, p&amp;lt;0.0001), reticulocytes (median 73 K/µl vs. 1522 K/µl, p&amp;lt;0.0001) and splenomegaly (median weight 68 mg vs. 270 mg, p&amp;lt;0.0001) compared to vehicle treatment. CD105+CD150- progenitors, committed erythroid progenitors (Pre-CFU-E), MEP, CD71-Ter119+ pro-erythroblasts and CD71+/Ter119+ erythroblasts were significantly decreased with C220 treatment [15.7% (p&amp;lt;0.0001), 36% (p=0.0004), 58% (p=0.01), 10% (p&amp;lt;0.0001) and 11% (p&amp;lt;0.0001), respectively, relative to vehicle]. In the MPLW515Ladoptive transfer model of ET/MF, C220 attenuated leukocytosis (WBC 11.1 K/µl vs. 155.3 K/µl, p=0.023), splenomegaly (136 mg vs. 423 mg, p=0.003), hepatomegaly (1118 mg vs. 1677 mg, p=0.004), and BM fibrosis (reticulin score 0.5 vs. 2+). C220 significantly reduced serum cytokines in the Jak2V617F(Eotaxin, GM-CSF, IL-12p40, LIX, KC, MCP1, MIP1a, MIP-2, M-CSF, RANTES, IP-10, IL-1b) and MPLW515L(MIP1b, TNF- alpha, RANTES, IP-10 and IL-1b) model consistent with inhibition of systemic inflammation characteristic of MPN. We next assessed the efficacy of combined PRMT5 and JAK inhibition. Dual targeting of JAK and PRMT5 displayed additive effects on SET2 cell proliferation in vitro and was superior to monotherapy with either agent in vivo. In the Jak2V617Fmodel, dual JAK/PRMT5 inhibition further reduced key features such as splenomegaly (median weight 39 mg vs. 68 mg or 127 mg, p=0.0004 and p&amp;lt;0.0001), elevated hematocrit (median 41.1% vs. 50.1% or 85.1%, p=0.0089 and p=0.0009), WBC (median 2.1 K/µl vs. 4.5 K/µl or 7.4 K/µl, p=0.0015 and p&amp;lt;0.0001) and led to a significant decrease in erythroid progenitor populations compared to PRMT5 or JAK inhibitor monotherapy. Dual JAK/PRMT5 inhibition showed increased efficacy in the MPLW515L model with more significant suppression of leukocytosis (median WBC 3.1 K/µl vs. 176.7 K/µl, p=0.0436), splenomegaly (median weight 117 mg vs. 438 mg, p=0.0062) and hepatomegaly (median weight 1105 mg vs. 1573 mg, p=0.0188). To further understand the mechanism by which C220 leads to therapeutic efficacy in MPN, we performed RNA-seq in sorted MEP from the Jak2V617FBMT model and from SET2 xenografts after vehicle or C220 in vivotherapy. GSEA revealed E2F targets as one of the major gene sets down regulated upon treatment with C220. Consistent with the potent suppression of E2F1 target gene expression in vivo, we found that E2F1 and PRMT5 physically interact in JAK2-mutant MPN cells. Moreover, PRMT5 inhibition altered the methylation status of E2F1, leading to reduced expression of E2F1 downstream targets, including genes involved in cell cycle and DNA damage repair. Functional investigation of key downstream targets is ongoing. Our data provide evidence that PRMT5 is a credentialed therapeutic target in MPN, alone and in combination with JAK inhibition. Moreover, the therapeutic effects of PRMT5 inhibition in MPN include attenuated expression of E2F targets, which our data suggests is mediated by PRMT5 methylation of E2F1. These data demonstrate a novel link between PRMT5, E2F1 gene regulatory function, and the survival of MPN cells and provide a strong mechanism-based rationale for therapeutic studies of PRMT5 inhibitors in MPN. Based on these studies and others, PRT543, a novel and selective PRMT5 inhibitor, is currently being evaluated in a Phase I clinical trial in advanced cancers, including myelofibrosis (NCT03886831). Disclosures Bhagwat: Prelude Therapeutics: Employment. Viny:Hematology News: Membership on an entity's Board of Directors or advisory committees; Mission Bio: Other: Sponsored travel. Grego:Prelude Therapeutics: Employment. Mehta:Prelude Therapeutics: Employment. Scherle:Prelude Therapeutics: Employment. Vaddi:Prelude Therapeutics: Employment. Levine:Novartis: Consultancy; Roche: Consultancy, Research Funding; Imago Biosciences: Membership on an entity's Board of Directors or advisory committees; Prelude Therapeutics: Research Funding; Celgene: Consultancy, Research Funding; Isoplexis: Membership on an entity's Board of Directors or advisory committees; C4 Therapeutics: Membership on an entity's Board of Directors or advisory committees; Loxo: Membership on an entity's Board of Directors or advisory committees; Qiagen: Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy; Lilly: Honoraria; Amgen: Honoraria.

Use of Lenalidomide Plus Rituximab in TP53-Mutated Mantle Cell Lymphoma (MCL) Outside of Clinic Trial: The Moffitt Experience

Introduction MCL is an incurable B-cell lymphoma, accounting for 3-8% of Non-Hodgkin Lymphoma (NHL). Efforts to increase frontline treatment intensity with cytarabine (AraC), autologous transplant, and prolonged Rituximab maintenance have improved outcomes for many. However, those with TP53 mutations do not show similar benefit, highlighting a need for novel approaches in this setting. Lenalidomide plus Rituximab (R2) has been shown to have activity in MCL, but little data exist in the context of TP53 alterations. Methods We retrospectively reviewed 145 patients diagnosed with MCL between 2005 and 2019. Cases were selected by diagnosis of MCL and clinical evaluation from July 2018 to June 2019. A total of 145 unique cases were identified, of which 63 had insufficient testing for TP53, 50 were negative, and 32 were mutation positive by cytogenetics, NGS, or FISH. Patients with mutated TP53 were further assessed for the primary outcome of event-free survival (EFS) and a secondary outcome of overall survival (OS). All statistical analyses were performed using SPSS software. Results Of 32 analyzed patients, 72% were male, with median age 67 years (46-87) and median WBC 15 (3-283). All but one patient presented with ECOG PS 0-1. LDH was elevated in 44%, with high MIPI in 56% of patients. Ki67 was available in 8 cases (median 30%), with 2 additional cases noted only as "blastoid." Frontline therapy consisted of Rituximab, Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (RCHOP) or Bendamustine plus Rituximab (BR) with maintenance Rituximab (6 patients), AraC, and/or transplant (8), R2 (8), BTK+Rituximab (2), or palliation (XRT 1, Rituximab 2, watchful waiting 5). Seven patients received R2 in the relapsed setting. With median followup of 44 months, the median OS was not reached (83%), and median EFS among all treated patients was 36 months. Among those who received frontline R2, 63% were male, with median age 68 (55-75), median WBC 74 (11-283), with elevated LDH in 50% and high MIPI in 88%. Ki67 was available for 2 patients, and measured 10% and 80%. The Median OS and EFS were 100% with median followup on therapy of 15 months. Conclusions Survival was surprisingly robust across this cohort of high risk MCL. Treatment with Lenalidomide plus Rituximab may provide an alternative regimen for TP53-mutated MCL in the first-line setting. Further analysis of long-term data will be beneficial to monitor durability of remission. Figure Disclosures Chavez: Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Bello:Celgene: Speakers Bureau. Sokol:EUSA: Consultancy. Pinilla Ibarz:Novartis: Consultancy; Teva: Consultancy; Janssen: Consultancy, Speakers Bureau; Abbvie: Consultancy, Speakers Bureau; TG Therapeutics: Consultancy; Bayer: Speakers Bureau; Sanofi: Speakers Bureau; Bristol-Myers Squibb: Consultancy; Takeda: Consultancy, Speakers Bureau. Shah:Celgene/Juno: Honoraria; Kite/Gilead: Honoraria; Incyte: Research Funding; Jazz Pharmaceuticals: Research Funding; Pharmacyclics: Honoraria; Adaptive Biotechnologies: Honoraria; Spectrum/Astrotech: Honoraria; Novartis: Honoraria; AstraZeneca: Honoraria.

Radiation Therapy Can be an Effective Bridging Strategy Prior to Axicabtagene Ciloleucel Therapy for Relapsed/Refractory Large B-Cell Lymphoma

Radiation Therapy Can be an Effective Bridging Strategy Prior to Axicabtagene Ciloleucel Therapy for Relapsed/Refractory Large B-Cell Lymphoma