Absolute Platelet Count Research Articles

Direct thrombin inhibitors for management of heparin-induced thrombocytopenia in patients receiving renal replacement therapy: Comparison of clinical outcomes

The clinical outcomes of patients receiving renal replacement therapy (RRT) and treated with direct thrombin inhibitors (DTIs) for the management of heparin-induced thrombocytopenia (HIT) were compared. A retrospective evaluation of clinical outcomes of patients receiving RRT with a presumed diagnosis of HIT treated with lepirudin, argatroban, or bivalirudin was conducted. Inpatients at the University of Pittsburgh Medical Center from January 1, 1995, through March 1, 2008, were included if they were receiving either continuous or intermittent RRT and argatroban, bivalirudin, or lepirudin; were exposed to heparin within the preceding 100 days (including a heparin-treated pulmonary artery catheter) or had a documented heparin allergy; and had at least one of following: (1) an absolute platelet count of <150,000 cells/μL, (2) a decline in platelets of >50% from baseline before exposure to heparin, or (3) a documented diagnosis of thrombocytopenia. The primary outcome assessed was a triple composite endpoint of thrombosis, hemorrhage, and inhospital mortality. A secondary assessment compared the pharmacodynamic relationship between activated partial thromboplastin time and the triple composite. For the primary endpoint, there was no statistically significant difference observed among DTIs. In patients receiving RRT, a lack of a previous heparin allergy, the degree of International Normalized Ratio elevation, and lower serum albumin were significantly correlated with increased morbidity and the occurrence of the composite endpoint. No differences in adverse events or other clinical outcomes were observed in this retrospective evaluation of DTI use in patients receiving RRT with presumed HIT.

Evaluation of the role of rhIL-11 on hematological recovery in lymphoma patients after autologous hematopoietic stem cell transplantation

To evaluate the effect of recombinant human interleukin 11 (rhIL-11) on hematological recovery after autologous hematopoietic stem cell transplantation (AHSCT) in patients with lymphoma. A retrospective study was carried out on 73 patients with lymphoma after AHSCT. The patients were divided into two groups. The study group (n = 35) received rhIL-11 1.5 mg daily from the fifth day after AHSCT to the day when platelets recovering to 80.0×10⁹/L. The control group (n = 38) did not receive rhIL-11 after AHSCT. All the 73 patients finished AHSCT from Mar 2003 to Dec 2008 in our department. Thirty-five patients received rhIL-11 and 38 patients did not. In the rhIL-11 group and control group, the nadir of platelet was (18.9 ± 5.0)×10⁹/L and (21.5 ± 6.0)×10⁹/L, respectively, with a significant difference (P = 0.04). The median time of platelet recovering to 50.0×10⁹/L was (14.3 ± 5.5) d and (13.2 ± 4.5) d (P = 0.37) in the two groups. There was no significant difference (P = 0.82) in the median numbers of platelet transfusion in the two groups. The curves of the mean of daily absolute platelet counts of the two groups were similar (P = 0.22). Adverse events related to rhIL-11 were not found in the rhIL-11 group. The results of this study do not show obviously accelerating effect of rhIL-11 on the platelet recovery in lymphoma patients after AHSCT and obvious increase of adverse events after rhIL-11 administration.

Prevalence of transcranial Doppler abnormalities in Nigerian children with sickle cell disease

Transcranial Doppler (TCD) ultrasonography helps to identify children with sickle cell disease (SCD) who are at an increased risk of stroke,making primary stroke prevention a reality. A cross-sectional study of145 Nigerian children aged ≥3 years with SCD was carried out to describe the pattern of cerebral blood flow (CBF) abnormalities. The mean time-averaged mean velocity (TAMV) was 152 ±27.0 cm/sec and122 ±22.0 cm/sec in Hb SS and Hb S1C group, respectively. Abnormal velocities were recorded in six (4.7%) of the Hb SS patients and none of the Hb S1C while conditional risk (CR) velocities were recorded in 19.7% of Hb SS (low conditional 11.0%, high conditional 8.7%) and low conditional in 5.6% of Hb S1C cases. Cerebral flow velocities showed a negative correlation with age and hematocrit. Compared with African-American children, Nigerian children with Hb SS disease have a considerably higher prevalence of CR velocities.

High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Rescue for Children with High-Risk Neuroblastoma. Experience of a Single Pediatric Center in Bogotá, Colombia

Neuroblastoma (NB) is the most common extracranial solid tumor in children. Prognosis of high risk NB is extremely poor. The use of high-dose chemotherapy with autologous hematopoietic stem cell rescue in consolidation has resulted in improvements in survival and appears to have the largest impact on the survival of the high risk subset of patients although long-term event-free survival remains less than 40–50%. The aim of this retrospective study was to analyze the outcome of children with high-risk neuroblastoma who underwent Autologous Stem Cell Transplantation (ASCT) in a new pediatric stem cell transplant facility. Between August 2008 to July 2011, 16 children underwent ASCT as part of a multimodality treatment approach consisted in induction chemotherapy, surgery, HDC and autologous stem cell rescue, radiotherapy and maintenance therapy with 13-cis retinoid acid. The conditioning regimen used in all cases consisted of Carboplatin (375 mg/m2 for 4 days), Etoposide (300 mg /m2 for 4 days), and Melphalan (60 mg/m2 for 3 days). There were 16 patients with NB consisting of 6 males and 10 females. The median age was 4.7 years (range 1-14 years). The median weight was 17,4kg (range 8-40kg). 12 patients had stage IV-NB and 4 had high-risk stage III-NB. The source of stem cells was peripheral blood in 15 patients and bone marrow in 1 patient. The median time to Absolute Neutrophil Count> 0.5 x 10 9/L was 13 days (range 9-35 days). The median time to an Absolute platelet count of >20 x 10 9/L was 23 days (range 9-35 days), one patient had a graft failure who presented adequate recovery after infusion of cryopreserved bone marrow back-up. The median follow up time was 492 days (range 55 days-1127 days). 4 of the 16 recipients had relapsed. At the present time, 13 patients are alive. Relapse was the only cause of death and Transplant Related Mortality was zero. we conclude that ASCT is a feasible and effective method of treatment for patients with high risk neuroblastoma. The inclusion of high-dose chemotherapy and autologous rescue have improved the chances of survival of children with high risk neuroblastoma in developing countries allowing to reproduce the results achieved in developed countries.

The Role of Complete Blood Cell Count in Prognosis—Watch this Space!

Prognostic factors in cancer patients provide information about possible clinical outcomes and help classify patients into different risk groups. Treatment and clinical management decisions are often challenging, thus the availability of reliable and accessible prognostic markers is vital when designing treatment plans and discussing them with patients. This article discusses the prognostic value of the complete blood cell count components (i.e., white blood cell count, absolute neutrophil count, absolute lymphocyte count, absolute monocyte count, hemoglobin level, and platelet count) in regard to clinical outcomes in patients with malignant disorders.

Azacitidine Has Limited Activity in Patients with MDS and AML

Abstract 5057 Background:The multicenter, randomized AZA-001 trial demonstrated that azacitidine (AZA) significantly improved overall survival in patients with intermediate-2/high risk MDS (including patients with AML < 30 % marrow blasts), compared with conventional care regimens, including supportive care, low dose cytarabine (LDAC) and intensive chemotherapy (Lancet Oncol 2009;10:223–32). Recent data has suggested that AZA may have limited efficacy in the “real life” situation (Hematol Oncol 2011Mar8; Epub ahead of print). This retrospective analysis evaluates the responses and outcomes of patients with MDS and AML < 30% marrow blasts who received AZA at the Princess Margaret Hospital. Methods:Between July 2009 and July 2011, 87 patients received AZA at the Princess Margaret Hospital. This analysis is restricted to patients with MDS and AML < 30% marrow blasts (n = 60), excluding AML with > 30% blasts (n = 6), MDS/myeloproliferative neoplasm (n = 1), and patients previously treated with intensive chemotherapy and/or alloSCT within the last 5 years (n = 20). Azacitidine was planned to be administered subcutaneously at the dose-schedule of 75 mg/m2/d for 6 days every 28 days. However, 8 patients received subsequent cycles of AZA in local centers at the dose schedule of 75 mg/m2/d for 5 days, 2 days off, followed by 75 mg/m2/d for 2 days (AZA 5-2-2). Results:Median age was 73 (range, 43 to 87), and 63% were male. Twenty-three patients (38%) had secondary or therapy-related MDS or AML. Two patients had received a prior organ transplant (heart and liver). Forty-two patients (70%) had MDS (7 RCMD, 10 RAEB-1, 17 RAEB-2, 3 CMML-1, 5 CMML-2). Cytogenetic risk (by IPSS criteria) was good in 19 (32%), intermediate in 6 (10%), and poor in 33 (55%) patients, respectively. Karyotype analysis failed in 2 patients (3%). IPSS was intermediate-1 in 4 (7%), intermediate-2 in 32 (53%), and high in 24 (40%) of the patients. Median baseline hemoglobin level, absolute neutrophil count and platelet count were 90.5 g/L, 0.9 × 109/L, and 44.5 × 109/L, respectively. Median prior therapies was 0 (range, 0–2) with 5, 3, 1, and 1 patients having previously received erythropoiesis-stimulating agent, hydroxyurea, LDAC, and decitabine, respectively.The median number of AZA cycles administered was 5.5 (range, 0–19). The best response was CR in 4 (7%), marrow CR in 8 (13%), and hematologic improvements in platelets, neutrophils, and erythroid in 15 (25%), 9 (15%), and 5 (8%) patients, respectively. Fifteen patients remain on treatment. Treatment discontinuation was mostly due to disease progression, lack of response, and/or intercurrent illness/infection, with 7 (12%) patients stopping therapy to proceed to an alloSCT. Twenty patients have died. Median overall survival was 36.7 weeks (range, 4.4 weeks-86.6+ weeks). Conclusions:Azacitidine has limited efficacy in this group of patients. Optimal therapy for this patient population still needs to be determined. Disclosures:Yee:Celgene: Honoraria. Schuh:Celgene: Honoraria.

Outcomes of High Dose Steroid Treatment with or without Aminocaproic Acid in Critically Ill Stem Cell Transplant Recipients with Diffuse Alveolar Hemorrhage

Abstract 3058 Background:Diffuse alveolar hemorrhage (DAH) complicates Hematopoietic Stem Cell Transplantation (HSCT) at a rate of 2–14%, and carries a mortality of 70 to 100%. For transplant patients that require intensive care unit (ICU) admission, the prevalence of DAH may be as high as 40%. Patients present with diffuse alveolar infiltrates with or without hemoptysis, and are diagnosed based on bronchoscopic and clinical findings. Retrospective studies have shown that high dose steroid therapy may improve outcomes and has thus been the traditional modality of treatment. A recent small retrospective study, however, cited improved mortality using high dose intravenous methylprednisolone (MP) combined with the anti-fibrinolytic agent aminocaproic acid (ACA) (Wanko et al. Biol Blood Marrow Transplant 2006.12: 949–953). We performed a larger study on the use of ACA and MP versus MP alone to evaluate outcomes on survival. Methods:We retrospectively analyzed all HSCT patients greater than 18 years of age admitted to the ICU that were diagnosed with DAH and treated with either high dose MP and ACA, or high dose MP alone in a consecutive 13 month period. Diagnosis of DAH was based on available bronchoscopic findings showing progressively bloody fluid and hemosiderin-laden macrophages, or a clinical presentation consistent with DAH. Mortality was measured from the time of DAH diagnosis to the time of death. Results:A total of 28 HSCT patients were included in the analysis. Of the transplants, 24 were allogeneic and 4 were autologous. The median patient age was 51 years, and the cancer categories included acute myelogenous leukemia (n=13), acute lymphoblastic leukemia (n=4), chronic myeloid leukemia (n=2), chronic lymphocytic leukemia (n=1), multiple myeloma (n=5), and lymphoma (2 Non-Hodgkins, 1 Hodgkins). Eleven of the transplants were from related donors, 14 were unrelated, and two were cord blood. Thirty-six percent of the patients were diagnosed with DAH within 30 days of transplantation, with a mean of 245 days post-transplant amongst the entire group. Overall, 82% of the patients required intubation and mechanical ventilation with an average of 14 ventilator days. A total of 57% (n=16) received high dose MP along with continuous ACA (4 gms IV load, followed by 1 gm/hr) vs. 43% (n=12) who received high dose MP alone. ICU severity of illness scores, coagulation parameters, and duration of steroid treatment were equivalent between the two groups. The incidence of GVHD was equivalent (25%) in each group, and there were no differences in mean absolute neutrophil count (5.6 +/− 4.8 vs. 4.2 +/−4.6, p=0.44) or mean platelet count (53.3 +/− 45.3 vs. 48.3 +/− 68.9, p=0.41) on ICU admission in the MP with ACA vs. MP groups respectively. The group receiving MP alone received a lower average daily dose of steroids (mean 300 mg/day, range 80–1000) as compared to the group receiving MP and ACA (mean 560 mg/day, range 100–1000) (p=0.03). There were no differences in 30, 60, 100 day mortality or overall survival between the two groups, with a 100-day mortality of 94% in the ACA with MP group vs. 92% in the MP alone group. The overall mortality was 100% in the ACA with MP group, and 92% in the MP alone group (p=0.68). Additionally, the average number of ventilator days, ICU length of stay (LOS), and hospital LOS did not differ between the two groups. There was no increase in thrombotic events including deep vein thrombosis, myocardial infarction, and ischemic stroke associated with ACA treatment. Conclusions:Combination therapy with high dose methylprednisolone and aminocaproic acid versus high dose methylprednisolone alone did not improve survival, decrease ventilator days, ICU length of stay or hospital length of stay in critically ill transplant patients with diffuse alveolar hemorrhage. Disclosures:Popat:Otsuka: Research Funding.

Laboratory HIT Testing in Critically Ill Patients

Abstract 198▪FN2▪This icon denotes a clinically relevant abstract Introduction:Many critically ill patients are frequently suspected of having HIT because heparin exposure is nearly universal and up to 45% of medical-surgical ICU patients have a platelet count of less than 150 × 109. Methods:Our objectives were: (1) To estimate the incidence of suspected and objectively confirmed HIT; and (2) To evaluate whether a published clinical prediction rule (the 4T’s score) reliably rules out HIT in ‘low risk’ ICU patients. PROTECT was a multinational, concealed, stratified, randomized blinded trial enrolling medical-surgical critically ill patients to evaluate thromboprophylaxis with the low molecular weight heparin (LMWH) dalteparin 5,000U daily vs unfractionated heparin (UFH) 5,000 twice daily on the primary outcome of proximal leg deep vein thrombosis (DVT). Patients were evaluated for HIT and included in this HITEC Substudy if 1) their platelet count decreased to less than 50 × 109/L, 2) if there was an otherwise unexplained platelet count decrease to less than 50% of the patient’s baseline (defined as the value found on the first platelet count after ICU admission as long as the count is >100 × 109/L), or 3) if venous thrombosis occurred, and 4) if HIT was otherwise suspected. There were 2 laboratory components to HIT testing (local and central). For local real-time clinical care, HIT was evaluated and treated as per local practice. Centrally, blood samples were analyzed at the laboratory of Dr Ted Warkentin at McMaster University. The 4Ts Score was completed by Research Coordinators (RCs) and by central adjudication. We defined HIT as a clinical suspicion of HIT and a positive serotonin release assay (SRA). Results:The PROTECT trial enrolled 3746 patients of whom 763 patients (397 allocated to UFH and 366 to LMWH) met HITEC enrollment criteria; 151 because of an absolute platelet count of less than 50×109, 253 because of a fall in their platelet count of greater than 50% from the time of ICU admission and 534 because venous thrombosis developed and 128 because of a clinical suspicion of HIT (categories are not mutually exclusive). Of these 763 patients, 475 had a central or local laboratory HIT test performed and were adjudicated. HIT was present in 15/3746 patients enrolled in the PROTECT study (0.4%, 95% CI 0.2% to 0.7%), and 15/475 (3.2%) with local or central testing, while 432 patients with RC 4Ts scores were matched to an adjudicated outcome. Using the 4Ts score, RCs and central adjudication classified patients as low risk (4Ts score of 3 or less) in 71.1% and 86.3% of cases, respectively, moderate risk (score or 4 or 5) in 25.7% and 12.0% of cases, and high risk (score of 6 or more) in 3.2% and 1.7% of cases. There was a good correlation between a low pretest probability according to the RCs’ scores and the absence HIT (prevalence of adjudication confirmed HIT 1.6% (95% CI 0.5 to 3.7%).There was a moderate correlation between a low pretest probability according to central adjudication and the absence HIT (prevalence of adjudication confirmed HIT 2.6% (1.3 to 4.7%). Discussion:HIT occured in less than 1% of medical-surgical critically ill patients, and in 3% of patients who had at least one criterion to suspect HIT. We failed to confirm our pre-specified criteria for successful implementation of the 4T's score (that the upper boundary the 95% confidence interval about the proportion of patients with confirmed HIT and a low 4Ts score was less than 3%) and thus we conclude that use of the 4Ts score does not rule out the presence of platelet-activating antibodies in medical surgical critically ill patients with clinically suspected HIT; SRA testing is recommended. Funding:Canadian Institutes for Health Research and Heart and Stroke Foundation of Canada Disclosures:Crowther:CSL Behring: Consultancy; Leo Pharma: Consultancy, Research Funding; BI: Research Funding; Bayer: Research Funding; Pfizer: Consultancy, Research Funding; Octapharm: Consultancy; Artisan: Consultancy. Off Label Use: Dalteparin is not indicated for prolonged DVT prophylaxis in medical intensive care unit patients. Zytaruk:Pfizer: donated study drug dalteparin for PROTECT. Cook:Pfizer: donated study drug dalteparin for PROTECT. Warkentin:GTI Diagnostics: Consultancy, Research Funding; GlaxoSmithKline: Consultancy, Research Funding; Pfizer Canada: Speakers Bureau; Sanofi-Aventis: Speakers Bureau; Informa: Patents & Royalties; Canyon Pharma: Consultancy, Speakers Bureau.

Allogeneic peripheral blood stem cell and bone marrow transplantation for hematologic malignancies: Meta-analysis of randomized controlled trials

Peripheral blood stem cells have emerged as an alternative to bone marrow for allogeneic transplantation. To elucidate the advantages and disadvantages of research evidence related to the effects of allogeneic peripheral blood stem cells transplantation (PBSCT) and bone marrow transplantation (BMT) for hematological malignancies, we conducted a systematic review of the literature of randomized controlled trials comparing PBSCT to BMT. We systematically searched Cochrane Library, MEDLINE, EMBASE and CNKI up to May 2011. Two reviewers independently identified the eligible studies and assessed the methodological quality of included trials. The relevant data were extracted and analysed using RevMan 5.1. Ten trials totaling 1224 patients have been assessed. Pooled comparisons of studies of PBSCT and BMT found that the overall survival in PBSCT group was non-significantly different from that in BMT group [RR 0.92, 95% CI (0.80–1.07)]. The disease-free survival and relapse rate in PBSCT group were significantly different from that in BMT group [RR 0.67, 95% CI (0.52–0.86) and RR 0.51, 95% CI (0.34–0.76), respectively]. The number of days to reach the absolute neutrophil and platelet count were shorter with PBSCT. The rates of acute and chronic graft-versus-host disease (GVHD) in PBSCT group were significantly higher than that in the BMT group. The mortality in PBSCT group was non-significantly different from that in BMT group. We concluded that PBSCT was associated with a similar overall survival and mortality, improved disease-free survival and a decrease in relapse, faster engraftment, more GVHD when compared with BMT in transplantation for hematologic malignancies.

Natural language processor as a tool to assess heparin induced thrombocytopenia awareness

The life-threatening consequences of heparin induced thrombocytopenia (HIT) may be prevented with early recognition, prompt heparin withdrawal and direct thrombin inhibitor use. To determine the level of HIT awareness, electronic term recognition software can be used to query the electronic medical record (EMR) to assess the thought process and test ordering behavior of health care providers confronted with falling platelet counts. We sought to assess the awareness of HIT in a large teaching institution using these tools. Mayo Clinic databases were queried to identify a cohort of hospitalized adults receiving heparin (06/1/08-06/1/09). Serial platelet counts for each patient were scrutinized for a 50% decrement from baseline. "Clinician awareness" was defined by mention of HIT (determined by electronic term recognition software) within the hospital record by any member of the healthcare team or requisition of platelet factor 4/heparin antibody testing. During this time period, 34,694 adults were hospitalized and 24,956 received heparin. Only 3,239 (13%) patients had more than 1 platelet count during the hospital stay. Of 199 patients (6.1%) with ≥50% platelet count drop, clinician awareness was 36%. The absolute platelet count was the only independent variable associated with HIT awareness (P<0.001). Both appropriate platelet count monitoring and HIT awareness are low at this large teaching institution. Software tools for monitoring awareness and providing realtime alerts of significant platelet count decrements may be useful.

Non‐palpable splenic enlargement as the Etiology of abdominal pain in an adolescent with Hemoglobin SC Disease

To the Editor: Hemoglobin SC disease (HbSC) has an incidence of approximately 1:833 live births in African-Americans 1. HbSC patients retain splenic function longer than HbSS patients resulting in an increased risk of splenic sequestration crisis and infarctions in older patients 2, 3. Herein, we report a unique presentation of remarkable splenomegaly in which the spleen enlarged in an anterior to posterior plane without evidence of splenic sequestration in an adolescent female with HbSC disease. An 11-year-old female was diagnosed with HbSC disease at birth via newborn screening. The past medical history was pertinent for a single episode of acute chest syndrome at 5 years of age and an episode of splenic sequestration 5 years later after returning from 3 months at sea level to an elevation of approximately 5,280 feet (1,609 m). Laboratory values of note included: a hemoglobin of 9.7 g/dl (baseline ≥10.9 g/dl), platelet count of 116,000/µl (baseline ≥166,000), and WBC 8.4 × 103/µl. Her spleen became non-palpable, and her laboratories returned to baseline in 2–3 months. Over the next 10 months, she complained of intermittent left upper quadrant abdominal pain necessitating admissions for acute pain control three times. However, there were not significant laboratory changes: her hemoglobin remained at 10.9–12.8 g/dl with a normal absolute neutrophil counts (2,340–5,378/µl) and platelet counts 166,000–594,000/µl. No palpable splenomegaly was noted on numerous abdominal examinations. On the fourth admission for abdominal pain with concomitant mild dyspnea, an abdominal CT scan was performed. An enlarged spleen was detected measuring 13 cm × 15 cm with mass effect on the stomach and left kidney, which did not extend below the left costal margin without evidence of splenic infarction (Fig. 1). CT imaging of the abdomen. A: Contrast-enhanced axial abdominal CT images show enlargement of the spleen more in the anterior–posterior relative to the cranial–caudal dimension and significant mass the effect on the left kidney by the enlarged spleen (arrow). B: Contrast-enhanced coronal reformatted abdominal CT images show enlargement of the spleen more in the anterior–posterior relative to the cranial–caudal dimension with a significant mass effect on the left kidney (arrow). The patient underwent a laparoscopic splenectomy without complications. The spleen weighed 537 g (expected weight for sex and age is 87 g) without evidence of infarction on histological review. She was discharged in good clinical condition without recurrence of abdominal pain in the past 12 months. Splenomegaly in adolescence and into adulthood is seen in more than 50% of individuals with HbSC disease; however, only 6% of HbSC patients develop splenic complications, including sequestration 2, 3. Of note, splenomegaly often portends this complication in patients with HbSC, for 46% of HbSC patients with splenic sequestration crisis had splenomegaly noted prior to the onset of symptoms with an average interval from detection of splenomegaly to sequestration of 3.6 years 3. This unique presentation of moderate abdominal pain, requiring hospital admission times four and complicated by mild dyspnea on the last admission, warranted imaging which demonstrated significant, non-palpable splenomegaly. Her abdominal pain resolved with splenectomy which revealed substantial splenic enlargement at five times the normal splenic weight for age. This case serves as a reminder that persistent abdominal pain in patient with HbSC should be evaluated thoroughly, as this unrecognized splenomegaly could have led to further complications. Lindsey Micel MD*, Rachelle Nuss MD* , Laura Fenton MD , Mark Lovell MD§, Christopher C Silliman MD, PhD christoper.silliman@ucdenver.edu* ¶, * The Department of Pediatrics, School of Medicine, University of Colorado Denver, Aurora, Colorado, Sickle Cell Treatment and Research Center, School of Medicine, University of Colorado Denver, Aurora, Colorado, The Departments of Radiology, The Children's Hospital Aurora, Colorado, § The Departments of Pathology, The Children's Hospital Aurora, Colorado, ¶ Research Department, Bonfils Blood Center, Denver, Colorado

Recombinant Human Granulocyte Colony-stimulating Factor in Preterm Neonates with Sepsis and Relative Neutropenia: a Randomized, Single-Blind, Non-placebo-controlled Trial

We performed a prospective, randomized, single-blind, non-placebo-controlled trial on preterm (<37 weeks) neonates (birth weight <2000g) with sepsis and absolute neutrophil counts (ANC) <5000 cells mm(-3) to study the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on all-cause-neonatal mortality and hematological parameters (total leucocyte (TLC, ANC, absolute monocyte and absolute platelet counts). The rhG-CSF group (n = 20) received 10 µg/kg/day of intravenous infusion of rhG-CSF once daily for 5 days along with conventional therapy, and the control group (n = 20) received conventional therapy alone. Hematological parameters on Days 0, 1, 3, 5, 7 and 14 of study entry and all-cause mortality rates at discharge were recorded. Baseline characteristics between the rhG-CSF and control group including mean birth weight (1395 ± 289 vs. 1500 ± 231g), mean gestational age (31.5 ± 2.68 vs. 32.6 ± 2.23 weeks), initial neonatal complaints and maternal characteristics were comparable. Mortality rates were significantly less among the rhG-CSF group (3/20 (15%) vs. 7/20 (35%), p < 0.05). By Day 5 (for TLC) and Day 3 (for ANC) of start of the intervention, rhG-CSF group had significantly higher TLC (8189 ± 1570 vs. 6936 ± 1128 cells mm(-3), p < 0.05) and ANC (4756 ± 1089 vs. 4213 ± 354 cells mm(-3), p < 0.05) compared to controls. ANC levels recovered to levels >5000 cells mm(-3) faster in the rhG-CSF group, with 80% babies having ANC >5000 cells mm(-3) by Day 7 of study entry compared with 35% in the control group (p < 0.05). Preterm neonates with sepsis and neutropenia treated with rhG-CSF adjunctive therapy have decreased all-cause mortality at discharge and a quicker recovery of their total leucocyte and ANC.

Immature and absolute platelet count changes and thrombocytopenia in malignant glioma

Temozolomide (TMZ) is commonly used for the therapy of malignant glioma and induces thrombocytopenia in a fraction of patients. Currently, no biomarkers predicting TMZ-induced thrombocytopenia are available. In this study, we investigated whether changes in platelet count (PLT) or the immature platelet fraction (IPF) may serve as predictor of TMZ-induced thrombocytopenia in malignant glioma patients. We prospectively included 52 malignant glioma patients receiving TMZ-containing therapy regimens in this study. Platelet counts and IPF were determined at each clinical follow-up visit (weekly during concomitant radiochemotherapy or at least monthly during TMZ monotherapy) using the Sysmex XE-2100 system. We explored the diagnostic utility of PLT change/day and IPF change/day from the last to the current follow-up visit for the prediction of clinically relevant thrombocytopenia (PLT < 100·000 μl(-1) ) at the next follow-up visit. Relevant thrombocytopenia was observed in 10 of 234 occasions. The areas under the receiver operating characteristic curves for PLT absolute change/day, PLT relative change/day and IPF relative change/day were 0·675, 0·703 and 0·663, respectively. The Youden indices (maximum sum of sensitivity and specificity minus one) were 0·31, 0·39, and 0·29, respectively. The corresponding positive predictive values were 16%, 57%, and 6·7%, and the negative predictive values were 97%, 97%, and 98%, respectively. The rather moderate diagnostic potential of our data indicate that the time course of PLT counts and IPF measured at routine clinical follow-up are not useful for the prediction of thrombocytopenia in glioma patients treated with TMZ.

Risk stratification using a new prognostic score for patients with secondary acute myeloid leukemia: results of the prospective AML96 trial

Patients with secondary acute myeloid leukemia (sAML) are generally thought to have a poor prognosis. As there are no prognostic risk stratification models for patients with sAML available, the aim of this study was to obtain a scoring system. Prognostic factors influencing overall survival (OS) and event-free survival (EFS) were analyzed in 305 sAML patients treated in the prospective AML96 trial. The obtained prognostic scoring system was then validated in an independent patient cohort included in the AML2003 and AML60+ trials. In addition to the known risk factors for AML, age and karyotype, we identified the absolute platelet count and the Nucleophosmin 1 mutational status at diagnosis as prognostic factors of sAML patients. A pronounced distribution of sAML patients into three score groups was achieved showing a 2-year OS/EFS of 52/44% for patients in the low-risk group, 21/12% in the intermediate-risk group and 7/3% in the high-risk group (both P<0.001). Validation of this scoring system in a second independent set of sAML patients revealed similar significantly different survival results. In conclusion, for the first time, a prognostic scoring system is provided for sAML patients, allowing differential treatment strategies in the future.

Sub-Optimal Inhibition of Thrombus Formation by Aspirin (as measured by RTTP analysis) In Primary Thrombocythemia

AbstractAbstract 4218Primary thrombocythemia (PT) is a myeloproliferative disease with a high incidence of thrombotic complications. First-line therapy is the inhibition of platelet aggregation with aspirin (via COX-1 inhibition) for the prevention of thromboembolic complications. However, this does not account for the potential for COX-2 expression in newly synthesized platelets. The purpose of the present study was 1) to determine whether aspirin reduces the thrombotic potential of PT patients who did not undergo cytoreductive therapy to the levels of those achieved in healthy volunteers (HV), and 2) to determine whether the presence of the JAK2V617F mutation is responsible for the elevated thrombotic potential in PT patients.We determined the thrombotic potential of a cohort of 16 PT patients and compared these values to those of 10 healthy volunteers all treated with 100mg aspirin QD. Thrombotic potential was determined using a custom built Real Time Thrombosis Profiler (RTTP). Whole blood anticoagulated with a Factor Xa inhibitor (to preserve physiological Ca++ concentration) with Rhodamine 6G-labeled platelets was perfused over a fibrillar collagen surface at shear rates approximating those in veins (100s-1), arteries (600 s-1) and moderately stenosed arteries (1600s-1). The deposition of fluorescently labeled platelets on the collagen surface was monitored in real time by fluorescence microscopy in the RTTP. Endpoint thrombosis (size of thrombi at t=300sec expressed as Mean Fluorescent Intensity/Area of coverage) and rate of thrombus growth (initial rate of platelet deposition) were recorded for each individual as measures of thrombotic potential and data are expressed as mean ± SEM (statistics performed using GraphPad Prism v4.03 using unpaired, 2-tailed Students t-test).Despite aspirin therapy, PT patients were characterized by significant increases in thrombotic potential at venous and arterial shear rates (Table 1) with a greater than 2-fold increase in the rate of platelet deposition. Interestingly only the size of thrombi formed but not the rate of formation was elevated in PT patients at moderately stenosed shear, likely a reflection of the increasing contribution of shear and decreasing dependence on absolute platelet count and other individual cellular factors in whole blood. The [Display omitted] Disclosures:No relevant conflicts of interest to declare.

Effects of Method of Peripheral Blood Hematopoietic Stem Cell Mobilization (G-CSF, G-CSF + Plerixafor, or Cyclophosphamide + G/GM-CSF) on Engraftment and Sustained Graft Function: Comparison Across Cohorts with Similar CD34+ Cell Dose

AbstractAbstract 2255Effects of Method of Peripheral Blood Hematopoietic Stem Cell Mobilization, G-CSF, G-CSF + Plerixafor, or Cyclophosphamide + G/GM-CSF, on Engraftment and Sustained Graft Function: Comparison Across Cohorts With Similar CD34+ Cell Dose. Introduction:Autologous peripheral blood hematopoietic stem cell transplantation (AHSCT) is a key therapeutic modality in the management of multiple myeloma (MM) and lymphomas (Ly). The dose of CD34+ cells/kg in the mobilized peripheral blood product has long been regarded as the main determinant of neutrophil and platelet engraftment after AHSCT. Whether the method of hematopoietic stem cell mobilization, namely G-CSF alone (G), G-CSF + plerixafor (G+P) or cyclophosphamide +G/GM-CSF (Cy+G/GM) independently affects engraftment and graft function is unknown. Method:We used a database of AHSCT patients with MM or Ly to define 3 groups with different mobilization strategies (G, G+P, Cy+G/GM) but receiving similar CD34+ cell doses. Mobilization strategies had been determined by the standard practice at the time of the transplant (Cy + G/GM) or, more recently, by an algorithm factoring in the target CD34+ cell dose and the peripheral blood CD34+ count after 4 days of G-CSF mobilization (G and G+P). Imbalances in cell doses across the three groups were resolved by eliminating from the analysis patients with extremes of CD34+ doses (without investigator awareness of the engraftment endpoints) so all groups had similar averages and variation in CD34+ doses. The three groups were compared in terms of engraftment of neutrophils (defined as the first of 3 consecutive days with neutrophil count >500/mm3) and platelets (first of 3 consecutive days with platelet count >20,000/mm3 without transfusion). Comparisons of sustained graft function were based on total white blood cell count, absolute neutrophil count, and platelet count on or near day 100 after transplantation. All patients received G-CSF support after transplantation at 10 mcg/kg/day from day 7 until neutrophil engraftment. Results:The initial database contained 123 (70 MM and 53 Ly) patients undergoing transplantation in the three groups (26 G, 38 G+P and 59 Cy+G/GM). The average (+/− SD) cell doses (×106 CD34+/kg) were 4.56 +/−1.85, 5.3 +/−3.07 and 6.63+/−4.31 in G, G+P and Cy+G/GM respectively. After elimination of patients with extremes of CD34+ dose to correct imbalances, 99 patients remained in the analysis (26 G, 33 G+P and 40 Cy+G/GM), defining three groups with similar average and distribution of cell doses. Average cell doses and endpoints are shown in the table. There were no statistically significant differences in time to neutrophil engraftment across the three groups. Platelet engraftment was significantly slower in G+P (16.2 +/− 8.2 days) than in G (12.7 +/− 3.3) or Cy+GM (11.7 +/− 8.2; ANOVA P=0.03). There were no significant differences on day 100 total white blood cell count, absolute neutrophil count or platelet count among the three groups. Conclusions:Mobilization with G+P may lead to delayed platelet engraftment independently of CD34+ cell dose. Whether this effect is determined by plerixafor itself or by pre mobilization factors associated with plerixafor use remains to be determined. Day 100 graft function is not affected by mobilization strategy.Mobilization StrategiesPG (n=26)G+P (n=33)Cy+G/GM (n=40)CD 34+ cell dose (× 106/kg)4.57 +/− 1.854.83 +/− 1.944.67 +/− 1.03Neutrophil engraftment (days)12.9 +/− 2.614.2 +/− 4.012.9 +/− 3.60.23Platelet engraftment (days)12.7 +/− 3.316.2 +/− 8.211.7 +/− 8.20.03D100 white blood cell count(103/mm3)5.23 +/− 2.114.57 +/− 1.75.25 +/− 2.070.37D100 neutrophil count (103/mm3)3.17 +/− 1.492.6 +/− 1.053.27 +/− 1.870.23D100 platelet count (103/mm3)136 +/− 56154 +/− 66156 +/− 820.63 Disclosures:No relevant conflicts of interest to declare.

Application of Mesenchymal Stem Cells Derived From the Umbilical Cord Instead of Bone Marrow In Hematopoietic Stem Cells Transplantation.

AbstractAbstract 4544Bone marrow-derived mesenchymal stem cells (BMMSCs) have been found to enhance engraftment of hematopoietic stem cell transplantation (HSCT), plus show effect against graft-versus host disease (GVHD) because of their immunosuppressive properties. However, harvesting these cells is an invasive and painful procedure. To substitute BMMSCs from alternative sources is necessary. We intravenously infused ex vivo-expanded third-party umbilical cord-derived mesenchymal stem cells (UCMSCs) obtained from a bank 8 times in 3 patients who developed severe, steroid-resistant acute GVHD after allogeneic HSCT. The acute GVHD improved with each infusion of UCMSCs. Besides, after cotransplantation of cord blood and UCMSCs in 5 patients, we found UCMSCs enhanced absolute neutrophil counts and platelet counts recovery. No adverse effects after UCMSCs infusions were noted. We also found that UCMSCs had superior proliferative potential and greater immunosuppressive effects than BMMSCs in vitro. This is the first report of UCMSCs in human clinical application. These findings suggest UCMSCs are effective in treating aGVHD and can enhance hematopoiesis after HSCT. Considering that they are not only easy to obtain but also proliferate rapidly, UCMSCs would be the ideal candidate for cell-based therapy, especially for diseases associated with immune responses because of their immunosuppressive effects. Disclosures:No relevant conflicts of interest to declare.

Combination Therapy with Entinostat (MS-275) and GM-CSF to Enhance Differentiation In Myeloid Malignancies

AbstractAbstract 3312 Background:Histone actylases (HAC and histone deacetylases (HDAC) are two important enzymes in epigenetic control that can affect transcription of important regulatory transcription factors. Entinostat is a HDAC inhibitor that has been shown in vivo and in vitro to have anti-proliferative effects on many cancer cell types (Abujamra Leukemia Res 2009). When administered at low concentration to leukemic cell lines, entinostat induced p21-mediated growth arrest and expression of differentiation markers; higher concentrations led to marked increase in reactive oxygen species, mitochondrial damage, caspase activation and apoptosis (Rosato Cancer Res 2003). A Phase I study using entinostat as a single agent in relapsed and refractory leukemia showed in vivo differentiation potential with several patients showing significant increases in their mature granulocyte population and increased acetylation of the CD34+ blast population (Gojo Blood 2006). GM-CSF has been shown to enhance the differentiation potential of various agents such as interferon-alpha, all-trans-retinoic acid, bryostatin, and numerous other anti-neoplastic agents. The effects of combination therapy with GM-CSF and entinostat in patients with high-risk MDS or refractory and/or relapsed AML are presented here. Methods:A Phase II study was conducted to assess the safety and efficacy of combination therapy with GM-CSF and entinostat in patients with high-risk MDS and relapsed or refractory AML who are not eligible for allogeneic bone marrow transplant (BMT). The combination of entinostat and GM-CSF was administered in 6-week (42 day) cycles for at least 2 cycles. Entinostat was originally give at 8 mg/m2 weekly but was eventually adjusted to 4 mg/m2 weekly for the first 4 out of 6 weeks due to toxicity. GM-CSF was given at a single dose of 125 micrograms/m2/day for days 1–35 in the cycles 1, 2, 4 and 6 and days 1–42 in cycles 3 and 5. Patients who tolerated two cycles of 4 mg/m2 were assessed for response through measurements of peripheral blood, bone marrow aspirate and biopsies. Transfusion requirements and adverse events (AE) were recorded on all subjects throughout the study period. Clinical responses for AML and MDS were measured according to International Working Group definitions of complete response (CR), partial response (PR), stable disease (SD), hematologic improvement, and progressive disease (PD). Results:A total of 24 patients met the eligibility criteria for response assessment. Median age was 71 (range 52–84) years and 15 (63%) were male. Of the 19 patients with AML, 8 had relapsed/refractory disease, 7 had AML arising from MDS, 3 had therapy-related AML, and 1 had de novo AML. The remaining 5 patients had a primary diagnosis of MDS. 10 patients (42%) completed 2 or more cycles at the 4 or 6 mg/m2 dose of MS-275. These patients completed a total of 33 cycles, 1 resulting in CR, 4 in PR, 24 in SD, and 4 in PD. In addition to these standard endpoints, improvements were also noted in peripheral neutrophil counts (p<0.019) and platelet counts (p<0.001), without an appreciable change in blast count as a result of treatment (p<0.50). These results were achieved with few toxicities at the noted dosing. A total of 38 cycles at the 4-mg/m2-dose were analyzed for Grade 3 or 4 toxicities, which included febrile neutropenia (n=3), neutropenic infection (n=3), bone pain (n=2), fatigue (n=1), pericardial effusion (n=1), and weakness (n=1). Conclusion:Although treatment with entinostat and GM-CSF did not result in durable remissions, there were notable improvements in absolute neutrophil and platelet counts without negatively impacting the blast percentage. These findings suggests that therapy with entinostat and GM-CSF differentially promotes growth of mature myeloid cells and appears associated with better marrow function by minimizing the need for platelet transfusions. Such strategies may be most effective when applied to patients with low disease burdens or as maintenance therapy for patients with high risk disease in remission. Disclosures:Matsui:Pfizer: Consultancy; Bristol-Meyers Squibb: Consultancy; Infinity Phamaceuticals: Consultancy, Patents & Royalties; Merck: Consultancy, Research Funding; Geron Corporation: Research Funding.

831 Patterns of Minor Bleeding in Neonates with Severe Thrombocytopenia: A Prospective Observational Study

Background and aim: A prospective cross sectional observational study to determine incidence and pattern of minor bleeding in neonates with severe neonatal thrombocytopenia (SNT) defined as platelet count 34 weeks, 28%. Neonates with early SNT ( 10 days (33%). Neonates with major bleeds did not show a higher incidence of minor bleeding events prior to the major haemorrhage. 41% of infants with nadir platelet counts ≤ 40 x109/L had minor bleeding. At platelet counts >40 x109/L 59% of infants had minor bleeding. Conclusion: Minor bleeding and in particular hematuria is common in thrombocytopenic neonates and appears to inversely correlate with gestational age but not absolute platelet count.

Iron chelation therapy with deferasirox in patients with aplastic anemia: a subgroup analysis of 116 patients from the EPIC trial

AbstractThe prospective 1-year Evaluation of Patients' Iron Chelation with Exjade (EPIC) study enrolled a large cohort of 116 patients with aplastic anemia; the present analyses evaluated the efficacy and safety of deferasirox in this patient population. After 1 year, median serum ferritin decreased significantly from 3254 ng/mL at baseline to 1854 ng/mL (P < .001). Decreases occurred in chelation-naive (3229-1520 ng/mL; P < .001, last-observation-carried-forward analysis), and previously chelated (3263-2585 ng/mL; P = .21, last-observation-carried-forward analysis) patients and were reflective of dose adjustments and ongoing iron intake. Baseline labile plasma iron levels were within normal range despite high serum ferritin levels. The most common drug-related adverse events were nausea (22%) and diarrhea (16%). Serum creatinine increases more than 33% above baseline and the upper limit of normal occurred in 29 patients (25%), but there were no progressive increases; concomitant use of cyclosporine had a significant impact on serum creatinine levels. The decrease in mean alanine aminotransferase levels at 1 year correlated significantly with reduction in serum ferritin (r = 0.40, P < .001). Mean absolute neutrophil and platelet counts remained stable during treatment, and there were no drug-related cytopenias. This prospective dataset confirms the efficacy and well characterizes the tolerability profile of deferasirox in a large population of patients with aplastic anemia. This study was registered at www.clinicaltrials.gov as #NCT00171821.