Significant Increase In Platelet Count Research Articles

JAK2V617F-Mutant Megakaryocytes Contribute to Stem Cell Expansion in Myeloproliferative Neoplasms

IntroductionThe myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET), are characterized by unregulated hematopoietic stem cell (HSC) expansion and overproduction of blood cells. The JAK2V617F mutation can be found in majority of MPN patients, but the mechanisms responsible for the MPN stem cell expansion remain incomplete. One hallmark feature of MPNs is megakaryocyte (MK) hyperplasia. We hypothesize that JAK2V617F -mutant MKs contribute to MPN pathogenesis by promoting HSC expansion.MethodsJAK2V617F Flip-Flop (FF1) mice and Pf4-Cre mice (from Radek Skoda, Switzerland) were crossed to generate a MK cell lineage-specific human JAK2V617F knock-in mouse strain (Pf4/FF1). Animal experiments were performed in accordance with the Institutional Animal Care and Use Committee guideline. Mice were sacrificed at 28 wk of age. Bone marrow and spleen cell flow cytometry analysis was performed on a FACSAriaTM III (BD). Mouse methylcellulose media and Megacult-C media (Stem Cell Technologies) were used to assay colony formation. The TaqMan¨ Gene Expression Assay (Applied Biosystems) was used for quantitative real-time polymerase chain reaction (qRT-PCR) to verify differential expression of fibroblast growth factor 1 (FGF1), platelet factor 4 (Pf4), transforming growth factor beta 1 (TGFb-1), chemokine (C-X-C motif) ligand 12 (CXCL12). For HSC transplantation experiments, wild-type CD45.1+ recipient mice (B6.SJL, Taconic) were lethally irradiated (950 cGy) and then received 5 x 106 nucleated marrow cells from Pf4/FF1 or age-matched littermate control mice (CD45.2).ResultsThrombocytosis was observed in Pf4/FF1 mice at 16wk of age. At 28wk there was a significant increase in platelet count (1406 vs. 808 x 109/L, p = 0.0009) in Pf4/FF1 mice but no change was noted in hemoglobin or white blood cell count compared with age-matched littermate controls. Splenomegaly was observed in 28wk old Pf4/FF1 mice compared to controls (spleen weight 0.101 vs. 0.070 gram, p = 0.040). Marrow cell colony assays demonstrated an increase in total hematopoietic progenitors (1.8-fold, p = 0.007) and in MK-committed progenitors (1.9-fold, p = 0.00009) in Pf4/FF1 mice compared to controls (Figure 1). Marrow cell flow cytometry analysis revealed that CD45+ EPCR+ CD48- CD150+ (E-SLAM) cells, a highly purified HSC population, were increased 3.2-fold (p = 0.028, n=4) in Pf4/FF1 mice compared to control mice, although the cells did not express JAK2V617F as determined by RT-PCR for FF1. CD41+ MK cells were also increased in Pf4/FF1 mice (Figure 2). Histologic analysis of marrow sections revealed an increased megakaryopoiesis with more MKs adjacent to the endosteal surface in Pf4/FF1 mice than in controls. In addition, there were dilated marrow sinusoids in Pf4/FF1 mice and sinusoidal endothelial cells (EC) were surrounded by MKs that conformed to the EC morphology (Figure 3). No marrow or spleen fibrosis was observed at 28 wk of age. To more directly test the effects of JAK2V617F -mutant MKs on HSCs, marrow cells from 28-wk old Pf4/FF1 mice or controls (CD45.2) were transplanted into lethally irradiated congenic CD45.1 recipients (n = 5 in each group). By 12 wks post transplantation, recipients of Pf4/FF1 marrow had already developed a higher platelet count (1105 vs. 772 x 109/L, p = 0.025) and a mildly elevated red cell count (10.7 vs. 9.9 x 1012/L, p = 0.017) than mice transplanted with the control marrow. To begin to understand the MK signals responsible for HSC expansion in Pf4/FF1 mice, qRT-PCR of purified CD41+ MK cells identified up-regulation of FGF1 (8.1-fold, p = 0.02), Pf4 (8.0-fold, p = 0.0003), and CXCL12 (3.1-fold, p = 0.005) and down-regulation of TGFβ-1 (75%, p = 0.0005) in Pf4/FF1 mice compared to controls.ConclusionsPf4/FF1 mice developed an ET phenotype with thrombocytosis, splenomegaly and increased numbers of E-SLAM HSCs and CD41+ MK cells, despite JAK2V617F expression being restricted to MKs. Marrow histology suggested that both the osteoblastic niche and vascular niche might be affected by the JAK2V617F -mutant MKs. In addition, marrow cells from Pf4/FF1 mice repopulated wild-type recipients and induced a MPN phenotype. MKs from such mice displayed an altered pattern of cytokine expression, possibly contributing to the observed effects but the precise mechanism by which JAK2V617F-bearing MKs affect the MPN marrow niche and HSC expansion deserve further investigation. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A life-saving therapy in Class I HELLP syndrome: Therapeutic plasma exchange

HELLP syndrome, which can affect multiple organ systems and cause maternal and fetal mortality, is a serious complication of pregnancy characterized by microangiopathic hemolytic anemia, elevation of liver enzymes, and thrombocytopenia. Delivering the infant usually suffices for the treatment of this syndrome. In cases with Class I HELLP syndrome, however, the clinical picture may rapidly deteriorate despite delivery. In this paper we presented the outcomes with the use of therapeutic plasma exchange in cases with class I HELLP syndrome. This study included 21 patients diagnosed with the Class I HELLP syndrome at Inonu University Faculty of Medicine, Department of Hematology between 2011 and 2014. A central venous catheter was placed and plasma exchange therapy was begun in patients unresponsive to delivery, steroid, and supportive therapy (blood and blood products, antihypertensive therapy, intravenous fluid administration, and antibiotics) within 24 hours after the diagnosis of Class I HELLP syndrome according to the Mississippi Criteria. All patients underwent therapeutic plasma exchange for three sessions each with a 1:1 volume. Hemogram and biochemical parameters of the patients were evaluated before and after the procedure. According to results, there was a statistically significant decrease in total bilirubin, LDH, AST, and ALT levels whereas a significant increase in platelet count was observed. Hemoglobin levels were increased, although this increase was not statistically significant. HELLP syndrome is primarily treated with the delivery of infant; however, some cases may show disease progression despite completion of delivery. As a potential cause of both maternal and fetal mortality, HELLP syndrome condition should be aggressively treated. Therapeutic plasma exchange is one of the available treatment options. Our study has found that postpartum use of plasma exchange therapy within 24 hours is an efficient and lifesaving treatment choice in Class I HELLP syndrome.

Case report: Follow-up, diagnosis, clinical evidence, laboratory evaluation, and treatment of Idiopathic thrombocytopenia using human Intravenous Immunglobulin in a terrier dog

The aim of the present case report is to describe the outcome, hematological and biochemical changes of treatment of idiopathic thrombocytopenia in a Terrier dog using human intravenous immunglobulin. The complete blood count, serum biochemistry, indirect immunofluorescence antibody and direct coomb’s tests, radiography and sonography were performed. Laboratory findings indicated sever thrombocytopenia (<15×103/µl) and mild leukocytosis. Increase in the erythrocyte sedimentation rate and total protein concentration were last up to 19 and 14 days, respectively .After it, areduction was observed and no relapse was reported. This case report provides the first successful treatment and clinical evidence of a terrier dog with idiopathic thrombocytopenia in which no underlying etiology has been identified. It was concluded that human intravenous immunoglobulin infusion (1 g/kg) is a safe treatment with a significant increase in platelet count without increase in hospitalization and the cost of patient care.

The prothrombotic paradox of severe obesity after cardiac surgery under cardiopulmonary bypass

BackgroundObesity is suggested to reduce postoperative bleeding in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB) but perioperative hemostasis variations have not been studied. Therefore, we investigated the effects of severe obesity (body mass index [BMI] ≥35kg/m2) on chest tube output (CTO) and hemostasis in patients undergoing cardiac surgery with CPB. Materials and MethodsWe prospectively investigated 2799 consecutive patients who underwent coronary and/or valve surgery using CPB between 2008 and 2012. 204 patients (7.3%) presented a severe obesity. ResultsIn the severe obesity group, the 6-h and 24-h CTO were significantly reduced by -21.8% and -14.8% respectively (P<0.0001) compared with the control group. A significant reduction of the mean number of red blood cell units transfused at 24h was observed in the severe obesity groups (P=0.01). On admission to the intensive care unit, a significant increase of platelet count (+9.2%; P<0.0001), fibrinogen level (+12.2%; P<0.0001) and prothrombin time (+4.1%; P<0.01) and a significant decrease of the activated partial thromboplastin time (-4.2%; P<0.01) were observed in the severe obesity group compared with the control group.In multivariate analysis, severe obesity was significantly associated to a decreased risk of excessive bleeding (24-h CTO >90th percentile; Odds ratio: 0.37, 95% CI: 0.17 to 0.82). No significant differences were observed regarding postoperative thromboembolic events between the two groups. ConclusionsSevere obesity is associated with a prothrombotic postoperative state that leads to a reduction of postoperative blood loss in patients undergoing cardiac surgery with CPB.

Marcadores hematológicos e bioquímicos após um torneio de Jiu-Jitsu Brasileiro em atletas de elite

The objectives of this study were to assess the effect of participation in a Brazilian Jiu-Jitsu (BJJ) competition on biochemical and hematological markers, and to determine whether the skill level of the athletes influenced these responses. Thirty BJJ fighters were divided into two groups: an elite group (EL) including 20 subjects classified as 1stto 3rdplace in the previous World Championship, and a non-elite group (NEL) including 10 BJJ athletes not participating in competitions. A BJJ tournament was simulated using the same rules as those of the World Championship. Each athlete performed five fights of up to 10 minutes each, with 5-minute resting intervals between fights. The fighting order was random and fights confronted athletes of the same group. Pre- and post-competition blood samples were collected to assess biochemical and hematological markers. Participation in the competition induced significant increases in the following variables in athletes of the two groups: glucose, uric acid, urea, creatinine, total protein, albumin, creatine kinase, leukocytes, neutrophils, rods, and monocytes. There was a significant increase in platelet count only in the NEL group. Total protein and mean platelet volume were higher in athletes of the EL group, whereas eosinophil and monocyte numbers were higher in the NEL group. A significant time x group interaction was only observed for serum creatinine, with higher mean values in the EL group pre- and post-competition.

The Role Of Splenectomy In The Treatment Of Myelofibrosis

BackgroundSplenectomy (SE) at the Myelofibrosis (MF) is one of the difficult operations on the techniques and perioperative complications. There are a lot of complications such as inflammatory and adhesive processes, a massive bleeding associated with disorders of hemostasis in thrombocytopenia or thrombocytosis, enlargement of varicose veins, concomitant pathology. A SE doesn't cure myelofibrosis but may be performed in some cases. Success is unpredictable, and the operative mortality of SE is on the order of 10%. ObjectivesEvaluate the clinical and hematologic SE efficiency in patients with MF, resistant to traditional treatment. Patients and methodsWe analyzed the medical case history of 52 patients with MF, which were observed in the National Research Center for Hematology from 2004 to 2013. All patients were performed SE. 47 patients diagnosed with primary MF, and 4 – post-polycitaemic MF and 1 patient post-trombocitaemic MF. PMF was diagnosed according to the criteria established by WHO (2008), which include bone marrow fibrosis, and splenomegaly leyko-eritroblastosis in peripheral blood. The average age at diagnosis was 47 years (24 – 78 years), and before the SE – 53 (25 – 79 years). Women and men ratio was 1.3:1. According to the predictive model of the Dynamic International Prognostic Score System - (DIPSS) 38 (73%) patients before the SE attributed to intermediate risk 2, 14 (27%) patients – high risk. BCR-ABL gene not found a single patient, and the gene mutation JAK2V617F at different stages of the disease is detected in 53% of cases. Genetic adverse factors are not taken into account because of the small number of studies. Massive and huge splenomegaly was present in 37 (71%) patients. Spleen weight 0.9 to 2.9 kg is removed in 15 (29%) patients, from 3 to 7 kg is removed in 35 (67%) patients. In two cases, removal of the spleen weight of 10 and 11 kg. Statistical analysis were done using SAS 9.3 and JMP 10.0 (SAS Institute Inc., Cary, NC). ResultsDisease duration was about 76 months and ranged from 1 to 240 months. Surgical complications occurred in 21 patients, including bleeding 3, thrombosis 1, infection 2. Surgical complications from SE in intra-and early postoperative period was 8% from 1978 to 2003. Surgical complications from SE in intra-and early postoperative period was not fixed from 2004 to 2013. After SE complications were hepatomegaly, resistant thrombocytosis (platelet count ≥ 600 × 109/L), leukocytosis (white blood cell count greater than 10 x 109/l) and blast transformation of the disease. More than 80% of patients after SE had no symptoms of intoxication. 22 patients with MF had transfusion dependent anemia, 11 (50%) had disappeared transfusion requirements after SE in and the effect lasted for about a year. Only 4 of the 15 patients with thrombocytopenia who underwent SE due to refractory thrombocytopenia were observed a significant increase in platelet count above 100h109 / L, for an average of 6 months. The possibility of the resumption of long-term cytoreductive therapy appeared in 30 (58%) patients. Currently alive 19 (37%) patients, mean follow-up was 37 months (4 to 72 months) after the SE and of 105 (12-264) months after diagnosis. 33 (63%) patients died during the observation period after SE (1 – 84 months, mean – 27 months). Among these, 27 (82%) patients died of transformation disease and 6 (18%) died of comorbidity. 19 (37%) patients, with a mean follow-up of 37 months after SE (from 4 to 72 months) continue treatment with hydroxyurea. Median survival after SE is 3 years (Figure 1), with a median overall survival - 11 years (Figure 2). [Display omitted] [Display omitted] ConclusionDespite the potential complications SE is an effective palliative method for patients with MF in the absence of leukemic progression. SE indicated in patients with drug refractory MF, acute constitutional symptoms, anemia, transfusion-dependent, and portal hypertension. Modern methods of surgery, as well as supporting therapy in the perioperative period can safely perform the SE. Disclosures:No relevant conflicts of interest to declare.

Abstract 496: Evaluation of Some Hemostatic Parameters in Patients With End-Stage Renal Disease: Relation to Dyslipidemia and Hemodialysis Therapy

Background: Patients with end stage renal disease (ESRD) are prone to hemorrhagic complications and simultaneously at risk for a variety of thrombotic complications. Abnormal lipid metabolism and endothelial cell injury are considered as potential risk factors for atherothrombosis in these patients. This study assessed the status of some hemostatic parameters in ESRD patients and define their relation to lipid profile and hemodialysis therapy. Patients and Methods: Twenty-four patients with end-stage renal disease were selected for the study (Ten of them were under conservative treatment and fourteen were under regular hemodialysis therapy).Ten age-and gender-matched healthy subjects were recruited as a control group. All patients and controls were subjected to routine laboratory work up as well as measurement of plasma lipids, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, soluble fibrin monomer, ADP-induced platelet aggregation, plasminogen and plasminogen activator inhibitor-1 (PAI-1). Results: We found statistically significant increase of triglycerides, LDL-C, fibrinogen and PAI-1 levels, prolongation of APTT and significant decrease of HDL-C level, platelet count, prothrombin activity and impairment of platelet aggregation response to ADP in ESRD patients compared to controls (P&lt; 0.05). Furthermore, we demonstrated a significant increase of platelet count in dialyzed compared to undialyzed ESRD patients (P&lt;0.05). Also we found a significant negative correlation between serum triglyceride level and plasminogen concentration (r = -0.644 ; P = 0.044) and between LDL-C levels and platelet count (r = - 0.709 ; P = 0.022) in undialyzed ESRD patients. Conclusions: Profound changes of hemostasis and plasma lipids do exist in ESRD patients and is not significantly corrected by hemodialysis therapy. Elevated fibrinogen level, low PAI-1 level and hypertriglyceridemia might contribute to hypercoagulability in ESRD patients which is not ameliorated significantly by the currently used hemodialysis therapy. Newer methods of dialysis or more biocompatible filters or techniques may offer potential benefits in these conditions.

RHD zygosity predicts degree of platelet response to anti-D immune globulin treatment in children with immune thrombocytopenia

Anti-D immunoglobulin is a common front-line treatment for childhood immune thrombocytopenia (ITP) that typically results in a rapid and significant increase in platelet count. Unpredictable treatment responses and interpatient variability limit more widespread use. We hypothesized that anti-D response variability is influenced by RHD gene zygosity and erythrocyte D antigen expression. We compared RHD zygosity and quantitative D antigen expression to anti-D treatment results. Hemizygous RHD subjects demonstrated significantly higher platelet increases and peak platelet counts than homozygous RHD subjects. Future studies should investigate the mechanisms by which RHD zygosity and D antigen expression affect platelet responses to anti-D immunoglobulin.

Diurnal variation of haemostatic response to exercise in young sedentary males.

The aim of this study was to evaluate diurnal variations in the haemostatic response to submaximal exercise performed by young, sedentary men. Fifteen healthy young sedentary males aged 25.6 ± 1.34 (mean ± SD) years performed two exercise sessions, morning and evening, at 70% of maximal oxygen consumption (O2max) on a cycle ergometer for 30 min. Platelet count (PC), activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) activity were measured as dependent variables. Exercise produced significant increases in PC and fibrinogen for both sessions (P ≤ 0.05), which returned to the resting values after recovery only in the evening session. APTT and PT shortened immediately after exercise, which remained after recovery for both sessions (P ≤ 0.01). Exercise presented significant increases in tPA activity (P ≤ 0.001), which returned to the baseline after recovery in both exercises. PAI-1 activity was significantly higher during the morning than evening (P ≤ 0.05), but no longer demonstrated exercise-related changes. It was found that exercise caused activation of both coagulation and fibrinolysis processes, partly related to the time of the day when the exercise was performed.

NOVEL INVESTIGATIONS ON THUJA OCCIDENTALIS EXTRACT ON RABBIT HEMATOLOGICAL AND BIOCHEMICAL PARAMETERS

Thuja occidentalis (family: Cupressaceae) has been used as antiseptic, expectorant, diuretic and in the treatme nt of cancer and removal of kidney stones in different system s of medicine . Th e present studies were carried out on T. occidentalis leaves extract to evaluate the h ematological and biochemical effects on rabbit s . The animals were divided in to control (A a nd B) and treated (C and D) male and female groups ( n= 5). T here was a slight decrease in Hemoglobin, Red blood cell count and Hematocrit/Packed cell volume values, while a significant increase in platelet count was observed in male and female treated group s . However, slight increase in total leukocyte count value in male treated group and decrease count with female treated group wa s also observed. Urea, Creatine phospho kinase, Creatine phospho kinase iso - enzyme, Direct Bilirubin, Gamma - glutamyl transpeptid ase , Cholesterol and Albumin/Globulin ratio values were elevated in male treated group . While Phosphorus, Uric acid, Lactate dehydrogenase , Serum glutamic oxaloacetic transaminase , serum glutamic - pyruvic transaminase , Alkaline Phosphatase, Cholesterol, Tri glycerides, High density lipoprotein, Low density lipoprotein, Very - low - density lipoprotein , Globulin and Blood Glucose values were found low . In female treated group almost same results were observed like male treated group except th at hypoglycemic effect was more pronounced in female treated group. These findings suggested that when results of hematological and biochemical parameters of test groups (C & D) were compared with their respective controls (A & B), significant changes were observed which contr ibutes towards the diversified therapeutic effect of T. occidentalis .

Thrombopoietin Can Induce Tolerogenic Responses Via the Modulation of Thymic and Splenic T Lymphocyte Populations in a Murine Model of Immune Thrombocytopenia (ITP)

AbstractAbstract 1088Clinical trials using thrombopoietin (TPO) mimetics have clearly shown their benefit in raising platelet counts in patients with immune thrombocytopenia (ITP), however, little is known whether TPO may affect immunologic responses. It has been demonstrated that, like other therapies, TPO treatment can rescue the peripheral CD4+CD25+FoxP3+ T regulatory cell (Tregs) deficiency that is commonly observed in patients with ITP (Bao W et al Blood 116;4639, 2010). Of interest, an earlier murine study also suggested that TPO could affect the production of T cells, particularly CD4+ T cells (Zhao JZ et al Haematologica 83:572, 1998). Using a murine model of ITP that demonstrates both antibody and T cell mediated thrombocytopenia, we studied T cell responses in ITP mice treated with TPO. ITP was induced in severe combined immunodeficient (SCID) mice by administration of 2×104 splenocytes from CD61 (GPIIIa) knockout mice immunized against CD61 and the mice where either treated or not with weekly subcutaneous injections of 1ug of murine TPO. Mice were bled weekly to count platelets and obtain sera for anti-platelet antibody production and at 3 weeks after the splenocyte transfer, they were sacrificed and their spleens and thymi were harvested. Splenocytes and thymocytes were isolated and examined by flow cytometry to quantify CD4+CD25+FoxP3+ (Tregs) and CD8+CD25+FoxP3+ (Tc-regs). We observed that TPO treatment caused an expected significant increase in platelet counts, however, the treatment also caused a significant reduction in the titre of serum anti-platelet antibodies. This was associated with significant changes in the proportions of both CD4+ Tregs and CD8+ Tc-regs within the thymus and spleen. TPO treatment rescued the peripheral splenic Treg and Tc-reg deficiencies and the cells ability to functionally suppress the proliferation of conventional CD4+CD25- T cells. The data suggests that in addition to its megakaryocyte-stimulating properties, TPO treatment has additional tolerance-inducing effects associated with anti-platelet antibody reduction and CD4+ Treg and CD8+ Tc-reg stimulation. Disclosures:No relevant conflicts of interest to declare.

Eculizumab (ECU) in Atypical Hemolytic Uremic Syndrome (aHUS) Patients with Progressing Thrombotic Microangiopathy (TMA): 2-Year Data.

AbstractAbstract 2084 Introduction:aHUS is a rare, life-threatening genetic disease marked by chronic, uncontrolled complement activation leading to TMA and subsequent kidney and vital organ damage. 33%–40% patients (pts) die or progress to end-stage renal disease after the first clinical manifestation. In a phase 2 extension trial (64-week [wk] median ECU duration), pts receiving the terminal complement inhibitor ECU had a highly significant increase in platelet count (98×109/L; P=0.0001)—a measure of TMA improvement—and 4 pts (80%) discontinued prior dialysis by data cutoff. Here we report 2-year (y) results. Methods:Pts ≥12 y with aHUS and progressing TMA enrolled in an open-label, phase 2 trial with long-term extension. Pts had ≥4 plasma exchange/infusion (PE/PI) sessions in the wk before screening. ECU was administered at 900 mg/wk × 4 wk, 1200 mg at wk 5 and 1200 mg q2 wk thereafter. Results:The 26-wk study enrolled 17 pts, and 13 entered the extension phase. Data analysis was on the intention-to-treat population (n=17). Median time from diagnosis to screening was 10 months (range 0.3–236). Four pts (24%) had no identified complement regulatory factor mutation. Seven pts (41%) had prior renal transplant. All pts had estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 prior to ECU. Median ECU duration was 100 wk (range 2–145).Suppression of terminal complement activity was sustained at data cutoff. Significant platelet count improvement from baseline was seen at the 2-y data cutoff (P<0.0001; Table), with 15 pts (88%) achieving and maintaining a platelet count ≥150×109/L. Hematologic normalizationa was achieved by 88% of pts for an average duration of 629 days (d). Fifteen pts (88%) achieved TMA event-free status,b and TMA intervention ratec decreased from a median 0.88 (range 0.04–1.59) prior to ECU to 0 (range 0–0.31) during ECU treatment. Significant improvements in eGFR were observed throughout the study period (P=0.0008; Table). Earlier intervention with ECU was associated with greater eGFR improvement (P<0.01). Results of a 3-piece linear model demonstrated a flat slope for eGFR change from d −42 to 0, followed by a steep positive slope from d 0 to 28 (P<0.0001), then a continuous increase from d 28 to 860 (P=0.03). Improvements in other renal endpoints, including serum creatinine, proteinuria, and chronic kidney disease (CKD) stage, were observed with ongoing ECU. Significant improvements in quality of life (QOL) were observed. Pts received benefit regardless of the presence or absence of an identified complement mutation. Treatment with ECU was generally well tolerated, with 1 report of a serious adverse event (SAE; hypertension) deemed possibly drug related, which resolved with no change in ECU dosing. Two pts discontinued treatment due to worsening renal function unrelated to ECU. Conclusions:Long-term ECU therapy inhibited complement-mediated TMA and resulted in significant and continuous time-dependent improvements in renal function. At a median duration of almost 2 y, all pts entering the extension phase remain alive and report better QOL. The low rate of SAEs is consistent with the known safety profile of ECU. These results highlight the ongoing benefit of earlier intervention and long-term treatment with ECU in aHUS.TableChange from baseline in key outcomes from 26 wk and 100 wk of ECU treatment (N=17)Key OutcomesWk 26Median 100 WkMean platelet count change (primary), ×109/L (95% CI)73 (40–105)88 (63–112)P=0.0001P<0.0001 (wk 96)Hematologic normalization (primary),a n (%)13 (76)15 (88)TMA event-free status,b n (%)15 (88)15 (88)eGFR increase of ≥15 mL/min/1.73 m2, n (%)8 (47)10 (59)CKD improvement ≥1 stage, n (%)10 (59)12 (71)Serum creatinine decrease ≥25%, n (%)11 (65)13 (76)Mean eGFR change, mL/min/1.73 m2 (95% CI)31 (17, 45)32 (15, 49)dP=0.0001P<0.0008 (wk 96)Proteinuria decrease ≥1 grade,e n/N12/157/9 (wk 96)Mean health-related QOL change,f0.32 (0.27, 0.38)0.33 (0.30, 0.36)EuroQOL 5D score (95% CI)P<0.0001P=0.0001 (wk 96)CI=confidence interval.cPE/PI or new dialysis events/pt/d.aNormal platelet and lactate dehydrogenase levels, ≥2 consecutive measurements, ≥4 wk apart.b≥12 wk of stable platelet count, no PE/PI and no new dialysis.dECU eliminated need for dialysis in 4/5 pts receiving dialysis at baseline. An additional pt initiated dialysis at wk 64 (eGFR, 19 mL/min/1.73 m2 at screening).eEvaluable pts.fClinically meaningful threshold ≥0.6. Disclosures:Greenbaum:Alexion Pharmaceuticals: Consultancy, Honoraria, Research Funding, Speakers Bureau. Legendre:Alexion Pharmaceuticals: Speakers Bureau. Babu:Alexion Pharmaceuticals: Honoraria, Research Funding. Cohen:Alexion Pharmaceuticals Inc.: Research Funding. Bedrosian:Alexion Pharmaceuticals: Employment. Loirat:Alexion Pharmaceuticals: Coordinator of Alexion trials of eculizumab in atypical HUS for France. Honoraria for conferences. Other.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

The concentrations of serum, plasma and platelet BDNF are all increased by treadmill VO2max performance in healthy college men

The most current human-based studies in which brain-derived neurotrophic factor (BDNF) levels in the peripheral blood system are analyzed use it as an indicator that represents BDNF levels in the CNS. However, whether circulating BDNF (serum and plasma) is positively or inversely associated with cardiorespiratory fitness levels (VO2max) is still controversial, and no study has done to investigate exercise effects on the concentration of BDNF stored in circulating platelets which, in fact, store a large amount of circulating BDNF. Thus, the purpose of this study was to determine the relation between VO2max and all circulating BDNF levels (serum, plasma and platelets) in college male students (N=18; age, 19±1 years; height, 173.22±7.65cm; weight, 78.25±14.25kg; body fat percent, 13.82±5.68%). Dual X-ray energy absorptiometry whole body scan was used to measure their body composition. After the overnight fast, all participants were performed VO2max test, and their blood was collected at rest and immediately after the exercise. Our data resulted in significant increases in platelet counts and serum, plasma and platelet BDNF levels immediately after the exercise (p<0.01). VO2max had a significant negative correlation with serum BDNF, plasma BDNF and platelet BDNF at rest (p<0.05) but a significant positive correlation with serum, plasma BDNF, and platelet BDNF immediately after the exercise (p<0.01). However, our data show no correlation between VO2max and platelet count both at rest and immediately after the exercise. In conclusion, this is the first study showing that basal BDNF levels are inversely correlated with cardiorespiratory fitness levels but that the inverse correlations turn into positive correlations with all circulating BDNF levels immediately after the exercise. Moreover, it is the first time to provide evidence that platelet BDNF levels are also positively affected by the exercise. However, future studies will be needed to investigate what tissues provide BDNF into the circulating system and to elucidate the role of circulating BDNF.

Effect of enhanced external counterpulsation treatment on mean platelet volume in patients affected by ischemic chronic heart failure

Mean platelet volume (MPV) is increased in chronic heart failure (CHF) and is an independent predictor of mortality in CHF patients. It is not known whether enhanced external counterpulsation (EECP) therapy leads to decreased MPV values or not. The purpose of this study was to examine the effects of EECP on platelet count and MPV values and to assess the influence of MPV on the risk of death and recurrent ischemic events in ischemic CHF patients. A total of 68 ischemic heart failure patients with CHF symptoms and refractory angina pectoris were included in the study, 47 consecutive patients (39 males and eight females) aged 44-82 years. Although follow-up period started after completion of EECP in treated patients, control group follow-up started at the end of 7-week treatment without EECP. All patients were monitored for a mean duration of 13 ± 8 months (range, 1-36 months). The primary endpoints of the study were effects of EECP treatment on platelets after treatment period (7 weeks) and the recurrence of ischemic events. Secondary endpoint was cardiovascular death during the follow-up period. We observed a significant increase in platelet count and decrease in MPV levels (P = 0.044 and P = 0.004, respectively) in the control group. There were no significant differences in platelet count and MPV levels in the EECP group (P > 0.05). After the treatment period, New York Heart Association functional classification (2.60 ± 0.75 vs. 1.72 ± 0.68, P < 0.001) and Canadian Cardiovascular Society functional classification of angina (2.50 ± 0.90 vs. 1.60 ± 0.74, P < 0.001) improved in patients with EECP treatment. In our study, we found that EECP therapy had a neutral effect on MPV values and platelet count.

Prasugrel Aggravates the Inflammatory Response in a PG-PS-Induce Arthritis Model,

Abstract 3268Prasugrel is a very potent and effective P2Y12 receptor antagonist, used primarily to prevent thrombotic events in patients managed for percutaneous coronary intervention (PCI). It is not recommended as prophylaxis antithrombotic therapy because prasugrel increases patient’s risk of bleeding. Even though indication of prasugrel treatment has been limited to the PCI procedure, there are not reports of the effects of prasugrel in patients with associated inflammatory diseases that undergo for PCI. Thus, we evaluate the effects of prasugrel, for 21 days, in a peptidoglycan polysaccharide (PG-PS)-induced arthritis rat model. Lewis rats were randomly separated into four groups from which only half of the animals were induced with PG-PS. There was a significant increase in the inflammatory changes observed in the PG-PS-induced animals treated with prasugrel compared to the PG-PS-induced control including a) increase joint diameter associated with visible signs of inflammation (during days 4 to 6 [p<0.05] and days 13 to 21 [p<0.001]); b) microscopic studies of hind joints showed marked increase in histomorphometric measurements including leukocyte infiltration, synoviocyte hyperplasia, fibrosis and neovascularization (significant increase in vessel number and size); and c) significant increase in platelet count (1,047 ± 89.03 × 103 vs. 710.8 ± 52.65 × 103, p<0.05). Platelet factor 4 (PF4) plasma levels were increased in PG-PS induced control as well as in PG-PS treated with prasugrel animals, however no significant differences were observed between these two groups. Plasma levels of cytokines such as IL-1 beta, IL-6, MIP1 alpha, MCP1, and RANTES were increased in PG-PS-induced animals (both, control and prasugrel treated animals). Only MIP1 alpha levels were significantly increased with additional treatment of prasugrel (p<0.05). In contrast, IL-10 levels were lower in the PG-PS-induced treated with prasugrel (p<0.05). In summary, treatment with P2Y12 receptor antagonist drugs, such as prasugrel, increases the inflammatory changes in PG-PS-induced arthritis model. Further investigations are in need to elucidate the potential unwanted effect of the P2Y12 receptor antagonists in patients afflicted with inflammatory illnesses. Disclosures:No relevant conflicts of interest to declare.

Eculizumab Is An Effective Long-Term Treatment In Patients with Atypical Hemolytic Uremic Syndrome (aHUS) Resistant to Plasma Exchange/Infusion (PE/PI): Results of An Extension Study

Abstract 193▪FN2▪This icon denotes a clinically relevant abstract INTRODUCTION:aHUS is a genetic, systemic disease with a devastating prognosis caused by chronic uncontrolled complement activation leading to thrombotic microangiopathy (TMA), progressive organ damage and premature mortality. In a 26-wk phase II trial, pts receiving ECU, a terminal complement inhibitor, had a highly significant increase in platelet count (a measure of TMA improvement) (primary endpoint: 73×109/L increase; p=0.0001). 13/15 pts with low platelet count at baseline (BL) (ITT) had platelet normalization at Wk 26. 15/17 pts (88%) achieved TMA event-free status (≥12 wks of stable platelet count, no PE/PI and no new dialysis). 13/13 pts treated with ECU for 26 wks had platelet normalization at Wk 26 and 15/15 treated with ECU for 26 wks achieved TMA event-free status. Median TMA intervention rate was 0 (no. of PE/PI and new dialysis events/pt/day). Importantly, 4/5 pts on dialysis with PE/PI discontinued dialysis with ECU. ECU was well tolerated (Legendre. ASN 2010). We report longer follow-up data from the extension phase of this ongoing trial. METHODS:Pts ≥12 yrs with aHUS and persistent TMA despite ≥4 PE/PI sessions 1 wk before screening were enrolled in a 26-wk, controlled, open-label, single-arm phase II trial and continued into an extension trial. ECU dosage: 900mg/wk for 4 wks, 1200mg at Wk 5, 1200mg q2 wks. All pts received a meningococcal vaccine and prophylactic antibiotics ≥14 days after vaccination. Efficacy analyses were based on ITT population. RESULTS:17 pts enrolled (2 discontinued at Wks 1 and 6; systemic lupus erythematosus [protocol violation] and an adverse event unrelated to ECU, respectively). Median time from diagnosis to screening=10mo (0.3–236). Median duration from overt clinical manifestations of aHUS to screening=0.75mo (0.2–4). Median number of PE/PI sessions per pt during aHUS current clinical presentation=17 (2–37). 5 patients (29%) required dialysis at baseline. Median age=28 yrs. 4 pts (24%) had no identified complement regulatory factor mutations (CRFM). ECU mean (SD) duration=58 (29) wks at data cut-off. Mean change (SD) in platelet count from BL was maintained (97×109/L [81] at Wk 26 vs 98×109/L [60] at 1 yr). All 13 pts who had platelet normalization at Wk 26 continued to maintain normal levels at data cut-off. The same 15/17 (88%) pts achieved TMA event-free status at data cut-off. All pts receiving sustained ECU treatment throughout the study achieved TMA event-free status at data cut-off. Renal function was maintained and continued to further improve in pts with ongoing ECU: improvement ≥1 CKD stage from BL: from 10 (59%) pts at Wk 26 to 11 (65%) pts at data cut-off and ≥25% decrease in creatinine from BL: from 11 (65%) pts at Wk 26 to 13 (77%) pts at data cut-off. With sustained ECU therapy, only 1 of the 5 pts at baseline continued on to require dialysis and no patient newly required dialysis (as of data cut off). Long-term chronic ECU was similarly effective in pts with/without identified CRFM. ECU was generally well tolerated; adverse events deemed related to ECU were reported in 12 pts (mostly mild to moderate, 1 severe). The extension trial continues. CONCLUSIONS:In aHUS, despite PE/PI, >50% of pts either die, require dialysis, or have permanent renal damage within the first year of diagnosis. In contrast, all pts treated with ECU for a mean duration of >1 yr remain alive, 4 out of 5 pts became dialysis free, and no pt newly required dialysis. This demonstrates that continued ECU treatment significantly transformed the clinical course of aHUS in this pt population. In addition, long-term ECU therapy suppressed TMA and dramatically improved renal function. These long-term follow-up data further strengthen the evidence for ECU as the new standard of care for aHUS. Disclosures:Greenbaum:Alexion: Consultancy, Honoraria, Research Funding, Speakers Bureau. Off Label Use: Eculizumab for the treatment of atypical hemolytic syndrome as part of clinical trials. Babu:Alexion: Research Funding. Furman:Alexion: Research Funding. Sheerin:Alexion: Research Funding. Cohen:Alexion: Research Funding. Gaber:Alexion: Research Funding. Delmas:Alexion: Research Funding. Loirat:Alexion: Research Funding. Bedrosian:Alexion: Employment. Legendre:Alexion: Research Funding.

The effects of continuous positive airway pressure therapy on mean platelet volume in patients with obstructive sleep apnea

Previous studies have reported increased platelet activation and aggregation in patients with obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) treatment has been shown to decrease platelet activation. We aimed to study the effects of nasal CPAP therapy has on MPV values in patients with severe OSA. Thirty-one patients (21 men; mean age 53.8 ± 9.2 years) with severe OSA (AHI > 30 events/hour) constituted the study group. An age, gender and body mass index (BMI) matched control group was composed 25 subjects (14 men; mean age 49.6 ± 8.5 years) without OSA (AHI < 5 events/hour). We measured MPV values in patients with severe OSA and control subjects and we measured MPV values after 6 months of CPAP therapy in severe OS patients. The median (IQR) MPV values were significantly higher in patients with severe OSA than in control group (8.5 [8.3–9.1] vs. 8.3 [7.5–8.8] fL; p = 0.03). The platelet counts were significantly lower in patients with severe OSA than in control group (217.8 ± 45.9 vs. 265.4 ± 64.0 × 109/L; p = 0.002). The six months of CPAP therapy caused significant reductions in median (IQR) MPV values in patients with severe OSA (8.5 [8.3–9.1] to 7.9 [7.4–8.2] fL; p < 0.001). Six months of CPAP therapy caused significant increase in platelet counts when compared with baseline values (217.8 ± 45.9 to 233.7 ± 60.6 × 109/L; p < 0.001). We have found that the MPV values of patients with severe OSA were significantly higher than those of the control subjects and 6 months CPAP therapy caused significant reductions in the MPV values in patients with severe OSA.

Alterations of serum erythropoietin and thrombopoietin levels in patients undergoing Coronary Artery Bypass Grafting (CABG)

The hormones erythropoietin (EPO) and thrombopoietin (TPO) are main regulators of erythro- and thrombopoiesis. Cell loss caused by operative procedures may alter serum levels of the hormones, resulting in well known phenomenons like reactice thrombocytosis. Blood samples from 10 patients (mean age 63 ± 9 years) were obtained before and at day 1, 5 and 10 after coronary artery bypass grafting (CABG). EPO and TPO levels were determined by commercially available ELISA-Kits (R&D Systems, Germany). In addition, platelet count (PC) and hemoglobin concentration (Hb) were determined. Prior to CABG, EPO (13.2 ± 8.2 mU/mL), TPO (189 ± 52 pg/mL), Hb (8.8 ± 1.1 mmol/L) and PC (254 ± 121/nL) were within a normal range. At day 1 after surgery, Hb and PC were significantly decreased to 6.6 ± 0.9 mmol/L and 138 ± 70/nL. In contrast, EPO and TPO were significantly elevated to 32 ± 18 mU/mL and 336 ± 96 pg/mL, respectively, in spite of hemodilution. In particular, TPO elevation was followed by a significant increase in PC (342 ± 144/nL) at day 10 after surgery compared to preoperative values. Appropriate to the decrease in hemoglobin concentration and platelet count, clear alterations of serum erythropoietin and thrombopoietin levels could postoperatively be observed. EPO levels showed an inverse correlation to hemoglobin concentrations, whereas a disturbed thrombopoietin feedback mechanism resulted in the phenomenon of reactive thrombocytosis.

Anti-CD20 therapy in patients with refractory systemic lupus erythematosus: a longitudinal analysis of 52 Hispanic patients

The objective of this study was to investigate the efficacy and safety of anti-CD20 treatment in Hispanic patients with refractory systemic lupus erythematosus and to determine whether baseline parameters predict disease flare. Fifty-two patients with systemic lupus erythematosus, 13 with active lupus nephritis, eight with thrombocytopenia, three with leukocytopenia, 25 with severe musculoskeletal involvement and three with skin involvement) refractory to conventional therapy were treated with anti-CD20 treatment (rituximab; MabThera, Roche) plus ongoing immunosuppressive treatment. Disease activity was assessed monthly using the SLEDAI validated for the Mexican population with a follow-up period of 6 months. At 6 months of follow-up, significant clinical improvements were detected, with a reduction in the global SLEDAI validated for the Mexican population score. Five of the 13 patients with lupus nephritis (38.4%) had a complete renal response and five (38.4%) had a partial response. Rituximab was also effective in patients with autoimmune thrombocytopenia, inducing a significant increase in platelet counts (p = 0.012). Nineteen of 25 patients with severe musculoskeletal involvement had remission of arthritis. Only one of the three patients with skin involvement had no lesions at 6 months. Rituximab treatment also allowed a reduction of the oral prednisone dose in the majority of patients. No baseline predictors of flare were found. Treatment was discontinued after the first infusion in two patients due to serum sickness and in another due to pulmonary infection. In conclusion, the addition of rituximab to conventional immunosuppressive therapy may be an effective strategy for lupus nephritis, autoimmune thrombocytopenia and inflammatory polyarthritis in patients with refractory systemic lupus erythematosus.