Peripheral Platelet Counts Research Articles

Platelet Recovery Prior to Stem Cell Transplantation Predicts for Post- Transplant Outcomes in Patients with AML

Achievement of complete remission (CR), with <5% blasts in bone marrow (BM), and peripheral blood platelet count >100K/ml remains the gold standard achievement of chemotherapy for AML. A significant fraction of patients proceed to HSCT with <5% blasts but without ever achieving platelet counts >100K/ml (CRp). It is possible that with new AML therapies, the proportion of patients in such a situation will increase. We hypothesized that achievement of CRp has a worse prognostic connotation than ‘classically’ defined CR, and sought to investigate this hypothesis in a cohort of AML patients transplanted between 7/1995 to 12/2007 at our institution (N=427).Methods: Patients were eligible for this analysis if they were in the following disease status at transplantation: compete remission (CR); first CR (CR1; <5% BM blasts and platelet count >100K/ml); second CR (CR2); first CRp (CRp1): patients that had <5% BM blasts but no platelet recovery following induction chemotherapy; primary induction failure (PIF): no CR with induction therapy (>5% and no platelet recovery); CRp2: patients that after first relapse achieved <5% BM blasts with salvage chemotherapy, but no platelet recovery; refractory: patients in first relapse that did not respond to salvage therapy (rel). A minimum of 30 days from the last day of chemotherapy to start of conditioning regimen elapsed for patients to be scored as CRp. Diagnosis were AML (n=376) or high-risk MDS (n=51). Conditioning included TBI-based (2%; n=8), oral/IV busulfan based-ablative regimens (61%; n=261), fludarabine/melphalan-based reduced intensity conditioning regimens (RIC) (36%; n=153), or other (1%; n=5). Fifty-eight percent of patients received matched sibling transplants (n=248), while 42% (n=179) received unrelated donor (UD) HSCT. Tacrolimus and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. ATG was administered to those who received grafts from UD.Results: Median age was 50 years (range 6–74); 51% of patients were 50 years or older (n=218); 55% were male (n=236). Disease status at HSCT was CR1 in 38% (n=164), CR2 in 24% (n=102), CRp1 in 11% (n=48), CRp2 in 7% (n=30); PIF 11% (n=47), and rel1 8% (n=36). Cytogenetics data were available for 90% (n=386) of patients. The proportion of poor-risk cytogenetics was comparable in patients who were in CR1 (39%) and CRp1 (44%), p=0.3, and in patients who were in CR2 (15%) and CRp2 (24%) p=0.2. Source of stem cells was BM in 41% of patients (n=174) and peripheral blood in 59% of patients (n=253). Ninety-six percent of patients engrafted. Fifty-one percent of patients have died (n=219); actuarial survival at 36-months was 49% for all patients. Thirty-one percent of patients (n=134) have progressed. Median follow-up among survivors is 42 months (range 3–131months).Non-relapse mortality (NRM) (figure 1), overall survival (OS) (figure 2), and hazard ratios for OS and NRM at 1-year (Table) favored patients who were transplanted in CR1 (vs. patients in CRp1 or PIF), or in CR2 (vs. CRp2 or rel1).Conclusion: In this cohort of patient with AML and MDS, patients in CR (CR1 or CR2) demonstrated significantly better OS and NRM compared to patients who underwent HSCT in CRp (CRp1 or CRp2). CRp conferred an intermediate prognostic status, better than refractory disease, but significantly worse than ‘classic’ CR. Our results suggest that achieving a CR prior to HSCT should remain the gold standard for patient in AML or MDS receiving allogeneic HSCT.Table. Hazard Ratios (HR) for non-relapse mortality (NRM) and overall survival (OS) at 1 year.NRMOSCR1 (n=164)ReferenceReferenceCR2 (n=102)1.4 (p=0.3)1.3 (p=0.3)CRp1 (n=48)2.4 (p=0.01)2.4 (p=0.001)CRp2 (n=30)1.7 (p=0.2)1.9 (p=0.05)PIF (n=47)3.7 (p=0.001)3.6 (p=0.001)First relapse (n=36)4.6 (p=0.001)6.7 (p=0.001)CR=complete remission; CRp=pathologic CR; PIF=primary induction failure. [Display omitted] [Display omitted]

ABT-737 Targets Intrinsic Apoptosis during Cooperation of BCL-2 and Oncogenic NRAS in An in Vivo Progression Model of Myelodysplasia/Acute Myeloid Leukaemia

OBJECTIVES: Activating RAS mutations and over-expression of BCL-2 are prognostic features of myelodysplastic syndromes/acute myeloid leukemia (MDS/AML) transformation. Using NRASD12 and BCL-2, we created two distinct transplantable in vivo models of MDS and AML. Expression of hBCL-2 in a primitive compartment by MMTV-LTR results in a disease resembling human MDS with bone marrow blasts of 15% with increased apoptosis assayed by TUNEL on liver sections, whilst the myeloid MRP8 promoter induces a disease with characteristics of human AML with marrow blasts of up to 90% with liver apoptosis patterns similar to wild type. In MDS mice RAS and BCL-2 do not co-localize in the mitochondria, but localize to the plasma membrane, where active pro-apoptotic RAS is normally located, whereas in the AML disease RAS and BCL-2 co-localize in the mitochondria, where BCL-2 is normally found; consistent with its anti-apoptotic properties. We next examine the mouse hematopoietic FDCP-1 in vitro model with stable exogenous expression of NRASD12, hBCL-2 or NRASD12 and hBCL-2. Furthermore, we report the in vivo effects of the BH-3 mimetic inhibitor ABT-737.RESULTS: FDCP-1 lines demonstrate that whilst hBCL-2 alone prevents staurosporine-induced mitochondrial-dependent (caspase-9-mediated intrinsic) apoptosis, both NRAS-D12 and NRASD12/hBCL-2 cell lines were pro-apoptotic. No significant difference was observed in cell-death receptor (caspase-8-mediated extrinsic) apoptosis between the cell lines following pharmacological induction with Fas-ligand or TRAIL. Annexin-V/Propidium Iodide flow cytometry and caspase activity assays on hematopoietic primary cells from the mouse models recapitulated the findings; namely the MDS-model demonstrates increased caspase-9-mediated apoptosis (within the Lin−/Sca-1+/KIT+ (LSK) sub-population), whilst the AML-model illustrate anti-apoptotic activity. This is concordant with the signaling profile where phosphorylated AKT is reduced in the RAS-mediated MDS mice and active-AKT is increased in the BCL-2 mediated AML disease. Expanded leukemic stem cell LSK populations had increased hBCL-2 expression in the RAS-GTP complex in both MDS/AML diseases. Thus we suggest that this complex can be a specific target for therapy. When hBCL-2 is switched off with doxycycline in the conditional MDS mice, only partial reversal of the phenotype was observed as RAS recruits endogenous mouse BCL-2 to remain active; thus demonstrating the role of the complex in the disease. In order to target both human and mouse BCL-2 the efficacy of in vivo treatment with the specific BH-3 mimetic inhibitor ABT-737 was determined. We show that the treatment significantly reduced the progression of the disease, increased the peripheral blood platelet counts, decreased the bone marrow blast and cleared the tissue invasion in the MDS mice or reduced tissue infiltration of the AML. In vivo imaging by single-photon emission computed tomography (SPECT) using 99mTc-labelled Annexin-V shows that ABT-737 induces apoptosis of the blast cells that infiltrate the liver and the spleen of the treated mice, which was confirmed by TUNEL on liver sections. Additionally, ABT-737 can reduce the myeloid colony growth and the LSK expansion in these mice; whilst abrogating BCL-2:RAS-GTP complex formation illustrated via biochemical and confocal assays.CONCLUSION: This represents the first in vivo progression model of MDS/AML dependent on the formation of a BCL-2:RAS-GTP complex rescued by ABT-737 via intrinsic apoptosis and thus support the case for BH-3 mimetic therapy.

Patients Are Willing to Trade off Efficacy, Safety, and Administration Attributes of Chronic Idiopathic Purpura (ITP) Therapy: Results from a Large North American Discrete Choice Study

OBJECTIVE: To quantify the willingness of patients with chronic idiopathic thrombocytopenic purpura (ITP) to trade off different attributes of ITP treatments, including efficacy, safety, and mode of administration. To determine the level of benefits, which balanced risks when faced with discrete choices.BACKGROUND: ITP is primarily a disorder of adults characterized by reduced platelet production and autoantibody-induced platelet destruction, leading to a low peripheral blood platelet count (<150 Gi/L; Cines, 2002). Patients may have few symptoms or may suffer bruising, purpura, or more serious complications, such as intracerebral bleeding. Treatment is aimed at elevating platelets to a hemostatic, safe range (≥50 to 400 Gi/L) to minimize the risk of bleeding. To date, the long-term management of patients with chronic ITP has been unsatisfactory, largely due to the variable efficacy, poor tolerability, and severe side effects associated with current treatment options. Treatment involves corticosteroids, intravenous immunoglobulins, immunosuppressive drugs, chemotherapy, splenectomy, and, more recently, monoclonal antibodies targeted against B cell antigens (Stasi, 2004). The relative importance of different treatment attributes from a patient perspective has not been previously studied.METHODOLOGY: Participants were recruited through an ITP patient support group and were to have reported a diagnosis of chronic ITP. They completed an online survey that included a series of stated-choice trade-off tasks. Respondents chose between pairs of hypothetical treatment alternatives defined by a different likelihood of achieving hemostatic platelet levels, need for concomitant corticosteroids, mode of treatment administration, risk of rebound thrombocytopenia, risk of elevated liver enzymes resulting in treatment discontinuation, and risk of blood clot. Mixed-logit methods were used to estimate relative preference weights for treatment attribute levels; regression model parameter estimates were used to derive the maximum accepted risk (MAR) of adverse events for specific increases in the likelihood of treatment success and the minimum acceptable benefit (MAB) required to justify a given level of adverse-event risk.RESULTS: The survey was completed by 1,542 respondents. Seventy-two percent of respondents were female, the mean age was 50 years, 92% were white, and 86% had education beyond high school. Patients with chronic ITP were willing to accept significant risks of side effects or adverse events to increase the likelihood of treatment success, to avoid the need for corticosteroids, and to attain a convenient mode of administration. In return for a 25–percentage-point increase in the likelihood of achieving a safe platelet level, patients were willing to accept an average risk for rebound thrombocytopenia of 18.8% (95% CI, 16.3%–21.3%). For avoiding corticosteroids, patients tolerated risk for rebound thrombocytopenia and blood clot of 20.2% (95% CI, 18.4%–23.7%) and 3.4% (95% CI, 2.7%–4.2%), respectively. Patients were willing to accept an additional risk of thromboembolism as high as 2% and a risk of liver-function test abnormalities or rebound thrombocytopenia as high as 13% if they could take 1 or 2 pills every day instead of going to a doctor's office for an injection once a week. When given a choice and all other factors being equal, 71% of patients stated that they would surely or probably choose 1 to 2 pills a day, while 8% of patients stated they would choose weekly injections in a physician's office (with remaining patients not stating a preference).CONCLUSIONS: In this large, rigorously conducted study, patients with chronic ITP were willing to accept significant risks of thromboembolic events, liver abnormalities, and rebound thrombocytopenia for greater efficacy benefit, as well as to avoid the use of corticosteroids. The majority of patients also preferred an orally administered therapy to an injectable therapy administered in a physician's office or at home.

Safety and Efficacy of Long-Term Treatment with Oral Eltrombopag for Chronic Idiopathic Thrombocytopenic Purpura.

INTRODUCTION: Eltrombopag (PROMACTA®/REVOLADE®; GlaxoSmithKline, Collegeville, PA) is the first oral, small molecule, non-peptide thrombopoietin receptor agonist under investigation for the treatment of thrombocytopenia due to various causes, including idiopathic thrombocytopenic purpura (ITP). Chronic ITP is characterized by autoantibody-induced platelet destruction and reduced platelet production, leading to chronically low peripheral platelet counts. Eltrombopag treatment has previously demonstrated a significant increase in platelet counts and a reduction in clinically relevant bleeding symptoms in 2 placebo-controlled trials evaluating a total of >200 patients with chronic ITP after up to 6 weeks of treatment. EXTEND is an ongoing open-label, phase III extension study to assess the long-term safety and efficacy of oral eltrombopag in ITP patients that have previously completed an eltrombopag trial.METHODS: Patients with previously treated, chronic ITP who completed a prior eltrombopag study were eligible to participate in EXTEND. Eltrombopag treatment was initiated at 50 mg once daily and then adjusted in order to maintain platelet counts ≥ 50,000/μL and <400,000/μL, with doses between 75 mg once daily and 25 mg once daily or less often than once daily, if necessary. Patients who achieved platelet counts ≥ 50,000/μL during treatment with eltrombopag were considered responders. Bleeding events were prospectively evaluated using the WHO Bleeding Scale: Grade 0 = no bleeding, Grade 1 = mild bleeding, Grade 2 = moderate bleeding, Grade 3 = gross bleeding and Grade 4 = debilitating blood loss.RESULTS: At the time of this analysis, 207 patients (median age, 50 years; 67% female) had received eltrombopag on this study. At baseline, 33% were receiving concomitant ITP medication and 40% were splenectomized. The majority of patients (70%) enrolled with baseline platelet counts <30,000/μL, followed by 18% and 12% with baseline platelet counts from ≥ 30,000/μL to ≤ 50,000/μL, and >50,000/μL, respectively. The duration of eltrombopag treatment ranged from 3 to 523 days. Seventy-nine percent (159/201) of patients achieved a platelet count ≥ 50,000/μL, and 24% (18/75) of patients who had received eltrombopag for at least 25 weeks maintained platelet counts ≥ 50,000/μL continuously for ≥ 25 weeks. Patients responded to eltrombopag regardless of splenectomy status (non-splenectomized: 78%, splenectomized: 81%) and use of baseline concomitant ITP medications (no baseline ITP medications: 79%, baseline ITP medications: 80%). Median platelet counts remained ≥ 50,000/μL throughout the observation period of the study (Figure 1) with only 3 exceptions, when the median platelet counts remained >40,000/μL. At baseline, 59% of patients reported bleeding symptoms (WHO Grades 1–4) compared with approximately 30% at months 1, 3, and 6. Adverse events (AEs) were reported in 150 patients (72%) while on therapy, the majority of which were mild to moderate. Headache (15%) was the most commonly reported on-therapy AE, followed by upper respiratory tract infection (13%), diarrhea (10%), and nasopharyngitis (9%). Six thromboembolic events were reported during the study. No clinically relevant effects of eltrombopag on patient bone marrow were detected. Thirty-nine serious AEs were reported by 17 patients (8%) while on therapy +1 day. Four deaths were reported in the study (2 deaths on therapy and 2 deaths >30 days after the last dose of eltrombopag); none were considered related to study medication.CONCLUSION: Oral eltrombopag is effective at raising platelet counts and decreasing bleeding symptoms during long-term treatment, regardless of splenectomy status or the use of baseline ITP medications. Eltrombopag is well tolerated during long-term treatment in patients with previously treated chronic ITP. [Display omitted]

Reticulated platelets as a marker of platelet recovery after allogeneic stem cell transplantation

Reticulated platelets (RP) are the youngest forms of platelets in blood and reflect the rate of bone marrow platelet production. In the present study, we used flow cytometric analysis to determine the percentage of RPs in patients undergoing allogeneic stem cell transplantation. We investigated 10 patients after transplantation from HLA identical siblings: five with acute myeloid leukemia (AML), four with chronic myeloid leukemia (CML), and one patient with myelodysplastic syndrome (MDS). Of the patients examined, four patients underwent allogeneic bone marrow transplantation and six patients underwent peripheral blood stem cell transplantation. It was observed that the initially reduced percentage of RPs (2.9 +/- 1.7%; mean +/- SD) was significantly higher (P = 0.0109) in all patients (13.6 +/- 6.4%) in the following 10-26 days. The RP percentage peak preceded the recovery of peripheral platelet count up to 45.6 x 10(9)/l on average by 3 days. We found no difference in RP% between the AML and CML patients but we did observe that in CML patients the RP percentage increased on average 7 days earlier than in AML patients. The elevated RP percentage reflects increased bone marrow regeneration and can be considered an additional marker of thrombopoietic recovery in the patients undergoing allogeneic stem cell transplantation.

Myelotoxicity of samarium Sm 153 lexidronam in patients receiving prior treatment with chemotherapy or radiotherapy

BackgroundThe effect of prior treatment with radiotherapy and/or chemotherapy on the myelotoxicity of samarium lexidronam (Sm 153) in patients with metastatic bone lesions and bone pain was described. MethodsSingle-institution retrospective chart review of patients receiving Sm 153. The effect of Sm 153 on peripheral white blood cell (WBC), platelet counts, and change from baseline was calculated. ResultsThe available hematologic data from records of 58 patients receiving 100 treatments with Sm 153 were reviewed. Prior treatment with radiotherapy or chemotherapy had no effect on changes from baseline or median nadir counts for either WBC or platelets when compared with patients not having such prior treatments. Multiple treatments with Sm 153 had no effect on change from baseline in WBC or platelet counts as compared with the initial administration. Median survival following the first dose of Sm 153 was 15 months. ConclusionsPrior treatment with radiotherapy or chemotherapy did not affect the rates of myelotoxicity. Multiple treatments with samarium Sm 153 lexidronam also had no effect on severity of myelotoxicity with successive courses. Patients with bone predominant metastatic disease may survive for extended periods of time and may safely be treated with multiple modalities of therapy.

Platelets and HIV-1 Infection: Old and New Aspects

In this review we summarize the data on interaction of platelets with HIV-1 infection. Thrombocytopenia is a common finding among HIV-1 infected patients; several combined factors contribute to low peripheral platelet counts, which are present during all the stages of the disease. In addition, a relationship between platelet count, plasma viral load and disease progression has been reported, and this shows the potential influence platelets may have on the natural history of HIV-1 disease. Several lines of evidence have shown that platelets are an integral part of inflammation, and can be also potent effector cells of innate immune response as well as of adaptive immunity. Thus, we rewieved the role of inflammatory cytokines, and chemokines as activators of platelets during HIV-1 infection. Moreover, platelets show a direct interaction with HIV-1 itself, through different pathogenic mechanisms as binding, engulfment, internalisation of HIV-1, playing a role in host defence during HIV-1 infection, by limiting viral spread and probably by inactivating viral particles. Platelets may also play an intriguing role on endothelial dysfunction present in HIV-1 infection, and this topic begins to receive systematic study, inasmuch as interaction between platelets and endothelial cells is important in the pathogenesis of atherosclerosis in HIV-1 infected patients, especially in those patients treated with antiretroviral drugs. Finally, this review attempts to better define the state of this emerging issue, to focus areas of potential clinical relevance, and to suggest several directions for future research.

Chemotherapy-resistant intravascular lymphoma accompanied by ADAMTS13 inhibitor successfully treated with rituximab

Intravascular large B-cell lymphoma (IVL) is a subtype of diffuse large B-cell lymphoma (DLBCL), in which lymphoma cells infiltrate blood vessels without mass formation, and its prognosis is generally poor due to diagnostic difficulties. The authors previously described a patient with IVL accompanied by features of thrombotic thrombocytopenic purpura (TTP), expression of ADAMTS13 inhibitor, and a severe deficiency in ADAMTS13 activity [1]. Although standard CHOP chemotherapy was initially effective, the disease gradually became resistant despite intensive high-dose chemotherapy with autologous peripheral blood stem cell support. However, the chimeric anti-CD20 monoclonal antibody, rituximab, induced complete remission (CR) for a prolonged period. We describe the clinical course of this patient and the unique effects of treatment with rituximab alone. A 54-year-old man was admitted to our hospital with the onset of a psychological disorder and convulsions. Laboratory data revealed obvious thrombocytopenia (3.6 9 10/ lL) accompanied by elevated levels of serum lactic dehydrogenase (LDH) and soluble interleukin-2 receptor. Multiple cerebral venous embolisms, bilateral adrenal gland swelling, and hepatosplenomegaly were present without nodal disease. Despite normal chest X-rays and thoracic CT scans, the patient developed rapidly progressive respiratory failure. A definitive diagnosis of IVL was made from transbronchial lung biopsy (TBLB) specimens. Bone marrow smears revealed no obvious lymphoma cell invasion and megakaryocyte hyperplasia without hemophagocytic syndrome (HPS), although the peripheral blood platelet count was markedly decreased. We concluded that the thrombocytopenia was caused by the same pathogenesis as TTP, since plasma ADAMTS13 activity had decreased to below 3%, and active ADAMTS13 inhibitor (IgG-type autoantibody) was confirmed. After standard CHOP chemotherapy cycles, the platelet counts immediately recovered to within normal limits and all symptoms improved. The ADAMTS13 activity improved to 49% and inhibitor levels, which had never been negative, decreased. Whole brain irradiation after chemotherapy resulted in relapse of systemic disease. Although we performed highdose conditioning chemotherapy followed by autologous peripheral stem cell transplantation, respiratory failure and high-grade fever appeared with severe thrombocytopenia and massive serum LDH elevation at day 50 after transplantation. Salvage combination chemotherapies had extremely limited effects against the disease, and we started to administer 375 mg/m of rituximab after its use for CD20-positive DLBCL was permitted according to the regulations established by the Japanese National Health Insurance system. The patient did not develop any major M. Kanno (&) Tumor Center, Nara Medical University Hospital, 840 Shijo-cho, Kashihara 634-8522, Japan e-mail: mkanno@naramed-u.ac.jp

Immune (idiopathic) thrombocytopenic purpura (ITP) treatment pattern and clinical efficacy

17529 Background: Immune (Idiopathic) Thrombocytopenic Purpura (ITP) is an autoimmune disorder characterized by persistent thrombocytopenia (peripheral blood platelet count <150 × 109/L). Few studies report efficacy of current therapies for ITP or resulting health-related quality of life (HRQoL). We present interim results of an international multi-center prospective observational study describing clinical efficacy of ITP treatments (trts). Methods: Patients (pts) with a diagnosis (dx) of ITP from community and academic centers were enrolled. Pts retrospective chart data provided date of 1st ITP dx, trts received and medical history. ITP trts, dose, response, and duration of response were collected prospectively for 12 months (mo). HRQoL was assessed with an ITP questionnaire (ITP-PAQ) where higher scores relate to better patient-reported outcomes. Results: Of the first 100 pts (43% male and mean age 70 years), 24 received a splenectomy and 74 received ITP-related trts. Among the 74 pts, corticosteroids (N=61), intravenous immunoglobulins (IVIG) (N=36), rituximab (N=27), and anti-D antibody (N=22) were the most frequently used. On average, pts received 2 to 3 types of ITP trts during the study period (median person years=2.97) with corticosteroids usually as 1st line of treatment. Median duration of response was 8 mo for rituximab, 10 mo for corticosteroids, 15 mo for IVIG and 17 mo for anti-D antibody. Hospitalizations per person year ranged from 0 (rituximab) to 0.8 (IVIG). ITP-PAQ scores significantly decreased in pts on corticosteroids (p<0.05), compared to other trt groups where ITP-PAQ scores increased. Conclusions: Efficacy of all ITP trts was limited in duration and pts receiving corticosteroids had significantly decreased HRQoL. Further studies are needed to assess the long-term impact of ITP trts on patient outcomes, health resource utilization, and downstream costs. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Amgen, Inc. Amgen, Inc. Amgen, Inc.

Association of the T1799A BRAF mutation with tumor extrathyroidal invasion, higher peripheral platelet counts, and over-expression of platelet-derived growth factor-B in papillary thyroid cancer

The relationship among BRAF mutation, platelet counts, and platelet-derived growth factor (PDGF) with respect to clinicopathological outcomes of papillary thyroid cancer (PTC) may play a role in PTC pathogenesis but remains undefined. We examined the T1799A BRAF mutation by direct genomic DNA sequencing in 108 primary PTC samples from a Chinese cohort and analyzed its relationship with clinicopathological, hematological, and other laboratory results as well as the levels of expression of PDGF in tumors. We found that the BRAF mutation was significantly associated with extrathyroidal invasion and advanced tumor stages III and IV. Specifically, extrathyroidal invasion was seen in 30/54 (56%) PTC with BRAF mutation versus 18/54 (33%) PTC without the mutation (P=0.02). Tumor stages III and IV were seen in 16/54 (30%) PTC with BRAF mutation versus 7/54 (13%) PTC without the mutation (P=0.04). The BRAF mutation was also significantly associated with a higher platelet count, with 249.28+/-53.76 x 10(9)/l in the group of patients with BRAF mutation versus 207.79+/-58.98 x 10(9)/l in the group without the mutation (P=0.001). An association of higher platelet accounts with extrathyroidal invasion was also seen, with 242.66+/-51.85 x 10(9)/l in patients with extrathyroidal invasion versus 218.49+/-59.10 x 10(9)/l in patients without extrathyroidal invasion (P=0.03). The BRAF T1799A-positive PTC tissues harbored a significantly higher level of PDGF-B than BRAF T1799A-negative PTC tissues. The data suggest that the BRAF T1799A mutation is associated with aggressive pathological outcomes of PTC in which high platelet counts and increased PDGF production may play a role.

Serum thrombopoietin compared with ZAP-70 and immunoglobulin heavy-chain gene mutation status as a predictor of time to first treatment in early chronic lymphocytic leukemia

In an effort to confirm previous reports we analyzed clinico-biological implications of increased serum levels of thrombopoietin (TPO) in a series of 71 previously untreated Binet stage A B-cell chronic lymphocytic leukemia (CLL) patients. Serum levels of TPO did not correlate with peripheral blood lymphocytosis (p = 0.928), Rai substages (p = 0.516), platelet count (p = 0.572), hemoglobin level (p = 0.228), LDH (p = 0.144) and β2-microglobulin (p = 0.520). The same applied when correlation with ZAP-70 (p = 0.562), CD38 (p = 0.258) or mutational status of IgVH (p = 0.0794) were sought. The risk of disease-progression according to known and putative prognostic parameters was also evaluated as time to first treatment (TFT). The univariate Cox proportional hazard model demonstrated that the absence of IgVH mutational status (p = 0.0005) and ZAP-70-positivity (p = 0.02) were associated with a shorter TFT. In contrast, Kaplan-Meier estimates of TFT, plotted after setting as cut-off the median value for TPO (i.e., 46 pg/mL), failed to demonstrate any statistical difference between two groups (p = 0.342). Looking for cellular source of TPO we investigated the presence of TPO at gene expression level in 60 B-CLL patients belonging to an independent series. Here we provide evidence for the presence of a low TPO gene expression transcript in B-CLL cells. In conclusion, our results indicate that in early B-cell CLL circulating level of TPO does not provide a useful insight into the complex interrelationship of prognostic variables.

Recovery of Donor Peripheral Blood Platelet Count Following Platelet Apheresis.

BACKGROUND: Apheresis platelet collection from healthy normal blood donors can reduce the donor peripheral blood platelet concentration by 50% or more. The kinetics of peripheral blood platelet count (PLT) recovery in the apheresis donors over the first 24 hours has not been described. The objective of this study was to determine the recovery kinetics of the donor peripheral blood platelet count following apheresis platelet donation.METHODS: Healthy apheresis platelet donors were enrolled following informed consent. The apheresis platelet collection was performed using the Gambro Trima system (Gambro BCT, Lakewood, CO) following local SOP and manufacturer's directions for use. The minimum predicted post-count was configured in the Trima to no less than 78K plt/μL. PLT was determined pre-procedure (Pre), immediately post procedure (Post), 4–11 h (FU1) and 11–41 h (FU2) post-donation using standard methods. The PLT recovery was evaluated as the increase in PLT following the donation (Delta). The effects of study site, time of sample, and the fraction of platelets collected (Fpc) at donation on Delta were evaluated using a random effects generalized linear regression model. A full regression model of Delta as a function of study site, follow-up period and Fpc with all main and interaction effects was used to test hypotheses.RESULTS: 548 subjects were entered into the study at 3 study sites; Pre-PLT 276±59 × 103 plt/μL, Post-PLT 205±47 × 103 plt/μL, Fpc 25±10%. No adverse events were reported by any subjects. Recovery of platelet count following apheresis platelet donation is variable between subjects; and the independent variables of study site, follow-period and Fpc accounted for 25% of the total variation in Delta. PLT increased 12.4±0.9 × 103 plt/μL by the time of follow-up sampling (p=0.01), although there was no difference between PLT at FU1 (214±49 × 103 plt/μL) and FU2 (212±47 × 103 plt/μL; p=0.15). None of the donors reached their pre-donation platelet count during the follow-up period. There was no difference in Delta between centers (p=0.23). Fpc had a significant affect on Delta (p<0.0001); with estimated Delta of 5.2±0.9 × 103 plt/μL at Fpc=15% and 16.0±.8 × 103 plt/μL at Fpc=30%.CONCLUSION: Platelet recovery following apheresis platelet donation was observed to be dependent on the fraction of platelets donated. Surprisingly, the recovery observed within the first 11 h was equivalent to that observed between 11–42 h, averaging 17.5% of the drop observed during apheresis. Recovery was not complete when observed for up to 41 h following donation in this study. Additional investigation of PLT recovery following apheresis donation is indicated to describe and differentiate the potential roles of de novo production, early pro-platelet release and platelet release from peripheral pools over the early post-donation period.

Menin Regulates the Function of Lymphoid Progenitors and Hematopoietic Stem Cells.

Menin is the product of the Men1 gene, a tumor suppressor gene that is mutated in patients with multiple endocrine neoplasia type I (MEN1). In addition to its effects in endocrine tissues, Menin interacts with the Mixed Lineage Leukemia (Mll) gene product as part of a multiprotein complex with H3K4 methyltransferase activity. Menin is required to mediate malignant transformation induced by Mll gene rearrangements, an activity associated with transcriptional activation of Homeobox (Hox) gene expression, presumably through epigenetic regulation. To explore the normal function of Menin in hematopoiesis, we studied bone marrow (BM) progenitors after inactivation of the Men1 gene in adult mice. Loss of Menin led to a modest reduction in peripheral blood neutrophil, lymphocyte and platelet counts. In the absence of hematopoietic stress, numbers of multilineage and myeloerythroid BM progenitors were preserved, but pro-B cells and downstream B lineage progenitor subsets were significantly decreased. Competitive BM transplantation assays revealed a marked defect in the function of Menin-deficient hematopoietic stem cells (HSCs), including long-term HSCs. Furthermore, Menin-deficient mice had impaired hematopoietic recovery after chemoablation with 5-fluorouracil. However, expression of Hox genes in BM HSCs was not impaired in the absence of Menin. These observations reveal an essential role of Menin in the homeostasis of hematopoietic stem and progenitor cells. Furthermore, they suggest that Menin may regulate normal hematopoiesis through mechanisms that are distinct from its role in Hox gene-dependent malignant transformation.

Matrix Metalloproteinase (MMP)-3 Polymorphism in Patients with HBV Related Chronic Liver Disease

A common and important problem in patients with chronic hepatitis B is the progression of liver fibrosis. Matrix metalloproteinases (MMPs) play an important role in the progression of liver fibrosis. Our aim of this study was to examine the association of MMP-3 polymorphism with liver cirrhosis in Korean patients with chronic hepatitis B. Genomic DNA was extracted from 127 patients with chronic hepatitis B (CHB), 92 patients with hepatitis B virus (HBV)-related liver cirrhosis (HBV-LC), and 146 healthy subjects. MMP-3 polymorphism was determined by polymerase-chain reaction-based assays, and the association with the progression of liver cirrhosis was investigated. With regard to MMP-3 polymorphism, there was no statistical difference in genotype distributions among the three groups. However, the peripheral platelet count of the 5A carriers was significantly lower than that of the 6A homozygotes in the HBV-LV group (85.0 +/- 36.9 vs. 109.8 +/- 47.0 x 10(9)/l; P = 0.02). With MMP-3 promoter polymorphism (rs3025058), a lower peripheral blood platelet count, which was related to advanced liver cirrhosis, was observed in 5A carriers. Therefore, more studies of MMP-3 gene polymorphism with larger populations should be conducted to further understand its role in the progression of liver cirrhosis.

The prognostic value of maturation-associated phenotypic abnormalities in myelodysplastic syndromes

Several phenotypic abnormalities of bone marrow (BM) hemopoietic precursors have been associated with disease progression in myelodysplastic syndromes (MDS). We analyzed the influence on overall survival of the expression of lineage and maturation-associated antigens of BM hemopoietic cells quantified in a previous study. In the univariate Cox regression the peripheral platelet count was a significant favourable factor for overall survival. Unfavorable prognostic factors were: WPSS, increase in BM CD34+ cells, increased mean fluorescence intensity (MFI) of CD13 on myelocytes, metamyelocytes and mature neutrophils as well as increased CD45 of myelocytes and mature neutrophils. In a model containing platelet count, WPSS and MFI of CD45 and CD13 on mature neutrophils, only hyperexpression of CD13 and degree of thrombocytopenia were independent risk factors. Therefore, phenotypic features that can also be obtained from PB might be useful for predicting survival in MDS.

Red cell aplasia and autoimmune hemolytic anemia following immunosuppression with alemtuzumab, mycophenolate, and daclizumab in pancreas transplant recipients

Acquired red cell aplasia (RCA) is a rare disorder and can be either idiopathic or associated with certain diseases, pregnancy, or drugs. In exceptionally rare cases, it has been reported to co-exist with other autoimmune cytopenias. We report a high incidence of RCA and autoimmune hemolytic anemia (AIHA) in pancreas transplant recipients on alemtuzumab-based maintenance therapy. Between February 2003 and July 2005, 357 pancreas transplant recipients were treated with immunosuppressive regimens containing the lymphocyte-depleting antibody alemtuzumab, the T-cell activation inhibitor daclizumab, and the anti-metabolite mycophenolate mofetil (MMF). We retrospectively reviewed medical records, blood bank data and bone marrow biopsy specimens of patients with a Transplant Information Services database diagnosis of RCA and AIHA from February 2003 to November 2005. Severe RCA, AIHA, and idiopathic thrombocytopenic purpura (ITP) occurred independently or in combination, in 20 out of 357 (5.6%) pancreas transplant recipients, 12 to 24 months following the initiation of the aforementioned immunosuppressive regimens. Severe opportunistic infections developed late in 14/20 (70%) of these patients. Atypical morphologic features, including variable dysgranulopoiesis, variable megakaryocytic hyperplasia with normal or low peripheral platelet counts, and atypical lymphoid aggregates were found in bone marrow trephine sections of 11 patients in whom the diagnosis of RCA was made. We hypothesize that the combination of alemtuzumab, daclizumab and MMF can result in immune dysregulation thereby permitting autoantibody formation. Because the use of these three immune suppressants is becoming increasingly common, it is important to recognize the severe hematologic complications that can arise.

A novel role for PECAM-1 in megakaryocytokinesis and recovery of platelet counts in thrombocytopenic mice

AbstractDuring thrombopoiesis, maturing megakaryocytes (MKs) migrate within the complex bone marrow stromal microenvironment from the proliferative osteoblastic niche to the capillary-rich vascular niche where proplatelet formation and platelet release occurs. This physiologic process involves proliferation, differentiation, migration, and maturation of MKs before platelet production occurs. In this study, we report a role for the glycoprotein PECAM-1 in thrombopoiesis. We show that following induced thrombocytopenia, recovery of the peripheral platelet count is impaired in PECAM-1–deficient mice. Whereas MK maturation, proplatelet formation, and platelet production under in vitro conditions were unaffected, we identified a migration defect in PECAM-1–deficient MKs in response to a gradient of stromal cell–derived factor 1 (SDF1), a major chemokine regulating MK migration within the bone marrow. This defect could be explained by defective PECAM-1−/− MK polarization of the SDF1 receptor CXCR4 and an increase in adhesion to immobilized bone marrow matrix proteins that can be explained by an increase in integrin activation. The defect of migration and polarization was confirmed in vivo with demonstration of altered spatial localization of MKs within the bone marrow in PECAM-1–deficient mice, following immune-induced thrombocytopenia. This study identifies a novel role for PECAM-1 in regulating MK migration and thrombopoiesis.

Liver Fibrosis Is Associated with Decreased Peripheral Platelet Count in Patients with Chronic Hepatitis B and C

Thrombocytopenia is a common complication of chronic liver diseases, but its pathogenesis is not clear. Although generally attributed to hypersplenism, other factors should also be considered. We investigated the relationship between the peripheral platelet count and the degree of fibrosis in patients with chronic viral hepatitis. In an effort to avoid the effects of hypersplenism, we excluded patients with splenomegaly and/or bi- or pan-cytopenia. Seven hundred eighty-four patients (265 chronic viral hepatitis C and 519 chronic viral hepatitis B) were included in the study. Univariate analysis showed that the peripheral platelet count had a negative correlation with fibrosis score, necroinflammatory activity, and age in both groups. In multivariate analysis, the peripheral platelet count had a similar correlation with the fibrosis score and age, but not with necroinflammatory activity, in both groups. The peripheral platelet count decreased more significantly in females with chronic hepatitis C but not in the chronic hepatitis B group. In conclusion, a decrease in peripheral platelet count may be a sign of an increase in the degree of fibrosis during the course of chronic viral hepatitis B and C and factors other than hypersplenism may play a role in this decrease in the peripheral platelet count.

Enhanced pharmacological activity of recombinant human interleukin-11 (rhIL11) by chemical modification with polyethylene glycol

In order to improve the pharmacological efficacy of recombinant human interleukin-11 (rhIL11) and to reduce the frequency of administration, we examined the feasibility of chemical modification of rhIL11 by polyethylene glycol. The rhIL11 was chemically modified by using branched type (PEG2), or linear type (PEG) polyethylene glycol-N-hydroxysuccinimide with various molecular weights. Plasma profiles of immunoreactive rhIL11 after i.v. injection of the 20 kDa PEG2 conjugated rhIL11 (PEG2 (20 K)-rhIL11) were determined by ELISA. Peripheral platelet counts after the administration of the various conjugates were measured. Pharmacokinetic analysis revealed that the mean residence time of PEG2 (20 K)-rhIL11 after i.v. injection extensively increased by a factor of ca 60 compared with the native rhIL11. Maximum peripheral platelet increase of 67% for PEG2 (20 K)-rhIL11 and that of 50% for PEG (20 K)-rhIL11 over the control was observed whereas no significant change was associated with the bolus i.v. injection of native rhIL11. On the other hand, the remaining biological activity of these PEGylated-rhIL11s was 14–16% of native rhIL11, suggesting that retention of rhIL11 in plasma is much effective in order to potentiate the pharmacological efficacy of the cytokine. Chemical modification of rhIL11 by PEG is a promising approach for improving the clinical efficacy of rhIL11 by prolonged retention in plasma.

Absence of prognostic impact of CD13 and/or CD33 antigen expression in adult acute lymphoblastic leukemia. Results of the GIMEMA ALL 0496 trial

The prognostic value of myeloid antigen (MyAg) expression in adult acute lymphoblastic leukemia (ALL) is still controversial. The aim of this study was to correlate the expression of MyAg with clinical, hematologic and biological parameters, and to analyze the impact on response to treatment and prognosis in a large series of adult ALL uniformly characterized and treated. We analyzed the expression of the MyAg CD13 and/or CD33 in a cohort of 377 adult patients with de novo ALL enrolled and treated in the GIMEMA ALL 0496 protocol. MyAg expression was documented in 35% of the 377 adult ALL cases analyzed. MyAg were significantly more frequently associated with B-lineage ALL (38%) than with T-ALL (24%) (p=0.02). No difference was found with regard to clinical features at presentation; a difference was found only for white cell count (p=0.03), percentage of peripheral blasts (p=0.004) and platelet count (p=0.004). No difference was observed in the expression of MyAg between patients with normal or abnormal cytogenetics or between those with high-risk (BCR-ABL+, ALL1-AF4+, E2A-PBX1+) or low-risk B-lineage ALL. We failed to observe any difference between MyAg-positive and MyAg-negative cases in terms of achievement of complete remission, disease-free survival and overall survival at 5 years. Our data indicate that ALL MyAg expression in adults with ALL is not associated with adverse presenting clinical and biological features, and that response to treatment and prognosis is comparable in MyAg-positive and MyAg-negative ALL patients with regards to both complete remission rate and overall survival. We suppose that these result are due to more intensive treatment modalities adopted in the GIMEMA ALL 0496 protocol.