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Background: Although associations have been reported linking pretreatment thrombocytosis to cancer survival outcomes, the validity and strength of existing observational evidence have been contested. This study aimed to conduct an umbrella review to comprehensively appraise the strength, validity and credibility of these reported associations., Methods: We searched Medline, Embase and Cochrane Database of Systematic Reviews from inception to 8 April 2023 to retrieve meta-analyses of observational studies. Meta-analyses were re-performed using a random-effect model and the strength of evidence was graded as convincing, highly suggestive, suggestive and weak according to seven pre-defined quantitative criteria reflecting statistical significance, amount of data, heterogeneity, and evidence of bias. The quality of review was appraised using the AMSTAR2 checklist. The umbrella review was reported adhering to the PRISMA guideline and was registered on PROSPERO (CRD42023455391)., Results: A total of 21 unique meta-analyses investigating ten cancer subtypes were included. All meta-analyses reported inferior survival outcome in cancer patients with pretreatment thrombocytosis, and 18 of them (85.7%) yielded statistically significant results (P < 0.05). Consistent effects were observed across meta-analyses that adopted different cut-off values (i.e. platelet count > 300 or 400 × 10 9 /L) to define thrombocytosis. Although evidence appraisal did not identify convincing evidence (Class I), the associations of thrombocytosis with inferior overall survival of lung, gastric, colorectal cancer and malignant mesothelioma were classified as highly suggestive evidence (Class II). According to AMSTAR2 ratings, no meta-analysis was identified with high or moderate quality., Conclusions: Our findings consolidated the association between pretreatment thrombocytosis and poor survival outcomes in various cancers. Nonetheless, the absence of convincing associations indicates a need for further large-scale, high-quality evidence to confirm whether platelets can serve as a prognostic predictor or a therapeutic target., (© 2024. The Author(s).)

The presence of schistocytes can be responsible for spurious thrombocytosis and spuriously low red blood count (RBC). The hemoglobin concentration will be correct (as the method usually used, destroys the red cells and converts a substantial proportion of the hemoglobin to a stable pigment) but mean corpuscular hemoglobin (MCH) is falsely high. The platelets and RBC histograms of the full blood count analyzers play an important role in the identification of schistocytes and must be carefully analyzed before reporting the previously full blood count parameters. In patients in ECMO, where can be expected the presence of a small number of schistocytes, this evaluation is particularly important to avoid wrong clinical decisions., (Copyright © 2024 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)

Context.—: In the Sysmex DI-60 digital morphology system, a platelet estimate factor (PEF) is used to calculate the estimated platelet count (PLT)., Objective.—: To determine the most accurate PEF by analyzing various specimens, including those with abnormal flag alerts, using both impedance (PLT-I) and optical fluorescent (PLT-F) PLT methods. A validation study was then conducted using random specimens to evaluate the accuracy of the PEF., Design.—: This study included 120 blood specimens without flag alerts, and 120 blood specimens with flag alerts related to platelet abnormalities to determine the PEF. Each group was equally divided into thrombocytopenia, normal count, and thrombocytosis specimens. The PEF values obtained from the PLT-I and PLT-F methods were analyzed. An additional 120 specimens were used to compare the estimated PLT from PEF with the PLT-F count. Unadjusted PEF disregarded platelet ranges and flag alerts, whereas adjusted PEF incorporated them., Results.—: The mean PEF values ranged within 9.95 to 12.99 for PLT-I-obtained values (PEF-I) and within 10.32 to 11.69 for PLT-F-obtained values (PEF-F) across different PLT ranges. The mean PEF values were significantly higher in specimens with flags compared with those without flags. The values were 12.43 compared with 10.19 for PEF-I and 11.45 compared with 10.4 for PEF-F. A significant difference was found between PEF-I and PEF-F in flagged specimens, with respective values of 12.43 and 11.45. There was excellent agreement between estimated PLTs using adjusted PEF and PLT-F. However, proportional biases were observed between estimated PLT using unadjusted PEF and PLT-F., Conclusions.—: Adjustment of PEF values according to specific platelet ranges and flag alert presence was shown to enhance the accuracy of PLT estimation using the Sysmex DI-60 system., Competing Interests: The author has no relevant financial interest in the products or companies described in this article., (© 2024 College of American Pathologists.)

Objective: To determine the role of platelet counts in the context of the decision to treat patients with non-compounded, non-surgically-treated blunt traumatic brain injury (NCNS-bTBI) with anticoagulants/antiaggregants., Methods: A retrospective analysis of 141 anticoagulants/antiaggregants-naïve patients with NCNS-bTBI. Changes in PT-INR and prolonged aPTT were examined and correlated with Marshall and Rotterdam scores, clinical and neuroradiological outcomes., Results: Three groups of platelet counts were identified. Group 1 (83% of patients) had normal platelet counts (150,000-450,000 platelets/mm 3 ) from admission to discharge. Group 2 (13%) developed transient thrombocytopenia (<150,000 platelets/mm 3 ) 2-3 days post-trauma. Group 3 (4%) developed extreme thrombocytosis > 1,000,000/mm 3 platelets 6-9 days post-trauma. Neither acute coagulopathy of trauma nor progressive hemorrhagic insults followed NCNS-bTBI. Moreover, while patients with thrombocytosis/extreme thrombocytosis presented with a worse Glasgow coma score (GCS) on admission (8.8 ± 2.9 vs. 13 ± 2, p  < 0.01) and had longer hospitalization (13.5 ± 10.4 vs. 4.5 ± 2.1 days), their improvement at discharge was the highest (delta GCS, 4 ± 2.8 vs. 1.2 ± 2.1, p  = 0.05). Traumatic subarachnoid hemorrhage was associated with isolated thrombocytosis and 'best improvement.' No thromboembolic or hemorrhagic complications occurred., Conclusion: NCNS-bTBI, thrombocytosis was correlated with better outcomes and was not associated with an increased risk for developing thromboembolism or hemorrhage, precluding the immediate need for any additional antiaggregates.

C-Mannosyl tryptophan (CMW), a unique glycosylated amino acid, is considered to be produced by degradation of C-mannosylated proteins in living organism. Although protein C-mannosylation is involved in the folding and secretion of substrate proteins, the pathophysiological function in the hematological system is still unclear. This study aimed to assess CMW in the human hematological disorders. The serum CMW levels of 94 healthy Japanese workers were quantified using hydrophilic interaction liquid chromatography. Platelet count was positively correlated with serum CMW levels. The clinical significance of CMW in thrombocytosis of myeloproliferative neoplasms (T-MPN) including essential thrombocythemia (ET) were investigated. The serum CMW levels of the 34 patients with T-MPN who presented with thrombocytosis were significantly higher than those of the 52 patients with control who had other hematological disorders. In patients with T-MPN, serum CMW levels were inversely correlated with anemia, which was related to myelofibrosis (MF). Bone marrow biopsy samples were obtained from 18 patients with ET, and serum CMW levels were simultaneously measured. Twelve patients with bone marrow fibrosis had significantly higher CMW levels than 6 patients without bone marrow fibrosis. Collectively, these results suggested that CMW could be a novel biomarker to predict MF progression in T-MPN., (© 2024. The Author(s).)

Background: The most ordered laboratory test worldwide is the complete blood count (CBC)., Content: In this primer, an introduction to platelet testing in the context of the CBC is provided with a discussion of the laboratory evaluation of platelet abnormalities including thrombocytopenia and thrombocytosis., Summary: As clinical chemists continue to be tasked to direct laboratories outside of the traditional clinical chemistry sections such as hematology, expertise must be developed. This primer is dedicated to that effort., (© Association for Diagnostics & Laboratory Medicine 2024. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

This case report describes a case of pseudonormokalemia, true hypokalemia. Often, only laboratory values outside the normal range gain attention and false normal results are at risk of not being noticed. However, a disease state may be masked by another pathological process. Here, a 50-year old male was admitted to the Department of Internal Medicine due to sepsis from a dental infection. Initially, serum potassium measurement revealed a normal value of 4 mmol/L (reference interval 3.8-5.1 mmol/L). Thrombocyte number was above 500x10 9 /L. Due to our policy to recommend a repeated measurement of potassium in whole blood or heparin plasma if a patient has thrombocytosis, pseudonormokalemia was identified because the heparin plasma potassium value was only 2.9 mmol/L (reference interval 3.5-4.8 mmol/L). The physiological difference between serum and plasma concentration is no more than 0.3 mmol/L. In this case, potassium concentration were falsely elevated in the serum sample, probably caused by the high number of platelets releasing potassium during clotting. Interpretative comments in patients with thrombocytosis over 500x10 9 /L recommending plasma potassium measurement are helpful. The best way to eliminate pseudohyperkalemia and pseudonormokalemia phenomena caused by thrombocytosis is to completely change towards heparin plasma as the standard material., Competing Interests: Potential conflicts of interest None declared, (Copyright Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Platelet counts in reactive thrombocytosis rarely exceed 1000 × 10 9 /L. We present the case of a male patient, aged 80 years, with quiescent rheumatoid arthritis who was found to have a platelet count of 1011 × 10 9 /L on routine laboratory testing. The patient was initially asymptomatic but developed leukocytosis to 23.1 × 10 9 /L on hospital day 2. Diagnostic work-up revealed obstructive nephrolithiasis and pyelonephritis, and the thrombocytosis and leukocytosis gradually resolved with empiric antibiotic treatment and ureteral stent placement. Tests for myeloproliferative disorders, including JAK-2V617F mutation, BCR-ABL for chronic myeloid leukemia and acute lymphocytic leukemia, and myeloproliferative neoplasms (MPL/CALR), were negative. Physicians should be aware that in rare cases reactive thrombocytosis can exceed 1000 × 10 9 /L, and that markedly elevated platelet counts in the setting of urinary tract infections may be an early sign of obstructive uropathy., (Copyright © 2024 Marshfield Clinic Health System.)

Introduction: Studies assessing the impact of preoperative and first-day postoperative values of leukocytes, thrombocytes, and platelet/leukocyte ratio (PLR) after radical cystectomy (RC) are sparse. We aimed to assess the impact of these factors on long-term survival after RC., Methods: An analysis of patients undergoing open RC from 2004 to 2023 at our center was performed. Leukocytosis was defined as ≥8,000 leukocytes/μL and thrombocytosis as ≥400,000 thrombocytes/μL. Similarly, the cutoff for PLR was set at 28. A multivariable Cox regression analysis was performed to assess the role of leukocytosis, thrombocytosis, and PLR on long-term survival after RC. For all analyses, hazard ratios (HRs) with the corresponding 95% confidence intervals (CIs) were estimated., Results: A total of 1,817 patients with a median age of 70 years (interquartile range [IQR]: 62-77) were included. Overall, 804 (44%), 175 (10%), and 1,296 (71%) patients presented with leukocytosis, thrombocytosis, and PLR ≥28 preoperatively. Accordingly, 1,414 (78%), 37 (2%), and 249 (14%) patients presented with leukocytosis, thrombocytosis, and PLR ≥28 on the first day after RC. At a median follow-up of 26 months (IQR: 8-68) after RC, 896 (49%) patients died. In the multivariate Cox regression analysis after adjusting for major perioperative risk factors, only preoperative leukocytosis (HR: 1.3, 95% CI: 1.1-1.6, p = 0.01), as well as both preoperative and first-day thrombocytosis (HR: 2.1, 95% CI: 1.5-2.9, and HR: 2.8, 95% CI: 1.6-5.1, p &lt; 0.001, accordingly) were associated with worse overall survival., Conclusion: PLR should not be used as a prognostic marker for survival after RC. On the contrary, preoperative leukocytosis, as well as preoperative and first-day thrombocytosis should raise awareness among clinicians performing RC since they were independently associated with worse survival after RC., (© 2024 S. Karger AG, Basel.)

Over 95% of Polycythemia Vera (PV) patients carry the V617F mutation in the tyrosine kinase Janus kinase 2 (JAK2), resulting in uncontrolled erythroid proliferation and a high risk of thrombosis. Using mass spectrometry, we analyzed the RBC membrane proteome and showed elevated levels of multiple Ca 2+ binding proteins as well as endoplasmic-reticulum-residing proteins in PV RBC membranes compared with RBC membranes from healthy individuals. In this study, we investigated the impact of JAK2 V617F on (1) calcium homeostasis and RBC ion channel activity and (2) protein expression and sorting during terminal erythroid differentiation. Our data from automated patch-clamp show modified calcium homeostasis in PV RBCs and cell lines expressing JAK2 V617F , with a functional impact on the activity of the Gárdos channel that could contribute to cellular dehydration. We show that JAK2 V617F could play a role in organelle retention during the enucleation step of erythroid differentiation, resulting in modified whole cell proteome in reticulocytes and RBCs in PV patients. Given the central role that calcium plays in the regulation of signaling pathways, our study opens new perspectives to exploring the relationship between JAK2 V617F , calcium homeostasis, and cellular abnormalities in myeloproliferative neoplasms, including cellular interactions in the bloodstream in relation to thrombotic events.

Background: Acquired von Willebrand syndrome (AVWS) is a rare, frequently underdiagnosed and underestimated bleeding disorder. Careful personal and family history and late-onset mucocutaneous bleeding could help clarify the etiology of bleeding deficiency., Case Presentation: An 82-year-old male patient was admitted to our clinic with a severe nosebleed on 30.05.2018. Laboratory results revealed thrombocytosis, elevated white blood cell count and high LDH. Basic coagulation parameters were normal. He was referred to our clinic, where a bone marrow biopsy was taken. His personal and family history had no mention of bleeding disorders, nor was he on anticoagulant therapy. We detected elevated VWF antigen and decreased VWF ristocetin cofactor activity. Loss of high molecular weight multimers was detected by using agarose gel electrophoresis. These laboratory results were indicative of AVWS. Hydroxyurea treatment was initiated, leading to a gradual decrease in platelet count. The histological examination revealed essential thrombocytosist while mutation analysis was JAK2/CALR/MPL negative. However, due to severe nosebleeds, the patient was hospitalized and needed blood transfusion. A cardiological check-up revealed the progression of aortic valve stenosis. After, balloon-dilation a transcatheter aortic valve implantation was performed. As a result, VWF activity and activity to antigen ratio returned to normal as did multimeric structure. In July 2019, the follow-up examination showed that the patient was in a satisfactory condition, with normal hematological parameters, and no new nosebleed episode occurred., Conclusions: The patient complained of recurring nosebleeds, which stopped completely after the resolution of both underlying conditions successful cytoreductive treatment of triple-negative ET and transcatheteric aortic valve replacement.

Objective: Endometrial cancer prognosis is related to stage, histology, myometrial invasion, and lymphovascular space invasion. Several studies have examined the association between pretreatment thrombocytosis and patient outcomes with contrasting results regarding prognosis. Our aim was to evaluate the association of pretreatment platelet count with outcomes in endometrial cancer patients., Methods: This is an Israeli Gynecologic Oncology Group multicenter retrospective cohort study of consecutive patients with endometrial cancer, who underwent surgery between January 2002 and December 2014. Patients were grouped as low risk (endometrioid G1-G2 and villoglandular) and high risk (endometrioid G3, uterine serous papillary carcinoma, clear cell carcinoma, and carcinosarcoma). Those with stage I disease were compared with stages II-IV. Disease stages were reviewed and updated to reflect International Federation of Gynecology and Obstetrics (FIGO) 2009 staging. All patients underwent pelvic washings for cytology and total abdominal or laparoscopic hysterectomy with bilateral salpingo-oophorectomy. Pelvic lymph node assessment was performed in patients with tumors of moderate-high risk histology or deep myometrial invasion. Para-aortic sampling was performed at the surgeon's discretion. Patients were categorized by pretreatment platelet count into two groups: ≤400×10 9 /L and >400×10 9 /L (defined as thrombocytosis). Clinical and pathological features were compared using Student t-test, χ 2 or Fisher's exact test. Survival measures were plotted with the Kaplan-Meier method and compared using the log-rank test. A Cox proportional hazards model was used for multivariable comparison of associations., Results: Of the 1482 patients included, most had stage I disease (961; 74.8%) and most had endometrioid histology (927; 64.1%). A total of 1392 patients (94%) had pretreatment platelet counts ≤400×10 9 /L and 90 (6%) had pretreatment thrombocytosis. Patients with thrombocytosis had a significantly higher rate of high-grade malignancy, advanced stage, lymphovascular space invasion, low uterine segment involvement, and lymph node metastases. They also had shorter 5 year disease-free survival (65% vs 80%, p=0.003), disease-specific survival (63% vs 83%, p<0.05) and overall survival (59% vs 77%, p<0.05). On multivariate analysis, an elevated pretreatment thrombocyte count remained a significant independent predictor for disease-specific survival and overall survival., Conclusions: Pretreatment thrombocytosis is an independent prognostic factor for decreased disease-specific survival and overall survival among patients with endometrial cancer, and can serve as a predictor of poor outcome., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Importance: Individuals with newly diagnosed cancer often have a high platelet count (thrombocytosis). Whether thrombocytosis is associated with the presence of an undiagnosed cancer remains unknown., Objective: To assess whether a new diagnosis of thrombocytosis is associated with a subsequent risk of cancer among adults., Design, Setting, and Participants: This population-based retrospective cohort study was conducted using linked laboratory data from Ontario, Canada, from January 1, 2007, to December 31, 2017, with follow-up until December 31, 2018. The study cohort included adults aged 40 to 75 years on the date of a routine complete blood count (CBC) test (index test) who had a normal platelet count in the 2 previous years and no history of cancer. Data analysis was performed in December 2020., Exposures: Exposed individuals were those with a platelet count greater than 450 × 109/L. Matched unexposed control individuals had a platelet count within the reference range (150 × 109/L to 450 × 109/L) reported within 30 days of the exposure., Main Outcomes and Measures: Incident cancers within 5 years after diagnosis of thrombocytosis. Absolute and relative risks for cancer associated with thrombocytosis were estimated for all cancers and for cancers at specific sites., Results: Of the 3 386 716 Ontario residents with a recorded routine CBC test result, 53 339 (1.6%) had thrombocytosis and a prior normal platelet count. Among individuals with thrombocytosis, the median age was 59.7 years (interquartile range, 50.2-67.4 years) and 37 349 (70.0%) were women. Among the 51 624 individuals with thrombocytosis included in the matched analysis, 2844 (5.5%) had received a diagnosis of a solid cancer in the 2-year follow-up period and 3869 (7.5%) had received a diagnosis within 5 years. The relative risk (RR) for developing any solid cancer within 2 years was 2.67 (95% CI, 2.56-2.79). Associations were found between thrombocytosis and cancers of the ovary (RR, 7.11; 95% CI, 5.59-9.03), stomach (RR, 5.53; 95% CI, 4.12-7.41), colon (RR, 5.41; 95% CI, 4.80-6.10), lung (RR, 4.41; 95% CI, 4.02-4.85), kidney (RR, 3.64; 95% CI, 2.94-4.51), and esophagus (RR, 3.64; 95% CI, 2.46-5.40)., Conclusions and Relevance: In this cohort study, an increased platelet count was associated with an increased risk of cancer for at least 2 years. The results suggest that individuals with unexplained thrombocytosis should be offered screening for several cancers.

Background: Iron deficiency anemia (IDA)-induced reactive thrombocytosis can occur in children and adults. The underlying mechanism for this phenomenon is indeterminate. Traditional cytokines such as thrombopoietin (TPO), interleukin-6 (IL-6), and IL-11 involved in megakaryopoiesis have not been shown to be the cause. Recent studies suggest that growth factors and signaling molecules involved with angiogenesis influence the proliferation and differentiation of megakaryocytes., Methods: We investigated the possible association between angiogenic cytokines with reactive thrombocytosis due to IDA in an iron-deficient (ID) rat model. Complete blood count, iron panels, and TPO levels were measured at baseline and 5 weeks later in both control (C) and ID rats. Angiogenic cytokines were evaluated in the bone marrow in all rats., Results: We successfully induced IDA in our rats by phlebotomy and reduced iron diet. We did not find an increase of TPO in ID rats. A review of the bone marrow showed an increase in the number of megakaryocytes, vascular structures, as well as increased intensity of stain for vascular endothelial growth factor (VEGF), and CXC chemokine receptor 4 (CXCR4) in rats with IDA compared to controls., Conclusions: Our results of histological bone marrow data suggest an important role for angiogenesis in the development of IDA-induced thrombocytosis., Impact: Thrombocytosis is common with IDA in both children and adults, but the mechanism is unclear. We confirmed that TPO is not the major driver of iron deficiency-associated thrombocytosis. We confirmed the increase in the number of megakaryocytes in the bone marrow despite stable TPO levels. We provided evidence supporting an important role of angiogenesis in megakaryocytopoiesis/thrombopoiesis with increased vascular structures and angiogenic cytokines in the bone marrow of iron-deficient rats. The demonstration that angiogenesis may play an important role in secondary thrombocytosis could lead to a new approach in treating symptomatic reactive thrombocytosis by targeting angiogenesis., (© 2021. The Author(s), under exclusive licence to the International Pediatric Research Foundation, Inc.)

Objective/hypothesis: Early and objective prediction of complications in head and neck reconstructive surgery could decrease morbidity and prolonged hospital stays but unfortunately most complications are not identified until their effect is fully realized. There are limited data regarding the association of platelet levels and post-operative complications. Post-operative thrombocytosis (POTCT) is proposed as a possible indicator for complications following free-flap reconstruction., Study Design: Retrospective review., Methods: A multisite retrospective chart review of patients undergoing free tissue transfer between 2013 and 2018 was undertaken. POTCT was recorded and data normalized between institutions. Data were compared between groups using t-tests and logistic regression (P < .05). A lag-1 difference was used to compare the rate of change in platelet values., Results: A total of 398 patients were included. POTCT and a rate of change of 30 K between POD5 and POD6 was significantly associated with the presence of post-operative complication (P = .007). Additionally, lag-1 difference demonstrated a significant association of change in daily platelet counts and complication rates., Conclusions: Isolated POTCT may be an early predictor of complications in HNC patients undergoing free-flap reconstruction., Level of Evidence: 4 Laryngoscope, 131:1542-1547, 2021., (© 2021 The American Laryngological, Rhinological and Otological Society, Inc.)

Destruction of liver sinusoidal endothelial cells (LSECs) is an initial event in sinusoidal obstruction syndrome (SOS) that leads to accumulation of platelets in the liver. Herein, we explored the role of platelets during progression of experimental SOS induced by monocrotaline (MCT) in mice. Depletion of platelets using an anti-CD41 antibody or anti-thrombocyte serum exacerbated MCT-induced liver injury in C57BL/6 mice, as indicated by an increase in the alanine transaminase (ALT) level, which was associated with hemorrhagic necrosis. Thrombocytosis induced by thrombopoietin (TPO) or the TPO receptor agonist romiplostim (ROM) attenuated MCT-induced liver injury, as evidenced by lower levels of ALT and mRNA encoding matrix metalloproteinase (MMP) 9, and higher levels of mRNA encoding vascular endothelial growth factor receptor (VEGFR) 2 and VEGFR3. The level of activated hepatic platelets was higher in TPO- and ROM-treated mice than in saline-treated mice. Co-culture with a high number of platelets increased the viability of LSECs and their mRNA levels of CD31, VEGFR2, and VEGFR3, and decreased their mRNA level of MMP9. The level of VEGF-A was increased in the culture medium of LSECs co-cultured with platelets. These results indicate that platelets attenuate MCT-induced liver injury by minimizing damage to LSECs., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to disclose., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To develop a composite disease activity score for systemic JIA (sJIA) and to provide preliminary evidence of its validity., Methods: The systemic Juvenile Arthritis Disease Activity Score (sJADAS) was constructed by adding to the four items of the original JADAS a fifth item that aimed to quantify the activity of systemic features. Validation analyses were conducted on patients with definite or probable/possible sJIA enrolled at first visit or at the time of a flare, who had active systemic manifestations, which should include fever. Patients were reassessed 2 weeks to 3 months after baseline. Three versions were examined, including ESR, CRP or no acute-phase reactant., Results: A total of 163 patients were included at 30 centres in 10 countries. The sJADAS was found to be feasible and to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha 0.64-0.65), fair ability to discriminate between patients with different disease activity states and between those whose parents were satisfied or not satisfied with illness outcome (P < 0.0001 for both), and strong responsiveness to change over time (standardized response mean 2.04-2.58). Overall, these properties were found to be better than those of the original JADAS and of DAS for RA and of Puchot score for adult-onset Still's disease., Conclusion: The sJADAS showed good measurement properties and is therefore a valid instrument for the assessment of disease activity in children with sJIA. The performance of the new tool should be further examined in other patient cohorts that are evaluated prospectively., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Platelets are critical components of a number of physiologic processes, including tissue remodeling after injury, wound healing, and maintenance of vascular integrity. Increasing evidence suggests that platelets may also play important roles in cancer. In ovarian cancer, thrombocytosis, both at the time of initial diagnosis and at recurrence, has been associated with poorer prognosis. This review describes current evidence for associations between thrombocytosis and ovarian cancer prognosis and discusses the clinical relevance of platelet count thresholds and timing of assessment. In addition, we discuss several mechanisms from in vitro , in vivo , and clinical studies that may underlie these associations and recommend potential approaches for novel therapeutic targets for this lethal disease., Competing Interests: The authors declare no conflict of interest.

The effects of TLR4 blocker on blood cell morphology, concentrations proinflammatory cytokines, and functional state of the liver and kidneys were studied in outbred male rats (n=60) after intravenous injection of 20 mg/kg LPS isolated from opportunistic Proteus mirabilis strain ATCC 51393. TLR4 blocker TLR4-IN-C34 was injected intravenously in a dose of 1 mg/kg/day over 3 days. Systemic inflammatory reaction induced by LPS was characterized by elevation of serum TNFα, IL-1β, IL-6, erythrocyte sedimentation rate, leukocytosis, and thrombocytosis. Increased activity of hepatocyte enzymes (ALT, alkaline phosphatase, and lactate dehydrogenase), retention of nitrogen metabolites (urea and creatinine), elevated content of protein oxidation products, and enhanced protein catabolism were also observed. Administration of TLR4 blocker reduced parameters of inflammatory reaction and prevented the development of hypercatabolic syndrome; endotoxicosis and kidney function indicators approached the normal levels.

There is an increasing number of studies showing that thrombocytosis-accompanying a variety of solid tumors including colorectal cancer (CRC)-is associated with shorter survival and earlier development of metastases. The mechanisms of cancer-associated thrombocytosis are not completely understood yet. The aim of our study was to evaluate the role of IL-6 in tumor development and thrombocytosis in mice with inflammation-induced CRC, using a CRISPR/cas9 IL-6 knockout (KO) strain. Adult male FB/Ant mice ( n = 39) were divided into four groups: (1) IL-6 KO controls ( n = 5); (2) IL-6 KO CRC model group ( n = 18); (3) Wild-type (WT) controls ( n = 6); and (4) WT CRC model group ( n = 10). CRC model animals in (2) and (4) received azoxymethane (AOM)/dextran sodium sulfate (DSS) treatment to induce inflammation-related CRC. Plasma and liver tissues were obtained to determine platelet counts, IL-6 and thrombopoietin-1 (TPO) levels. In 1 WT and 2 IL-6 KO mice in vivo confocal endomicroscopy and 18F-fluorodeoxyglucose (FDG) PET/MRI examinations were performed to evaluate the inflammatory burden and neoplastic transformation. At the end of the study, tumorous foci could be observed macroscopically in both CRC model groups. Platelet counts were significantly elevated in the WT CRC group compared to the IL-6 KO CRC group. TPO levels moved parallelly with platelet counts. In vivo fluorescent microscopy showed signs of disordered and multi-nuclear crypt morphology with increased mucus production in a WT animal, while regular mucosal structure was prominent in the IL-6 KO animals. The WT animal presented more intense and larger colonic FDG uptake than IL-6 KO animals. Our study confirmed thrombocytosis accompanying inflammation-related CRC and the crucial role of IL-6 in this process. Significantly higher platelet counts were found in the WT CRC group compared to both the control group and the IL-6 KO group. Concomitantly, the tumor burden of WT mice was also greater than that of IL-6 KO mice. Our findings are in line with earlier paraneoplastic IL-6 effect suggestions.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease in 2019 (COVID-19) which rapidly evolved from an outbreak in Wuhan, China into a pandemic that has resulted in over millions of infections and over hundreds of thousands of mortalities worldwide. Various coagulopathies have been reported in association with COVID-19, including disseminated intravascular coagulation (DIC), sepsis-induced coagulopathy (SIC), local microthrombi, venous thromboembolism (VTE), arterial thrombotic complications, and thrombo-inflammation. There is a plethora of publications and conflicting data on hematological and hemostatic derangements in COVID-19 with some data suggesting the link to disease progress, severity and/or mortality. There is also growing evidence of potentially useful clinical biomarkers to predict COVID-19 progression and disease outcomes. Of those, a link between thrombocytopenia and COVID-19 severity or mortality was suggested. In this opinion report, we examine the published evidence of hematological and hemostatic laboratory derangements in COVID-19 and the interrelated SARS-CoV-2 induced inflammation, with a focussed discussion on platelet count alterations. We explore whether thrombocytopenia could be a potential disease biomarker and we provide recommendations for future studies in this regard.

Introduction: The spleen plays a role in the immune and coagulative responses, yet a splenectomy may be required during ovarian cancer surgery to achieve complete cytoreduction. The aim of the study was to correlate hematologic changes with the development of infection and venous thromboembolism in patients undergoing splenectomy., Methods: This single-institution retrospective review includes all patients undergoing splenectomy during cytoreductive surgery for advanced ovarian cancer, March 2001 to December 2016. We compared postoperative hematologic changes (evaluated daily before discharge) in patients developing infection within 30 days' post-surgery (Infection group) with those who did not (No-Infection group). We also compared patients developing venous thromboembolism with those without., Results: A total of 265 patients underwent splenectomy. Median age was 64 years (range 22-88): 146 (55%) patients had stage IIIC and 114 (43%) patients had stage IV. The majority, 201 (76%) patients underwent splenectomy during primary debulking. A total of 132 (50%) patients comprised the Infection group (most common: urinary tract infection, 54%). Median time from surgery to infection was 8 days (range, 0-29). After initial rise in white blood cell count in both groups, the Infection group had a second peak on postoperative day 10 (median 16.6K/mcL, IQR 12.5-21.2) not seen in the No-Infection group (median 12K/mcL, IQR 9.3-16.3). A total of 40 (15%) patients developed venous thromboembolism, median time of 6.5 days (range, 1-43). All patients demonstrated a continuous rise in platelets during postoperative days 0-15. Thrombocytosis was present in 38/40 (95%) patients with venous thromboembolism vs 183/225 (81%) patients without (P=0.036). Median days with thrombocytosis was higher in venous thromboembolism (8 days, range 1-15) vs non groups (6 days, range 1-16, P=0.049)., Conclusion: We identified initial leukocytosis after splenectomy in all patients. The Infection group had a second peak in white blood cell count on postoperative day 10, not present in the No-Infection group. Among patients with venous thromboembolism, thrombocytosis was more frequent and of longer duration., Competing Interests: Competing interests: None declared., (© IGCS and ESGO 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose of Review: Thrombocytosis is common to all myeloproliferative neoplasms (MPN), including essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis. Despite the traditionally held belief amongst many clinicians that thrombocytosis correlates with thrombosis risk, there is little evidence in the literature to support that claim. Herein we critically analyze the literature to better understand the relationship between thrombocytosis and risk of thrombosis in MPN., Recent Findings: Both retrospective and prospective studies argue against associations between thrombocytosis and risk of thrombosis in patients with ET and PV. Rather, most studies suggest that the presence of extreme thrombocytosis is instead associated with an increased risk of hemorrhagic events, a paradoxical phenomenon with important clinical implications. Thrombosis risk has a multifactorial set of etiologies in MPNs. While qualitative abnormalities of the platelets may contribute, associations between platelet quantity and thrombosis risk are weak in MPN patients.

Aims: This study was aimed at investigating the prognostic impact of pretreatment thrombocytosis in epithelial ovarian cancer (EOC) patients in Lagos, Nigeria., Methods: This was a retrospective cohort study involving the review of the clinical record of 72 patients with histologically confirmed EOC who were managed at the Lagos University Teaching Hospital, Lagos, Nigeria over a 7-year period from January 2010 to December 2016. Information on the sociodemographic data and platelet counts at diagnosis of EOC were retrieved from the patients' medical records. Descriptive statistics were then computed for all baseline patients' characteristics. Survival analyses were carried out using the Kaplan-Meier estimates. Multivariate analysis of these data was performed with the Cox proportional hazards model., Results: This study revealed that the prevalence of pretreatment thrombocytosis was 41.7% among the women with EOC. Fifty-three (73.6%) of the women had the advanced-stage disease (FIGO stage III-IV) while 52 (72.2%) had high-grade disease (II-III). The majority (66.7%) of the women had a serous histological type of EOC while 76.4% had documented recurrence. Pretreatment thrombocytosis was significantly associated with the women's parity (P = 0.009), serum carbohydrate antigen 125 levels (P = 0.018), median progression-free survival (PFS) (P < 0.001), 3-year median overall survival (OS) (P < 0.001), type of primary treatment (P = 0.002), extent of cytoreduction (P < 0.001), presence of ascites (P = 0.002), International Federation of Gynecology and Obstetrics (FIGO) stage (P = 0.008), and histological type (P = 0.011). Pretreatment thrombocytosis was negatively associated with PFS (hazard ratio [HR] = 0.25; 95% CI 0.83, 0.75; P = 0.014) and 3-year OS (HR = 0.03; 95% CI 0.03, 0.27; P = 0.002)., Conclusions: The study suggests that pretreatment thrombocytosis may be a useful predictor of survivals in EOC patients., Competing Interests: None

Aim: We investigated blood parameters in patients with inoperable stage III non-small cell lung cancer (NSCLC) to predict individual outcomes after definitive chemoradiotherapy (CRT)., Patients and Methods: Blood parameters of consecutive patients undergoing definitive CRT between 2010 and 2016 for inoperable stage III NSCLC before multimodal treatment and at first follow-up were measured and analyzed., Results: Blood parameters from 99 patients were evaluated. Histologically, about 50% of patients had an adenocarcinoma. All patients received platinum-based sequential or concurrent CRT. The median total dose to the primary tumor was 60 (range=48-70) Gy. On multivariate analysis after adjustment for all co-founders, median overall survival for pre-treatment cutoffs were: lactate dehydrogenase (LDH) >250 U/l was 17 vs. 27 months [hazard ratio (HR)=2.05, 95% confidence intervaI (CI)=1.15-3.66; p=0.015], thrombocytosis >400×10 6 /l: 11 vs. 23 months (HR=2.75, 95% CI=1.1-6.88; p=0.03), hypoalbuminemia <3.5 g/dl: 12 vs. 24 months (HR=2.42, 95% CI=1.21-4.84; p=0.013) and post-treatment neutrophilia >7×10 6 /l: 12 vs. 27 months (HR=2.5, 95% CI=1.21-5.17; p=0.013)., Conclusion: Pre-treatment elevated LDH, thrombocytosis, hypoalbuminemia and post-treatment neutrophilia were associated with significantly worse overall survival in patients with inoperable stage III NSCLC treated with CRT. Patients with both pre-therapeutic elevated LDH and hypoalbuminemia demonstrated a dismal prognosis despite completion of multimodal treatment., (Copyright© 2020, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

A considerable proportion of patients with chronic myeloid leukaemia (CML) may present at diagnosis with high platelet counts. This may result in thrombosis or bleeding complications due to binding of von Willebrand factor (VWF) multimers to platelets. Paediatric CML is very rare and no systematic investigation on clinical complications of elevated platelets has been reported. Data on platelet count and associated haemostaseological complications were retrospectively analysed in a cohort of 156 children with CML. Fifty-one percent (81/156) patients presented with thrombocytosis (platelet count> 500 × 10 9 /l), and were extreme (>1 000 × 10 9 /l) in 23/156 (16%). There were no cases of thrombosis but mild bleeding signs were present in 12% (n = 9) children with thrombocytosis. Bleeding occurred without correlation to elevated platelet counts and was associated with reduced large VWF multimers, indicating a diagnosis of acquired von Willebrand syndrome (AVWS), which resolved after initiation of CML treatment. Patients with paediatric CML frequently exhibit high platelet counts not resulting in thrombosis. In patients with thrombocytosis mild bleeding signs due to a low percentage of large VWF multimers can be demonstrated. AVWS may be underdiagnosed in paediatric CML (Clinical-Trials.gov NCT00445822, 9 March 2007)., (© 2019 British Society for Haematology and John Wiley & Sons Ltd.)

Besides their vital role in hemostasis and thrombosis, platelets are also recognized to be involved in cancer, where they play an unexpected central role: They actively influence cancer cell behavior, but, on the other hand, platelet physiology and phenotype are impacted by tumor cells. The existence of this platelet-cancer loop is supported by a large number of experimental and human studies reporting an association between alterations in platelet number and functions and cancer, often in a way dependent on patient, cancer type and treatment. Herein, we shall report on an update on platelet-cancer relationships, with a particular emphasis on how platelets might exert either a protective or a deleterious action in all steps of cancer progression. To this end, we will describe the impact of (i) platelet count, (ii) bioactive molecules secreted upon platelet activation, and (iii) microvesicle-derived miRNAs on cancer behavior. Potential explanations of conflicting results are also reported: Both intrinsic (heterogeneity in platelet-derived bioactive molecules with either inhibitory or stimulatory properties; features of cancer cell types, such as aggressiveness and/or tumour stage) and extrinsic (heterogeneous characteristics of cancer patients, study design and sample preparation) factors, together with other confounding elements, contribute to "the Janus face" of platelets in cancer. Given the difficulty to establish the univocal role of platelets in a tumor, a better understanding of their exact contribution is warranted, in order to identify an efficient therapeutic strategy for cancer management, as well as for better prevention, screening and risk assessment protocols., Competing Interests: The authors declare no conflict of interest.

Introduction: Platelets play a fundamental role in the pathogenesis of acute coronary syndrome (ACS). The platelet count (PC) at hospital admission is easy to obtain, but whether thrombocytopenia or/and thrombocytosis impact long-term mortality (LTM) after ACS is unclear., Objective: To evaluate the effect of PC at hospital admission on LTM in patients with ACS., Methods: This retrospective cohort study included patients with the ICD-10 codes for unstable angina (I.20) and acute myocardial infarction (I.21, I.22). Thrombocytopenia was defined as a blood PC <150 G/L and thrombocytosis as a PC >450 G/L. Additional platelet indices which were tested included plateletcrit (PCT), the mean platelet volume (MPV), the platelet distribution width (PDW), and the platelet larger cell ratio (P-LCR). Data on all-cause death were obtained from the National Health Fund database., Results: The study included 3,162 patients with a median follow-up of 27.2 months (interquartile range 12.5-46.8 months; max 68.7 months). Patients with thrombocytopenia and thrombocytosis yielded a higher maximal analyzed 5-year mortality rate in comparison with normal PC patients (45.8 and 47.7 vs. 24.2%, respectively; p < 0.00001) which was mainly driven by higher deaths at 1-2 years after ACS. The 5-year LTM was also significantly higher in patients with abnormal PCT and MPV levels in comparison with patients with PCT and MPV within the normal range. Other platelet indices (PDW, P-LCR) were not associated with a worse outcome. The Cox proportional hazards model revealed that thrombocytopenia at admission was independently associated with higher LTM after ACS (RR 1.83; 95% CI 1.1-3.0; p = 0.01)., Conclusions: Both thrombocytopenia and thrombocytosis at hospital admission in post-ACS patients are associated with a significant almost two times higher 5-year mortality rate., (© 2020 S. Karger AG, Basel.)

Background: Preoperative thrombocytosis (PTC) is frequently observed in various solid malignancies and often associated with an unfavourable oncological outcome., Objectives: The aim of this study was to investigate the influence of PTC in patients undergoing radical cystectomy (RC) for urothelial carcinoma (UC) of the bladder on the oncological prognosis and additionally on perioperative blood transfusions (PBT)., Method: A retrospective analysis of 866 patients undergoing RC in a tertiary care centre was performed. PTC was defined as a platelet count >400 G/L. A chi-square test and Mann-Whitney test were used to investigate the association of PTC with categorical clinicopathological variables. A logrank test and multivariable Cox regression analyses were used to assess the association of PTC with cancer-specific survival., Results: PTC was detected in 8% (n = 67) of the patients and was significantly associated with muscle invasion (p = 0.004), advanced tumour stages (p = 0.003) and nodal metastases (p < 0.001) and with a higher rate of PBT (p< 0.001). In the multivariate analysis, PTC was significantly related to poor oncological survival (hazard ratio 2.23, 95% CI 1.51-3.30, p < 0.001)., Conclusion: PTC is significantly associated with an impaired oncological outcome in patients undergoing RC for UC. PTC therefore represents an independent and easy to determine prognostic parameter for patients' oncological outcome. Intriguingly, PTC is significantly associated with an increased rate of PBT., (© 2019 S. Karger AG, Basel.)

Background: Information regarding the significance of platelet (PLT) count on outcome of atrial fibrillation (AF) patients who are treated with anticoagulants is limited., Methods: We conducted a monocentric observational retrospective cohort study of AF patients treated with either warfarin (n = 6287) or non-vitamin K antagonist oral anticoagulants (NOACs) (n = 5240). Patient were divided into 3 subgroups; low, normal and high PLT for counts < 150 K/ μl, 150-450 K/ μl and > 450 K/ μl, respectively. A multivariate Cox-regression was used to evaluate the association between PLT subgroups and clinical outcomes., Results: During follow-up [median = 40.6 months (IQR 17.6-60)], mortality (HR 1.36, 95 CI 1.1-1.74, p = 0.01) and rate of myocardial infarction (MI) (HR 2.4, 95 CI 1.28-4.57, p = 0.007) were higher in patients with high compared to normal PLT. Transient ischemic attack or cerebrovascular accident (TIA/CVA) rate was lower in patients with low compared to normal PLT (HR 0.69, 95 CI 0.51-0.93, p = 0.02). A comparison between NOACs and warfarin demonstrated a significantly better clinical outcome for patients on NOACs in both the low (lower mortality rates) and normal PLT subgroup (lower mortality, TIA/CVA and systemic emboli rates). For patients on NOACs, low and high compared to normal PLT were associated with a higher combined outcome (HR 1.12, 95 CI 1-1.38, p = 0.047), and a higher systemic emboli rate (HR 7.07, 95 CI 1.66-30.25, p = 0.008), respectively., Conclusions: Abnormal PLT count is associated with different clinical outcome of AF patients on anticoagulants. Further studies are needed in order assess whether PLT level should influence strategies of anticoagulation., Competing Interests: The study was supported by grants Bayer and Pfizer. Bayer and Pfizer had no role in the design and conduct of this study; collection, management, analysis, and interpretation of the data; and preparation or approval of the article. MKM reports receiving honoraria, research and travel grants from Novartis and Pfizer. YM, RK, NS, and IG report no conflict of interest. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Solid tumors are a common cause of secondary (reactive) thrombocytosis, a paraneoplastic syndrome that is also a prognostic factor for various cancers. However, cutoff values for platelet count specific to gastric cancer and their prognostic roles are unknown., Methods: We retrospectively analyzed records of 4643 patients with gastric cancer who underwent radical surgery from 2007 to 2010. The minimum P-value approach was used with the log-rank test to determine the optimal prognosis predicting threshold for preoperative platelet count. Change in perioperative platelet count over time was evaluated with a generalized estimating equation. Clinicopathologic features and prognostic significance were analyzed according to platelet count., Results: Thrombocytosis prevalence (platelet count ≥40 × 10 4 /μL) was 1.6% (75 of 4643 patients). The platelet count cutoff value with the lowest P-value was ≥25.5 × 10 4 /μL, and patients with higher platelet count had more advanced disease. Multivariate analysis showed that cutoff value was an independent prognostic factor of overall survival (hazard ratio 1.19, 95% confidence interval 1.03-1.37, P = 0.017). Patients who underwent adjuvant chemotherapy (n = 1300) and had a greater than 10% increase in platelet count at postoperative 1 y compared to before surgery had significantly poorer overall survival (hazard ratio 1.65, 95% confidence interval 1.11-2.45, P = 0.013)., Conclusions: Elevated preoperative platelet count (≥25.5 × 10 4 /μL) and increased platelet count (≥10%) at postoperative 1 y in an adjuvant chemotherapy group were unfavorable prognostic factors. Platelet count could be a cost-effective biomarker for screening and monitoring patients with unfavorable survival outcomes., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Introduction: Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare disease in the 2016 revised World Health Organization (WHO) classification. Diagnostic criteria include the following: persistent thrombocytosis (>450 × 10 9 /L) with clustering of atypical megakaryocytes, refractory anemia, dyserythropoiesis with ring sideroblasts, and the presence of the spliceosome factor 3b subunit (SF3B1) mutation. It is unclear if anemia should be a required criterion for this diagnosis as cases which show all other features of MDS/MPN-RS-T but without anemia exist., Methods: We searched for borderline cases of MDS/MPN-RS-T in which refractory anemia was absent at diagnosis in two major academic institutes., Results: Three cases without anemia were identified. These cases all showed other classic morphologic and clinical features of MDS/MPN-RS-T, including thrombocytosis, atypical megakaryocytes with clustering, and characteristic SF3B1 and JAK2 V617F mutations., Conclusion: Given these findings, the requirement of refractory anemia as a diagnostic criterion for MDS/MPN-RS-T should be re-evaluated. Removal of refractory anemia as a diagnostic criterion would incorporate current borderline cases and extend the spectrum of this disorder., (© 2019 John Wiley & Sons Ltd.)

Objective: The aim of this study is to evaluate the performance of different platelet counting methods (optical, impedance, fluorescence and hand counting) applied in different analysers by comparing with the international flow cytometric reference method (IRM)., Methods: A total of 333 blood samples from different subgroups (168 cases with thrombocytopenia, 136 cases with normal platelet counts and 29 cases with thrombocytosis) were tested. Regarding IRM as the gold standard, we compared the accuracy and precision of different platelet count methods; i.e. LH780 (impedance), BC-6000 Plus (optical (O) and impedance (I)), Sysmex XN-9000 (optical (O), impedance (I), fluorescence (F)), and hand counting., Results: Sysmex XN-9000-F (r = 0.988) had the best correlation with IRM for thrombocytopenic samples; BC-6000 Plus-I (r = 0.966) was more relevant to IRM than any other method for samples with normal platelet counts. Correlation between Sysmex XN-9000-I (r = 0.960) and IRM was the highest among these methods for samples with thrombocytosis. For bias evaluation, the average bias of Sysmex XN-9000-F was -1.5 × 109/L (95% LA = -9.4 to +6.4) for samples with thrombocytopenia, compared with IRM. BC-6000 Plus-I had a small mean difference with IRM for samples with normal platelet counts or thrombocytosis. Moreover, all evaluated methods had acceptable sensitivity, specificity, and concordance rates as compared with IRM in the diagnosis of thrombocytopenia and thrombocytosis., Conclusions: Platelet counting by Sysmex XN-9000-F is more accurate than other methods for thrombocytopenic samples. BC-6000 Plus-I has superior association and consistency for normal platelet counts. As for thrombocytosis patients, Sysmex XN-9000-I has the highest correlation with IRM while Sysmex XN-9000-O has the highest diagnosis efficacy., Competing Interests: The study was sponsored by Shenzhen Mindray Bio-Medical Electronics Co., Ltd. Mindray provided BC-6000Plus hematology analyzer, reagents and other consumable materials, in addition to operational training for the instrument. The authors have declared that no competing interests exist. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Objective: This study aims to explore the role of thrombopoietin (TPO) production in extreme thrombocytosis that is often observed after pancreatectomy with islet autotransplantation (IAT) and the effectiveness of hydroxyurea in thrombocytosis management., Methods: Retrospective chart review was performed for all patients who underwent pancreatectomy with IAT at our institution between April 1, 2015, and December 31, 2016. Data evaluated included demographics, platelet counts, TPO levels, and thrombocytosis management strategies., Results: Twelve total and 1 subtotal pancreatectomy with IAT cases were reviewed. All operations included splenectomy. No major surgical or thrombotic complications occurred. Thrombopoietin levels, normal preoperatively, rose significantly (median, 219 pg/mL) soon after surgery, peaking on median postoperative day 3. Platelet counts, also normal preoperatively, increased within a week of surgery, with 92% over 1000 K/μL (median peak platelet count, 1403 K/μL). Platelet counts and TPO levels dropped after hydroxyurea initiation in most patients., Conclusions: After pancreatectomy with IAT, patients experienced marked TPO rise and subsequent thrombocytosis, and both decreased significantly after hydroxyurea initiation. These data suggest that TPO elevation and associated increased platelet production may be one driver of early extreme post-total pancreatectomy with islet autotransplantation thrombocytosis, and this process may be modulated by hydroxyurea.

Disease Overview: Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T)., Diagnosis: MDS-RS is a lower-risk MDS, with single or multilineage dysplasia (SLD/MLD), <5% bone marrow (BM) blasts and ≥ 15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet count ≥450 × 10(9)/L and large atypical megakaryocytes., Mutations and Karyotype: Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F, ASXL1, DNMT3A, SETBP1, and TET2 mutations. Cytogenetic abnormalities are uncommon in both., Risk Stratification: Most patients with MDS-RS-SLD are stratified into lower-risk groups by the revised-IPSS. Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia. Both diseases have a low risk of leukemic transformation., Treatment: Anemia and iron overload are complications seen in both and are managed similar to lower-risk MDS and MPN. The advent of luspatercept, a first-in-class erythroid maturation agent will tremendously boost the ability to manage anemia. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs remains uncertain., (© 2019 Wiley Periodicals, Inc.)

Background: Anemia and transfusion of blood in the peri-operative period have been shown to be associated with increased morbidity and mortality across a wide variety of non-cardiac surgeries. While tests of coagulation, including the platelet count, have frequently been used to identify patients with an increased risk of peri-operative bleeding, results have been equivocal. The aim of this study was to assess the effect of platelet level on outcomes in patients undergoing elective surgery., Materials and Methods: Retrospective cohort analysis of prospectively-collected clinical data from American College of Surgeons National Surgical Quality Improvement Program (NSQIP) between 2006-2016., Results: We identified 3,884,400 adult patients who underwent elective, non-cardiac surgery from 2006-2016 at hospitals participating in NSQIP, a prospectively-collected, national clinical database with established reproducibility and validity. After controlling for all peri- and intraoperative factors by matching on propensity scores, patients with all levels of thrombocytopenia or thrombocytosis had higher odds for perioperative transfusion. All levels of thrombocytopenia were associated with higher mortality, but there was no association with complications or other morbidity after matching. On the other hand, thrombocytosis was not associated with mortality; but odds for postoperative complications and 30-day return to the operating room remained slightly increased after matching., Conclusions: These findings may guide surgeons in the appropriate use and appreciation of the utility of pre-operative screening of the platelet count prior to an elective, non-cardiac surgery., Competing Interests: The authors have declared that no competing interests exist.

Background: Several previous studies have confirmed that thrombocytosis was related to reduced survival in many solid tumors. However, the prognostic significance of thrombocytosis in endometrial carcinoma (EC) was still controversy. Therefore, we conducted this study to assess the prognostic value of thrombocytosis in EC., Methods: The database including PubMed, MEDLINE, EMBASE, and Web of Science was searched to explore available literature. Above all, the hazard ratio (HR), odds ratios (OR) with 95% confidence intervals (CIs) was used to investigate the correlation between thrombocytosis and overall survival (OS) and disease-free survival (DFS). Moreover, the association between thrombocytosis and patient clinicopathological characteristics was explored. Publication bias and sensitivity analysis also were conducted in this study., Results: Overall, 11 studies involving 3439 patients were contained in this study. The results revealed that pretreatment thrombocytosis was significantly related to a decreased OS (pooled HR = 2.99; 95% CI = 2.35-3.8; P < 0.001) and DFS (pooled HR = 2.86; 95% CI = 2.27-3.6; P <  0.001) in patients with EC. Moreover, thrombocytosis was correlated with adverse clinicopathological parameters., Conclusions: Pretreatment thrombocytosis is an adverse prognostic marker in patients with EC.

Background: Pulmonary tuberculosis (PTB) can lead to lung tissue damage (LTD) and compromise the pulmonary capacity of TB patients that evolve to severe PTB. The molecular mechanisms involved in LTD during anti-tuberculous treatment (ATT) remain poorly understood. Methods and findings: We evaluated the role of neutrophil extracellular trap (NET) and the occurrence of LTD through chest radiographic images, the microbial load in sputum, and inflammatory serum profile (IL-12p40/p70, IL-8, IL-17A, IL-23, VEGF-A, MMP-1, and -8, galectin-3, citrunillated histone H3-cit-H3, alpha-1-antitrypsin-α1AT, C-reactive protein-CRP and albumin) in a cohort of 82 PTB patients before and after 60 days of ATT. Using univariate analysis, LTD was associated with neutrophilia and increase of several inflammatory proteins involved in the neutrophil-mediated response, being cit-H3 the more related to the event. In the multivariate analysis, neutrophilia and cit-H3 appear as directly related to LTD. The analysis of the ROC curve at day 60 presented AUC of 0.97 (95.0% CI 0.95-1). Interestingly, at day 0 of ATT, these biomarkers demonstrated fine relation with LTD showing an AUC 0.92 (95.0% CI 0.86-0.99). Despite of that, the same molecules have no impact in culture conversion during ATT. Conclusions: Our data revealed that NETs may play a key role in the pathway responsible for non-specific inflammation and tissue destruction in PTB. High level of cit-H3 and low level of α1AT was observed in the serum of severe TB patients, suggesting a breakdown in the intrinsic control of NET-driven tissue damage. These data show a new insight to knowledge TB immunopathogenesis, the role of neutrophil and NET pathway. Likewise, we identified possible biomarkers to screening of PTB patients eligible to adjuvants therapies, as anti-inflammatories and alpha-1-antitrypsin.

Acquired amegakaryocytic thrombocytopenia (AATP) is a rare disease characterized by thrombocytopenia and the disappearance of marrow megakaryocytes. A 43-year-old man was admitted because of thrombocytopenia of 1.0×10 9 /L. Bone marrow aspirate demonstrated normal hematopoiesis lacking megakaryocytes, and AATP was diagnosed. The serum concentration of thrombopoietin (TPO) was high (7.72 fmol/mL). Prednisolone (PSL) at 60 mg/day was started and the platelet count recovered to 1,335×10 9 /L; however, excessive megakaryocytopoiesis and subsequent decline in platelet count were noted 14 days later. At the peak platelet count, the TPO remained at 3.79 fmol/mL and returned to a normal level of 0.40 fmol/mL during the period of normal platelet count after PSL tapering. The marked thrombocytosis in response to prednisolone may have been caused by the high TPO after the resolution of suppressed megakaryopoiesis. Marked rebound thrombocytosis beyond 1,000×10 9 /L after successful PSL treatment for AATP has not been previously reported.

A variety of laboratory tests have been developed, which can diagnose a number of both congenital and acquired disorders of platelet function. Many tests of platelet function measure the ability of platelets to adhere to each other, forming platelet aggregates, which represent the major constituents of hemostatic plugs and of arterial thrombi. Light transmission aggregometry (LTA) is still considered the gold standard of platelet aggregation tests, but other platelet aggregation-based tests are also available. Among them, the flow cytometry-based methods may be more convenient than LTA for the study of patients with very low or very high platelet counts. The use of platelet aggregation tests has also been advocated to monitor the treatment with antiplatelet agents (mostly the P2Y 12 antagonist clopidogrel) of patients with thrombotic arterial occlusions, with the aim of improving their efficacy and safety. However, randomized clinical trials failed to show any advantage of this strategy; as a consequence, international guidelines now recommend against laboratory monitoring of antiplatelet therapy.

Pseudohyperkalaemia is defined as a rise in serum potassium with concomitantly normal plasma potassium. The case of long undiagnosed pseudohyperkalaemia in an 84-year-old lady with thrombocytosis post splenectomy is presented. Presenting a historical perspective and the multifactorial aetiology of pseudohyperkalaemia the author underlines the importance of detecting apparent hyperkalaemia by testing the plasma potassium. Awareness of the possible causes of pseudohyperkalaemia increases the likelihood of it being detected earlier thereby decreasing the risk of harming the patient. Unnecessary treatment and investigation of pseudohyperkalaemia can cause harm to the patient in the form of undesired side effects, unnecessary investigations and concerns, and potentially dangerous iatrogenically induced cardiac arrhythmias.

Platelets are key regulators of vascular integrity; however, their role in anaphylaxis, a life-threatening systemic allergic reaction characterized by the loss of vascular integrity and vascular leakage, remains unknown. Anaphylaxis is a consequence of inappropriate cellular responses triggered by antibodies to generally harmless antigens, resulting in a massive mediator release and rapidly occurring organ dysfunction. Human platelets express receptors for immunoglobulin G (IgG) antibodies and can release potent mediators, yet their contribution to anaphylaxis has not been previously addressed in mouse models, probably because mice do not express IgG receptors on platelets. We investigated the contribution of platelets to IgG-dependent anaphylaxis in human IgG receptor-expressing mouse models and a cohort of patients suffering from drug-induced anaphylaxis. Platelet counts dropped immediately and markedly upon anaphylaxis induction only when they expressed the human IgG receptor FcγRIIA/CD32A. Platelet depletion attenuated anaphylaxis, whereas thrombocythemia substantially worsened its severity. FcγRIIA-expressing platelets were directly activated by IgG immune complexes in vivo and were sufficient to restore susceptibility to anaphylaxis in resistant mice. Serotonin released by activated platelets contributed to anaphylaxis severity. Data from a cohort of patients suffering from drug-induced anaphylaxis indicated that platelet activation was associated with anaphylaxis severity and was accompanied by a reduction in circulating platelet numbers. Our findings identify platelets as critical players in IgG-dependent anaphylaxis and provide a rationale for the design of platelet-targeting strategies to attenuate the severity of anaphylactic reactions., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)