A Case of Pseudothrombocytopenia due to Pre-Analytical Issues Revealed by the Presence of Fibrin in a Blood Film.

BACKGROUND: Pseudothrombocytopenia (PTCP) can be caused by anticoagulants or pre-analytical issues. The authors present a case of PTCP attributed to pre-analytical issues in a 68-year-old male patient. METHODS: The platelet count results were obtained using both the impedance and fluorescence channels of Sysmex XN-10. The blood film was scanned using both Cellavision DM96 and a microscope. RESULTS: The flag for PLT-Clumps and the scattergram from the PLT-F channel indicated the presence of platelet aggregation. Fibrin could be observed at the feathered end of the blood film. A diagnosis of PTCP resulting from pre-analytical issues was made. CONCLUSIONS: The presence of fibrin in a blood film is a critical indicator for diagnosing PTCP due to pre-analytical issues.

How We Interpret Thrombosis with Thrombocytopenia Syndrome?

Platelets play an important role in hemostasis, and a low platelet count usually increases the risk of bleeding. Conditions in which thrombosis occurs despite low platelet counts are referred to as thrombosis with thrombocytopenia syndrome, including heparin-induced thrombocytopenia, vaccine-induced immune thrombotic thrombocytopenia, paroxysmal nocturnal hemoglobinuria, antiphospholipid syndrome, thrombotic microangiopathy (TMA), and disseminated intravascular coagulation. TMA includes thrombotic thrombocytopenic purpura, Shiga toxin-producing Escherichia coli-associated hemolytic uremic syndrome (HUS), and atypical HUS. Patients with these pathologies present with thrombosis and consumptive thrombocytopenia associated with the activation of platelets and the coagulation system. Treatment varies from disease to disease, and many diseases have direct impacts on mortality and organ prognosis if therapeutic interventions are not promptly implemented. Underlying diseases and the results of physical examinations and general laboratory tests as part of a thorough workup for patients should promptly lead to therapeutic intervention before definitive diagnosis. For some diseases, the diagnosis and initial treatment must proceed in parallel. Utilization of not only laboratory tests but also various scoring systems is important for validating therapeutic interventions based on clinical information.

Prediction Model for Severe Thrombocytopenia Induced by Gemcitabine Plus Cisplatin Combination Therapy in Patients with Urothelial Cancer.

BACKGROUND: Chemotherapy-induced thrombocytopenia is often a use-limiting adverse reaction to gemcitabine and cisplatin (GC) combination chemotherapy, reducing therapeutic intensity, and, in some cases, requiring platelet transfusion. OBJECTIVE: A retrospective cohort study was conducted on patients with urothelial cancer at the initiation of GC combination therapy and the objective was to develop a prediction model for the incidence of severe thrombocytopenia using machine learning. METHODS: We performed receiver operating characteristic analysis to determine the cut-off values of the associated factors. Multivariate analyses were conducted to identify risk factors associated with the occurrence of severe thrombocytopenia. The prediction model was constructed from an ensemble model and gradient-boosted decision trees to estimate the risk of an outcome using the risk factors associated with the occurrence of severe thrombocytopenia. RESULTS: Of 186 patients included in this study, 46 (25%) experienced severe thrombocytopenia induced by GC therapy. Multivariate analyses revealed that platelet count ≤ 21.4 (×104/µL) [odds ratio 7.19, p < 0.01], hemoglobin ≤ 12.1 (g/dL) [odds ratio 2.41, p = 0.03], lymphocyte count ≤ 1.458 (×103/µL) [odds ratio 2.47, p = 0.02], and dose of gemcitabine ≥ 775.245 (mg/m2) [odds ratio 4.00, p < 0.01] were risk factors of severe thrombocytopenia. The performance of the prediction model using these associated factors was high (area under the curve 0.76, accuracy 0.82, precision 0.68, recall 0.50, and F-measure 0.58). CONCLUSIONS: Platelet count, hemoglobin level, lymphocyte count, and gemcitabine dose contributed to the development of a novel prediction model to identify the incidence of GC-induced severe thrombocytopenia.

A case of tick-borne Yezo virus infection: Concurrent detection in the patient and tick.

A 76-year-old woman infected with Yezo virus (YEZV) developed liver dysfunction and thrombocytopenia following a tick bite. Despite the severity of her elevated liver enzymes and reduced platelet counts, the patient's condition improved spontaneously without any specific treatment. To our knowledge, this represents the first documented case where the YEZV genome was detected simultaneously in a patient's serum and the tick (Ixodes persulcatus) that bit the patient. This dual detection not only supports the hypothesis that YEZV is a tick-borne pathogen but also underscores the importance of awareness and diagnostic readiness for emerging tick-borne diseases, particularly in regions where these ticks are prevalent.

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia.

OBJECTIVES: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature. MATERIALS AND METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients. RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia. CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

[Child with sitosterolemia initially presenting with hemolytic anemia and thrombocytopenia: a case repore and literrature review].

This article focuses on a case study of sitosterolemia in a child who initially presented with hemolytic anemia and thrombocytopenia. Sitosterolemia is a rare autosomal recessive lipid metabolism disorder, difficult to diagnose due to its non-typical clinical manifestations. The 8-year-old patient was initially misdiagnosed with pyruvate kinase deficiency. Comprehensive biochemical and molecular biology analyses, including gene sequencing, eventually led to the correct diagnosis of sitosterolemia. This case highlights the complexity and diagnostic challenges of sitosterolemia, emphasizing the need for increased awareness and accurate diagnosis in patients presenting with similar symptoms.

Accuracy of Diagnosing Heparin-Induced Thrombocytopenia.

Importance: Heparin-induced thrombocytopenia (HIT) is a life-threatening condition that requires urgent diagnostic clarification. However, knowledge of the diagnostic utility of the recommended diagnostic tests is limited in clinical practice. Objective: To evaluate the current diagnostic practice for managing the suspicion of HIT. Design, Setting, and Participants: This prospective diagnostic study was conducted from January 2018 to May 2021 among consecutive patients with suspected HIT from 11 study centers in Switzerland, Germany, and the United States. Detailed clinical data and laboratory information were recorded. Platelet factor 4/heparin antibodies were quantified using an automated chemiluminescent immunoassay (CLIA). A washed-platelet heparin-induced platelet activation (HIPA) test was used as a reference standard to define HIT. Exposures: Suspicion of HIT. Main Outcomes and Measures: The primary outcome was the diagnostic accuracy of the 4Ts score, the CLIA, and the recommended algorithm serially combining both tests. Results: Of 1448 patients included between 2018 and 2021, 1318 were available for the current analysis (median [IQR] age, 67 [57-75] years; 849 [64.6%] male). HIPA was positive in 111 patients (prevalence, 8.4%). The most frequent setting was intensive care unit (487 [37.0%]) or cardiovascular surgery (434 [33.0%]). The 4Ts score was low risk in 625 patients (46.8%). By 2 × 2 table, the numbers of patients with false-negative results were 10 (9.0%; 4Ts score), 5 (4.5%; CLIA), and 15 (13.5%; recommended diagnostic algorithm). The numbers of patients with false-positive results were 592 (49.0%; 4Ts score), 73 (6.0%; CLIA), and 50 (4.1%; recommended diagnostic algorithm), respectively. Conclusions and Relevance: In this diagnostic study of patients suspected of having HIT, when the recommended diagnostic algorithm was used in clinical practice, antibody testing was required in half the patients. A substantial number of patients were, however, still misclassified, which could lead to delayed diagnosis or overtreatment. Development of improved diagnostic algorithms for HIT diagnosis should be pursued.

Autoimmune cytopenias in children: When to think of primary immunodeficiency?

Autoimmune cytopenias are defined by autoantibodies' immune destruction of one or more blood elements. Most often it is autoimmune hemolytic anemia or immune thrombocytopenia or both that define Evans syndrome. It may be secondary to infection or to underlying pathology such as systemic autoimmune disease or primary immunodeficiency, especially when it becomes chronic over several years. Primary Immunodeficiencies or inborn errors of immunity (IEI) are no longer defined solely by infections: autoimmunity is part of the clinical features of several of these diseases. It is dominated by autoimmune cytopenias, in particular, immune thrombocytopenia (ITP) and autoimmune hemolytic anaemia (AIHA). The challenges for the clinician are the situations where autoimmune cytopenias are chronic, recurrent and/or refractory to the various long-term therapeutic options. Most of these therapies are similar in action and generally consist of non-mediated immune suppression or modulation. In these situations, primary Immunodeficiencies must be diagnosed as soon as possible to allow the initiation of a targeted treatment and to avoid several ineffective therapeutic lines.

Multianticoagulant Pseudothrombocytopenia in a Patient with Primary Carcinoma of the Liver with Hypersplenism.

BACKGROUND: Pseudothrombocytopenia (PTCP) is a relatively rare phenomenon in vitro, the mechanism is not completely clear, and there is no unified solution for it. How to identify and solve PTCP accurately is a challenge for laboratory personnel. METHODS: According to the patient's clinical manifestations, thrombocytopenia caused by hypersplenism was excluded. PTCP was confirmed by platelet volume histograms, scattergrams and platelet clumps on the blood smears. Commonly used alternative anticoagulants such as sodium citrate or heparin were used for platelet counting. The corrective effect of the platelet count was not good, so non-anticoagulant blood was collected and tested immediately, and blood smears were used to count platelets manually. RESULTS: The PTCP of the patient could not be solved using sodium citrate and heparin anticoagulation. By collecting non-anticoagulant blood and testing immediately, the platelet count returned to normal (180 x 109/L), which is consistent with the results of manual counting on the patient's blood smears (175 x 109/L). CONCLUSIONS: When PTCP is confirmed, commonly used alternative anticoagulants can be used. If these do not work, non-anticoagulant blood can be collected and tested immediately, and blood smears can be used to count platelets manually.

Marked Underestimation of Platelet Count and a Characteristic Platelet Histogram as Clues to MYH9-Related Disorders.

BACKGROUND: The rapid development of automatic blood cell analyzers has greatly optimized complete blood count results. However, erroneous results relevant to automatic blood cell analyzers still exist. Pseudothrombocytopenia can be observed in both cases of anticoagulant-induced platelet aggregation, and the presence of large and giant platelets. METHODS: A rare case of a MYH9-related disorder, in which marked underestimation of platelet count was led by large and giant platelets using the impedance count by an automated hematology analyzer. Moreover, lancet-shaped and Dohle body-like cytoplasmic inclusions were detected in almost all white blood cells of the patient. RESULTS: The platelet count was done by an optical platelet counter or a fluorescence platelet counter, and peripheral blood smear was evaluated. In addition, the diagnosis of MYH9-related disorder was established by the molecular findings. CONCLUSIONS: Identification of the peripheral blood smear and familial history will eliminate the need for further laboratory testing and bone marrow examination.

Effects of canine influenza infection and DA2PP vaccination on the development of platelet-associated immunoglobulins and platelet counts in dogs.

BACKGROUND: Immune thrombocytopenia (ITP) is commonly associated with platelet-associated immunoglobulins (PAIg). Demonstration of PAIg can help determine etiologies for thrombocytopenia. In humans, ITP and thrombocytopenia have been associated with various vaccinations and influenza infections, respectively. OBJECTIVES: We aimed to evaluate platelet counts and PAIg in research dogs with H3N2 and in research and client-owned dogs routinely vaccinated for distemper, adenovirus-2, parainfluenza, and parvovirus (DA2PP). The hypotheses were that H3N2 infection but not DA2PP vaccination would decrease platelet counts, and neither would result in the detection of PAIg. METHODS: Three pilot studies. Platelet counts and PAIg, measured by direct flow cytometry as %IgG, were evaluated in eight research Beagles following experimental infection with H3N2 (experiment 1), nine research Beagles vaccinated for DA2PP (experiment 2), and thirty client-owned dogs vaccinated for DA2PP (experiment 3). All animals were considered healthy at the start of the experiments. RESULTS: Transient, self-resolving decreases in platelet counts and increases in %IgG occurred following H3N2 infection, and one dog became thrombocytopenic and positive for PAIg. Following DA2PP vaccination, %IgG increased in research and client-owned dogs, but only one dog was considered positive for PAIg with a concurrent increase in platelet count. Mean PAIg increased from baseline in client-owned dogs following vaccination. CONCLUSIONS: Transient PAIg and thrombocytopenia can occur following H3N2 infection, while routine vaccination for DA2PP in this group of dogs was not associated with the development of thrombocytopenia or clinically relevant formation of PAIg.

Autoimmune cytopenia and Kabuki syndrome in paediatrics: Insights in 11 patients.

Kabuki syndrome (KS) is now listed in the Human Inborn Errors of Immunity (IEI) Classification. It is a rare disease caused by KMT2D and KDM6A variants, dominated by intellectual disability and characteristic facial features. Recurrently, pathogenic variants are identified in those genes in patients examined for autoimmune cytopenia (AIC), but interpretation remains challenging. This study aims to describe the genetic diagnosis and the clinical management of patients with paediatric-onset AIC and KS. Among 11 patients with AIC and KS, all had chronic immune thrombocytopenic purpura, and seven had Evans syndrome. All had other associated immunopathological manifestations, mainly symptomatic hypogammaglobinaemia. They had a median of 8 (5-10) KS-associated manifestations. Pathogenic variants were detected in KMT2D gene without clustering, during the immunological work-up of AIC in three cases, and the clinical strategy to validate them is emphasized. Eight patients received second-line treatments, mainly rituximab and mycophenolate mofetil. With a median follow-up of 17 (2-31) years, 8/10 alive patients still needed treatment for AIC. First-line paediatricians should be able to recognize and confirm KS in children with ITP or multiple AIC, to provide early appropriate clinical management and specific long-term follow-up. The epigenetic immune dysregulation in KS opens exciting new perspectives.

Clinical characteristics and influencing factors of severe fever with thrombocytopenia syndrome complicated by viral myocarditis: a retrospective study.

OBJECTIVE: This study aimed to investigate the clinical characteristics of severe fever with thrombocytopenia syndrome complicated by viral myocarditis (SFTS-VM) and analyze relevant influencing factors. METHODS: Retrospective analysis was conducted on clinical data from 79 SFTS-VM patients, categorized into common (SFTS-CVM, n = 40) and severe groups (SFTS-SVM, n = 39). Clinical manifestations, laboratory results, cardiac ultrasonography, and electrocardiogram features were analyzed. Univariate and multivariate analyses identified significant indicators, which were further assessed using ROC curves to predict SFTS-SVM. RESULTS: SFTS-SVM group exhibited higher rates of hypotension, shock, abdominal pain, cough with sputum, and consciousness disorders compared to SFTS-CVM group. Laboratory findings showed elevated platelet count, ALT, AST, amylase, lipase, LDH, D-dimer, procalcitonin, TNI, and NT-proBNP in SFTS-SVM. Abnormal electrocardiograms, especially atrial fibrillation, were more prevalent in SFTS-SVM (P < 0.05). Multivariate analysis identified elevated LDH upon admission (OR = 1.004, 95% CI: 1-1.008, P = 0.050), elevated NT-proBNP (OR = 1.005, 95% CI: 1.001-1.008, P = 0.007), and consciousness disorders (OR = 112.852, 95% CI: 3.676 ~ 3464.292, P = 0.007) as independent risk factors for SFTS-SVM. LDH and NT-proBNP had AUCs of 0.728 and 0.744, respectively, in predicting SFTS-SVM. Critical values of LDH (> 978.5U/L) and NT-proBNP (> 857.5pg/ml)) indicated increased likelihood of SFTS progression into SVM. CONCLUSION: Elevated LDH, NT-proBNP, and consciousness disorders independently correlate with SFTS-SVM. LDH and NT-proBNP can aid in early identification of SFTS-SVM development when above specified thresholds.

Reproducibility and stability of the immature platelet fraction using Sysmex XN-10.

BACKGROUND: The Immature Platelet Fraction (IPF) is an indicator of thrombopoiesis which is a useful parameter in thrombocytopenia. It demonstrates compensatory mechanisms in production of platelets, but currently not implemented in routine clinical practice. The aim of this study was to establish the reproducibility and stability of IPF, for both percentage (%-IPF) and absolute (A-IPF) measurements.Material/methods: A total of 71 samples, of which 45 for reproducibility and 26 for stability analysis, were assayed for full blood count using the Sysmex XN-10 analyser at room temperature (RT:19-25 °C). For reproducibility analysis, IPF measurements were analysed 11 times by different appraisers using the same sample, while for stability analysis, IPF was measured over fourteen hourly-intervals up to 24 h (n = 21) and then separately extended beyond the point of stability to 72 h (n = 5). RESULTS: Reproducibility analysis of %-IPF and A-IPF (n = 45) showed very reliable results, with the range of mean CV% values between 1.25-8.90% and 1.70-9.96%, respectively. On the other hand, overall, stability analysis of %-IPF and A-IPF (n = 21) at RT over 24 h showed reliable results, with pooled mean CV% values of 1.32% and 1.43%, respectively, with no significant difference between %-IPF and A-IPF (p = 0.767 and p = 0.821). All %-IPF and A-IPF values had exceeded the set acceptance criterion of stability (CV% ≥ 10.0%) before 72 h. CONCLUSIONS: Overall, %-IPF and A-IPF reproducibility and storage at RT for 24 h predominantly demonstrates the suitability of their usage for testing on the Sysmex XN-series analysers.

TAFRO syndrome is associated with anti-SSA/Ro60 antibodies, in contrast to idiopathic castleman disease.

TAFRO syndrome is an acute systemic inflammatory disease characterized by thrombocytopenia, anasarca, fever, reticulin fibrosis/renal dysfunction, and organomegaly. There have been increasing reports that TAFRO is a disease distinct from idiopathic multicentric Castleman disease and that TAFRO patients may be positive for anti-SSA antibodies. To assess anti-SSA antibody positivity and the clinical characteristics of the two diseases, we retrospectively compared 7 TAFRO and 10 iMCD patients in our hospital. The mean age of onset of TAFRO and iMCD was 48.0 (interquartile range [IQR], 41-53) and 45.0 (IQR, 35-53) years, respectively. The TAFRO and iMCD groups had 6 (86%) and 4 (40%) male patients, respectively, and the following pretreatment laboratory values: platelet count, 3.8 (IQR, 2.2-6.4) and 35.5 (IQR, 22.2-42.8) × 104/µL, respectively; C-reactive protein, 10.2 (IQR, 6.8-21.4) and 9.5 (IQR, 6.2-13.6) mg/dL, respectively; IgG, 1431 (IQR, 1112-1815) and 4725 (IQR, 3755-5121) mg/dL, respectively. RNA immunoprecipitation (5 cases for anti-SSA) or protein array (5 cases for anti-SSA/Ro60) detected anti-SSA antibodies in six (86%) TAFRO patients but not in iMCD patients; it did not detect anti-SSB antibodies in any of the patients. None of the patients were diagnosed with Sjögren syndrome. All iMCD patients treated with tocilizumab (TCZ) responded well. Meanwhile, two of six TAFRO patients treated with TCZ showed inadequate responses; thus, both patients were switched to rituximab, following which they achieved remission. TAFRO and iMCD have different clinical features. TAFRO may be categorized as a severe phenotype of the anti-SSA antibody syndrome.

Predictive Modeling of Drug-Related Adverse Events with Real-World Data: A Case Study of Linezolid Hematologic Outcomes.

Electronic health records (EHRs) provide meaningful knowledge of drug-related adverse events (AEs) that are not captured in standard drug development and postmarketing surveillance. Using variables obtained from EHR data in the University of California San Francisco de-identified Clinical Data Warehouse, we aimed to evaluate the potential of machine learning to predict two hematological AEs, thrombocytopenia and anemia, in a cohort of patients treated with linezolid for 3 or more days. Features for model input were extracted at linezolid initiation (index), and outcomes were characterized from index to 14 days post-treatment. Random forest classification (RFC) was used for AE prediction, and reduced feature models were evaluated using cumulative importance (cImp) for feature selection. Grade 3+ thrombocytopenia and anemia occurred in 31% of 2,171 and 56% of 2,170 evaluable patients, respectively. Of the total 53 features, as few as 7 contributed at least 50% cImp, resulting in prediction accuracies of 70% or higher and area under the receiver operating characteristic curves of 0.886 for grade 3+ thrombocytopenia and 0.759 for grade 3+ anemia. Sensitivity analyses in strictly defined patient subgroups revealed similarly high predictive performance in full and reduced feature models. A logistic regression model with the same 50% cImp features showed similar predictive performance as RFC and good concordance with RFC probability predictions after isotonic calibration, adding interpretability. Collectively, this work demonstrates potential for machine learning prediction of AE risk in real-world patients using few variables regularly available in EHRs, which may aid in clinical decision making and/or monitoring.

Diagnosis and management of heparin-induced thrombocytopenia: third edition

This guideline updates and widens the scope of the previ-ous British Society for Haematology (BSH) Clinical guide-lines for Diagnosis and Management of Heparin-Induced Thrombocytopenia: Second Edition1 to include functional assays in the diagnosis of heparin-induced thrombocytope-nia (HIT), when to use direct-acting oral anti-coagulants, and the role of intravenous (IV) immunoglobulins and plasma exchange in the management of HIT and spontane-ous HIT.HIT is an immune-mediated, highly pro-thrombotic dis-order of platelet activation caused by pathogenic antibodies against a platelet factor 4 (PF4)­heparin complex. It is the most frequent drug-induced immune thrombocytopenia and may lead to life-threatening thrombosis. There are two distinct forms of HIT: type I, also known as heparin-asso-ciated thrombocytopenia, which is a non-immunological response to heparin treatment, mediated by a direct interac-tion between heparin and circulating platelets causing plate-let clumping or sequestration, and type II, which is immune mediated.

Alport syndrome: A puzzling case of thrombocytopenia and giant unusual platelets in blood smear.

A puzzling case of thrombocytopenia and giant unusual platelets in blood smear reveals a past diagnosis of Alport syndrome in 44-year-old woman with end-stage renal disease and abnormal CBC values.

Decision-Making Error in Platelet Transfusion Caused by EDTA-Dependent Pseudothrombocytopenia: a Case Report and Literature Review.

BACKGROUND: Ethylenediaminetetraacetic acid-dependent pseudothrombocytopenia (EDTA-PTCP) is a rare phenomenon characterized by pseudo low platelet counts when using EDTA as anticoagulant and can result in false decision making of platelet transfusion. METHODS: An application for platelet transfusion from a patient who planned to undergo spinal surgery was received by the Department of Transfusion service. The preoperative laboratory test results showed thrombocytopenia (platelet counts: 27 x 109/L). The surgeon planned to transfuse platelets before the operation to avoid bleeding in operation due to thrombocytopenia. However, the lab technologist found that there was aggregation of platelets under the microscope. Samples used with sodium citrate and heparin as anticoagulants were rechecked. RESULTS: The platelet count of the patient was normal in sodium citrate and heparin anticoagulant tubes. The patient had no history and clinical symptoms of thrombocytopenia. Therefore, the doctor canceled the platelet order. We also reviewed the relevant literature of EDTA-PTCP. CONCLUSIONS: EDTA-PTCP is rare and may result of a wrong decision of platelet transfusion. Correct understanding and treatment of this situation can avoid unnecessary platelet transfusion.