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Pseudothrombocytopenia caused by platelet clumping (PC) can lead to unnecessary platelet transfusions or underdiagnosis of hematologic neoplasms. To overcome these limitations, we assessed the capacity of the Sysmex DI-60 digital morphology analyzer (Sysmex, Kobe, Japan) for detecting PC and determining an accurate platelet count in the presence of PC. For this purpose, 135 samples with or without PC (groups Y and N, respectively) were processed by an examiner (a hematologic specialist) using both the Sysmex XN-9000 and DI-60 analyzers. Although the platelet aggregate (PA) and giant platelet (GP) counts reported by the DI-60 and the examiner exhibited strong correlations, they proved inadequate as effective indicators for screening samples containing PC. Between the PA and GP counts and four platelet indices (the platelet distribution width [PDW], mean platelet volume [MPV], platelet large cell ratio [P_LCR], and plateletcrit [PCT]) reported by the XN9000, we observed statistically significant correlations (both overall and with group Y), but they were relatively weak. The platelet counts determined using the DI-60 and light microscopy in group Y showed substantial variations. Although the performance of the DI-60 was reliable for detecting PA and GP in smear images, such fixed areas are not representative of whole samples. Further, in the presence of PC, the resulting platelet counts determined using the DI-60 were not sufficiently accurate to be accepted as the final count. [ABSTRACT FROM AUTHOR]

Background: EDTA-induced pseudothrombocytopenia (PTCP) during whole blood collection requires significant laboratory resources to obtain accurate results. We evaluated platelet-deaggregation function in EDTA-induced PTCP and platelet-clump flagging by the BC-6800Plus hematology analyzer using integrated digital image analysis. Methods: We prospectively collected 132 whole blood samples suspected of platelet clumping (102 in EDTA and 30 in sodium citrate) from 88 individuals. We compared platelet counts determined using the platelet count by impedance (PLT-I) function of the DxH 900 hematology analyzer and the PLT-I or optical platelet count (PLT-O) function of the BC6800Plus. Platelet clumping was verified through manual inspection and the MC-80 digital image analyzer. Results: Among the 132 whole blood samples, 43 EDTA samples showed platelet clumping. The DxH 900 PLT-I and BC-6800Plus PLT-I results demonstrated a strong correlation (r=0.711) for the EDTA samples but only a moderate correlation with the BC-6800Plus PLT-O results (r=0.506 and 0.545, respectively). The BC-6800Plus PLT-O results were consistent with the sodium citrate platelet counts, with a median dissociation rate of 102.5% (range, 74.9%–123.1%). The DxH 900 and BC-6800Plus analyzers had sensitivity values of 0.79 and 0.72, respectively, for platelet-clump flagging. When integrating the MC-80 digital image analysis results, the sensitivity of BC-6800Plus improved to 0.89 (standard mode) or 1.0 (PLT-Pro mode). Conclusions: BC-6800Plus PLT-O measurement results are close to the actual values obtained by platelet deaggregation with PTCP samples. Integrating the BC-6800Plus with a digital imaging analyzer effectively improved the diagnosis of PTCP and reduced the requirement for additional laboratory procedures. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Methods Results Conclusions This study aimed to determine a definition for significant platelet clumping (PC) and evaluate the performance of the Sysmex XN instrument for detecting platelet clumps.For part 1, 372 specimens with a ‘PLT_clump?’ flag in XN‐9000 were classified into five groups according to the average number of PCs. We compared the initial platelet count (measured by XN‐9000 using impedance method) and corrected platelet count (counted optically or re‐analyzed by XN‐9000 using vortexed or re‐collected sample) of each group. For part 2, 1000 specimens with a PC flag divided into three subgroups {group N (PC = 0), Y (PC ≥ 1), and Z (microscopic fibrin clot)} and additional two groups {group S (PC(+) specimens without any flag and with flags of other categories) and group NC (negative control)} were collected. Positive predictive value (PPV), negative predictive value (NPV), sensitivity and specificity of PC detection of XN‐9000 were obtained and the platelet counts and four indices (PDW, MPV, P_LCR, and PCT) of groups NC, N, Y, Z, and S were compared to detect PC more precisely.In part 1, all groups showed significant difference between the initial and corrected platelet counts. In part 2, PPV, NPV, prevalence, sensitivity, and specificity were 41.5%, 56.5%, 43.4%, 2.18%, and 98.3%, respectively. The platelet counts and four indices showed statistical differences for detecting PCs, and especially PDW and P_LCR were significantly smaller in group Z than group N or Y.We suggest the definition of significant PC by the presence of at least three platelets. In addition, utilizing platelet‐related indices should be developed to improve the efficiency of the PC detection. [ABSTRACT FROM AUTHOR]

Background: In EDTA-induced pseudothrombopenia, citrate or MgSO4 are recommended for platelet counting. Pre-analytical conditions are poorly defined for tubes containing MgSO4 or citrate. In this study, we analyzed the impact of agitation of these tubes on platelet counts. Methods: K2EDTA, citrate, and MgSO4 tubes from 70 patients were gently agitated on a wheel rotating at 20 rpm. Platelets were analyzed on the Sysmex XN analyzer at different times, and the percentage of platelet deviation from T0 was assessed and compared with the desirable bias of the EFLM. Results: at 180 min in fluorescence, the relative variation of platelets after shaking is 1.17% for K2EDTA, −29.76% for citrate, and −33.18% for MgSO4, while for unshaken MgSO4 platelets the variation is −1.3%. The reduction in platelet numbers when citrate or MgSO4 tubes are shaken is linked to the appearance of platelet clusters. Conclusions: agitation of MgSO4 and especially citrate tubes led to a decrease in platelet counts due to the formation of platelet aggregates; on the other hand, platelet counts on EDTA are virtually stable. During transport, we recommend putting sodium citrate and MgSO4 tubes in an upright position and avoiding shaking them to avoid giving an erroneous platelet result. [ABSTRACT FROM AUTHOR]

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions (i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management (i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions (i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results. [ABSTRACT FROM AUTHOR]

Pseudothrombocytopenia (PTCP) can be an analytical error in the automatic blood cell count. Blood samples containing autoantibodies against platelets collected in ethylenediaminetetraacetic acid (EDTA) tubes can lead to platelet accumulation at room temperature. Agglutinated platelets are detected as larger cells using automated counters, which incorrectly leads to falsely low results. Hence, when a low platelet count is noted, PTCP must also be considered. In this study, we report a case of EDTA-dependent PTCP in a patient who has Hashimoto’s thyroiditis with the current literature review.

Background: Pseudothrombocytopenia is a commonly obtained false negative result when analyzing feline platelet count by automated machine. It is related to ethylenediamine tetra-acetic acid (EDTA), a widely utilized anticoagulant in blood collection tube, resulting in EDTA-dependent pseudothrombocytopenia (EDTA-PTCP). Aim: To investigate whether treated with kanamycin enhanced the quantity of platelet aggregations in feline blood specimens collected using EDTA-PTCP. Methods: Thirty-one blood samples were obtained using EDTA tubes. The complete blood count was analyzed using automated Mindray-BC-5000Vet. Both Manual cell counts and thin blood smears were performed to estimate the amount of RBC, WBC and platelets as well as to evaluate the severity scores of platelet clumping, respectively. Comparisons were made between those pre-treated and treated with kanamycin in EDTA tube. Results: There were significantly different mean platelet counts in the samples before and after they were treated with kanamycin, both on automated (156.6  76.4 vs 260.3  115.5; p < 0.001) and manual (168.5  92.1 vs 262.8  119.6; p < 0.001) readings, with a 95% confidence interval (CI) of 0.19 (0.022–0.365). Conclusion: This study suggests that in clinical laboratory practice, kanamycin should be added to feline blood specimens with EDTA-PTCP. [Open Vet J 2024; 14(5.000): 1199-1205]

Objective: To analyze the significance of platelet histograms and peripheral smears in understanding thrombocytopenia and compare them for the incidence of pseudothrombocytopenia. Methods: This prospective study was conducted in the Department of Pathology at a tertiary care medical institute. The study included 200 cases of thrombocytopenia. Platelet parameters (PCT, PDW, MPV) were obtained using an autoanalyzer, and peripheral smears were examined manually. Thrombocytopenia cases were classified into hyper-destructive, hypo-productive, and abnormal pooling categories based on etiology and platelet histogram patterns. The incidence of pseudothrombocytopenia was also compared. A P value of less than 0.05 was considered statistically significant. Results: The gender distribution showed a male preponderance (56% male, 44% female). The mean age of the patients was 26.8 years. The study found hyper-destructive thrombocytopenia to be the most common type, with viral fever, sepsis, and malaria being the common etiologies for this type of thrombocytopenia. Histogram analysis revealed distinct patterns for different types of thrombocytopenia. The study also noted a higher incidence of pseudothrombocytopenia in automated analysis compared to manual methods, with a statistically significant difference. Conclusion: Platelet histograms combined with peripheral smear analysis provide crucial information about the etiology and nature of thrombocytopenia. This integrated approach enhances diagnostic accuracy and aid in effective patient management.

Background: Pseudothrombocytopenia is a commonly obtained false negative result when analyzing feline platelet (PLT) count by an automated machine. It is related to ethylenediamine tetra-acetic acid (EDTA), a widely utilized anticoagulant in blood collection tubes, resulting in EDTA-dependent pseudothrombocytopenia (EDTA-PTCP). Aim: To investigate whether treated with kanamycin enhanced the quantity of PLT aggregations in feline blood specimens collected using EDTA-PTCP. Methods: Thirty-one blood samples were obtained using EDTA tubes. The complete blood count was analyzed using an automated Mindray BC-5000Vet. Both Manual cell counts and thin blood smears were performed to estimate the amount of red blood cell, white blood cell, and PLTs as well as to evaluate the severity scores of PLT clumping, respectively. Comparisons were made between those pre-treated and those treated with kanamycin in the EDTA tube. Results: There were significantly different mean PLT counts in the samples before and after they were treated with kanamycin, both on automated (156.6 ± 76.4 vs. 260.3 ± 115.5; p < 0.001) and manual (168.5 ± 92.1 vs. 262.8 ± 119.6; p < 0.001) readings, with a 95% confidence interval of 0.19 (0.022-0.365). Conclusion: This study suggests that in clinical laboratory practice, kanamycin should be added to feline blood specimens with EDTA-PTCP. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Pseudothrombocytopenia is a condition in which platelets are seen in sufficient numbers and aggregated in the peripheral smear although the platelet count is low in the complete blood count analysis of the patient. One of the causes of pseudothrombocytopenia is the Ethylenediamine Tetraacetic acid (EDTA) anticoagulant used for routine complete blood count samples. EDTA has a calcium chelator effect and changes the structure of the GPIIb/IIIa integrin complex found in platelets. The hidden GPIIb epitope is revealed as a result of the change in the structure of the GPIIb/IIIa integrin complex, and antibodies are formed against this epitope. These antibodies cause platelet aggregation. Due to aggregation of platelets, complete blood count analysis may give erroneous results and may be confused with true thrombocytopenia. Pseudothrombocytopenia is not a bleeding diathesis, but patients may be subjected to unnecessary diagnostic procedures and treatments. This case report was prepared to emphasize the clinical picture of EDTA-induced pseudothrombocytopenia. In our case, thrombocytopenia was observed as a result of the analysis of the EDTA whole blood count sample taken from the patient who was admitted to the internal medicine outpatient clinic for routine controls. Complete blood count analysis over the past three years also observed thrombocytopenia. It was deemed appropriate to send a complete blood count sample from the patient in a citrate tube. In the analysis of the citrated complete blood count sample obtained from the patient, it was observed that the platelet count was normal. A simultaneous peripheral smear was reported as pseudothrombocytopenia. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Pseudothrombocytopenia (PTCP) can be an analytical error in the automatic blood cell count. Blood samples containing autoantibodies against platelets collected in ethylenediaminetetraacetic acid (EDTA) tubes can lead to platelet accumulation at room temperature. Agglutinated platelets are detected as larger cells using automated counters, which incorrectly leads to falsely low results. Hence, when a low platelet count is noted, PTCP must also be considered. In this study, we report a case of EDTA-dependent PTCP in a patient who has Hashimoto's thyroiditis with the current literature review. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Automated hematology analyzers have become mainstream of complete blood count (CBC) during the past two decades; they are potential, more accurate to produce results of CBCs. However, often automated analyzers can give false results too, specially, falsely low platelet count due to platelets aggregates, which have to be confirmed on peripheral smears. Aims and Objectives: The aim and objective of the study was to diagnose thrombocytopenia (TCP) cases and differentiate them from pseudothrombocytopenia (PTCP) cases by analyzing platelet histogram and to determine the sensitivity and specificity of platelet histograms for diagnosing TCP and PTCP. Materials and Methods: The present study was conducted in the Department of Pathology at Shyam Shah Medical College, Rewa, M.P., after obtaining ethical clearance from the Institutional Ethics Committee. It was prospective study conducted for a period of 15 months from January 2021 to May 2022 on 1000 samples. Results: The sensitivity and specificity of platelet histogram flags and presence of multiple peaks to diagnose TCP and PTCP cases were calculated as 73.60% and 93.60%, respectively. The present study also interpret that mean platelet volume and platelet distribution width cannot use as indicator to differentiate between TCP and PTCP. Conclusion: The present study concludes that analysis and interpretation of histogram more specifically platelet histogram flagging provide clue for early detection of PTCP cases prior peripheral smear examination and also helpful in differentiating them from true TCP cases. These platelet histogram flagging can be used as a screening parameter for the detection of PTCP and these are helpful in preventing unnecessary stress for clinician, patients, and their relatives. However, the peripheral smear examination will remain the gold standard to differentiate TCP from, PTCP.

To better characterize occurrence and extent of anticoagulant-associated pseudothrombocytopenia (PTCP) in the daily routine of a high-throughput clinical laboratory in order to draw conclusions on a more precise definition of this phenomenon.

This case report describes the finding of EDTA-dependent Pseudothrombocytopenia in an 8-month-old infant, an extremely rare condition not reported in the literature. The patient presented with a fever due to insect bite and was diagnosed with abscessed cellulitis. A complete blood count showed a thrombocytopenia of 47 mil/L, with no history of bleeding or hematologic disease. The following day a new test was performed, which showed a platelet count of 214 mil/L, which was not consistent with the expected evolution of a real thrombocytopenia. Pseudothrombocytopenia was suspected and confirmed by observing platelet aggregates in the blood smear and upon recounting in a tube with sodium citrate, showed a normal value of 298 mil/L. Treatment consists of avoiding the use of EDTA as an anticoagulant and using other anticoagulants such as citrate or heparin. Timely identification of this phenomenon is essential to avoid diagnostic confusion and unnecessary or harmful treatment. This case brings to the scientific literature an example of EDTA-dependent Pseudothrombocytopenia in a pediatric patient, which can be easily confused with other causes of thrombocytopenia and requires a high index of clinical suspicion.

Background: Automated hematology analyzers have become mainstream of complete blood count (CBC) during the past two decades; they are potential, more accurate to produce results of CBCs. However, often automated analyzers can give false results too, specially, falsely low platelet count due to platelets aggregates, which have to be confirmed on peripheral smears. Aims and Objectives: The aim and objective of the study was to diagnose thrombocytopenia (TCP) cases and differentiate them from pseudothrombocytopenia (PTCP) cases by analyzing platelet histogram and to determine the sensitivity and specificity of platelet histograms for diagnosing TCP and PTCP. Materials and Methods: The present study was conducted in the Department of Pathology at Shyam Shah Medical College, Rewa, M.P., after obtaining ethical clearance from the Institutional Ethics Committee. It was prospective study conducted for a period of 15 months from January 2021 to May 2022 on 1000 samples. Results: The sensitivity and specificity of platelet histogram flags and presence of multiple peaks to diagnose TCP and PTCP cases were calculated as 73.60% and 93.60%, respectively. The present study also interpret that mean platelet volume and platelet distribution width cannot use as indicator to differentiate between TCP and PTCP. Conclusion: The present study concludes that analysis and interpretation of histogram more specifically platelet histogram flagging provide clue for early detection of PTCP cases prior peripheral smear examination and also helpful in differentiating them from true TCP cases. These platelet histogram flagging can be used as a screening parameter for the detection of PTCP and these are helpful in preventing unnecessary stress for clinician, patients, and their relatives. However, the peripheral smear examination will remain the gold standard to differentiate TCP from, PTCP. [ABSTRACT FROM AUTHOR]

The platelet antibodies that cause pseudothrombocytopenia (PTCP) act only in vitro and do not produce clinical bleeding. Most studies on PTCP have focused on improving differential diagnosis with true thrombocytopenia but studies on the characteristics of patients with PTCP are limited. In this study, we aimed to evaluate the clinical and biological characteristics of 192 patients with PTCP. In addition to general variables, we evaluated automated and microscopic platelet counts, platelet clumps, platelet diameters, immature platelet fraction (IPF), and platelet antibodies. Adult women accounted for the largest subgroup of patients (n=82; 42.7%) and 67 patients (34.9%) were grouped into families. Forty-four patients (22.9%) had one or more associated autoimmune disorders (ADs); 39 relatives of these patients (19.8%) had ADs and 45 relatives (23.4%) had immune thrombocytopenia (ITP) or unspecified thrombocytopenia. Platelet cryptantibodies and/or autoantibodies were positive in 56 patients (30.1%). Most patients (n=169; 80%) had automated platelet counts >80×109/L. In all patients, microscopic platelet counts were ≥150×109/L. The platelet clump index (% increase in microscopic platelet count compared to automatic count) ranged from 30 to >7000%. Platelet diameters and IPF parameters were significantly greater in the PTCP versus healthy controls (p<0.001). A total of 17 patients (8.8%) had had previous ITP or the PTCP evolved into ITP. Our data suggest that PTCP should be considered a situation of autoimmunity; the assessment of platelet clumps has a high diagnostic value; the close association between ITP and PTCP suggests that these conditions could be different phases of the same process. [ABSTRACT FROM AUTHOR]

Background: Pseudothrombocytopenia may lead to the erroneous diagnosis of thrombocytopenia, resulting in unnecessary testing and treatment. The addition of exogenous substances to blood samples prior to collection has been shown to mitigate platelet (PLT) clumps in blood samples. Postcollection additives aiming to disaggregate PLT clumps have been largely unexplored. Objectives: We aimed to determine if the addition of amikacin to blood samples postcollection aids in the disaggregation of PLT clumps in cats and dogs. Methods: For this prospective study, EDTA‐collected blood samples from 28 cats and 17 dogs were obtained from a hospital population at UC Davis Veterinary Medical Teaching Hospital. Samples had PLT clumps detected on blood smears and thrombocytopenia per analyzer count. Amikacin was added to samples postcollection, and an additional CBC was performed. Flow cytometry was performed to assess PLT‐fibrinogen binding in amikacin‐treated aliquots. Results: PLT‐clumped samples treated with amikacin significantly increased PLT numbers by 134% and decreased mean platelet volume (MPV) values by 14% (P ≤ 0.0001) in cats, and increased PLT numbers by 32% (P = 0.04) and increased MPV values by 9% (P = 0.02) in dogs. Mean cell volume (MCV) slightly increased (<4%) for both species. No other CBC parameters were substantially affected by the addition of amikacin. Flow cytometry showed decreased PLT‐fibrinogen binding in the majority of cats but was not significant (P > 0.05). Conclusions: Adding amikacin to PLT‐clumped blood samples postcollection may be a convenient solution for pseudothrombocytopenia in cats and dogs. Future studies are needed to elucidate the mechanism of amikacin and its effectiveness under different storage conditions. This is the first reported use of amikacin postcollection to disaggregate PLT clumps in blood samples from animals. [ABSTRACT FROM AUTHOR]

Pseudothrombocytopenia (PTCP) refers to the aggregation of platelets in anticoagulant blood in vitro and causes a false lower platelet count (PLT). For the purpose to achieve an accurate PLT, we presented an alternative vortex method to disaggregate platelet clumps and consequently generate a reliable PLT without a second venous puncture for patients. PLT, mean-platelet-volume (MPV), red blood cells (RBCs), hematoglobin (Hb), hematocrit (Hct) and white blood cells (WBCs) were evaluated before and after vortex in 221 specimens with PTCP using vortex method, and the PLT was also compared with 85 specimens disaggregated by citrate method. Twenty control samples were used to investigate mixing effect on complete blood counts in normal samples. One thrombocytopenia specimen was used to evaluate reproducibility of vortex. The mean PLT, MPV, RBCs, Hb, Hct and WBCs of 20 control specimens pre-vortex were 260.7 ± 53.4 × 109/L, 11.65 ± 0.85, 4.87 ± 0.46 × 1012/L, 147.6 ± 13.8 g/L, 45.31 ± 4.04, 6.46 ± 1.41 × 109/L, and results of post-vortex were 252.9 ± 50.2 × 109/L, 11.66 ± 0.92, 4.95 ± 0.48 × 1012/L, 149.1 ± 13.8 g/L, 45.19 ± 4.03, 6.35 ± 1.36 × 109/L respectively. Specimens with platelet clumps using vortex mixer had higher PLT after mixing, the mean pre-vortex PLT was 54.3 ± 35.2 × 109/L, and after vortexing PLT increased to 157.5 ± 58.8 × 109/L (p < 0.05). MPV, RBCs, Hb, Hct and WBCs in 221 specimens were comparable before and after vortex mixing (all p > 0.05). Vortex method might disaggregate platelet clumps sufficiently in most PTCP specimens, and obtain a relatively reliable PLT without the need of a second venous puncture. [ABSTRACT FROM AUTHOR]

Abstract We herein report a case of peripheral blood stem cell transplantation (PBSCT) involving a donor with EDTA‐induced pseudothrombocytopenia (PTCP). The apheresis product was inspected for 24 h and there was no platelet clumping or thrombocytopenia. In the first 14 months after PBSCT, there has been no transfer of PTCP symptoms.

Introduction: The aim of this study was to investigate the diagnostic accuracy of the flag PLT‐Clumps from the WNR/WDF and the PLT‐F channels from Sysmex XN and to study how different cut‐offs for investigation for pseudothrombocytopenia (PTCP) and the definition of platelet aggregation affected the diagnostic accuracy. Methods: A smear review was performed for samples with platelet count <150 × 109/L and samples flagged for platelet aggregation by Sysmex XN‐20. The samples were investigated for platelet aggregation in 30 fields using 40× objective. Findings were classified by size and quantity using two definitions of aggregation: the Norwegian quality improvement of laboratory investigations (Noklus) and the Groupe Francophone de'Hematologie Cellulaire (GFHC). The Q‐values for the PLT‐Clumps flag from the WNR/WFD channel and the PLT‐F channel were compared with smear findings. Results: ROC analysis showed that the diagnostic accuracy of the PLT‐clumps flags increased with increasing stringency of the definition of platelet aggregation and when only samples with thrombocytopenia were investigated. With the most stringent PTCP definitions, the diagnostic accuracy of the PLT‐Clumps flag from PLT‐F was very high (AUC 0.97–0.98) and markedly better than for WNR/WDF. Conclusion: The diagnostic accuracy of PLT‐F from Sysmex XN‐20 for identification of PTCP was very good and superior to the WNDR/WDF channel in samples with platelet count <150 × 109/L and a moderate to high number of aggregates in the smear. There is a need for a more precise definition of platelet aggregation. [ABSTRACT FROM AUTHOR]

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Pseudothrombocytopenia caused by platelet clumping (PC) can lead to unnecessary platelet transfusions or underdiagnosis of hematologic neoplasms. To overcome these limitations, we assessed the capacity of the Sysmex DI-60 digital morphology analyzer (Sysmex, Kobe, Japan) for detecting PC and determining an accurate platelet count in the presence of PC. For this purpose, 135 samples with or without PC (groups Y and N, respectively) were processed by an examiner (a hematologic specialist) using both the Sysmex XN-9000 and DI-60 analyzers. Although the platelet aggregate (PA) and giant platelet (GP) counts reported by the DI-60 and the examiner exhibited strong correlations, they proved inadequate as effective indicators for screening samples containing PC. Between the PA and GP counts and four platelet indices (the platelet distribution width [PDW], mean platelet volume [MPV], platelet large cell ratio [P&#95;LCR], and plateletcrit [PCT]) reported by the XN-9000, we observed statistically significant correlations (both overall and with group Y), but they were relatively weak. The platelet counts determined using the DI-60 and light microscopy in group Y showed substantial variations. Although the performance of the DI-60 was reliable for detecting PA and GP in smear images, such fixed areas are not representative of whole samples. Further, in the presence of PC, the resulting platelet counts determined using the DI-60 were not sufficiently accurate to be accepted as the final count.

Background: EDTA-induced pseudothrombocytopenia (PTCP) during whole blood collection requires significant laboratory resources to obtain accurate results. We evaluated platelet-deaggregation function in EDTA-induced PTCP and platelet-clump flagging by the BC-6800Plus hematology analyzer using integrated digital image analysis., Methods: We prospectively collected 132 whole blood samples suspected of platelet clumping (102 in EDTA and 30 in sodium citrate) from 88 individuals. We compared platelet counts determined using the platelet count by impedance (PLT-I) function of the DxH 900 hematology analyzer and the PLT-I or optical platelet count (PLT-O) function of the BC-6800Plus. Platelet clumping was verified through manual inspection and the MC-80 digital image analyzer., Results: Among the 132 whole blood samples, 43 EDTA samples showed platelet clumping. The DxH 900 PLT-I and BC-6800Plus PLT-I results demonstrated a strong correlation (r=0.711) for the EDTA samples but only a moderate correlation with the BC-6800Plus PLT-O results (r=0.506 and 0.545, respectively). The BC-6800Plus PLT-O results were consistent with the sodium citrate platelet counts, with a median dissociation rate of 102.5% (range, 74.9%-123.1%). The DxH 900 and BC-6800Plus analyzers had sensitivity values of 0.79 and 0.72, respectively, for platelet-clump flagging. When integrating the MC-80 digital image analysis results, the sensitivity of BC-6800Plus improved to 0.89 (standard mode) or 1.0 (PLT-Pro mode)., Conclusions: BC-6800Plus PLT-O measurement results are close to the actual values obtained by platelet deaggregation with PTCP samples. Integrating the BC-6800Plus with a digital imaging analyzer effectively improved the diagnosis of PTCP and reduced the requirement for additional laboratory procedures.

Pseudothrombocytopenia (PTCP) is defined by the occurence of spouriously low platelet count as a consequence of in vitro platelet aggregation. It is a rare and benign artifact, not associated with any specific disorder or therapy, that becomes clinically relevant when it is not timely and reliably recognized. Thus, it may result in inappropriate clinical decisions ( i.e. unnecessary further testing, misdiagnoses and potential patients' mismanagement) unavoidably compromising patient safety. The most common form of PTCP is caused by ethylenediaminetetraacetic acid (EDTA). Several approaches for the management of samples with EDTA-induced PTCP have been described in the literature. However, expert recommendations are scarce. The scope of these recommendations is to assist in achieving national harmonisation in laboratory management ( i.e. detecting and reporting platelet counts) of samples with EDTA-induced PTCP. These minimal recommendations were prepared by the members of the joint working group of the Croatian Chamber of Medical Biochemists and Working group for Laboratory Hematology of the Croatian Society of Medical Biochemistry and Laboratory Medicine, and might be customized according to specific conditions ( i.e. personnel and equipment) of each individual laboratory. These recommendations are primarily intended to all laboratory professionals involved in the management of samples with EDTA-induced PTCP, but also to other healthcare professionals involved in collecting samples and interpreting complete blood count results., Competing Interests: Potential conflict of interest None declared., (Croatian Society of Medical Biochemistry and Laboratory Medicine.)

Thrombocytopenia with platelet count < 50 × 109/L is common laboratory finding in a severely ill newborn in neonatal intensive care units (ICU). Neonates with severe thrombocytopenia are at risk of bleeding. Most dangerous is intracerebral hemorrhage (ICH) frequently leading to death or lifelong neurological sequels. Pseudothrombocytopenia (PTCP) is a rare in vitro phenomenon of falsely low platelet count determined on hematology analyzers due to platelet clumping in ethylenediaminetetraacetic acid (EDTA) anticoagulated blood. PTCP was also reported in pregnant women with isolated thrombocytopenia. EDTA-PTCP in the neonate due to the transplacental transmission of maternal antibodies has been reported only in a few cases. Although PTCP is rare phenomenon, it should always be excluded in newborns with isolated thrombocytopenia to avoid erroneous interpretation of platelet and leukocyte count, unnecessary laboratory investigation of false positive antiplatelet antibodies and needless platelet transfusions. We report on two cases of transient PTCP in a neonate due to transplacental transfer of maternal EDTA-dependent autoantibodies of IgG class from the same mother. [ABSTRACT FROM AUTHOR]

We herein report a case of peripheral blood stem cell transplantation (PBSCT) involving a donor with EDTA‐induced pseudothrombocytopenia (PTCP). The apheresis product was inspected for 24 h and there was no platelet clumping or thrombocytopenia. In the first 14 months after PBSCT, there has been no transfer of PTCP symptoms. In our case, pseudothrombocytopenia (PTCP) symptoms were not transferred from a stem cell donor to the recipient, and the apheresis products harvested with appropriate anticoagulants did not exhibit PTCP. Peripheral blood stem cell transplantation involving PTCP donors may be managed identically to that involving non‐PTCP donors. [ABSTRACT FROM AUTHOR]

Abstract: One of the most widely used anticoagulants for a complete blood count is ethylenediaminetetraacetic acid (EDTA). Pseudothrombocytopenia (PTCP) may be caused by EDTA, this condition may lead to inappropriate diagnosis and treatment. We report a 25-year-old female with unspecific headache and joint pain with very low platelet count since 1 month before hospital admission. She was diagnosed with Dengue fever infection and got some platelet transfusion from the previous secondary hospital. She was carried out for a blood test with another anticoagulant (sodium citrate) and bone marrow aspiration. The results showed that she had normal platelet count and bone marrow cellularity. When a patient was identified with thrombocytopenia without any bleeding manifestation, hematology disease, and family history, PTCP should be taken into consideration to prevent unnecessary intervention. Keywords: platelet, pseudothrombocytopenia, ethylenediaminetetraacetic acid, Dengue fever

Introduction: Physiologically, feline platelets are more reactive and prone to aggregation, which interferes with platelet counts using automated counters and manual methods. The use of aminoglycoside amikacin in association with EDTA has proven to be efficient in preventing platelet aggregates in cases of pseudo thrombocytopenia (PTP) in people. Objectives: This study evaluated the efficacy of amikacin in preventing platelet aggregation in EDTA‐containing feline blood samples and investigated the possible effects on hematologic measurands. Materials and methods: Blood samples (1.0 mL) collected from 100 healthy cats were stored in two EDTA tubes: 0.5 mL in a microtube containing 10 μL of 250 mg/mL amikacin (EDTA‐AMK group) and 0.5 mL in a microtube containing only K2 EDTA 10% (EDTA group). A CBC was executed with an automated impedance blood analyzer, and a microscopic examination of the blood smears was performed. Results: Platelet clumps were observed in 56% of samples from the EDTA group and 5% of samples from the EDTA‐AMK group. Platelet counts (PLT), plateletcrit (PCT), and WBC counts were significantly higher (P <.001) in the EDTA‐AMK group compared withi the EDTA group. Conclusions: Amikacin prevents platelet aggregation in feline venous blood samples and does not cause clinically relevant changes in other hematologic measurands. To our knowledge, this is the first report showing the use of amikacin in preventing platelet aggregation in feline blood samples. Based on this study, amikacin could be added to EDTA collection tubes for complete blood counts in cats. [ABSTRACT FROM AUTHOR]

Reports of side effects of vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are increasing worldwide. Capillary leak syndrome and vaccine-induced immune thrombotic thrombocytopenia are very rare but life-threatening adverse events that should be identified early and treated. However, isolated thrombocytopenia can indicate pseudothrombocytopenia. In certain people, ethylenediaminetetraacetic acid (EDTA) induces an in vitro platelet aggregation, resulting in misleading underestimation of platelet counts. It is essential to recognize pseudothrombocytopenia to prevent diagnostic errors, overtreatment, anxiety, and unnecessary invasive procedures. We present a case who developed generalized edema and persistent pseudothrombocytopenia after the first dose of the ChAdOx1 nCoV-19 vaccine (AstraZeneca).

Platelet aggregation in the presence of ethylenediaminetetraacetic acid (EDTA), is called EDTA-related pseudothrombocytopenia (EDTA-PTP), resulting in low platelet count by automatic cell counters. Herein, we present a case of a 5-year-old female, who was referred to our laboratory due to persistent thrombocytopenia. Our case report discusses the efficiency of the histograms and flag warnings of the cell counter, indicating the importance of these variables. [ABSTRACT FROM AUTHOR]

No hemorrhagic manifestations, presence of platelet clumps on the peripheral blood smear, normal manual count, and normal autoanalyzer count after collecting blood in citrate vial help confirm the diagnosis of EDTA-dependent thrombocytopenia. [ABSTRACT FROM AUTHOR]

Background Hepatosplenic schistosomiasis mansoni (HS) is associated with thrombocytopenia. Accurate platelet counts are required for identification and management of HS patients. EDTA-dependent pseudothrombocytopenia (EDTA-PTCP) is an in vitro phenomenon of anticoagulant-activated platelet agglutination resulting in low platelet counts by automated methods. The prevalence of EDTA-PCTP in schistosomiasis is unknown and only one case has been described. Our aims were to determine the prevalence of EDTA-PTCP in HS and evaluate alternative methods to overcome this analytical error. Methods Blood samples from 56 HS patients and 56 healthy volunteers were collected, and platelet counts were obtained using standard microscopy and automated (electric impedance) methods. Automated platelet counts and the presence of platelet clumps in blood smears were evaluated in samples collected in EDTA or sodium citrate tubes 20 and 180 min after blood collection. Results EDTA-PTCP was more frequent in HS patients than healthy volunteers (8.92% vs 0.00%, p<0.0285). Platelet clumps and PTCP were also observed in samples collected in sodium citrate tubes, refuting its use as an alternative method. Conclusions Automated platelet counts in blood samples from HS patients should be performed right after blood collection in EDTA tubes and verified by manual counts in blood smears. [ABSTRACT FROM AUTHOR]

Abstract No hemorrhagic manifestations, presence of platelet clumps on the peripheral blood smear, normal manual count, and normal autoanalyzer count after collecting blood in citrate vial help confirm the diagnosis of EDTA‐dependent thrombocytopenia.

Background: To explore the application of SF-Cube 2.0 technology in platelet count in patients with EDTA-dependent pseudothrombocytopenia (EDTA-PTCP). Methods: Twenty-two out-patients and in-patients with EDTA-PTCP in our hospital were selected from February 1, 2020, to August 31, 2020. With the permission of each patient, blood samples of EDTA and sodium citrate anticoagulant tubes were collected. EDTA anticoagulant samples were tested by using the "complete blood cell count and white blood cell differential count"(CD) mode, and "complete blood cell count, white blood cell differential count, and reticulocyte count" (CDR) mode of the Mindray BC-6800Plus automated hematology analyzer, and the platelet counts were compared with the sample of sodium citrate anticoagulant from this patient. Results: As SF-Cube 2.0 technology (implemented by using the CDR mode of the Mindray BC-6800Plus) was used, the platelet count of EDTA-PTCP sample was consistent with that of sodium citrate anticoagulant, which was significantly higher than that of CD detection mode. Conclusions: SF-Cube 2.0 technology can effectively correct the platelet counts in people with known or suspected EDTA-PTCP. [ABSTRACT FROM AUTHOR]

Thrombocytopenia is a clinically important condition that can lead to several problems when not correctly diagnosed. A decrease of platelet counts due to an in vitro phenomenon, Pseudothrombocytopenia, can be misunderstood and unnecessarily treated. The present case study describes a 57-year-old male with a history of pancreas adenocarcinoma and a current Staphylococcus aureus infection without any signs or symptoms that could explain the low levels of platelets obtained after blood analysis. Blood smear evaluation detected both platelet satellitism and phagocytosis by neutrophils. As this sample was anticoagulated with ethylenediaminetetraacetic acid (EDTA), a new blood sample with citrate was analyzed. Platelet count was normal and no morphological abnormalities were detected. This case emphasizes the need for considering not only laboratory results but also the patient clinical information to guarantee the correct diagnosis and the best treatment possible.

Hemodialysis (HD) is the most important treatment for patients with end‐stage renal disease (ESRD). Thrombocytopenia is a potential treatment complication related to dialysis. Under normal circumstances, the platelet count would slightly decrease within the first hour of HD, but get restored towards the end of procedure. In most patients, the platelet count can be maintained within the normal range, and the occurrence of thrombocytopenia is relatively rare in clinical practice. Therefore, the possibility of thrombocytopenia in HD patients is often ignored. Moreover, thrombocytopenia might be misdiagnosed and mistreated. At present, almost all articles on the subject, apart from some case reports, focus on pseudothrombocytopenia and heparin‐induced thrombocytopenia. In this review, we summarized various underlying causes, mechanisms, and diagnostic approaches to thrombocytopenia in HD patients. The review aims to provide a guide for clinicians interested in the causes and adequate treatment of thrombocytopenia. [ABSTRACT FROM AUTHOR]

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Background: Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia is a rare phenomenon. Spurious pseudothrombocytopenia has also been described in other circumstances, while artifactual platelet count in whole blood samples anticoagulated with sodium citrate is an exceptional occurrence. Case report: In this study, we describe the case of a 44-year-old ostensibly healthy woman who attended the local outpatient clinic for routine laboratory testing, including platelet count in EDTA and sodium citrate, for suspected artifactual pseudothrombocytopenia previously identified in another center. The results of hematological testing on both specimens were essentially normal, except for mild anemia. Nevertheless, the platelet number was 425 × 109/L in K2EDTA and 266 × 109/L (293 × 109/L after correcting for sample dilution) in sodium citrate, respectively. Microscopic revision of blood smears revealed the presence of platelet aggregates and satellitism only in the sodium citrate specimen. Conclusion: Unlike previous occasional reports of concomitant EDTA- and sodium citrate-dependent pseudothrombocytopenia, we first describe a paradigmatic case of artifactual platelet count attributable to platelet clumping and satellitism, exclusively developing in blood anticoagulated with sodium citrate. [ABSTRACT FROM AUTHOR]

Introduction: Clinically, the most important pseudothrombocytopenia is described in pregnant women and also in their newborns if blood sample is taken using EDTA. Case report: Patient, 35 years old pregnant woman, 36 weeks of gestation, was admitted to Gynecological and Obstetrics Clinic in the CCS because of pregnancy monitoring. The EDTA thrombocytes result was 34.0 x 10e9/L and patient was without any symptoms of bleeding tendency. Pseudothrombocytopenia was suspected. We decided to check it by examination of blood smear and incubating EDTA sample on 37°C degrees for an hour. The platelets value on 37°C degrees was 32.0 x 10e9/L. Blood smear showed a platelet aggregation. The platelet count with the Sodium Citrate was 253.0 x 10e9/L, with the Ammonium oxalate 266.0 x 10e9/L and with Mg-sulphate 284.0 x 10e9/L. Newborn was healthy. The Complete Blood Count of newborn revealed normal parameters apart from a low platelet count 49.0 x 10e9/L. A blood smear was ordered and it revealed platelet aggregations. Platelet count of newborn blood sample taken on sodium-citrate was 189.0 x 10e9/L which clearly indicated pseudothrombocytopenia. Conclusions: Although PTP does not require clinical-therapeutic intervention, undiagnosed PTP can lead to therapeutic intervention (unnecessary administration of platelet concentrate) and seriously deteriorate both mother's and child's health. Therefore, the authors suggest examination of blood smear in every case when thrombocytopenia is diagnosed.

EDTA dependent pseudothrombocytopenia (EDTA-PCTP) is a phenomenon that characterized by a spurious decrease of platelets in vitro due to the aggregation of platelets in EDTA anticoagulant blood samples. We report the first case of a transient appearance of EDTA-PCTP in a patient with 2019 novel coronavirus pneumonia (COVID-19). A 59-year-old woman was admitted to the isolated ward for severe type of 2019 novel coronavirus pneumonia. At the time of admission, her platelet count was in a normal range. Two days later, her platelet count decreased gradually without any signs or symptoms of bleeding. Since the peripheral blood smear showed a platelet aggregation, a blood sample anticoagulanted with citrate was tested and the number of platelet was normal. The phenomenon disappeared after 17 days when the patient was cured. This case emphasized the importance of peripheral blood smear and clinical manifestation, especially in the differential diagnosis of thrombocytopenia.

However, PS and platelet clumps were significantly decreased, even though a few attached platelets to neutrophil membrane and small portions of platelet clumps were still observed (Figure 2A). These platelet aggregates may detach from the neutrophil membrane and form free platelet clumps, which explains the co-existence of both PS and platelet clumps in the blood smear. [Extracted from the article]

Introduction: Pseudo thrombocytopenia (PTP) is a phenomenon of falsely low platelet counts obtained on Hematology Analyzers (HA) due to in vitro platelet clumping in the presence of anticoagulants. Methods: Papers on the subject of pseudothrombocytopenias effects were searched for in biomedical journals indexed in MEDLINE from 1969 to 2016. All other thrombocytopenia types were not analyzed. Topic: Pseudothrombocytopenia occurs using the EDTA and other anticoagulants, in the process of determining the platelet count on the HA. Agglutination of platelets occurs at temperatures lower than 34° C and sample enhances if exposed to longer period of time. Agglutination of platelets is most expressed 4 hours after blood sampling. Agglutination occurs by binding of IgM, IgG and IgA immunoglobulin to antigen or crypto- antigen of platelets. Hematologic cell Analyzers, (HA) do not count platelets from large agglutinations, therefore, the number of platelets that provides HA represents the sum of the number of free non-agglutinating platelets and small agglutinations consisting of 3-5 platelets. Pseudothrombocytopenia shall be suspected in the case of the absence of clinical signs of hemorrhagic diathesis. Undiagnosed pseudothrombocytopenia may lead to unnecessary aggressive diagnostic procedures such as biopsy or puncture of the bone marrow, inadequate treatment and even transfusion of platelets. The fallowing types of pseudothrombocytopenias are described herein: a) pseudothrombocytopenia occurred due to platelet agglutination, b) platelet satellitism and c) aggregation of platelets and leukocytes. Conclusion: In order to obtain the actual count of platelets, peripheral blood smear shall be done for all samples with low values of thrombocytes (