Automated Platelet Counts Research Articles

Comparison of Manual Versus Automated Platelet Count In Predicting Haemorrhagic Manifestations In Patients With Dengue

Objective: To compare the manual versus automated platelet count in predicting haemorrhagic manifestations in patients with dengue presenting at our hospital in one year. Study Design: Prospective longitudinal study. Place and Duration of Study: Pak Emirates Military Hospital, Rawalpindi Pakistan, from Jan 2019 to Jan 2020. Methodology: This study included 280 cases with confirmed diagnoses of dengue fever. All the patients underwent manual and automated platelet counts within 24 hours of diagnosis confirmation. They were then followed up for 12 weeks to look for haemorrhagic complications. Thrombocytopenia on each method and other socio-demographic factors were compared among the patients with and without haemorrhagic complications. Results: The mean age of study participants was 36.3±2.75 years. 163(74.1%) were males, while 57(25.9%) were females. 98(44.5%) patients had thrombocytopenia at manual platelet count, while 99(45%) had thrombocytopenia at the automated count. 44(20%) showed the presence of haemorrhagic complication within the 12-week time, while 176(80%) did not manifest any haemorrhagic complication. Pearson chi-square analysis revealed that thrombocytopenia at automated platelet count and advancing age were the factors strongly linked with the presence of haemorrhagic complications among the patients suffering from dengue fever in our setting. Conclusion: Hemorrhagic complications were common among patients suffering from dengue fever. The results showed that a low platelet count on automated platelet count emerged as a strong predictor for haemorrhagic complications compared to the manual platelet count.

Pseudothrombocytopenia, beyond a laboratory phenomenon: study of 192 cases

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.

Macrothrombocytopenia: Role of Automated Platelet Data in Diagnosis.

Inherited macrothrombocytopenia is an underdiagnosed condition and may result in misdiagnosis and inappropriate management. This research was done to study this condition in a hospital setting. This study was conducted over 6 months in a teaching hospital. Patients whose complete blood count (CBC) samples were sent to the hematology laboratory were included. Patients were suspected to have inherited macrothrombocytopenia according to pre-defined criteria. Demographic information, automated CBC and peripheral smear examination was carried out. Seventy five healthy individuals and 50 patients with secondary thrombocytopenia were also analyzed. Likely inherited macrothrombocytopenia was identified in 75 patients. Automated platelet count in these patients ranged from 26 × 10^9/L to 106 × 10^9/L while MPV ranged from 11.0 to 13.6 fL. There was significant difference (p < .001) in mean platelet volume (MPV) and platelet large cell ratio (P-LCR) amongst patients with likely inherited macrothrombocytopenia, those with secondary thrombocytopenia and the control group. Mean platelet diameter was significantly higher (3.5 ± 1.1μm) in patients with likely inherited macrothromboctopenia compared to those with secondary thrombocytopenia (2.4 ± 0.7μm) and control group (1.9 ± 0.7μm). All patients with suspected inherited macrothrombocytopenia showed abnormal platelet histograms with descending limb in the high volume and red cell zone. Four distinct histogram patterns were identified. Inherited macrothrombocytopenia is an underdiagnosed condition. The patient's history, clinical examination, judicious use of automated CBC data including platelet histograms and careful review of the peripheral blood smear are useful tools to suspect this condition. The online version contains supplementary material available at 10.1007/s12288-022-01590-6.

Spurious thrombocytopenia in the mother and baby – A red herring clinical entity

Spurious thrombocytopenia or pseudothrombocytopenia (PTCP) is an important clinical entity, in which the presence of autoantibodies or anticoagulants used during blood sampling causes in vitro clumping of platelet and thereby resulting in a falsely low automated platelet count. The most common cause of platelet clumping is ethylenediaminetetraacetic acid used as an anticoagulant in the blood samples. The other reasons for PTCP include the presence of autoantibodies such as cold agglutinin, giant platelet, and platelet satellitism. There are very few cases of spurious thrombocytopenia in the newborn period published in the literature. We are reporting a case of PTCP due to platelet satellitism in a baby born to a mother with a similar condition.

Pseudothrombocytopenia – frequency, causes, and evaluation in a clinical lab.

Objective: To find out frequency, different causes of pseudothrombocytopenia andtheir further evaluation to reach a final diagnosisMethodology: This cross-sectional study was conducted at Muhammad MedicalHospital, Mirpurkhas between October 2021 to January 2022. All patients who hadan automated platelet count less than 100 were included in the study. While patients with a known cause of thrombocytopenia were excluded. Data was collectedwith the help of designed proforma. Complete blood count was performed by anautomated hematology analyzer. The samples with platelet count less than 100(flag on platelet counts) were selected for peripheral blood smear review for manual counting to ascertain the cause of thrombocytopenia.Results: A total of 1800 blood samples were analyzed. 95 patients (5.27%) had isolated platelet count &lt; 100 with no previous history. Peripheral blood smear reviewwas done, 84 patients (88%) had true thrombocytopenia that is low platelet countby both automated and manual techniques. The incidence rate of pseudothrombocytopenia was 0.61%. Clumping due to EDTA was found in 0.27% cases followed byplatelet satellitism in 0.05% cases.Conclusion: Our study reported an incidence of pseudothrombocytopenia to be0.61%. Further breakdown revealed clumping due to EDTA to be the most commoncause. Platelet Satellitism was found to be the cause of pseudothrombocytopenia in0.05% cases.&#x0D; Keywords: pseudothrombocytopenia, PTCP, spurious, thrombocytopenia.

Platelet count estimation on peripheral smear: What should be an acceptable; multiplication factor

Context: Automated cell counters have revolutionised laboratory medicine and are being used worldwide. They give accurate results, can run large number of samples and generate accurate results within a short span of time. Quality check procedures in this equipment ensure accuracy of results. However, for platelet counts, the pathologist is still dependent on confirming the results by manual methods, especially in situations of low platelet count and flagging by the electronic counter. Different laboratories use different methods for manual estimation of platelet counts. Aims: This study was done to compare the platelet counts assessed on peripheral smear examination by different multiplication factors, and to identify the multiplication factor which derives the most accurate platelet count. Settings and Design: This was an observational study. Methods: Peripheral smears prepared from 100 ethylenediaminetetraacetic acid-anticoagulated blood samples were manually examined under oil immersion field (OIF) for platelets. Platelet count was further calculated by multiplying the number of platelets per OIF using multiplication factors of 10,000, 15,000 and 20,000. This was compared with platelet (PLT)/red blood cell (RBC) method and automated platelet counts. Accuracy of various manual methods was evaluated by calculating the per cent difference of the methods with automated analyser counts. Statistical Analysis Used: Descriptive statistics was used for statistical analysis. Results: Manual platelet count estimation on peripheral smear employing multiplication factor of 15,000 was found to have comparable accuracy to analyser counts, followed by the PLT/RBC ratio method. Conclusions: This study confirms that for manual estimation of platelet counts on peripheral smear, a standard multiplication factor of 15,000 on OIF gives the most accurate result, which is closest to counts obtained by automated analysers.

COVID-19-associated pseudothrombocytopenia.

COVID-19-associated pseudothrombocytopenia.

EDTA-dependent pseudothrombocytopenia in patients with hepatosplenic schistosomiasis mansoni: a clinical management alert.

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. 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. 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. 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.

Platelet function in cats with hyperthyroidism.

Cats with hyperthyroidism have been reported to develop thromboembolism, with and without echocardiographic abnormalities consistent with hyperthyroidism. The objective of this study was to compare platelet function in cats with hyperthyroidism with euthyroid age-matched cats. We hypothesized that cats with hyperthyroidism have shortened collagen and adenosine diphosphate (C-ADP) closure times as measured with the platelet function analyzer (PFA-100) in comparison with healthy, age-matched controls. Sixteen hyperthyroid and nine euthyroid healthy cats >7 years of age were recruited from the hospital population. Platelet function, measured using the C-ADP closure times by the PFA-100, and platelet count were measured in healthy euthyroid cats and cats with hyperthyroidism. Mean ± SD closure times were not significantly different between control (66.3 ± 9.6 s) and hyperthyroid cats (65.9 ± 11.5 s; P = 0.75). The mean ± SD closure times of hyperthyroid cats that either were untreated or received methimazole for ⩽3 weeks (n = 6; mean 68.5 ± 15.4 s) was not different than that of cats treated for >3 weeks (n = 10; mean 64.3 ± 8.9 s; P = 0.57). The mean automated platelet count was higher in the hyperthyroid group than in the control group (P = 0.023). Platelet function, as measured by closure time under high shear conditions using C-ADP as an agonist, was not affected by hyperthyroidism in this group of cats. Further research is needed to determine if a hypercoagulable state exists in hyperthyroid cats and the potential roles platelets and von Willebrand factor may have.

Evaluation of verification criteria for platelet scan for automated platelet counts generated by beckman Coulter LH-780 hematology analyser

Aims & Objectives: To evaluate verification criteria for reflex ordering of platelet scans for automated platelet counts generated by Beckman Coulter LH-780 Hematology Analyzer. Materials & Methods: The study uses automated platelet counts /=40x103/µL and within 20% for counts

170: Manual vs automated platelet counts for severe thrombocytopenia pregnant women in labor

To compare automated to manual platelet counts in pregnant women with severe thrombocytopenia through labor, in order to allow them neuraxial blocks. A retrospective cohort study of anesthetic and obstetric data of 385 women in labor with automated platelet counts< 100000μ/L, who were admitted to single referral center during 2013-2018. These automated platelets were compared with manual platelet counts, using standard hematological method. The study group was divided into 3 subgroups according to the severity of the thrombocytopenia as measured by the automated platelets, Group I (75-99000/μL), Group II (50000-74000/μL) and Group III (< 50000/μL) and compared it with the manual counts, respectively. 75000μ/Land 100000 μ/L manual platelet counts were used as a lower cutoff for placing neuraxial blocks. The manual platelet counts were significantly higher than automated count across all study group and subgroups with p< 0.001(table1). Number of women with manual platelet counts of >100000/μL were 70.95% (171/241) in group I, 27.6% (31/112) in group II and 9.38% (3/32) in group III. When we used cutoff of >75000/μL the number of women with manual platelet counts were 96.68%(233/241) in group I, 72.3%(81/112) in group II and 31.25% (10/32) in group III (Figure 1). No women had an epidural or spinal hematoma. Using manual platelet counts allow more women to be with neuraxial blocks.

Platelet Transfusion Thresholds: How Low Can We Go in Respect to Platelet Counting?

Platelet transfusion is conventionally used to prevent or treat bleeding in patients with low platelet counts or impaired platelet function. The identification of accurate thresholds of platelet count for guiding platelet transfusion practices is a crucial aspect in health care to prevent adverse events, side effects, unwarranted costs for the health care service, and deprivation of supplies. This article is therefore aimed at providing a narrative overview on current guidelines and recommendations for platelet transfusion across many clinical settings, including platelet function disorders, and critically analyzing the available platelet transfusion thresholds according to the current analytical performance of platelet counting with automated hematological analyzers. Overall, universal agreement on the definition of platelet transfusion thresholds has not been reached. The degree of accuracy and imprecision of many fully automated hematological analyzers appears also unsatisfactory, especially at the lower thrombocytopenic range, and this may thus jeopardize the managed care of patients who are candidates for platelet transfusions. Potential solutions to overcome the current shortcomings of automated platelet counting are also discussed, encompassing the use of alternative tests for guiding platelet transfusion (e.g., thrombin generation assays or thromboelastography) along with innovative approaches for platelet enumeration (e.g., fluorescent labeling and flow cytometry).

Platelet count correlation: automated versus manual on peripheral smear

Platelet count correlation: automated versus manual on peripheral smear - IJPO- Print ISSN No: - 2394-6784 Online ISSN No:- 2394-6792 Article DOI No:- 10.18231/j.ijpo.2019.074, Indian Journal of Pathology and Oncology-Indian J Pathol Oncol

PB2242 COMPARISON BETWEEN MANUAL AND AUTOMATED PLATELET COUNTS OF ADULT PATIENTS WITH THROMBOCYTOPENIA AT ST. PAUL'S HOSPITAL ILOILO (SPHI), PHILIPPINES

Background:Platelets are more difficult to count compared to other blood cells. Platelet counting is a significant tool used in clinical investigation to prevent bleeding complications. There is a general agreement that automation bring precision and accuracy for platelet counts in healthy individuals. Automation of platelet counting has been embraced in most part of the world, particularly in more developed countries. However, manual platelet counting &amp; estimation is still being done by skilled medical technologist to generate platelet results in most developing countries like ours. The method of platelet counting in thrombocytopenic patients is still controversial.Aims:To compare if there is significant difference between automated and manual platelet counts of adult patients with thrombocytopenia at the clinical laboratory of Saint Paul Hospital Iloilo City, Philippines.Methods:This is a retrospective‐analytical study of 384 samples of complete blood count (CBC) results with thrombocytopenia that contain both automated and manual platelet count values.Results:Out of the 384 adult patients with thrombocytopenia, there was an approximately 1:1 ratio based on sex. Thrombocytopenia was most common between 6th to 8th decades of life affecting 36% of patients. The mean of the automated platelet levels was approximately 76 × 109/L with the standard deviation of 45; while the manual platelet count results was 170 × 109/L with the standard deviation of 99. Among adult patients with thrombocytopenia, there was a significant difference between manual and automated platelet count results with p value &lt; 0.05).Summary/Conclusion:Thrombocytopenia affect both male and female sex equally. The higher the age group, the higher is the incidence of thrombocytopenia. Manual platelet counts are highly variable compared to the automated values. There was a significant difference between manual and automated platelet count results.

A STUDY OF EDTA DEPENDENT PSEUDOTHROMBOCYTOPENIA

Objective: To find out the frequency of Ethylenediaminetetraaceticacid (EDTA) Dependent Pseudothrombocytopenia (EDTA-PTCP) in all blood counts&#x0D; Material and Methods: 130 cases of suspected EDTA-PTCP were assessed for its correctness using manual platelet count as the gold standard, and compared the platelet counts in two different anticoagulants (EDTA and CPT) at different times from the time of collection of blood sample. The collected data was analysed and statistics were made accordingly.&#x0D; Result: Total 151750 haemograms were done during the study period of which 2428 cases showed thrombocytopenia, accounting for 1.6%. Amongst these, the pseudothrombocytopenia was suspected in 130 cases and was found to be correct in 119 cases, thus accounting for the incidence of EDTA-PTCP in 0.07% cases of total haemograms and 4.9 % cases of total thrombocytopenia. In 11 cases, the suspicion of Pseudothrombocytopenia was found to be incorrect. Of the total 130 cases included in the study, with M: F ratio of 1:1.3. The age of the patients varied from 3-85 years with the mean age of 36.78 ± 20.33 years&#x0D; Conclusion: In all the cases of thrombocytopenia showed by automated blood cell counters, the examination of peripheral blood film is must for the presence of platelet clumps to detect the cases of EDTA- dependent Pseudothrombocytopenia. To get correct platelet count in these cases, the manual platelet count is the ‘gold standard’. CPT is the better alternative anticoagulant for EDTA in cases of EDTA –PTCP for automated platelet counts.&#x0D; Keywords: EDTA-PTCP, haemogram, CPT, exvivo agglutination

Analytical performance of automated platelet counts and impact on platelet transfusion guidance in patients with acute leukemia

The aim of this study was to evaluate the performance of automated impedance platelet counts by Beckman Coulter LH780 (PLT-LH), Sysmex XN-3000 (PLT-XNi) and fluorescence method by Sysmex XN-3000 (PLT-F) in patients with acute leukemia. Blood specimens were subjected to platelet measurements by evaluated methods and then compared against the international reference method (IRM). Eighty-two blood specimens were included. Bland–Altman plots of the differences between the evaluated methods and IRM demonstrated mean biases of PLT-LH, PLT-XNi and PLT-F of 9 × 109/L, 11 × 109/L and 2 × 109/L, respectively. For platelet transfusion guidance, all evaluated methods had acceptable accuracy. For platelet transfusion guidance, the sensitivities of PLT-LH, PLT-XNi and PLT-F were 33.3, 25.0 and 83.3%, respectively, at a transfusion threshold of 10 × 109/L, and 73.1, 61.5 and 84.6%, respectively, at transfusion threshold of 20 × 109/L. High blast count was associated with inaccurate PLT-LH and PLT-XNi. In conclusion, the PLT-F demonstrated excellent performance for diagnosis of thrombocytopenia and for platelet transfusion guidance in the evaluated specimens from acute leukemia patients. With respect to clinical relevance, careful blood smear review is necessary in case of high blast counts.

Role of peripheral blood smear examination and manual platelet counts as an adjunct to automated platelet counts

Role of peripheral blood smear examination and manual platelet counts as an adjunct to automated platelet counts

Methods for manual platelet count: Comparison of automated platelet count with multiple manual method findings

Methods for manual platelet count: Comparison of automated platelet count with multiple manual method findings

Short-Term Storage of Platelet-Rich Plasma at Room Temperature Does Not Affect Growth Factor or Catabolic Cytokine Concentration.

The aim of this study was to provide clinical recommendations about the use of platelet-rich plasma (PRP) that was subjected to short-term storage at room temperature. We determined bioactive growth factor and cytokine concentrations as indicators of platelet and white blood cell degranulation in blood and PRP. Additionally, this study sought to validate the use of manual, direct smear analysis as an alternative to automated methods for platelet quantification in PRP. Blood was used to generate low-leukocyte PRP (Llo PRP) or high-leukocyte PRP (Lhi PRP). Blood was either processed immediately or kept at room temperature for 2 or 4 hours prior to generation of PRP, which was then held at room temperature for 0, 1, 2, or 4 hours. Subsequently, bioactive transforming growth factor beta-1 and matrix metalloproteinase-9 were measured by ELISA (enzyme-linked immunosorbent assay). Manual and automated platelet counts were performed on all blood and PRP samples. There were no differences in growth factor or cytokine concentration when blood or Llo PRP or Lhi PRP was retained at room temperature for up to 4 hours. Manual, direct smear analysis for platelet quantification was not different from the use of automated machine counting for PRP samples, but in the starting blood samples, manual platelet counts were significantly higher than those generated using automated technology. When there is a delay of up to 4 hours in the generation of PRP from blood or in the application of PRP to the patient, bioactive growth factor and cytokine concentrations remain stable in both blood and PRP. A manual direct counting method is a simple, cost-effective, and valid method to measure the contents of the PRP product being delivered to the patient.

Spurious Thrombocytopenia in Automated Platelet Count.

Spurious thrombocytopenia is a well-known phenomenon observed with the widespread use of hematology analyzers (HAs). In this study, 355 specimens with pseudo-thrombocytopenia (PTCP) were evaluated via epidemiology, identification, remedies, and platelet (PLT) count. Data showed that anticoagulants such as citrate and/or heparin-dependent PTCP (16.0%) became increasingly common, whereas ethylenediaminetetraacetic acid (EDTA)-induced PTCP (49.1%) remained the most frequent. We note that that nearly half of the patients with PTCP had veritable decreased PLT counts, even after PLT levels had been corrected. Our findings suggest that there were seasonal changes in patients with PTCP: PLT levels were higher in spring, compared with other seasons, with winter levels being the lowest. There were higher risks of PTCP for individuals with malignant neoplasms, liver diseases, infection, and hematologic disease, compared with other conditions. PTCP is related to diseases, rather than being a simple phenomenon, and thus demands careful attention.