Reagent Effects on the Activated Partial Thromboplastin Time Clot Waveform Analysis: A Multi-Centre Study.

(1) Background: The activated partial thromboplastin time (APTT)- based clot waveform analysis (CWA) quantitatively extends information obtained from the APTT waveform through its derivatives. However, pre-analytical variables including reagent effects on the CWA parameters are poorly understood and must be standardized as a potential diagnostic assay. (2) Methods: CWA was first analysed with patient samples to understand reagent lot variation in three common APTT reagents: Pathromtin SL, Actin FS, and Actin FSL. A total of 1055 healthy volunteers were also recruited from seven institutions across the Asia-Pacific region and CWA data were collected with the Sysmex CS analysers. (3) Results: CWA parameters varied less than 10% between lots and the linear mixed model analysis showed few site-specific effects within the same reagent group. However, the CWA parameters were significantly different amongst all reagent groups and thus reagent-specific 95% reference intervals could be calculated using the nonparametric method. Post-hoc analysis showed some degree of influence by age and gender with weak correlation to the CWA (r < 0.3). (4) Conclusions: Reagent type significantly affects APTT-based CWA with minimal inter-laboratory variations with the same coagulometer series that allow for data pooling across laboratories with more evidence required for age- and gender-partitioning.

Understanding the knowledge, awareness, and attitudes of the public towards liver diseases in Malaysia.

BACKGROUND: Viral hepatitis B and C (HBV, HCV) and non-alcoholic fatty liver disease (NAFLD) are the commonest etiologies of liver-related deaths in Malaysia. Herein, this study aims to explore and understand the knowledge and attitudes of the public toward liver-related health and diseases in Malaysia. METHODS: A cross-sectional, self-reported, web-based questionnaire was conducted among 500 adults between February and March 2020. Questionnaire items pertained to the knowledge and attitudes toward liver-related health and diseases. RESULTS: Half of the respondents were aged ≥35 years and 52.0% were males. Gaps in knowledge included the lack of awareness of different types of hepatitis, including the potential transmission risks and complications of HBV and HCV. About half acknowledged liver fibrosis and cirrhosis as key determinants of liver-related disease progression. A higher proportion rightly recognized the diagnostic test for HCV (40.8%) than HBV (30.0%) despite more being aware of HBV than HCV. Less than one-third were aware of the risk factors, screening tests, and complications of NAFLD. Despite the majority (92.8%) agreeing that regular screening was important for liver health, only 67.0% attended recent health screening and one-fifth were unlikely to seek medical consultation upon exposure to viral hepatitis risk factors. Reasons for this low urgency included the perception of being healthy, cost-related concerns, and societal discrimination. CONCLUSION: Robust education efforts are needed to raise awareness and empower the community with knowledge of liver-related diseases, particularly viral hepatitis and NAFLD in Malaysia.

Enhanced Thrombin Generation Is Associated with Worse Left Ventricular Scarring after ST-Segment Elevation Myocardial Infarction: A Cohort Study.

Acute myocardial infarction (AMI) is associated with heightened thrombin generation. There are limited data relating to thrombin generation and left ventricular (LV) scarring and LV dilatation in post-MI LV remodeling. We studied 113 patients with ST-segment elevation myocardial infarction (STEMI) who had undergone primary percutaneous coronary intervention (PPCI) (n = 76) or pharmaco-invasive management (thrombolysis followed by early PCI, n = 37). Endogenous thrombin potential (ETP) was measured at baseline, 1 month and 6 months. Cardiovascular magnetic resonance imaging was performed at baseline and 6 months post-MI. Outcomes studied were an increase in scar change, which was defined as an increase in left ventricular infarct size of any magnitude detected by late gadolinium enhancement, adverse LV remodeling, defined as dilatation (increase) of left ventricular end-diastolic volume (LVEDV) by more than 20% and an increase in left ventricular ejection fraction (LVEF). The mean age was 55.19 ± 8.25 years and 91.2% were men. The baseline ETP was similar in the PPCI and pharmaco-invasive groups (1400.3 nM.min vs. 1334.1 nM.min, p = 0.473). Each 10-unit increase in baseline ETP was associated with a larger scar size (adjusted OR 1.020, 95% CI 1.002-1.037, p = 0.027). Baseline ETP was not associated with adverse LV remodeling or an increase in LVEF. There was no difference in scar size or adverse LV remodeling among patients undergoing PPCI vs. pharmaco-invasive management or patients receiving ticagrelor vs. clopidogrel. Enhanced thrombin generation after STEMI is associated with a subsequent increase in myocardial scarring but not LV dilatation or an increase in LVEF at 6 months post-MI.

The immature platelet fraction, a predictive tool for early recovery from dengue-related thrombocytopenia: a prospective study.

BACKGROUND: There is a paucity of predictive factors for early recovery from thrombocytopenia related to dengue. The immature platelet fraction (IPF%) is reflective of megakaryopoiesis and may correlate with recovery from dengue-related thrombocytopenia. Our objective was to assess the predictive value of IPF% on days 2 and 3 of illness for recovery from dengue-related thrombocytopenia. METHODS: A prospective study was conducted among patients with dengue admitted to our institution (Nawaloka Hospital PLC) from December 2019 to October 2020. Dengue was diagnosed based on positive non-structural antigen 1 or IgM. IPF% data were extracted from the Sysmex-XN-1000 automated hematology analyzer. Clinical data were obtained from electronic medical records. Statistical analyses were performed using SPSS version 20. RESULTS: We included 240 patients. An IPF% on day 2 of illness of >7.15% had a sensitivity of 80.0% and specificity of 70.4% for prediction of platelet recovery (defined as platelet count ≥60×109/L) on day 7 of illness. An IPF% of >7.25% on day 3 of illness had a sensitivity of 88.9% and specificity of 47.1% for predicting platelet recovery >60×109/L on day 8 of illness. The IPF% was significantly lower in patients with severe dengue. Platelet recovery was observed within 48 h after the peak IPF% was reached, regardless of severity. CONCLUSION: We propose that IPF% values on days 2 and 3 of illness are a promising predictive tool for early recovery from dengue-related thrombocytopenia.

Efficacy and safety of next-generation tick transcriptome-derived direct thrombin inhibitors.

Despite their limitations, unfractionated heparin (UFH) and bivalirudin remain standard-of-care parenteral anticoagulants for percutaneous coronary intervention (PCI). We discovered novel direct thrombin inhibitors (DTIs) from tick salivary transcriptomes and optimised their pharmacologic activity. The most potent, ultravariegin, inhibits thrombin with a Ki of 4.0 pM, 445-fold better than bivalirudin. Unexpectedly, despite their greater antithrombotic effect, variegin/ultravariegin demonstrated less bleeding, achieving a 3-to-7-fold wider therapeutic index in rodent thrombosis and bleeding models. When used in combination with aspirin and ticagrelor in a porcine model, variegin/ultravariegin reduced stent thrombosis compared with antiplatelet therapy alone but achieved a 5-to-7-fold lower bleeding time than UFH/bivalirudin. Moreover, two antibodies screened from a naïve human antibody library effectively reversed the anticoagulant activity of ultravariegin, demonstrating proof-of-principle for antidote reversal. Variegin and ultravariegin are promising translational candidates for next-generation DTIs that may reduce peri-PCI bleeding in the presence of antiplatelet therapy.

Image Analysis Using Machine Learning for Automated Detection of Hemoglobin H Inclusions in Blood Smears - A Method for Morphologic Detection of Rare Cells.

BACKGROUND: Morphologic rare cell detection is a laborious, operator-dependent process which has the potential to be improved by the use of image analysis using artificial intelligence. Detection of rare hemoglobin H (HbH) inclusions in red cells in the peripheral blood is a common screening method for alpha-thalassemia. This study aims to develop a convolutional neural network-based algorithm for the detection of HbH inclusions. METHODS: Digital images of HbH-positive and HbH-negative blood smears were used to train and test the software. The software performance was tested on images obtained at various magnifications and on different scanning platforms. Another model was developed for total red cell counting and was used to confirm HbH cell frequency in alpha-thalassemia trait. The threshold minimum red cells to image for analysis was determined by Poisson modeling and validated on image sets. RESULTS: The sensitivity and specificity of the software for HbH+ cells on images obtained at ×100, ×60, and ×40 objectives were close to 91% and 99%, respectively. When an AI-aided diagnostic model was tested on a pilot of 40 whole slide images (WSIs), good inter-rater reliability and high sensitivity and specificity of slide-level classification were obtained. Using the lowest frequency of HbH+ cells (1 in 100,000) observed in our study, we estimated that a minimum of 2.4 × 106 red cells would need to be analyzed to reduce misclassification at the slide level. The minimum required smear size was validated on 78 image sets which confirmed its validity. CONCLUSIONS: WSI image analysis can be utilized effectively for morphologic rare cell detection. The software can be further developed on WISs and evaluated in future clinical validation studies comparing AI-aided diagnosis with the routine diagnostic method.

Admission ultrasonography as a predictive tool for thrombocytopenia and disease severity in dengue infection.

BACKGROUND: Ultrasound (US) is an investigation available in many acute care settings. Thrombocytopenia is a well-described complication of dengue infection and has been shown to correlate with disease severity. The purpose of this study was to assess the utility of admission ultrasonography in predicting thrombocytopenia and disease severity in patients infected with dengue virus. METHODS: Data were collected prospectively on 176 patients (male, n=86; female, n=90) admitted to the Nawaloka Hospital, Sri Lanka with dengue infection between December 2016 and August 2018. All patients had an US scan on admission and disease severity was determined using the World Health Organization 2009 classification. RESULTS: There were 106 (60.2%) cases of dengue with/without warning signs and 70 (39.8%) cases of severe dengue. Patients with an abnormal US on admission were more likely to have severe dengue. Gallbladder wall thickening was the most common US abnormality. Abnormal US findings significantly correlated with more pronounced thrombocytopenia from day 2 of admission. CONCLUSIONS: An abnormal US scan on admission can aid in identification of patients at risk of developing severe dengue and can be used as a novel clinical tool to identify patients at risk of severe thrombocytopenia.

The psychological impact of COVID-19 on 'hidden' frontline healthcare workers.

BACKGROUND: The novel coronavirus disease (COVID-19) pandemic has led to rising death tolls and stressed healthcare systems, resulting in an unprecedented psychological stress on healthcare workers worldwide. However, the majority of studies only accounted for frontline healthcare workers with direct patient exposure. AIM: This study aims to look at the psychological impact of COVID-19 in a specific, vulnerable and yet hidden group of healthcare workers, namely laboratory healthcare workers who are at high risk exposure to SARS-CoV-2 virus from handling infected patients' blood samples, in addition to a marked increase in workload. METHOD: A multicentre study was conducted in Singapore via online questionnaire looking at psychological and physical impact of COVID-19 on laboratory healthcare workers. The Generalized Anxiety Disorder 7-item (GAD-7) scale, Zung Self-Rating Depression Scale (SDS) and Numeric rating scale on fear (NRS) were validated scores used in this study. Data analysis was performed using SPSS statistical software version 23 (IBM Corp). RESULTS: A total of 122 staffs participated and more than half of the cohort experienced mild to severe fear, anxiety and depression. Increase in depression score was also found to be associated with increased physical exhaustion (OR = 6.1, 95% CI 1.4-29.1, p = .02), loss of appetite (OR = 2.7, 95% CI 1.2-6.0, p = .02), poor sleep quality (OR = 7.5, 95% CI 2.9-19.4, p = .005), and the use of sedative (OR = 3.9, 95% CI 1.1-13.5, p = .03). CONCLUSIONS: Hence, it is imperative that prompt action needs to be taken to address the psychological needs of this vulnerable group of healthcare workers as the pandemic continues.

Triple positivity for nonstructural antigen 1, immunoglobulin M and immunoglobulin G is predictive of severe thrombocytopaenia related to dengue infection.

BACKGROUND: The early identification of patients at risk of severe dengue infection (DI) is critical to guide clinical management. Non-structural antigen 1 (NS-1), immunoglobulin M (IgM) and immunoglobulin G (IgG) are used routinely for the diagnosis of DI. OBJECTIVES: We sought to evaluate whether positivity for NS-1, IgM and IgG individually or together is predictive of severe complications of DI. METHODS & MATERIALS: A prospective study was conducted among patients with DI admitted to our institution between 2014 and 2019. DI was diagnosed based on a positive NS1 or IgM. IgG was also tested on all the patients. Clinical data was obtained from electronic medical records at NH. Statistical analyses were performed using SPSS version 20. RESULTS: We collected data on 3504 patients. Patients who were positive for NS1, IgM and IgG (triple positive: TP) were more likely to develop severe DI (63.8 %) in comparison to those who were only NS1 positive (single positive: SP) (3.0 %) and patients with positive NS1 and IgM (double positive: DP) (7.5 %). [p = 0.001]. Regression analysis confirmed that TP status on admission was predictive of severe complications. (p < 0.01). Receiver operator characteristic curve (ROC) analysis showed (AUC: 84.8; sensitivity = 90.7 and specificity = 83.2) that TP status on admission is predictive of thrombocytopenia on day 5. The predictive power of TP status was superior to that of NS1 and IgG positivity. CONCLUSIONS: We propose that TP status on admission is a novel predictive factor for severe DI. Further studies are required to explore the biological basis for this finding.

Patients with acute and chronic coronary syndromes have elevated long-term thrombin generation.

Coronary artery disease is a leading cause of morbidity and mortality worldwide. Despite significant advances in revascularization strategies and antiplatelet therapy with aspirin and/or P2Y12 receptor antagonist, patients with acute coronary syndrome (ACS) continue to be at long-term risk of further cardiovascular events. Besides platelet activation, the role of thrombin generation (TG) in atherothrombotic complications is widely recognized. In this study, we hypothesized that there is an elevation of coagulation activation persists beyond 12 months in patients with ACS and chronic coronary syndrome (CCS) when compared with healthy controls. We measured TG profiles of patients within 72 h after percutaneous coronary intervention, at 6-month, 12-month and 24-month. Our results demonstrated that TG of patients with ACS (n = 114) and CCS (n = 40) were persistently elevated when compared to healthy individuals (n = 50) in peak thrombin (ACS 273.1 nM vs CCS 287.3 nM vs healthy 234.3 nM) and velocity index (ACS 110.2 nM/min vs CCS 111.0 nM/min vs healthy 72.9 nM/min) at 24-month of follow-up. Our results suggest a rationale for addition of anticoagulation to antiplatelet therapy in preventing long-term ischemic events after ACS. Further research could clarify whether the use of TG parameters to enable risk stratification of patients at heightened long-term procoagulant risk who may benefit most from dual pathway inhibition.

The atypical lymphocyte count: a novel predictive factor for severe thrombocytopenia related to dengue.

BACKGROUND: Early identification of patients at risk of severe dengue disease (DD) is critical to guide its management. We evaluated whether the atypical lymphocyte count (ALC), generated from the Sysmex automated full blood count analyzer, is predictive of severe thrombocytopenia secondary to Dengue infection. METHODS: We prospectively collected data on patients admitted with DD between December 2017 and October 2018. ALC data were extracted from the Sysmex XS500i analyzer from day 1 to day 7 of admission. Clinical data were obtained from patients' medical records. RESULTS: We enrolled 256 patients with DD. A negative correlation between ALC on admission and platelet count on day 5 to day 7 (Spearmen's correlation; day 5:-0.485, day 6:-0.428 and day 7:-0.344) (p=0.001) was observed. Based on receiver operator characteristic curve analysis, we found that an ALC of >0.5x103/L had 90% sensitivity and 70% specificity for severe thrombocytopenia (platelet count <50x109/L) on day 5. The positive and negative predictive values were 74.4 and 91.2%, respectively (power 84.7). CONCLUSIONS: We propose that ALC on admission may be a novel negative predictive factor for severe thrombocytopenia on day 5 to day 7 of DD. Further studies are required to validate our findings and evaluate whether ALC is predictive of other complications of DD.

Atypical lymphocyte count correlates with the severity of dengue infection.

INTRODUCTION: The early identification of patients at risk of severe dengue infection (DI) is critical to guide clinical management. There is currently no validated laboratory test which can predict severe complications of DI. The Atypical lymphocyte count (ALC) is a research parameter generated at no extra cost when an automated Full Blood Count (FBC) is performed. The purpose of this study was to assess the association of ALC with the severity of DI. METHODS: We prospectively collected data on patients admitted to Nawaloka Hospital Sri Lanka (NH) with DI between December 2016 and November 2017. DI was diagnosed based on a positive Non-structural antigen 1 (NS1) or dengue IgM antibody. ALC (absolute ALC and percentage) data were extracted from the Sysmex XS500i automated full blood count (FBC) analyzer (Sysmex Corporation Kobe, Japan). Clinical data was recorded from medical records and the computerized data base maintained by NH. RESULTS: 530 patients were enrolled. Patients with clinical manifestations of severe dengue have a significantly higher AL % compared to dengue without warning signs. Patients who presented with respiratory compromise had statistically significantly higher AL% compared to those without. (AL%; 8.65±12.09 vs 2.17±4.25 [p = 0.01]). Similarly, patients who developed hypotension had higher AL% compared to those who did not suffered from shock (AL%; 8.40±1.26 vs 2.18±4.25 [p = 0.001]). The AL% of dengue patients presenting with bleeding, at 4.07%, is also higher than those without bleeding complications, at 2.15%. There was a significant negative association between platelet count and AL% (p = 0.04). CONCLUSIONS: Clinical manifestations of severe dengue have a significantly higher AL % compared to dengue without warning signs. AL % at presentation may be predictive of severe DI and future larger prospective longitudinal studies should be done to determine if AL % on admission is predictive of the complications of DI.

Evaluation of Thalassaemia Screening Tests in the Antenatal and Non-Antenatal Populations in Singapore.

INTRODUCTION: Haemoglobinopathy testing is performed for carrier screening and evaluation of microcytic anaemia. We evaluated the effectiveness of thalassaemia screening tests at our institution and suggest ways of improving the testing algorithm. MATERIALS AND METHODS: A total of 10,084 non-antenatal and 11,364 antenatal samples with alkaline gel electrophoresis (AGE), capillary electrophoresis (CE), haemoglobin H (HbH) inclusion test, mean corpuscular haemoglobin (MCH) and mean corpuscular volume (MCV) were retrospectively reviewed. A subgroup of 187 samples with genetic testing was correlated with HbH inclusions and MCH/ MCV. The effect of iron deficiency on percentage hemoglobin A2 (HbA2) was studied. RESULTS: HbH inclusion test showed low sensitivity of 21.43% for α-thalassaemia mutations but higher sensitivity of 78.95% for --SEA deletion. By receiver operating characteristic (ROC) analysis, MCH ≤28 pg or MCV ≤80 fl for non-antenatal samples and MCH ≤27 pg or MCV ≤81 fl for antenatal samples had >98% sensitivity for HbH inclusions. Above these thresholds, the probability that HbH inclusions would be absent was <99% (negative predictive value [NPV] >99%). MCH ≥28 pg had 100% sensitivity (95% CI 95.63%-100%) for α-thalassaemia mutations and 97.68% calculated NPV in the antenatal population. Detection of haemoglobin variants by CE correlated highly with AGE (99.89% sensitivity, 100% specificity). Severe iron deficiency reduced HbA2 in hemoglobin (P <0.001) and α-thalassaemia (P = 0.0035), but not in ß-thalassaemia. CONCLUSION: MCH/MCV thresholds have adequate sensitivity for α-thalassaemia in the antenatal population, and genotyping plays an important role as HbH inclusion test shows low sensitivity. CE without AGE, may be used as initial screening for haemoglobin variants. Our study provides contemporary data to guide thalassaemia screening algorithms in Singapore.

A report of rare adverse tissue reaction to Ethilon® Nylon Suture.

This report describes a rare severe tissue reaction, as demonstrated in clinical photographs, to nylon sutures and illustrates how simple immediate removal of sutures isolates the irritant stimulus and results in rapid resolution, without the risk, cost and inconvenience of antibiotic treatment.

Evaluation of sorafenib in Chinese unresectable hepatocellular carcinoma patients with prior surgery and portal vein tumor thrombosis: A subset analysis of GIDEON study data.

The purpose of this study was to examine the safety and efficacy of sorafenib in Chinese patients with unresectable hepatocellular carcinoma. Data of 338 Chinese patients from the Global Investigation of therapeutic DEcisions in hepatocellular carcinoma and Of its treatment with sorafeNib study database were included. Patients were divided into those who received and did not receive sorafenib prior to surgical resection and those with and without portal vein tumor thrombosis. In the non-surgery group, the median survival was 302 days (95% confidence interval: 244-371), and the median time from diagnosis to death was 428 days (95% confidence interval: 352-556); in the surgery group, half of the patients survived for 345 days and the median time from diagnosis to death was 1000 days (95% confidence interval: 750-2816). Median progression-free survival and median time to progression were not different between the two groups. Median overall survival was 360 days (95% confidence interval: 309-435) in the non-portal vein tumor thrombosis group and 240 days (95% confidence interval: 181-296) in the portal vein tumor thrombosis group; median time between hepatocellular carcinoma diagnosis and death was 750 days (95% confidence interval: 472-1000) and 420 days (95% confidence interval: 252-567), respectively, in the two groups. Median progression-free survival was 209 days (95% confidence interval: 166-264) for patients without portal vein tumor thrombosis and 154 days (95% confidence interval: 112-202) for patients with portal vein tumor thrombosis; median time to progression was 295 days (95% confidence interval: 209-463) and 221 days, respectively. Adverse events were generally comparable regardless of prior surgery and portal vein tumor thrombosis status. We thus conclude that earlier administration of sorafenib may result in improved outcomes in patients with unresectable hepatocellular carcinoma and portal vein tumor thrombosis.

Patterns of sorafenib and TACE treatment of unresectable hepatocellular carcinoma in a Chinese population: subgroup analysis of the GIDEON study.

To analyze safety and efficacy of patterns of sorafenib and TACE therapy under real-life clinical practice conditions. A total of 338 Chinese patients with unresectable hepatocellular carcinoma (HCC) from the international database of the GIDEON non-interventional trial were included in this analysis. Endpoints were overall survival (OS), progression-free survival (PFS), time to progression (TTP) and safety. Two major patterns in the use of sorafenib observed in current Chinese clinical practice were: sorafenib administration subsequent to transarterial chemoembolization (TACE) treatment (n = 226, 66.9%) and sorafenib administration concomitant to TACE (n = 80, 35.4%). Patients receiving TACE prior to sorafenib had worse liver function (43.8% BCLC stage Cat diagnosis and 62.1% BCLC stage C at study entry) than those receiving TACE concomitant to sorefenib (35.0% BCLC stage C at diagnosis and 51.3% BCLC stage three at study entry). For patients undergoing prior TACE and concomitant TACE treatment, median OS time was 354 days vs. 608 days, PFS time was 168 days vs. 201 days, and TTP was 214 days vs. 205 days; and the percentage of patients who experienced drug-related adverse effects after sorafenib therapy in these two groups were 33.3 and 50.0%, respectively. Sorafenib treatment is usually administered in cases of tumor progression or poor liver function status after TACE treatment in China. Under such conditions, patients still gained a relatively satisfactory survival outcome. In addition, the present study suggests that concomitant sorafenib and TACE treatments may lead to a better prognosis, although differences in baseline characteristics may have contributed in part to the better outcomes.

A Practical Guide to Ordering and Interpreting Coagulation Tests for Patients on Direct Oral Anticoagulants in Singapore.

INTRODUCTION: Direct oral anticoagulants (DOACs) are establishing themselves as principle choices for the treatment of a variety of thrombotic disorders. DOACs are also known to affect common coagulation tests which are routinely performed for patients in clinical practice. An understanding of their varied effects is crucial for the appropriate ordering of coagulation tests and their interpretation. MATERIALS AND METHODS: Laboratories in public and private healthcare institutions and commercial sectors were surveyed on coagulation tests offered and their methods. A Medline and bibliography search, including a search on search engines, was performed for publications reporting the effects of dabigatran, apixaban and rivaroxaban on these coagulation tests. These papers were reviewed and summarised for consensus recommendations. RESULTS: Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are variably affected by the DOACs and dependent of the coagulation assays used. Clinicians must know which laboratory has performed these tests to logically interpret test results. A normal PT or aPTT does not exclude the presence of residual DOACs effect. The thrombin time is sensitive to dabigatran but not apixaban or rivaroxaban. Specialised coagulation tests such as thrombophilia tests are also variably affected by the DOACs. All laboratories in Singapore however, employ similar test methods permitting a common set of recommendations for specialised coagulation testing. CONCLUSION: Knowledge of the effects of DOACs on coagulation testing is essential to determine the appropriateness of performing such tests and interpreting them coherently. Practical recommendations which are tests and location-specific are set out in this paper.