Prothrombin Concentration Research Articles

Characteristics of diabetes mellitus patients with nonviral chronic liver disease who developed hepatocellular carcinoma.

Type 2 diabetes mellitus (T2DM) is a well-known risk factor for hepatocellular carcinoma (HCC). However, HCC is often diagnosed at an advanced stage in patients with diabetes because of the lack of the best criteria for surveillance candidates. The aim of this study was to identify risk factors for HCC development in patients with diabetes with nonviral chronic liver disease. Three hundred thirty T2DM patients with nonviral chronic liver disease who underwent surveillance for HCC by imaging techniques between 2009 and 2020 were enrolled in this multicenter cross-sectional retrospective study. Theclinical and laboratory parameters of patients with and without HCC were compared. Age ≥65years, alcohol intake, lack of hepatic steatosis, triglyceride level <111mg/dL, Mac2 binding protein glycosylation isomer (M2BPGi) ≥0.9 cut-off index (COI), α-fetoprotein concentration ≥5ng/mL, and des-γ-carboxy prothrombin concentration ≥26mAU/mL were independently associated with HCC development. When stratified by age, only alcohol intake (odds ratio [OR] 114.19, p<0.001) was associated with HCC development in patients aged <65years, and medication for diabetes mellitus (OR 5.72, p=0.001), lack of hepatic steatosis (OR 4.47, p=0.002), lactate dehydrogenase ≥198IU/L (OR 2.751, p=0.031), M2BPGi ≥1.18 COI (OR 9.05, p<0.001), and FIB-4 index ≥2.59 (OR 3.22, p=0.017) were associated with HCC development in patients aged ≥65years. In addition to age and advanced liver fibrosis, alcohol intake in younger T2DM patients and medication for DM and lack of hepatic steatosis in older T2DM patients should be considered for HCC surveillance by imaging.

Correlation between Serum Betatrophin Level and Histological Grading of Nonalcoholic Fatty Liver Disease

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is recognized as the hepatic manifestation of metabolic syndrome frequently co-existing with obesity, dyslipidemia, and insulin resistance. It is characterized by hepatic steatosis in the absence of secondary causes such as significant alcohol consumption, chronic viral hepatitis, medications that induce steatosis, or other chronic liver diseases such as autoimmune hepatitis, hemochromatosis, or Wilson’s disease. NAFLD can be subcategorized into nonalcoholic fatty liver and nonalcoholic steatohepatitis (NASH). Aim of the Work to find out the role of Serum Betatrophin in predicting the presence of Nonalcoholic Fatty Liver Disease (NAFLD) and determining the correlation between Serum Betatrophin and Histological Grades of Nonalcoholic Fatty Liver Disease. Patients and Methods 90 Patient from Hepatology outpatient clinic in Ain Shams university hospital and Ahmed Maher Teaching Hospital was included in our study. The study population was assigned in two groups: Group A: Patient with biopsy proved NAFLD. Group B: Patient with healthy liver. Results In addition to Renal Function Test: Serum Creatinine &amp; Blood Urea, Lipid Profile (Serum Cholesterol, TAG, LDL, HDL),Thyroid Function Test (TSH, FreeT3, FreeT4), FBS, PPBS, HbA1c%, Iron Profile (Iron, Ferritin) ceruloplasmin level, and serum Betatrophin Level. Pelviabdominal ultrasouography. Liver Biopsy using 16-G Non reusable Needle for group A was done. All the liver biopsy samples was include at least 10 total portal tracts and it was as long as 20 mm, stained with Haematoxlin &amp; Eosin and Masson Trichome for histopathology. Conclusion NAFLD is a disease which occur more common in male and obese people. Patients with NAFLD may have low hemoglobin level low platelet count and reduced number of white blood cells. Liver function test such as liver enzyme, bilirubin level, Prothrombin concentration and Alpha Feto protein all are affected with NAFLD. Increase level of triglycerides is an independent risk factor in pathogenesis of NAFLD. Glycemic control and HBA1C level play a vital role in the occurrence of NAFLD also poor control of blood glucose lead to increase risk of NASH and progression to fibrosis.

Evaluation of the Role of Neutrophil to Lymphocyte Ratio, Platelet to Lymphocyte Ratio and Mean Platelet Volume as Predictors of the Outcome in Patients with Hemotoxic Snake Bite: A Prospective Study on Patients in Poison Control Centers Ain Shams University Hospitals and Assiut University Hospitals

Abstract Background Snakebite envenomation is considered a major health problem especially in developing centuries. Snakebite envenomation cause major morbidities, disabilities and mortalities. Novel biomarkers as; neutrophils to lymphocytes Ratio (NLR) and plateletto lymphocytes Ratio (PLR)are hematological inflammatory indices that can be a guide for diagnosis, prognosis of the snakebite envenomation. Methodology This was a prospective case control study, which was carried out on 60 hemotoxic snake bite envenomed patients that admitted at Poisoning Control Center AinShams University Hospitals (PCCAUH) and Assiut University Hospitals (AUH) in the period from 1st of July 2019 to 31st of October 2021. In addition, 60 healthy volunteers were used as control subjects. The study aimed to evaluate the role of NLR, PLR and Mean Platelet Volume (MPV) at admission as predictors of the outcome in patients with hemotoxic snakebite envenomation. The patients were divided into mild, moderate and severe groups according to severity of snake envenomation. Result Sixty hemotoxic snake bite envenomed patients (28 patients admitted at PCC-ASUH and 32 admitted at AUH), were divided into (38.4%) mild, (31.6%) moderate and (30%) severe groups according to the severity of snake envenomation. Maximum incidence was found in male (95%) from rural areas (80%) and were farmers (43.3%) from total cases. It was observed that bite was more frequent at lower limbs (70%), outdoors (81.6%), at night (51%) and during autumn season (43.3%). It was found that there was significant positive correlation between NLR at admission and duration of hospitalization, PLR, creatine phosphokinase (CPK) level and whitebloodcells (WBCs) count. While, significant negative correlation was found between NLR and prothrombin concentration (PC), red blood cells(RBCs) and plateletcounts. Also, significant positive correlation was found between PLR at admission and duration of hospitalization, NLR, CPK level and platelets count. Inaddition, significant positive correlation was found between MPV and PT. About 47 (78.33%) patients had complete recovery and about 13 (21.67%) patients recovered with complications including; local complications in (21.67%), systemic complications in (13.33%) and chronic complications In (5%). There were no recorded deaths in the study. It was found that hemotoxic snake bit eenvenomed patients Admitted at PCC-ASUH were significantly more severe,required more antivenom vials and more intensive care unit(ICU) admission than those admitted at AUH. Conclusion NLR and PLR values at admission were significantly high in hemotoxic snake bite envenomed patients and can be used as predictors for diagnosis and prognosis of hemotoxic snake envenomation.In addition, NLR and PLR had significant association with severity of envenomation, duration of hospitalization.

Correlation between blood international normalised ratio (INR) value and saliva prothrombin concentration in patients under warfarin therapy: An observational analytics study

Introduction: Oromaxillofacial surgery has a bleeding risk complication. Increasing bleeding risk can be caused by the use of blood clotting inhibitors, including warfarin. Warfarin is an anticoagulant that works by inhibiting coagulation factors in the cascade. International normalised ratio (INR) indicates warfarin monitoring and bleeding risk during surgical procedures. INR examination currently uses blood plasma. This research analyses the correlation between blood INR value and salivary prothrombin concentration. Methods: This research was an analytical observational with a correlational design on 19 samples examined using a human prothrombin reagent from Elabscience. The samples used were blood and saliva, and then ELISA tests were carried out on them. Data results were analysed with linear regression and correlation tests. Results: In this study, 19 samples were collected from 6 male and 13 female subjects. The average value of salivary prothrombin concentration in this study was 227.63 (ng/ml), and the blood INR value was 1.85. The normality test result showed that the data distribution was normal; therefore, the correlation and simple linear regression tests can be conducted. The correlation and regression tests showed a positive correlation between blood INR value and salivary prothrombin concentration with a correlation coefficient of r = 0.81 (p &lt; 0.001). Conclusion: There is a positive relationship between blood INR value and salivary prothrombin concentration in oromaxillofacial patients under warfarin therapy.

Study of the lipid status and indicators of hemostasis among young men of different ethnic groups to assess thrombogenic risk

The aim of the study was to investigate the lipid status and indicators of the system of hemostasis in healthy young men of different linguistic families of the North Caucasus region to assess the risk of development of thrombogenic states.. Material and methods. A survey of young men aged 18 to 21 years was carried out with the subsequent establishment of region of residence and nationality to form ethnic groups. Based on the information received during the survey, 62 people were selected: 32 young men of the Indo-European language family (Russians, Greeks, Armenians) and 30 young men of the North Caucasian language family (Chechens, Ingush, Avars, Dargins). The assessment of lipid status was carried out by the photocolorimetric method on a biochemical analyzer, and the analysis of indicators of the hemostasis system was carried out by the clotting method on an automatic coagulometer analyzer. Homocysteine levels were determined by chemiluminescent immunoassay on a microplate device. Genetic polymorphisms of the hemostatic system were identified using the real-time PCR. Results. Young men of the Indo-European language family have significantly more low density lipoprotein, triglyceride, homocysteine and antithrombine III content, than representatives of the North Caucasian language family (p &lt; 0.001), and less total number and average platelet volume, prothrombin index, prothrombin concentration according to Quick (p &lt; 0.001). There was also a significantly more frequent occurrence of mutations of the gene encoding fibrinase (p &lt; 0.05) in young men of the Indo-European language family. Conclusions. A comprehensive study among young men of different ethnicities illustrates ethnic differences in lipid status and homocysteine level. Analysis of the main indicators of coagulogram and genetic polymorphism of the hemostasis system allowed us to establish a higher risk of thrombogenic conditions and atherosclerosis in young men of the North Caucasian language family

The effect of prothrombin, the precursor of thrombin, on the proliferation and migration of colorectal cancer cells

Thrombotic disorders are some of the main comorbidities in cancer patients. So far, research has indicated that thrombin, a key regulator of hemostasis, contributes to cancer progression. However, data on its origin in tumor microenvironments remain elusive. Based on previous research, we analyzed the RNA and protein expression of prothrombin, a precursor of thrombin, in selected colorectal cancer (CRC) cell lines. Since the effect of prothrombin in cancer development has not been previously reported, we treated the cells for 24 h and 48 h with different prothrombin concentrations and assessed the effect on cell proliferation and migration. Our results show that the tested CRC cell lines expressed prothrombin and that prothrombin inhibited proliferation and migration. The presented results suggest that prothrombin may contribute to CRC etiopathology and could serve as a potential diagnostic biomarker and therapeutic target. The mechanisms underlying prothrombin expression in cancer cells, potential prothrombin activation, and the underlying processes driving the described effects warrant further investigation.

Management of traumatic cervical epidural hematoma in patients on Xa-inhibitors: a case report and review of the literature

BackgroundCervical epidural hematoma (CEH) is defined as a collection of blood in the suprameningeal space. Mechanisms of this rare pathology include spontaneous, postsurgical, and traumatic as the main subtypes. This unique case of traumatic CEH represents an even smaller subset of these cases. Management varies by symptom presentation, mechanism of injury, and other contraindications.Case presentationThis case presents a 32 year old African American female on an oral anticoagulant sustaining traumatic cervical hematoma after a motor vehicle collision. Patient complained of neck, abdominal, and back pain. Imaging revealed a cervical spinal hematoma at the level of C3–C6. This case discusses the management of CEH for the general population and in the setting of anticoagulation.ConclusionManagement of each case of CEH must be carefully considered and tailored based on their symptom presentation and progression of disease. As the use of anticoagulation including factor Xa inhibitors becomes more prevalent, there is greater need to understand the detailed pathophysiological aspect of the injuries. Targeted reversal agents such as Prothrombin Concentrate can be used for conservative treatment. Adjunct testing such as thromboelastogram can be used to help guide management.

Comparative Evaluation of the Clinical Severity of COVID-19 Produced by the Omicron Variant Versus the Wuhan Strain

Abstract Purpose: Starting from the observations of the in vitro studies that describe a lower pathogenicity of the Omicron variant, we proposed to comparatively analyze two groups of patients admitted to our clinic, one at the beginning of the COVID-19 pandemic, and the other one at the beginning of the Omicron wave of the pandemic, and to compare the severity of disease episodes. Patients and methods: 2 groups of patients with COVID-19, one group of 480 patients hospitalized in our clinic in March-August 2020 and one group of 320 patients admitted in January-June 2022, were selected. Demographic data, paraclinical profile at admission, comorbidities, the type and duration of treatment and the evolution of the patients in the two groups, were analyzed comparatively. Results: Our study showed statistically significant differences between group A compared to the group B, which support the aggressiveness of the Wuhan strain and the severity of its disease forms, such as: the predominance of pulmonary opacity on radiographies, a higher need for immunosuppressive therapies, a lower oxygen saturation, and a higher average values of inflammatory markers at admission, in the first group. Also, some factors with predictive potential for a severe clinical form, with predominance in group 2 (older age, a higher score of cumulative comorbidities, a higher value of D-dimers and aspartateaminotransferase, a lower value of concentration of prothrombin, and the higher average CURB-65 score, at admission) were observed. Conclusion: Our study identified predictive parameters of severity (D-dimers, aspartate-aminotransferase, prothrombin concentration, CURB-65 Score), statistically significant modified in the Omicron wave group compared to the Wuhan wave group, which draw attention to the possibility of severe and unfavorable evolution of the infection with Omicron in elderly population with multiple comorbidities.

Hypoxia inducible factor-1α (HIF-1α) as an early predictor of acute hydrogen cyanamide (Dormex) poisoning

Hydrogen cyanamide (Dormex) is a plant growth regulator that is classified as a highly toxic poison. There are no definite investigations to help in its diagnosis and follow-up. This study aimed to investigate the role of hypoxia-inducible factor-1α (HIF-1α) in the diagnosis, prediction, and follow-up of Dormex-intoxicated patients. Sixty subjects were equally divided into two groups: group A, the control group, and group B, the Dormex group. Clinical and laboratory evaluations, including arterial blood gases (ABG), prothrombin concentration (PC), the international normalized ratio (INR), a complete blood count (CBC), and HIF-1α, were done on admission. CBC and HIF-1α were repeated for group B 24 and 48 h after admission to track abnormalities. Group B also had brain computed tomography (CT). Patients with abnormal CT scans were referred for brain magnetic resonance imaging (MRI). Significant differences in levels of HB, WBCs, and platelets were also detected in group B up to 48 h after admission, as white blood cells (WBCs) rose with time and hemoglobin (HB) and platelets diminished. The results described a highly significant difference in HIF-1α between the groups, and it depended on the clinical condition; therefore, it can be used in the prediction and follow-up of patients up to 24 h after admission.

Evaluation of the outcome of a proposed more physiological bypass surgery technique in morbid obesity: Long term 3 years follows up.

Obesity is a chronic condition that affects millions globally; consequently, bariatric surgery is the key to this serious issue. Bariatric procedures are rapidly expanding in number and methods to address the recognized problems. So, it would make a sense for surgeons and patients if there is a more physiological bypass surgery technique in Morbid obesity. This study aims to evaluate the outcome proposed technique. The present study is a retrospective analysis on 256 participants subjected to the proposed bypass procedure from December 1999 to January 2017, the participants were followed up for an interval of 3years. The findings of the present study revealed a significant Excess Weight Loss (EWL). In addition, patients experienced decreased calcium, iron, vitamin B12, Hemoglobin, zinc, and Prothrombin Concentration. However, three to six months after surgery, they experienced a significant improvement until they reached normal levels without any supplement by the end of 12,18 months, with a three-year follow-up. This proposed Bypass Operation aims to adequate digestions as well as selective absorption without inducing any vital deficit. Most of study's population showed no elements inadequacies, although few percentages emerged during the interval of maximal weight reduction, and it were transient and minimal. No minerals or vitamins were needed.

Coagulation parameters abnormalities and their relation to clinical outcomes in hospitalized and severe COVID-19 patients: prospective study

There has been growing attention toward the predictive value of the coagulation parameters abnormalities in COVID-19. The aim of the study was to investigate the role of coagulation parameters namely Prothrombin concentration (PC), activated Partial thromboplastin Time (aPTT), D-Dimer (DD), Anti Thrombin III (ATIII) and fibrinogen (Fg) together with hematological, and biochemical parameters in predicting the severity of COVID-19 patients and estimating their relation to clinical outcomes in hospitalized and severe COVID-19 Patients. In a prospective study, a total of 267 newly diagnosed COVID-19 patients were enrolled. They were divided into two groups; hospitalized group which included 144 patients and non-hospitalized group that included 123 patients. According to severity, the patients were divided into severe group which included 71 patients and non-severe group that included 196 patients who were admitted to ward or not hospitalized. Clinical evaluation, measurement of coagulation parameters, biochemical indices, outcome and survival data were recorded. Hospitalized and severe patients were older and commonly presented with dyspnea (P ≤ 0.001). Differences in coagulation parameters were highly significant in hospitalized and severe groups in almost all parameters, same for inflammatory markers. D-dimer, AT-III and LDH showed excellent independently prediction of severity risk. With a cut-off of > 2.0 ng/L, the sensitivity and specificity of D dimer in predicting severity were 76% and 93%, respectively. Patients with coagulation abnormalities showed worse survival than those without (p = 0.002). Early assessment and dynamic monitoring of coagulation parameters may be a benchmark in the prediction of COVID-19 severity and death.

Increased levels of circulating platelet microparticles as a risk of hypercoagulable state in β-thalassemia intermedia patients

Introduction Thromboembolism is a frequent complication in thalassemia. Platelet microparticles (PMPs) may have a role in the hypercoagulability in thalassemia. Objective To determine the levels of PMPs in β-thalassemia intermedia (β-TI) patients and whether increased levels of PMPs in these patients are correlated with coagulation parameters or not. Patients and methods Sixty-three β-TI patients, classified into 46 nonsplenectomized (NS) patients, 17 splenectomized (S) patients, and 20 age-matched and sex-matched volunteers as controls. For all, full medical history, through clinical examination, and laboratory investigations: complete blood count, prothrombin time, prothrombin concentration, activated partial thromboplastin time, FVIII, FXI, fibrinogen, D-dimer, and PMPs were detected by using flow-cytometry approach. Results PMPs were significantly higher in S and NS β-TI patients than controls (P&lt;0.001, P=0.002), respectively. FVIII and D-dimer were significantly higher in S patients than controls (P=0.004, 0.048), respectively. Fibrinogen level was significantly lower in both NS and S β-TI patients than in controls (P&lt;0.001). A significant positive correlation between PMPs and platelet count in S patients (r=0.549, P=0.023). Conclusion Thrombotic risk in β-TI patients is related to increased circulating PMPs and platelet count. Splenectomy was considered a risk factor of thrombosis in our study.

Acute Syphilitic Hepatitis in the Early Secondary Phase: A Case Report and Literature Review

Background: The incidence of syphilis is clearly increasing. It is a source of visceral damage, particularly in the secondary phase. Acute syphilitic hepatitis is a rare clinical entity classically described but under-diagnosed because of its non-specific presentation. Case Presentation: We report the case of a 25-year-old French woman, without comorbidity, sexually active, having unprotected sex with only one partner. She was admitted to our unit for jaundice and a disturbed liver function test preceded 3 weeks earlier by a rash. The patient did not consume alcohol and did not report the introduction of a new medication. A skin rash compatible with syphilitic roseola and generalized adenopathy were found. The liver workup showed alanine aminotransferase (ALT) at 1984 U/L, aspartate aminotransferase (AST) at 1377 U/L, total bilirubin at 221 μmol/L, alkaline phosphatase activity (APL) at 419 U/L, gamma glutamyl transferase activity (GGT) at 229 U/L and a prothrombin concentration at 73%. The search for the most common etiologies of acute hepatitis was negative. Syphilitic serology was positive with a Treponema Pallidum Hemagglutinations Assay (TPHA) titration of 5120 IU and Veneral Disease Research Laboratory (VDRL) of 64 IU. Abdominal ultrasound revealed only homogeneous hepatomegaly and splenomegaly with no focal lesions. Other sexually transmitted infections (STI) were negative and her partner had positive syphilis serology. After a single dose of Benzathine benzylpenicillin, the clinical signs regressed after one week and the hepatic balance tended to normalize 20 days later. Conclusion: This highlights the need for a high index of suspicion for syphilitic hepatitis in sexually active patients presenting with acute hepatitis associated with a cutaneous rash.

Порівняльна характеристика лікувальних методів усунення гемоконцентрації у хворих із судинними захворюваннями головного мозку

Актуальність. Розведення крові (гемодилюцію) давно застосовують у практичній медицині у вигляді водного навантаження (посилене пиття) і парентерального введення водно-електролітних і плазмозамінних розчинів. Гемодилюція покращує реологічні властивості крові таким чином, що приплив кисню та поживних речовин до мозку покращується, і нейрони, яким загрожувала смерть, можуть вижити. Гемодилюція може бути досягнута кровопусканням (видалення крові), введенням розчинів у вигляді інфузій чи шляхом комбінації обох методів. Розчини, які використовуються при гемодилюції, можуть бути сольовими та колоїдними. Колоїдні розчини, які складаються з більшості нерозчинних молекул і призначення яких — збереження інтраваскулярної рідини, є більш ефективним засобом гемодилюції. В багатьох країнах гемодилюція використовується в клінічному лікуванні пацієнтів із 70-х років ХХ століття. Матеріали та методи. Проведено ретроспективний аналіз найбільш ефективного методу усунення гемоконцентрації у хворих на цереброваскулярні захворювання та іншу патологію, що лікувалися в ангіоневрологічному відділенні клініки нейрохірургії та неврології Військово-медичного клінічного центру Західного регіону з січня по червень 2018 року. Результати. Обстежено 212 хворих віком від 20 до 80 років. Середній вік пацієнтів становив 50 років. Чоловіків було 164 (73 %), жінок — 48 (23 %). Гемоконцентрація спостерігалася у 32 (15 %) пацієнтів. Порушення реологічних властивостей крові мало місце у 28 (17 %) чоловіків і 7 (14 %) жінок. При ішемічному інсульті (ІІ) порушення реологічних властивостей крові спостерігалось у 10 (24 %) пацієнтів, із наслідками перенесеного ІІ у 12 (24 %) пацієнтів, при дисциркуляторній енцефалопатії (ДЕ) у 8 (8 %) пацієнтів, аномалії Кімерлі — в 1 (20 %) пацієнта, вегетосудинній дистонії (ВСД) на фоні гострого періоду закритої черепно-мозкової травми (ЗЧМТ), струсу головного мозку — 1 (3 %) пацієнта. Питний режим був ефективний у 3 пацієнтів при ДЕ, ВСД на фоні гострого періоду ЗЧМТ, струсу головного мозку та аномалії Кімерлі. Позитивний ефект гіперволемічної гемодилюції (ГГ) спостерігався у 17 пацієнтів, ізоволемічної гемодилюції (ІГ) у 12 пацієнтів при гострому перебігу ІІ, наслідках перенесеного ІІ та ДЕ. При посиленому питному режимі, ГГ та ІГ рівень показників гемоглобіну та гематокриту нормалізовувався; показники протромбіну в середньому знижувалися на 10 одиниць. Рівень фібриногену, електролітного обміну, тромбоцитів при посиленому питному режимі суттєво не змінювався. Концентрація тромбоцитів при ГГ та ІГ незначно підвищувалася. Побічних реакцій не спостерігалося. Висновки. Порушення реологічних властивостей крові з тенденцією до гемоконцентрації найбільш характерне для пацієнтів віком 40–50 років чоловічої статі при ІІ та наслідках перенесеного ІІ. Найменш ефективний метод розрідження крові — питний режим, більш ефективний — ГГ. Питний режим недостатньо ефективний при ІІ та перенесених його наслідках. При даній патології показана ГГ чи ІГ. При неефективності ГГ доцільно застосовувати ІГ, для досягнення ефективності достатньо одного сеансу. Дані методи лікування є безпечними.

Human Prothrombin Variants with Modifications in the Active Site S4 Subpocket Demonstrate Resistance to Dabigatran

Chymotrypsin-like serine proteases are hallmarked by a protease domain comprising the catalytic triad residues His57, Asp102, and Ser195 (chymotrypsinogen numbering) situated in the active site cleft. While the catalytic triad in conjunction with the oxyanion hole residues regulate substrate cleavage, the active site subpockets (S1-4) control substrate recognition and binding. The high structural homology of the serine protease domains allows for analogous strategies in drug design, which is underscored by the direct oral anticoagulants (DOACs) for the prophylactic management of stroke in atrial fibrillation and prevention and treatment of venous thrombosis. DOACs inhibit coagulation serine proteases by reversibly engaging the active site with high affinity. To expand the repertoire of DOAC-specific reversal agents we have previously successfully modified the S4 active site subpocket of human factor Xa to prevent DOAC binding while preserving catalytic activity [Verhoef 2017 Nature Commun.]. To explore whether an analogous strategy can be applied to create DOAC resistance in the serine protease thrombin, specific substitutions or sequences in or around the dabigatran-binding S4 subsite derived from naturally occurring serine proteases or plasma proteins were introduced in prothrombin.A panel of prothrombin variants was generated and transfected into HEK293 cells to allow for stable protein expression. In some of the generated prothrombin variants comprising insertions in amino acid sequence 91-99 that is directly adjacent to the S4 subsite protein expression was severely impaired. This indicates that exchange of any surface-exposed serine protease or plasma protein region into the prothrombin protease domain is not necessarily compatible with protein expression. In contrast, exchange of the human prothrombin 91-99 sequence for that of human kallikrein 3 or targeted amino acid replacement of S4 subsite residue Ile174 resulted in prothrombin protein expression levels similar to wild-type prothrombin.Following expression, prothrombin variants were purified to homogeneity using the CaptureSelect tm affinity matrix that selects for fully gamma-carboxylated prothrombin. The specific prothrombin clotting activity analyses of the purified prothrombin variants KL3 (0.7 ± 0.2 U/mg), I174A (0.8 ± 0.2 U/mg), and I174F (0.8 ± 0.3 U/mg) demonstrated an overall ~10-fold reduced specific activity relative to wild-type prothrombin (7.5 ± 0.1 U/mg). As such, modification of the S4 subsite likely interferes with the binding and subsequent conversion of fibrinogen by thrombin. To determine whether the prothrombin variants supported tissue factor-initiated thrombin formation in human plasma, prothrombin-deficient plasma was supplemented with increasing plasma concentrations of prothrombin variant (90-180 ug/mL). Consistent with their reduced specific clotting activity, 180 ug/mL prothrombin variant was required to obtain substantial thrombin generation but with reduced thrombin generation parameters (peak thrombin, ETP) relative to supplementation with plasma concentrations of wild-type prothrombin (90 ug/mL). This calibrated automated thrombin generation assay set-up was used to assess the DOAC-resistance of the prothrombin variants. While thrombin formation reached half-maximum inhibition at 532 ± 58 nM dabigatran in wild-type prothrombin-supplemented plasma, addition of the prothrombin variants displayed a ~2-fold reduced sensitivity to dabigatran inhibition (IC50: 1186 ± 136 nM prothrombin-KL3; 851 ± 97 nM prothrombin-I174F; 772 ± 80 nM prothrombin-I174A). This demonstrates that the S4 subsite-modified prothrombin variants are able to support thrombin generation in the presence of physiological plasma concentrations of inhibitor.Collectively, our findings indicate that human prothrombin variants comprising a single point mutation at position Ile174 in the S4 subsite or at a region directly adjacent to the S4 subsite are able to generate thrombin in plasma inhibited by dabigatran. Hence, serine proteases with S4 subpocket modifications have the potential to bypass DOAC therapy and could provide a generic strategy in the development of novel DOAC-bypassing agents. [Display omitted] DisclosuresReitsma: VarmX. B.V.: Current Employment, Current holder of individual stocks in a privately-held company, Current holder of stock options in a privately-held company, Patents & Royalties. Verhoef: VarmX. B.V.: Current Employment, Current holder of individual stocks in a privately-held company. Bos: VarmX B.V.: Research Funding; uniQure Biopharma B.V.: Research Funding.

Potential value of the calibrated automated thrombogram in patients after a cerebral venous sinus thrombosis; an exploratory study

BackgroundCerebral venous sinus thrombosis (CVST) is a relatively rare, but potentially lethal condition. In approximately 15% of the patients, the cause of CVST remains unclear. Conventional clotting tests such as prothrombin time and activated partial thromboplastin time are not sensitive enough to detect prothrombotic conditions nor mild haemostatic abnormalities. The calibrated automated thrombogram (CAT) is a physiological function test that might be able to detect minor aberrations in haemostasis. Therefore, we aimed to detect the presence of a prothrombotic state in patients who endured idiopathic CVST with the CAT assay.MethodsFive adult patients with an idiopathic, radiologically proven CVST that had been admitted during the past 3 years were included in this study. The control group consisted of five age/gender matched healthy volunteers. Exclusion criteria were known haematological disorders, malignancy (current/past) or hormonal and anticoagulant therapy recipients. We obtained venous blood samples from all participants following cessation of anticoagulation. Using the CAT assay, we determined lag time, normalized endogenous thrombin potential (ETP), ETP reduction and normalized peak height. In addition, prothrombin concentrations were determined.ResultsWe found no significant differences in lag time (4.7 min [4.5–4.9] vs 5.3 min [3.7–5.7], p = 0.691), normalized ETP (142% [124–148] vs 124% [88–138], p = 0.222), ETP reduction (29% [26–35] vs 28% [24–58], p > 0.999), and normalized peak height (155% [153–175] vs 137 [94–154], p = 0.056) between patients and their age/gender matched controls. In addition, prothrombin concentrations did not significantly differ between patients and controls (120% [105–132] vs 127% [87–139], p > 0.999).ConclusionReasons for absent overt hypercoagulability within this study population may be the small patient sample, long time since the event (e.g. 3 years) and avoidance of acquired risk factors like oral contraception. Given the fact that CVST is a serious condition with a more than negligible risk of venous thrombosis event recurrence, exclusion of clinically relevant hypercoagulability remains a challenging topic to further study at the acute and later time points, particularly in patients with idiopathic CVST.

Measuring serum prothrombin in patients treated with warfarin or direct oral anticoagulants

BackgroundWarfarin therapy influences generation of γ-carboxyglutamyl (Gla) residues in prothrombin, causing reduced coagulation activity. It will leave such inactive prothrombin in serum after clot formation, resulting in serum prothrombin constituting total inactive prothrombin in these patients. MethodsAn ELISA was developed to measure biologically inactive prothrombin in serum, and applied to serum from warfarin therapy causing a decrease in Gla residues or direct oral anticoagulant (DOAC) therapy as its contrast. ResultsThe concentrations of serum prothrombin in both the warfarin and DOAC groups were higher than those in the healthy group (p < 0.01 and p < 0.001, respectively). When serum in the previous three groups was treated with barium carbonate to exclude prothrombin, which lost several Gla residues, the prothrombin concentration in the DOAC group decreased to the same level as that in the healthy group, indicating that prothrombin was obtained at a high level only in the warfarin group (p < 0.01). ConclusionsWarfarin and DOAC led to increase in serum prothrombin concentration. The reason is that DOAC decreases prothrombin recruitment during fibrin clot formation, while warfarin leads to the accumulation of inactive prothrombin, which have a decreased number of Gla residues.

Пребывают ли младенцы, которых кормят исключительно грудным молоком, в состоянии дефицита витамина К? (К 20-летию истории вопроса)

Актуальность. «Are breast-fed infants vitamin K deficient?» — этот вопрос F.R. Greer сформулировал в 2001 году в исследовании, ставшем классическим. Цель: определение концентрации субстанции Рrotein induced by vitamin K absence ІІ (PIVKA-II) и протромбинового комплекса как маркеров скрытого дефицита витамина К у детей первых 6 месяцев жизни, получающих исключительно естественное вскармливание. Материалы и методы. Всего исследованы 264 ребенка в возрасте от рождения до 6 месяцев, которые находились в удовлетворительном состоянии и не имели изменений в общих анализах крови и результатах тестов гепатобилиарной системы. Результаты. В раннем неонатальном периоде 62 (83,8 %) ребенка из 74, не получавших витамин К, имели показатели PIVKA-II больше нормы, составляющей 40 усл.ед/мл. У 17 (77,3 %) из 22 детей в возрасте от 8 до 28 суток жизни, не получавших витамин К после рождения, уровень PIVKA-II был в пределах нормы. Из 31 младенца, которые получили профилактический болюс витамина К1, на первой неделе жизни 92 % имеют показатели PIVKA-II в пределах нормы. У 12 (54,5 %) из 22 детей в возрасте от 28 до 180 дней, обследованных после лечения антибиотиками, показатели PIVKA-II были выше нормы. Применение антибиотиков у детей было ассоциировано с повышенным концентрациями РIVKA-II, что может свидетельствовать о скрытом приобретенном дефиците витамина К, или о его возобновлении после рождения. Исследование протромбинового комплекса у этих же детей установило по медианам и квартальным оценкам (Me 25–75) снижение содержания протромбина по Квику до 62 % (18–91 %), удлинение протромбинового времени до 18 с (13–22 с) и увеличение международного нормализованного отношения до 1,4 (1,1–2,6). Выводы. Таким образом, у детей указанной группы возникло состояние гипокоагуляции, при совпадении других неблагоприятных обстоятельств вполне достаточное для развития поздней геморрагической болезни.

Clinical outcome of hepatic resection for malignant liver tumors in elderly patients

Background: Aging hinders the liver capacity to restitute its volume and function after partial hepatectomy. Concomitant hepatic parenchyma disorders and major resections may increase the susceptibility of elderly patients to worse postoperative outcome.Methods: Prospectively collected medical records of adult patients who underwent elective partial hepatectomy for malignant liver tumors at Sohag University Hospital (June 2014–May 2020) were analyzed. A group of elderly (≥65 years) were compared with a matched control group of non-elderly (&lt;65 years) patients as regards posthepatectomy liver failure (PHLF) and overall complications, including mortality. Markers associated with PHLF and postoperative death were investigated.Results: Forty-eight patients were enrolled, 24 per group. 34 were males (71%). All patients had primary hepatic malignancy or metastatic tumors. Hepatocellular carcinoma (HCC) was the most common indication for liver resection in both groups (32 patients, 66.6%). Elderly patients exhibited significantly higher grades of overall postoperative complications (p&lt;0.05). PHLF was significantly increased in the elderly group, in evident connection with significant persistence of higher bilirubin levels and reduced prothrombin concentration (p&lt;0.05) until 5th postoperative day. Subgroup analysis showed that major resections and cirrhosis correlated with increased morbidity among elderly compared with younger patients. Postoperative mortality occurred in 3 elderly cirrhotic patients, who failed to recover normal platelet count postoperatively.Conclusions: In elderly patients, major liver resection for malignant tumors is associated with worse outcome, particularly in those with coexisting cirrhosis. Predictors include early postoperative thrombocytopenia and persistent hyperbilirubinemia and coagulopathy.

Effect of acute and chronic liver diseases on the thyroid function in children

BackgroundThyroid hormones modulate hepatic function through regulation of basal metabolic rate in addition; the liver metabolizes the thyroid hormones and regulates their endocrine effects.ObjectivesTo assess thyroid functions in children with acute and chronic liver diseases.Methods85 studied children were divided into 4 groups; group 1 (20 children) with acute hepatitis (AH), group 2 (20 children) chronic liver disease1 (CLD1; relatively preserved liver functions including Child-Pugh stage A), group 3 (20 children) chronic liver disease2 (CLD2; includes Child-Pugh stage B or C), group 4 (25 children) controls. All groups were subjected to detailed history, physical examination, Complete blood count, liver, renal function tests, viral markers, and thyroid functions (FT3, FT4, TSH).ResultsFree T3 levels were lower in children with AH, CLD1 and CLD2. There was significant increase in TSH serum levels in CLD2.In acute hepatitis a negative correlation between serum free T4 and AST (r = -0.991), positive correlation between serum TSH and AST, VLDL, and cholesterol levels (r= 0.503, 0.533 and 0.498). A positive correlation between free T3 levels and prothrombin concentration (r= 0.991). Negative correlations between free T3 levels and PT, serum bilirubin and LDL serum levels in children with CLD2 (r= -0.992) (r= -0.902) and (r= -0.946)ConclusionAcute and chronic liver diseases affect thyroid function in children and is correlated with the disease severity.