No abstract available.
Partial Thromboplastin Time*

Introduction: To date, there are no reference intervals for prothrombin time (PT) and activated partial thromboplastin time (APTT) based on “normal” Filipino adults. The common practice in most laboratories is to adopt manufacturer provided values or foreign literature even if the importance of establishing or at least verifying laboratory reference intervals has been stressed by Clinical Laboratory Standards Institute (CLSI). Objectives: Here we aim to describe our experience in using a simple non-parametric method to generate reference intervals for PT and APTT, from healthy Filipino volunteer blood donors. Methodology: We used a de novo, a priori non-parametric estimation method following the CLSI guidelines on establishing reference intervals. Results: The non-parametric lower reference limit for PT is 12.55 seconds, with 90% confidence interval of 12.3 to 12.75 seconds. While the non-parametric upper reference limit for PT is 16.15 seconds, with 90% confidence interval of 15.55 to 16.55 seconds. The non-parametric lower reference limit for activated partial thromboplastin time is 26.12 seconds, with 90% confidence interval of 22.95 to 27.1 seconds, and the non-parametric upper reference limit for activated partial thromboplastin time is 37.44 seconds, with 90% confidence interval of 36.75 to 38.65 seconds. The PT and APTT reference intervals were different from foreign sources and manufacturer provided values in terms of interval width and values of the reference limits by 2 to 4 seconds. Conclusion and Recommendations Estimation of coagulation reference intervals from volunteer health blood donors is doable, simple, and practical. Collaborative multi-center efforts may be done to expand the pool of reference individuals that are included and increase the representativeness of the reference intervals generated. This simple method can also be used to generate reference intervals for other clinical laboratory assays and may also be extended to at least verify reference intervals in special populations like pregnant women, the elderly, and the pediatric population.
Prothrombin Time ; Partial Thromboplastin Time

Objective: This study aimed to determine the demographic profiles of admitted COVID-19 patients, the association of coagulation and platelet tests on COVID-19 severity and compare the coagulation and platelet profile across the spectrum of the disease in terms of severity among adult COVID-19 patients admitted to the Philippine General Hospital from March 2020 to December 2022. : Methodology. Medical records of a sample of adult COVID-19 patients admitted to the emergency room of the Philippine General Hospital from March 2020 to December 2022 were reviewed. The demographics, initial COVID-19 diagnosis and initial coagulation and platelet test results were gathered and tabulated. Comparison of the initial coagulation and initial platelet results were made per disease category. Results: Three hundred eighty-five (385) patients were included; 194 were males, and 191 were females. The mean age of all patients was 56.18 years old. There was a total of 30 patients classified as mild and 105 patients are under moderate category. 141 patients were classified as severe, whereas 109 patients were classified as critical. Platelet count test and Activated Partial Thromboplastin Time (APTT) were mostly normal in all disease categories. Prothrombin time was normal in a majority of patients from the mild and severe categories. INR and D-dimer were all elevated mostly in all disease categories. Conclusion Platelet counts and APTT were mostly normal in all disease categories. Prothrombin time and D-dimer had a significant association with disease severity. Platelet count, APTT and INR did not show significant association with disease severity. Prothrombin time, APTT, INR and D-dimer means had significant differences versus disease categories.
Partial Thromboplastin Time ; OVID-19 ; Patient Acuity

BACKGROUND: Newly developed ACL9000 automatic coagulation analyzer was evaluated in measurement of prothrombin time(PT), activated partial thromboplastin time(aPTT) and fibrinogen. METHODS: We studied precision including withtin-run and between-day precision. Normal reference ranges for PT, aPTT and fibrinogen were obtained in 60 healthy normal controls. The heparin sensitivity for aPTT and heparin interference for PT and fibrinogen were also determined. Lastly ACL9000 was compared with another coagulation analyzer, MLA Electra 1600. RESULTS: Precision of PT, aPTT and fibrinogen were acceptable, mostly. The normal reference ranges were as followings: 10.7-12.4 sec for PT, 28.7-40.8 sec for aPTT and 165-468 mg/dL for fibrinogen. The ranges of aPTT were from 49.8 sec to 84.7 sec in therapeutic heparin concentration(0.2-0.4 IU/mL) and heparin interfered determination of PT and fibrinogen in high concentrations. The comparability between ACL9000 and MLA Electra 1600 was good in determinations of PT and fibrinogen but not in determination of aPTT. CONCLUSIONS: We concluded that the performance of ACL9000 was acceptable and ACL9000 would be a useful analyzer for routine coagulation tests.
Fibrinogen* ; Heparin ; Partial Thromboplastin Time ; Prothrombin ; Prothrombin Time ; Reference Values ; Thromboplastin

PURPOSE: Although coagulation activation has been reported in chronic urticaria, data pertaining to detailed changes in coagulation factors and global coagulation status are lacking. The current study evaluated global coagulation status in patients with chronic urticaria using thrombin generation assay (TGA) and the levels of individual coagulation factors. METHODS: Patients with chronic urticaria (n=57) and 20 healthy controls were enrolled. TGA was performed under stimulation with 2 concentrations of tissue factor (TF). Coagulation factors and conventional coagulation assays were also analyzed. RESULTS: Although patients with chronic urticaria showed prolonged activated partial thromboplastin time, prothrombin time did not differ significantly between patients and controls. In both 1 pM and 5 pM TF-stimulated TGA, peak thrombin and endogenous thrombin potential (ETP) levels were markedly decreased in patients with chronic urticaria. As expected, intrinsic coagulation factors (VIII, IX, and XII), as well as coagulation factors of the common pathway (II, V, and X), were consistently decreased. Additionally, D-dimer was significantly increased in patients as compared to controls. In multivariate regression analysis, the presence of chronic urticaria was the only significant independent contributor to the low ETP value. CONCLUSIONS: Chronic urticaria is characterized by in vivo coagulation activation through the intrinsic coagulation pathway, which can be measured with sensitivity using TGA.
Blood Coagulation Factors ; Humans ; Partial Thromboplastin Time ; Prothrombin Time ; Thrombin ; Thromboplastin ; Urticaria*

BACKGROUND: Despite the lack of supporting evidence, intravenous heparin is still given frequently in the treatment of cerebral ischemia. However, there is only one study for the use of heparin nomogram in ischemic stroke or TIA. We evaluated the usefulness of a patient-specific, as well as weight-based, nomogram for the intravenous heparin in patients with ischemic stroke or TIA. METHODS: From Sep. 2004 to Sep. 2005, we recruited ischemic stroke patients treated according to the specifically designed heparin nomogram. The therapeutic range (TR) of activated partial thromboplastin time (aPTT) and dose adjustment were specified as a ratio of each patient's baseline aPTT. The first time to achieve TR (TR-time), to exceed therapeutic threshold (TE-time) and the fraction of time in TR (total time in TR/total time of heparin use, %) were analyzed. RESULTS: A total of 45 patients were included. The mean fraction of time in TR was 72.7+/-14.4%. Although TR-time and TE-time did not differ according to the use of bolus injection, the fraction of first aPTT at 6 hours after start of infusion in TR was higher with bolus than without bolus (84.8 vs. 58.3, p<0.05). CONCLUSIONS: Our nomogram could achieve and maintain therapeutic heparin anticoagulation effectively. Initial bolus injection may be better to achieve therapeutic anticoagulation more rapidly.
Brain Ischemia ; Heparin* ; Humans ; Nomograms* ; Partial Thromboplastin Time ; Stroke*

BACKGROUND: Unfractionated heparin (UFH) has unstable pharmacokinetics and requires close monitoring. The activated partial thromboplastin time (aPTT) test has been used to monitor UFH therapy for decades in Korea, but its results can be affected by numerous variables. We established an aPTT heparin therapeutic range (HTR) corresponding to therapeutic anti-Xa levels for continuous intravenous UFH administration, and used appropriate monitoring to determine if an adequate dose of UFH was applied. METHODS: A total of 134 ex vivo samples were obtained from 71 patients with a variety of thromboembolisms. All patients received intravenous UFH therapy and were enrolled from June to September 2015 at Gyeongsang National University Hospital. All laboratory protocols were in accordance with the Clinical and Laboratory Standards Institute guidelines and the College of American Pathologist requirements for aPTT HTR. RESULTS: An aPTT range of 87.1 sec to 128.7 sec corresponded to anti-Xa levels of 0.3 IU/mL to 0.7 IU/mL for HTR under our laboratory conditions. Based on their anti-Xa levels, blood specimen distribution were as follows: less than 0.3 IU/mL, 65.7%; 0.3–0.7 IU/mL (therapeutic range), 33.6%; and more than 0.7 IU/mL, 0.7%. No evidence of recurring thromboembolism was observed. CONCLUSION: Using the conventional aPTT target range may lead to inappropriate dosing of UFH. Transitioning from the aPTT test to the anti-Xa assay is required to avoid the laborious validation of the aPTT HTR test, even though the anti-Xa assay is more expensive.
Heparin* ; Humans ; Korea ; Partial Thromboplastin Time ; Pharmacokinetics ; Thromboembolism

BACKGROUND: The commonly recommended therapeutic range is an activated partial thromboplastin time(APTT) of 1.5 to 2.5 times the control value, which may be inappropriate for some reagents. The aim of this study is to evaluate the correlation of APTT and anti-Xa activity and to compare two methods of determining the therapeutic range of APTT during unfractionated heparin treatment. METHODS: We measured anti-Xa activity and APTT in 80 plasmas from patients treated with unfractionated heparin. We performed correlation analysis between anti-Xa activity and APTT or APTT ratio(heparinized APTT/baseline APTT). The therapeutic range determined by anti-Xa activity of 0.35-0.7 U/mL was compared with the therapeutic range based on minimizing potential thrombosis and bleeding error. RESULTS: The anti-Xa activity-vs-APTT correlation was slightly, but not significantly, improved by converting APTT(r=0.835) to APTT ratio(r=0.883). The APTT therapeutic range predicted by anti-Xa activity-vs-APTT regression analysis was 68.7 to 139.5 seconds(66.6-127.9 seconds for logarithmatically transformed APTT), whereas the range predicted by minimization-of-error technique was 68 to 97 seconds. CONCLUSIONS: The established therapeutic APTT range based on linear regression analysis was not considered to be optimal. The therapeutic range based on minimizing the potential clinical errors may further improve error rate, but prospective study with a larger number of patient samples would be required to apply in clinical field.
Hemorrhage ; Heparin* ; Humans ; Indicators and Reagents ; Linear Models ; Partial Thromboplastin Time* ; Plasma ; Thromboplastin ; Thrombosis

Effects of root, stem and leaf extract of sancho (Zanthoxylum schinifolium) on the inhibition of lipid peroxidation in the hepatic microsome of rat, DPPH radical scavenging activity and activated partial thromboplastin times (APTT) were examined in vitro. The highest inhibition of hepatic microsomal lipid peroxidation was observed by ethyl acetate fraction than that of methylene chloride fraction of the root and stem extracts. The high inhibition of lipid peroxidation was determined in the leaf, the root and the stem in order. The DPPH radical scavenging activity of ethyl acetate fraction was higher than that of n-butanol fraction and it was similar to the root and the steam extract. It was similar to the inhibition of hepatic microsomal lipid peroxidation. The DPPH radical scavenging activity was the highest in 2.500 mg/mL of ethyl acetate fraction and it was 4.4 fold higher than that of h-tocopherol, as an antioxidant standard. The DPPH radical scavenging activity was dependent on the extract concentration in the range of 0.125 - 5.000 mg/mL. The thromboplastin times were higher than that of n-butanol fraction and it was similar to the root and the steam extracts. The leaf extract showed the highest antithrombogenic effect followed by the stem and then the root extract. The activated partial thromboplastin times were dependent on the extract concentration in the range of 0.100 - 2.000 mg/mL. Consequently, the effects of antioxidative, DPPH radical scavenging activity and antithrombogenic of Z. schinifolium was observed due to the inhibition of lipid peroxidation and the DPPH radical scavenging activity by methylene chloride, n-butanol and ethyl acetate fraction of the leaf extract.
1-Butanol ; Animals ; Lipid Peroxidation ; Methylene Chloride ; Microsomes ; Partial Thromboplastin Time ; Rats ; Steam ; Thromboplastin ; Zanthoxylum*

Factor Vll deficiency has an estimated incidence of 1/500,000 in the general population and autosomal recessive pattern of inheritance. Factor Vll deficiency is characterized by prolonged prothrombin time (PT), and normal activated partial thromboplastin time (aPTT) and bleeding time (BT). Definite diagnosis of this condition requires a specific Factor Vll assay. The clinical features are variable and do not always correlate with the Factor Vll level. We experienced a case of Factor Vll deficiency presenting as hemarthroses in a 2-years-old girl, whose chief complaint was pain, swelling of right knee joint and limping gait. The laboratory findings were prolonged PT and prominent deficiency of factor Vll. So, we report a case of Factor Vll deficiency with a brief review of the related literature.
Bleeding Time ; Diagnosis ; Female ; Gait ; Hemarthrosis* ; Humans ; Incidence ; Knee Joint ; Partial Thromboplastin Time ; Prothrombin Time ; Wills