China
Africa
Explore chapters and articles related to this topic
Granulomatous Diseases
Published in Ayşe Serap Karadağ, Lawrence Charles Parish, Jordan V. Wang, Roxburgh's Common Skin Diseases, 2022
Albert Alhatem, Robert A. Schwartz, Muriel W. Lambert, W. Clark Lambert
Laboratory studies: Complete blood count (CBC) with a peripheral smear, prothrombin time (PT) with an international normalized ratio (INR), and activated partial thromboplastin time (aPTT) can help establish the diagnosis of any underlying conditions. The CBC identifies abnormalities in different hematologic cell components, including platelet number and presence of anemia or leukopenia, and provides evidence for intravascular hemolysis. The PT evaluates the extrinsic clotting pathway (factors VII, IX, II, X, V, and fibrinogen), and aPTT assesses the intrinsic pathway (factors HWMK, kallikrein, XII, XI, IX, VIII, II, X, V, and fibrinogen).
Congenital and acquired disorders of coagulation
Published in Jennifer Duguid, Lawrence Tim Goodnough, Michael J. Desmond, Transfusion Medicine in Practice, 2020
Jeanne M Lusher, Roshni Kulkarni
Laboratory findings consist of an abnormal PT or APTT, and decreased or undetectable levels of clotting factors. Lack of correction on mixing studies (performed on a 1: 1 mixture of patient’s plasma and normal plasma) indicates the presence of a neutralizing antibody. Other indicators of inhibitors are a shortened plasma half-life of infused clotting factor, indicating rapid clearance.
Anticoagulation
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
Louis M. Fink, Nicole A. Massoll, Alex A. Pappas
The diagnosis of thrombophlebitis and PE was made and the patient was started on heparin. An IV bolus injection of 5000 U of porcine heparin was administered, followed by an IV infusion of 700 U/hr. The aPTT at 2 hr was 30 sec (aPTT normal range is 22–37 sec). The IV dose of heparin was then raised to 1,000 U/hr, and at 4 hr the aPTT was 34 sec. The next morning (15 hr after admission) the patient’s aPTT was 37 sec. An AT-III was found to be 80 U/dL (normal range 90–127%). The heparin concentration measured using an Xa inhibition assay was found to be subtherapeutic. The heparin dose was then raised to 1500 U/hr and 2 hr later the aPTT was 49 and the heparin was 0.6 U/mL. The ratio of pre-heparin aPTT to post-heparin aPTT was 1.58. The patient was switched to warfarin and treated for 3 months. There was resolution of the PE and the patient had an uneventful recovery.
Testing strategies used in the diagnosis of rare inherited bleeding disorders
Published in Expert Review of Hematology, 2023
[17–20]Screening tests like the prothrombin time (PT) and activated partial thromboplastin time (APTT) are the most commonly ordered initial tests in evaluation of suspected bleeding disorders; the assays assess the different coagulation pathways (Figure 1). However, the PT and APTT have limitations in their sensitivity to mild coagulation factor deficiencies, which vary based on reagent/instrument combinations and may result in a missed diagnosis [21–26]. Laboratory professionals are generally aware of these limitations; however, the majority of clinicians are not aware of limitations of assay sensitivity. Examples of sensitivity of PT and APTT to commonly ordered coagulation factor assays are shown in Figure 2a–h. The most commonly performed coagulation factor assay is the one-stage factor assay [27], where the assay end point is the detection of a fibrin clot. Chromogenic assays, where the end point is the detection of the release of a chromogenic substrate, are more expensive, have limited availability, and are rarely performed except for the diagnosis of HA and HB [28] and to monitor selected extended half-life coagulation factor concentrates.
Outcomes of wasp and bee stings in Taiwan
Published in Clinical Toxicology, 2023
Thi Ngat Nguyen, Mei-Jy Jeng, Nai-Yu Chen, Chen-Chang Yang
The patients with wasp or bee stings might manifest local effects, organ injury following toxic reactions, and anaphylactic reactions. Local effects included swelling, redness, necrosis, blister and itching. Organ injuries caused by a bee or wasp venom could be acute kidney injury (AKI), rhabdomyolysis, aminotransferase elevation, and coagulation abnormality such as prolongation of activated partial thromboplastin time (aPTT) [12,15]. Acute kidney injury was classified into stage I, stage II, and stage III based on Acute Kidney Injury Network (AKIN) [16]. A diagnosis of rhabdomyolysis was based on a creatine kinase (CK) concentration greater than 1000 U/L [17]. Aminotransferase elevation was defined as an aspartate aminotransferase (AST) or alanine aminotransferase (ALT) concentration greater than three times the upper limit of normal (ULN) [18]. The aPTT levels were categorized as less than 90 seconds or greater than or equal to 90 seconds [19].
Application of anti-Xa assay in monitoring unfractionated heparin therapy in contemporary antithrombotic management
Published in Expert Review of Hematology, 2023
Michael Safani, Steve Appleby, Ryan Chiu, Emmanuel J Favaloro, Emanuel T. Ferro, Jimmy Johannes, Milan Sheth
The anti-Xa assay is a measure of UFH activity, not UFH concentration. UFH dose and anti-Xa activity share a linear relationship. This relationship provides the ease for achieving the anti-Xa goal of 0.3–0.7 IU/ml in less time and with fewer dose adjustments compared to the aPTT. While shorter time periods with fewer dose adjustments to reach the desired anti-Xa goal may be considered advantageous, these results also reflect a limitation of the anti-Xa assay, being predicated upon its ability to measure just one component in the amphitheater of hemostasis, the UFH anti-Xa activity. In contrast, the aPTT reflects the test that more comprehensively monitors the influence of other major players on hemostasis: the various clotting factors. Clearly, the anti-Xa assay is insensitive to many of the other variables that may profoundly influence the overall hemostasis process in vivo, and as such does not reflect global physiological hemostasis.