Abstract
Primary hemostasis begins with endothelial injury. VWF, produced by endothelial cells, binds to platelets and links them to subendothelial collagen. Platelet-derived ADP and thromboxane ...activate non-adhered platelets via their GPIIb/IIIa receptors, allowing these platelets to participate in platelet aggregation. Secondary hemostasis is initiated with the binding of factor VII to extravascular tissue factor (TF). Factors II, VII, IX and X are vitamin K-dependent factors. The role of vitamin K is to assist in the addition of gamma carboxylate groups to glutamic acids in the “GLA” domains of these factors.
In vitro the intrinsic pathway is initiated when fresh whole blood is placed in a glass tube. The negative charge of the glass initiates the “contact pathway” where FXII is activated and then FXIa cleaves FIX to FIXa. The extrinsic pathway is triggered when tissue factor, phospholipid and calcium are added to plasma anticoagulated with citrate. In vitro, FVII is activated to FVIIa, and TF-FVIIa preferentially converts FX to FXa activating the common pathway.
The prothrombin time is commonly used to monitor warfarin anticoagulant therapy. To correct for differences in reagent and instrument, the international normalized ratio was developed to improve standardization of PT reporting globally. The activated partial thromboplastin time (aPTT) is used to evaluate the intrinsic and common pathways of coagulation. The aPTT is useful clinically as a screening test for inherited and acquired factor deficiencies as well as to monitor unfractionated heparin therapy although the anti-Xa assay is now the preferred measure of the effects of unfractionated heparin. The Clauss assay is the most commonly performed fibrinogen assay and uses diluted plasma where clotting is initiated with a high concentration of reagent thrombin.
The mixing study assists in the assessment of an abnormally prolonged PT or aPTT. An equal volume of citrated patient plasma is mixed with normal pooled plasma and the PT or aPTT are repeated on the 1:1 mix. Factor activity assays are most commonly performed as a one-stage assay. The patient’s citrated plasma is diluted and mixed 1-to-1 with a single factor-deficient substrate plasma. A PT or aPTT is performed on the above mix, depending on the factor being tested.
Factor inhibitors are antibodies that are most commonly diagnosed in male patients with severe hemophilia A (FVIII deficiency) where they are induced by factor replacement therapy.
Factor inhibitors can also appear in the form of spontaneous autoantibodies in both male and female individuals who were previously well. This is an autoimmune condition called “acquired hemophilia.”
Most coagulation laboratories can measure the plasma concentration of VWF protein (VWF antigen) by an immunoturbidimetric technique. Testing the functional activity of VWF, utilizes the drug ristocetin.
The state of multimerization of VWF is important and is assessed by electrophoresis on agarose gels. Type 2a and 2b VWD are associated with the lack of intermediate- and high molecular weight multimers.
The antiphospholipid syndrome (APLS) is an acquired autoimmune phenomenon associated with an increased incidence of both venous and arterial thromboses, as well as fetal loss. Typically, there is a paradoxical prolongation of the aPTT in the absence of any clinical features of bleeding. This is the so-called “lupus anticoagulant (LA) effect.” The laboratory definition of the APLS requires the presence of either a “lupus anticoagulant” or a persistent titer of antiphospholipid antibodies.
There are now 2 broad classes of direct-acting oral anticoagulants (DOACs): 1 The oral direct thrombin inhibitors (DTIs) such as dabigatran; and 2 The oral direct factor Xa inhibitors such as rivaroxaban and apixaban. The PT and aPTT are variably affected by the DOACs and are generally unhelpful in monitoring their concentrations. Most importantly, a normal PT or aPTT does NOT exclude the presence of any of the DOACs.
ADAMTS13 is a metallopeptidase primarily synthesized in the liver. Its main function is to cleave von Willebrand factor (VWF) on the endothelial surface, and thus regulate platelet adhesion at the ...sites of vascular injury; VWF acts as a scaffold at the site of injury for platelet activation, platelet binding, and clot formation. Platelet activation also results in the release of platelet-dense granule components (such as cytokines, pro- and anti-inflammatory factors and other bioactive molecules) that are essential regulators of coagulation, but are also associated with inflammation.
Reduced activity of ADAMTS13 is found in human patients with acquired thrombotic thrombocytopenic purpura (TPP), sepsis, and DIC. Both human TTP and equine colic are histologically characterized by the presence of microthrombi. Cleavage of VWF is dependent upon allosteric activation of ADAMTS13, which is broadly conserved in many animals, including horses. Human TTP and equine idiopathic colic share several interesting clinical similarities. Both have seasonal variations, typically in summer, can be associated with viral and bacterial infections, may be hereditary, have autoimmune associations, and recur. Both TTP and equine colic are clinically characterized by fever, abdominal pain renal failure, and neurologic symptoms. Microangiopathy is the predominant pathology in both TTP and equine colic.
Using tissues obtained from thirteen horses euthanized for non-thrombotic conditions, immunohistochemical stains indicate the presence of ADAMTS13 in equine liver and colon. Furthermore, in one horse with colic, immunohistochemical staining of the resected colon indicates the presence of ADAMTS13 in the aboral margin (Figure 1) and the absence ADAMTS13 staining in the diseased tissue.
These findings suggest that equine colic may be an animal model of thrombotic microangiopathy, very similar to TTP. Future studies will investigate immunohistochemical detection of ADAMTS13 in human tissues.
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No relevant conflicts of interest to declare.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
BACKGROUND
The Pragmatic, Randomized Optimal Platelets and Plasma Ratios (PROPPR) trial was a randomized clinical trial comparing survival after transfusion of two different blood component ratios ...for emergency resuscitation of traumatic massive hemorrhage. Transfusion services supporting the study were expected to provide thawed plasma, platelets, and red blood cells within 10 minutes of request.
STUDY DESIGN AND METHODS
At the 12 Level 1 trauma centers participating in PROPPR, blood components transfused and delivery times were tabulated, with a focus on universal donor (UD) plasma management. The adequacy of site plans was assessed by comparing the bedside blood availability times to study goals and the new American College of Surgeons guidelines.
RESULTS
Eleven of 12 sites were able to consistently deliver 6 units of thawed UD plasma to their trauma‐receiving unit within 10 minutes and 12 units in 20 minutes. Three sites used blood group A plasma instead of AB for massive transfusion without complications. Approximately 4700 units of plasma were given to the 680 patients enrolled in the trial. No site experienced shortages of AB plasma that limited enrollment. Two of 12 sites reported wastage of thawed AB plasma approaching 25% of AB plasma prepared.
CONCLUSION
Delivering UD plasma to massively hemorrhaging patients was accomplished consistently and rapidly and without excessive wastage in high‐volume trauma centers. The American College of Surgeons Trauma Quality Improvement Program guidelines for massive transfusion protocol UD plasma availability are practicable in large academic trauma centers. Use of group A plasma in trauma resuscitation needs further study.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The congestive heart failure syndrome includes a systemic illness with wasting of soft tissues and bone. We hypothesized secondary hyperparathyroidism (HPT) would be found in hospitalized patients ...with decompensated congestive heart failure (CHF), where secondary aldosteronism is expected, and who were either untreated or treated medically.
In 9 consecutive patients (7 males, 2 females; 8 African-American, 1 Caucasian; 33-60 yrs) admitted to the Regional Medical Center during a 28-day period with chronic left ventricular systolic dysfunction (EF<35%) and decompensated CHF (5 untreated; 4 treated with an angiotensin converting enzyme inhibitor, furosemide, and small-dose spironolactone), we measured: plasma parathyroid hormone (PTH); serum calcium corrected for albumin, magnesium, and phosphorus; serum creatinine and calculated creatinine clearance.
Plasma PTH was elevated above the normal range (6-65 pg/mL) in both untreated and treated patients with CHF (204+/-60 and 134+/-14 pg/mL, respectively). Serum corrected calcium was normal (8.4-10.2 mg/dL) in both untreated and treated CHF (9.7+/-0.l and 9.1+/-0.2 mg/dL, respectively) as were serum magnesium and phosphorus. Calculated creatinine clearance did not differ between untreated and treated patients (74+/-15 and 83+/-21 mL/min, respectively).
Secondary HPT was found in 5 untreated and 4 treated patients consecutively hospitalized over a 28-day period with decompensated CHF. Corrected serum calcium was normal. Plasmaionized calcium, a determinant of PTH secretion, was not measured. Although vitamin D levels were not assessed, the presence of hypovitaminosis D in these housebound patients with symptomatic CHF cannot be discounted. HPT may contribute to the systemic illness that accompanies CHF, including bone wasting.
Coronavirus disease 2019, first reported in China in late 2019, has quickly spread across the world. The outbreak was declared a pandemic by the World Health Organization on March 11, 2020. Here, we ...describe our initial efforts at the University of Florida Health for processing of large numbers of tests, streamlining data collection, and reporting data for optimizing testing capabilities and superior clinical management. Specifically, we discuss clinical and pathology informatics workflows and informatics instruments which we designed to meet the unique challenges of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing. We hope these results benefit institutions preparing to implement SARS-CoV-2 testing.
BACKGROUND:Thrombelastography (TEG) fibrinolysis shutdown after trauma is associated with increased mortality due to hypercoagulability-associated organ failure. However, a lack of mechanistic data ...has precluded the development of novel interventions to treat shutdown.
OBJECTIVES:To define the pathophysiology of TEG shutdown in severely injured, bleeding patients through secondary analysis of the PROPPR trial.
METHODS:Fibrinolysis was characterized in PROPPR subjects using admission TEG lysis at 30 min (LY30) or plasmin-antiplasmin (PAP) levels. LY30 categories were low (<0.9%), moderate (0.9–2.9%), or high (≥ 3%). PAP was classified as low (<1,500 μg/L), moderate (1,500–20,000 μg/L), or high (>20,000 μg/L). Demographics, outcomes, admission TEG values, platelet count and function, standard coagulation tests, and coagulation proteins were compared.
RESULTS:Five hundred forty-seven patients had TEG data and 549 patients had PAP data available. Low LY30 was associated with reduced platelet count and aggregation, poorer TEG clot formation, prolonged clotting times, and reduced fibrinogen and alpha2 antiplasmin. Compared to moderate PAP, low PAP subjects had similar platelet parameters, TEG values, fibrinogen, and alpha2 antiplasmin, but reduced tPA, and elevated PAI-1. D-Dimer values increased as PAP increased, however patients with low LY30 had elevated D-Dimer compared with moderate LY30 patients. Most low LY30 deaths were due to TBI (45%) and hemorrhage (42%) versus one of each cause (TBI, hemorrhage, MOF) in low PAP patients.
CONCLUSIONS:Low TEG LY30 does not reflect shutdown of enzymatic fibrinolysis with hypercoagulability, but rather a coagulopathic state of moderate fibrinolysis with fibrinogen consumption and platelet dysfunction that is associated with poor outcomes.
There are opportunities for development of modularized, inexpensive protein biomarker sensors in clinical applications. In this review we focus on two of these, namely early diagnosis of acute ...myocardial infarction (AMI) and detection of cerebral spinal fluid (CSF). Evaluation of patients with acute chest pain is challenging due to the heterogeneity of the underlying conditions, leading to patients with AMI being mistakenly sent home from emergency rooms or those at low risk for an adverse cardiac event being unnecessarily admitted without precise cardiac biomarker testing. Cardiac troponin I (cTnI) in cardiac muscle tissue is a standard clinical biomarker for AMI, as its concentration rises quickly in the blood during release from myocardial cells following cell death. The time-dependence of the cTnI concentration is the basis of antigen-antibody methodologies such as radioimmunoassay and enzyme-linked immunosorbent assay (ELISA). These methods are time consuming, leading to delays in diagnosis and higher costs. The challenge is to develop a real-time, accurate, low-cost point-of-care heart attack sensor. The coefficient of variation must be precise, within the parameters established by the American College of Cardiology. Similarly, leakage of cerebrospinal fluid (CSF) is a critical condition with a high risk of meningitis and potential mortality. The primary methods of detection for the biomarker β2-Transfferin (B2T) are immunofixation electrophoresis (IFE) and ELISA. Consistent IFE results down to 2 μg/mL can be obtained in patient samples, but requires a minimum 2.5-hour testing period, which is not expedient for real time feedback during surgery in or around the central nervous system. Additionally, to achieve good sensitivity and handle the inherently low concentration of B2T in CSF, lab procedures require samples to be concentrated or run in duplicate to ensure accurate detection. Real time turnaround is on the order of days. To alleviate the slow turn-around times, there is strong interest in electronic detection methods for proteins using biologically functionalized transistors, which provide an electronic readout and are readily integrated with wireless data transmission.
The transfusion of older packed RBCs may be harmful in critically ill patients. We seek to determine the association between packed RBC age and mortality among trauma patients requiring massive ...packed RBC transfusion.
We analyzed data from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios trial. Subjects in the parent trial included critically injured adult patients admitted to 1 of 12 North American Level I trauma centers who received at least 1 unit of packed RBCs and were predicted to require massive blood transfusion. The primary exposure was volume of packed RBC units transfused during the first 24 hours of hospitalization, stratified by packed RBC age category: 0 to 7 days, 8 to 14 days, 15 to 21 days, and greater than or equal to 22 days. The primary outcome was 24-hour mortality. We evaluated the association between transfused volume of each packed RBC age category and 24-hour survival, using random-effects logistic regression, adjusting for total packed RBC volume, patient age, sex, race, mechanism of injury, Injury Severity Score, Revised Trauma Score, clinical site, and trial treatment group.
The 678 patients included in the analysis received a total of 8,830 packed RBC units. One hundred patients (14.8%) died within the first 24 hours. On multivariable analysis, the number of packed RBCs greater than or equal to 22 days old was independently associated with increased 24-hour mortality (adjusted odds ratio OR 1.05 per packed RBC unit; 95% confidence interval CI 1.01 to 1.08): OR 0.97 for 0 to 7 days old (95% CI 0.88 to 1.08), OR 1.04 for 8 to 14 days old (95% CI 0.99 to 1.09), and OR 1.02 for 15 to 21 days old (95% CI 0.98 to 1.06). Results of sensitivity analyses were similar only among patients who received greater than or equal to 10 packed RBC units.
Increasing quantities of older packed RBCs are associated with increased likelihood of 24-hour mortality in trauma patients receiving massive packed RBC transfusion (≥10 units), but not in those who receive fewer than 10 units.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Endotheliopathy of trauma is characterized by breakdown of the endothelial glycocalyx. Elevated biomarkers of endotheliopathy, such as serum syndecan-1 (Synd-1) ≥ 40 ng/mL, have been associated with ...increased need for transfusions, complications, and mortality. We hypothesized that severely injured trauma patients who exhibit elevated Synd-1 levels shortly after admission have an increased likelihood of developing sepsis.
We analyzed a subset of patients from the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial who survived at least 72 hours after hospital admission, and we determined elevated Synd-1 levels (≥ 40 ng/mL) 4 hours after hospital arrival. Sepsis was defined a priori as meeting systemic inflammatory response criteria and having a known or suspected infection. Univariate analysis was performed to identify variables associated with elevated Synd-1 levels and sepsis. Significant variables at a value of p < 0.2 in the univariate analysis were chosen by purposeful selection and analyzed in a mixed effects multivariate logistic regression model to account for the 12 different study sites.
We included 512 patients. Of these, 402 (79%) had elevated Synd-1 levels, and 180 (35%) developed sepsis. Median Synd-1 levels at 4 hours after admission were 70 ng/dL (interquartile range IQR 36 to 157 ng/dL) in patients who did not develop sepsis, and 165 ng/dL IQR 67 to 336 ng/dL in those who did (p < 0.001). Adjusting for treatment arm and site, multivariable analyses revealed that elevated Synd-1 status, Injury Severity Score (ISS), and total blood transfused were significantly associated with an increased likelihood of developing sepsis.
Elevated Synd-1 levels 4 hours after admission in severely injured adult trauma patients who survived the initial 72 hours after hospital admission are associated with subsequent sepsis.
Wrong Tissue in Block Weaver, Kaitlin D; De Los Santos, Yanel; Gaffar, Maira ...
American journal of clinical pathology,
09/2021, Volume:
156, Issue:
4
Journal Article
Peer reviewed
Open access
Abstract
Objectives
Maintaining specimen identity during surgical pathology tissue processing is critical. Epic Beaker Laboratory Information System requires sequential scanning of specimen label and ...grossed blocks (block confirmation) to ensure specimen identity. We report our institution’s experience with wrong tissue in block (WTIB) grossing errors before and after adopting block confirmation.
Methods
During the first 18 months of Beaker implementation, block confirmation was not required. We then mandated block confirmation for a 3-month period. To ensure compliance, we then built a “hard stop” feature that prevents scanning any unconfirmed blocks onto a packing list. We reviewed WTIB incidents pre- and postimplementation of these solutions.
Results
Before using block confirmation, we had WTIB incidents involving 17 (0.043%) of 38,848 cases. When we mandated block confirmation use, we had WTIB involving 2 (0.043%) of 4,646 cases. After implementing the hard stop feature, we had WTIB incidents involving 2 (0.005%) of 42,411 cases. Overall, there was an 88.4% (0.043% vs 0.005%; P < .001) reduction in WTIB incidents using block confirmation with a hard stop.
Conclusions
Beaker is a customizable platform that can be tailored to a laboratory’s workflow. By using barcoding, implementing custom-built features, and improving workflow protocols, we significantly reduced WTIB errors.
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