Abstract Number: PB1788
Meeting: ISTH 2020 Congress
Background: Coagulation profile subsequent to pneumonia is hardly assessed by conventional coagulation tests or measurement of pro- and anticoagulant factors when taken in isolation. Conversely, thrombin generation assays (TGA) evaluating thrombin-generation and decay, is more suited to assess the balance between pro- and anticoagulants as it occurs in-vivo.
Aims: To assess the coagulation profile and detect hypercoagulability (if any) in patients with pneumonia at the onset and at recovery (one month later) of disease.
Methods: We investigated 20 consecutive patients admitted to hospital because of pneumonia and 20 healthy subjects (controls). Blood was collected into vacuum-tubes containing 1/10 volumes of 0.109M citrate at onset of the disease (T0) and at recovery (T1). TGA was assessed according to Hemker with a homemade method by addition to plasma of tissue-factor (1pM) and synthetic phospholipids (1µM). TGA was performed with and without thrombomodulin (TM). Results were expressed as endogenous thrombin potential (ETP) and as ratio of ETP with/without TM (ETP-TM ratio). Increased ETP or ETP-TM ratio were taken as indexes of hypercoagulability. Factor VIII (FVIII), protein C (PC) and their ratio (FVIII/PC) were also evaluated. Comparison of results for ETP or ETP-TM ratio (patients vs controls) were performed and p values < 0.05 were considered statistically significant.
Results: : ETP with TM and ETP-TM ratio in patients at T0 were significantly higher than controls (p< 0.001). ETP (regardless of TM) and ETP-TM ratio in patients at T1 were significantly lower than T0 (p< 0.01), but ETP-TM ratio was still higher than controls (p< 0.05). Changes of FVIII/PC ratio taken as an additional index of hypercoagulability paralleled those of ETP-TM ratio (table).
Conclusions: The hypercoagulability shown by ETP and ETP-TM ratio is likely due to the reduction of PC (anticoagulant driver) and increase of FVIII (procoagulant driver). The study contributes to define the mechanism of hypercoagulability associated with pneumonia.
|Controls||Patients at onset||Patients at recovery|
|ETP (nM*min)||1993 (1655-2617)||1950 (1359-2722)||1819 (1384-2380)§§|
|ETP-with-TM (nM*min)||1340 (827-1905)||1762 (973-2359)**||1304 (826-1928)§§|
|ETP-TM-ratio||0.65 (0.47-084)||0.87 (060-0.96)***||0.80 (0.44-0.88)**§|
|FVIII (%)||134 (87-227)||195 (103-364)***||143 (70-274)§|
|PC (%)||116 (80-137)||93 (44-136)**||114 (61-154)§§|
|FVIII/PC-ratio||1.16 (0.75-1.90)||2.02 (1.39-7.28)***||1.37 (0.62-2.31)§§§|
[table. Results [median (range)] * p-value, Mann-Withey test; § p-value, Wilcoxon test.]
To cite this abstract in AMA style:Scalambrino E, Clerici M, Rossi S, Chantarangkul V, Monzani V, Peyvadi F, Tripodi A. Coagulation Profile in Patients with Pneumonia Assessed by Thrombin Generation Procedures [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/coagulation-profile-in-patients-with-pneumonia-assessed-by-thrombin-generation-procedures/. Accessed December 6, 2023.
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