The aim of this study was to determine the thrombogenicity of lupus anticoagulant (LA) antibodies using a modified thrombin generation assay (TGA) with the addition of activated protein C (APC) in a group of 85 patients with LA-positive samples. Of these, 58 patients had clinical manifestations of antiphospholipid syndrome (APS) according to the Sydney criteria classification, i.e., each patient had thrombosis or foetal loss, and 27 patients did not show any clinical manifestations of APS. A comparison of the two groups' TGA results revealed statistically significant differences (Fisher's test p = 0.0016). The group of patients exhibiting clinical manifestations of APS showed higher thrombogenicity in 56.9% of patients, while the group of patients not yet exhibiting clinical manifestations of APS showed higher thrombogenicity in 25.9% of patients. There were no significant differences in the specificity of the TGA test between the groups of patients exhibiting similar clinical manifestations. Receiver operating characteristic curve analysis showed a more significant relationship (p = 0.0060) for TGA than for LA titre (p = 0.3387). These data suggest that the determination of LA thrombogenicity with the TGA assay leads to an increased prediction of the manifestation of a thromboembolic event. Our findings appear to be particularly relevant for the prediction of thrombotic events in patients with laboratory-expressed APS and no clinical manifestations.
- Publikační typ
- časopisecké články MeSH
Cíl: Zhodnocení laboratorní účinnosti námi nejčastěji používaných protidestičkových léčiv: kyseliny acetylsalicylové (ASA), clopidogrelu a ticagreloru. Posouzení efektivity ticagreloru jako alternativní léčby u pacientů, kterým jsme zjistili in vitro rezistenci, neboli HTPR (high on-treatment platelet reactivity) na clopidogrel. Metodika: V našem souboru byla testována účinnost protidestičkových léčiv metodou light transmission aggregometry (LTA) od 16. září 2020 do 5. prosince 2022. Byla sledována účinnost léčby u pacientů převedených na alternativní léčivo a byla hodnocena úspěšnost změny terapie. Výsledky: Ve sledovaném období bylo otestováno celkem 529 krevních vzorků, v případě clopidogrelu (n = 216), ticagreloru (n = 59) a ASA (n = 254). Účinnost léčby clopidogrelem byla 45,4 %, resp. ticagrelorem 93,2 % (p < 0,000). V případě převedení z clopidogrelu na ticagrelor byla léčba úspěšná u 49 z 54 pacientů (90,7 %). Závěr: U testovaných protidestičkových léčiv byly prokázané statisticky významné rozdíly v dosažené účinnosti. V případě clopidogrelu je ticagrelor vhodnou alternativou statisticky významně redukující výskyt HTPR. Zařazením testování účinnosti protidestičkové léčby do algoritmu endovaskulárních výkonů lze významně snížit počet pacientů s HTPR podstupujících implantaci stentů/flow-diverterů.
Purpouse: Evaluation of the laboratory effectiveness of the antiplatelet drugs we use: clopidogrel, ticagrelor, aspirin. Assessment of the effectiveness of ticagrelor as an alternative treatment in patients with in vitro resistance, or HTPR (high on-treatment platelet reactivity) to clopidogrel. Methods: In our set of patients, the effectiveness of antiplatelet drugs was tested using the light transmission aggregometry (LTA) method from 16. 9. 2020 to 5. 12. 2022. The effectiveness of treatment in patients switched to an alternative medicine was monitored and the success of the change in therapy was evaluated. Results: In the monitored period, a total of 529 blood samples were tested for clopidogrel (n = 216), ticagrelor (n = 59) and aspirin (n = 254). The efficacy of clopidogrel treatment was 45.4 %. On the other hand, the efficacy of ticagrelor was 93.2 %, statistically significantly higher (p < 0.000). In case of conversion from clopidogrel to ticagrelor, treatment was successful in 49 of 54 patients (90.7 %). Conclusion: For the antiplatelet drugs tested, statistically significant differences in the effectiveness were demonstrated. In the case of clopidogrel, ticagrelor is a suitable alternative, significantly reducing incidence of HTPR. The number of patients with HTPR undergoing stent/flow diverter implantation can be significantly reduced by including platelet function testing in the algorithm of endovascular procedures.
- MeSH
- Aspirin aplikace a dávkování MeSH
- inhibitory agregace trombocytů * aplikace a dávkování MeSH
- klopidogrel aplikace a dávkování MeSH
- léková rezistence MeSH
- lidé MeSH
- statistika jako téma MeSH
- techniky in vitro MeSH
- ticagrelor aplikace a dávkování MeSH
- tromboembolie prevence a kontrola MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- hodnotící studie MeSH
Antiphospholipid syndrome (APS) is a hypercoagulable state accompanied by the presence of heterogeneous antiphospholipid antibodies (aPL), which nonspecifically affect hemostasis by the presence of lupus anticoagulans (LA), anticardiolipin antibodies (aCL), antibodies against β2-glycoprotein-I (anti-β2GPI), but also non-criteria antibodies such as antibodies against β2-glycoprotein-I domain I (anti-DI), anti-phosphatidylserine/prothrombin (anti-PS/PT), anti-annexin V, and many others. The main target of the antibodies is the activated protein C (APC) system, the elimination of which can manifest itself as a thrombotic complication. The aim of this study was to determine the thrombogenicity of antibodies using a modified protein C-activated thrombin generation assay (TGA) on a group of 175 samples suspected of APS. TGA was measured with/without APC and the ratio of both measurements was evaluated (as for APC resistance), where a cut-off was calculated ≤4.5 (90th percentile) using 21 patients with heterozygous factor V Leiden mutation (FV Leiden heterozygous). Our study demonstrates the well-known fact that multiple positivity of different aPLs is a more severe risk for thrombosis than single positivity. Of the single antibody positivity, LA antibodies are the most serious (p value < 0.01), followed by aCL and their subgroup anti-DI (p value < 0.05). Non-criteria antibodies anti-annexin V and anti-PT/PS has a similar frequency occurrence of thrombogenicity as LA antibodies but without statistical significance or anti-β2GPI1 positivity. The modified TGA test can help us identify patients in all groups who are also at risk for recurrent thrombotic and pregnancy complications; thus, long-term prophylactic treatment is appropriate. For this reason, it is proving increasingly beneficial to include the determination antibodies in combination with modified TGA test.
- MeSH
- antifosfolipidové protilátky MeSH
- antifosfolipidový syndrom * komplikace MeSH
- antikardiolipinové protilátky MeSH
- beta-2-glykoprotein I MeSH
- fosfatidylseriny MeSH
- lidé MeSH
- protein C MeSH
- protrombin MeSH
- těhotenství MeSH
- thrombin MeSH
- trombóza * etiologie MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: The effect of direct oral anticoagulants (DOAC) on laboratory tests dependent on the production of their targets, factor IIa and factor Xa, is a well-known problem and can cause both false positive and negative results. In particular, the situation in patients who develop lupus anticoagulant (LA) antibodies is highly complex. To evaluate the effectiveness of DOAC therapy in lupus-positive patients, 31 samples were enrolled in this retrospective study. All patient samples were spiked with three types of DOAC (dabigatran, DABI; rivaroxaban, RIVA; and apixaban, API) in a concentration that significantly influenced the screening test for LA and thus can mask the presence of LA. Subsequently, the DOAC was always unbound by the DOAC-Stop procedure. DOAC levels before and after binding were determined by functional assays, followed by liquid chromatography coupled with mass spectrometry (LC-MS) analysis. METHODS: The determination of DOAC levels was performed by direct thrombin assay and determination of anti-Xa activity with specific calibration as functional tests for DABI and xabans (API and RIVA). To determine concentration levels of API, DABI, and RIVA, our in-house LC-MS method was used. RESULTS: The results of LA-positive samples show significant differences between functional tests and the LC-MS method both before and after DOAC binding. CONCLUSIONS: The acute findings of the presence of LA-type antibodies fundamentally affects the determination of DOAC by functional tests, and in this case, it is necessary to use LC-MS analysis to determine the true value. If patients treated with DOAC develop LA of medium and higher titers, we do not recommend checking DOAC levels with functional tests.
- Publikační typ
- časopisecké články MeSH
Antiphospholipid syndrome (APS) is a hypercoagulation condition associated with the incidence of heterogenic antiphospholipid antibodies (aPLs), which non-specifically affect hemostasis processes. APS is clinically manifested by recurrent arterial and venous thromboses and reproduction losses. The aPL antibodies, which may induce clinical manifestations of APS, include criteria antibodies anti-cardiolipin, anti-β2-glycoprotein-I, and lupus anticoagulant, but also non-criteria antibodies, for example anti-β2-glycoprotein-I domain I, anti-phosphatidylserine/prothrombin, anti-annexin V, and many others. APS occurs mostly in patients of younger and middle age, most frequently in females. Laboratory diagnostics of APS are quite difficult, as they include a wide spectrum of examining methods, which are based on various principles of detection and are performed using various laboratory techniques. The objective of the review is to describe the current state of potentially examined biomarkers and methods in APS diagnostics. The aforementioned biomarkers are lupus anticoagulant, anti-β2-glycoprotein-I, anti-cardiolipin, anti-β2-glycoprotein-I domain I, anti-phosphatidylserine/prothrombin, anti-β2-glycoprotein-I IgA, anti-cardiolipin IgA, anti-annexin V and II, anti-prothrombin, anti-cardiolipin/vimentin, anti-protein S/protein C, and antibodies against phospholipid antigens for whose diagnostics we may use some of the methods established for a long time and some of the modern methods-the coagulation method for the determination of lupus anticoagulant (LA), enzyme-linked imunosorbent assay (ELISA), chemiluminescence analysis (CLIA), multiplex fluorescence flow immunoassay (MFFIA), fluorescence enzyme immunoassay (EliA), line immunoassay (LIA), multiline dot assay (MLDA), and thin-layer chromatography (TLC). Conclusion: Antibodies against phosphatidylethanolamine, phosphatidic acid, phosphatidylserine, phosphatidylinositol, cardiolipin/vimentin complex, and annexin V are currently the most studied new markers. However, these assays have not been standardized until now, both from the laboratory and clinical point of view. In this review we summarize the evidence of the most studied aPL markers and their potential clinical significance in seronegative APS (SN-APS).
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Pneumatic tube transport systems (PTS) for delivery of patient samples to a hemostasis laboratory are often used to reduce turnaround time for vital analyses. PTS in our hospital has the ability to regulate the transport speed in the range of 3-6 m/s with acceleration control technology. We evaluated the effects of PTS transport for routine coagulation tests, platelet function tests and special global coagulation tests. Duplicate samples were collected from 29 patients and 40 healthy individuals. One sample was sent using PTS and the other was carried by personnel to the lab for determination of protrombin time, activated partial thromboplastin time, trombin time, fibrinogen, antitrombin and thrombin generation test. Platelet function was measured by means of a Apact 4004® analyzer using the inductors (ADP, Arachidonic acid and Epinephrine). Samples transported using PTS with normal transport speed 6 m/s does not affect basic coagulation tests (PT, aPTT, FIB, TT and AT), but TGT has significantly altered. The use of PTS with controlled acceleration regulated the increase in thrombin generation from 10% to 3%, which is not statistically signifiant. The use of PTS with controlled acceleration did not show a significant difference even with the highly sensitive method of platelet aggregation. We conclude that PTS with acceleration control with transport speed from 3 to 6 m/s does not affect to platelet activity as measured by LTA and also global coagulation test - TGT. The advantage of PTS transport is very rapid assessment laboratory testing. From the above validation study, it is clear that PTS should always be validated for specialized laboratory methods and appropriately adapted to specific transport conditions.
- MeSH
- agregace trombocytů * MeSH
- lidé MeSH
- trombocyty * MeSH
- vyšetření krevní srážlivosti MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
