Pomen dodajanja eksogenega antitrombina pri merjenju preostale aktivnosti faktorja Xa po zavrtju z nizkomolekularnim heparinom

Lenarčič, Kaja (avtor), Božič Mijovski, Mojca (mentor), Trampuš Bakija, Alenka (komentor)

Preiskava anti-Xa predstavlja zlati standard za merjenje antikoagulacijskega učinka heparina in njegovih derivatov v krvi. Metoda je avtomatizirana in dobro uveljavljena v klinični rutini, vendar se sooča s slabo standardizacijo, ki se odraža z različno izmerjenimi vrednostmi anti-Xa med različnimi uporabljenimi metodami. Te se med seboj razlikujejo predvsem po prisotnosti eksogenega antitrombina, kot tudi dekstran sulfata, zato smo v magistrski nalogi sistematično proučili vpliv njunega dodajanja pri merjenju anti-Xa. V nalogi smo med seboj primerjali 5 različnih metod, ki se med seboj razlikujejo po vsebnosti antitrombina in dekstran sulfata: štiri metode istega proizvajalca in ena primerljiva metoda drugega proizvajalca. Metode smo testirali na vzorcih, ki smo jim in vitro dodajali različne koncentracije nizkomolekularnega heparina in različne aktivnosti antitrombina. Na podlagi rezultatov statistične analize smo ugotovili, da se metode kljub značilni korelaciji med seboj razlikujejo. Statistično značilna razlika se je pokazala med skupinama metod z dodanim antitrombinom in brez njega, kjer sta metodi z dodanim antitrombinom izmerili pomembno višje vrednosti anti-Xa v primerjavi z metodami brez njega. S tem smo potrdili, da so izmerjene vrednosti anti-Xa odvisne od eksogenega antitrombina. Statistično značilna sprememba med metodami je bila opazna v intervalu aktivnosti endogenega antitrombina med 68 in 81 %, zato bi izbira metode pri osebah z aktivnostjo antitrombina pod in znotraj tega intervala verjetno imela večji vpliv. Teorijo bi bilo potrebno potrditi na vzorcih pacientov. Skupini metod z dodanim dekstran sulfatom in brez njega se med seboj nista značilno razlikovali, zato smo prišli do zaključka, da izmerjene vrednosti anti-Xa od njega niso odvisne ali pa je vpliv dekstran sulfata bistveno manjši od vpliva antitrombina.

• Jezik: Slovenski jezik
• Ključne besede: anti-Xa, antitrombin, dekstran sulfat, heparin, hemostaza
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: FFA - Fakulteta za farmacijo
• Leto izida: 2024
• PID: 20.500.12556/RUL-154239
• Datum objave v RUL: 03.02.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: The importance of exogenous antithrombin addition at measuring residual factor Xa activity after inhibition with low molecular weight heparin

Izvleček

The anti-Xa assay is the gold standard for measuring the anticoagulant effect of heparin and its derivatives in blood. The method is automated and well established in clinical practice, but it is insufficiently standardized, which means that the measured anti-Xa values vary between the different methods used. These methods differ mainly in the presence of exogenous antithrombin and dextran sulphate. Therefore, in this master thesis we systematically investigated the influence of their addition in the measurement of anti-Xa. In the master's thesis, we compared five different methods that differ in their antithrombin and dextran sulphate content: four methods from the same manufacturer and one comparable method from a different manufacturer. The methods were tested on samples to which different concentrations of low-molecular-weight heparin and different antithrombin activities had been added in vitro. The results of the statistical analysis show that the methods differ from each other despite a significant correlation. A significant difference was found between the groups of methods with and without added antithrombin, with the methods with added antithrombin measuring significantly higher anti-Xa values than the methods without antithrombin. This confirms that the measured anti-Xa values are dependent on exogenous antithrombin. A significant variation among methods was observed within the range of endogenous antithrombin activity between 68 and 81 %. Therefore, the choice of method is likely to have a greater influence in individuals with antithrombin activity below and within this range. This theory should be confirmed in patient samples. The method groups with and without the addition of dextran sulphate did not differ significantly from each other, suggesting that the measured anti-Xa values are not dependent on this or that the influence of dextran sulphate is significantly less than the influence of antithrombin.

• Ključne besede: anti-Xa, antithrombin, dextran sulphate, heparin, haemostasis