Author: Akhmetova Aigerim
Editor: Merentsova Anastasia
Antiphospholipid syndrome (APS) is an autoimmune condition caused by antiphospholipid antibodies. Phospholipid-binding proteins include beta-2-glycoprotein 1, prothrombin, annexin A5. If autoantibodies displace annexin A5, the surfaces of endotheliocytes (cells on the inner surface of blood vessels) are stimulated and begin to produce procoagulants, provoking arterial or venous thrombosis. APS provokes the formation of blood clots (thrombosis) in both arteries and veins, as well as complications associated with pregnancy: miscarriage, stillbirth, premature birth and severe preeclampsia.
Two types of drugs are commonly used to prevent blood clots in people with APS: anticoagulants, such as warfarin (which inhibit proteins that form blood clots), and antiplatelet drugs, such as aspirin (which prevent cells called platelets from sticking together).
Eight studies were conducted with the participation of 811 people, the average age of which was from 36 to 50 years. Three studies compared rivaroxaban (a new oral anticoagulant) with standard dose warfarin (a vitamin K antagonist -VKA). Two more studies compared two VKA anticoagulation intensities with high and standard dose. The standard dose VKA plus aspirin was also compared with the standard dose VKA without aspirin. The remaining studies compared different combinations of anticoagulants or antiplatelet drugs (eg, aspirin). The interventions lasted from 180 days to 58.4 months on average.
Three studies comparing rivaroxaban (NOAC) with a standard dose of VKA had the same number of patients who subsequently developed clotting, bleeding, or even death (moderate-certainty evidence), but there were more participants in the NOAC group than in the group VKA (moderate certainty evidence). In two studies comparing high-dose versus standard-dose VKA, similar proportions of participants had coagulation problems and major bleeding (low-certainty evidence), but participants in the high-dose group were at greater risk of minor bleeding and any bleeding.
The remaining studies comparing different combinations of antiplatelet agents and / or VKA did not provide definitive results in terms of benefits or harms (low or very low certainty evidence). Most of the results were inaccurate and did not clearly indicate benefit or harm, suggesting the need to continue clinical trials.
Source: https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012169.pub3/full
