Abstract
Thrombosis is the most common manifestation of antiphospholipid syndrome (APS), but
concurring evidence of the mechanisms leading to a hypercoagulable state and thereby
thrombosis is lacking. Existing reviews on this topic often include both animal and
in vitro models. Additionally, studies with a systematic approach and stringent methodology,
focusing exclusively on human studies, are lacking. Therefore, we conducted a scoping
review of studies with human subjects, focusing on the mechanisms contributing to
hypercoagulability in thrombotic APS (T-APS). The process was guided by the PRISMA
Extension for Scoping Reviews and performed according to a preregistered protocol
in Open Science Framework (https://osf.io/tjdwv). A systematic search of Ovid (EMBASE) and MEDLINE (PubMed) was performed on October
10, 2024. Records investigating mechanisms of hypercoagulability in adults (≥18 years)
with T-APS, published between January 2000 and October 2024, were included. A total
of 4,160 titles and abstracts were screened, 115 articles were assessed in full text,
of which 35 studies fulfilled the predefined eligibility criteria for inclusion. Of
the included studies, 8 focused on primary hemostasis, 10 on secondary hemostasis,
9 on fibrinolysis, 4 on neutrophil extracellular traps, 6 on endothelial cells, 3
on complement factors, 5 on monocytes, 3 on oxidized low-density lipoprotein complexes,
2 on oxidative stress, and 1 on amyloid-β1-40. No clear consensus was found regarding
the underlying cause of hypercoagulability in T-APS, highlighting the need for further
studies with human subjects. Nonetheless, this scoping review indicates that hypercoagulability
in T-APS is possibly multifactorial, with no single mechanism being solely responsible.
Keywords
antiphospholipid syndrome - hypercoagulability - thrombosis - mechanism - human
