New insights into the pathogenic mechanisms and treatment of arterial thrombosis in antiphospholipid syndrome

Antiphospholipid antibodies in patients with antiphospholipid syndrome

Antiphospholipid syndrome (APS) is a rare systemic autoimmune disease characterized by recurrent pregnancy morbidity or thrombosis in combination with the persistent presence of antiphospholipid antibodies (aPLs) in plasma/serum. Antiphospholipid antibodies are a heterogeneous, overlapping group of autoantibodies, of which anti-β2-glycoprotein I (aβ2GPI), anticardiolipin (aCL) antibodies and antibodies that prolong plasma clotting time in tests in vitro known as lupus anticoagulant (LAC) are included in the laboratory criteria for the diagnosis of APS. The presence of LAC antibodies in plasma is indirectly determined by measuring the length of coagulation in two tests - activated partial thromboplastin time (aPTT) and diluted Russell's viper venom time (dRVVT). The concentration of aβ2GPI and aCL (immunglobulin G (IgG) and immunoglobulin M (IgM) isotypes) in serum is directly determined by solid-phase immunoassays, either by enzyme-linked immunosorbent assay (ELISA), fluoroimmunoassay (FIA), immunochemiluminescence (CLIA) or multiplex flow immunoassay (MFIA). For patient safety, it is extremely important to control all three phases of laboratory testing, i.e. preanalytical, analytical and postanalytical phase. Specialists in laboratory medicine must be aware of interferences in all three phases of laboratory testing, in order to minimize these interferences. The aim of this review was to show the current pathophysiological aspects of APS, the importance of determining aPLs-a in plasma/serum, with an emphasis on possible interferences that should be taken into account when interpreting laboratory findings.

Primary antiphospholipid syndrome with and without limb ischemia: A retrospective observational study

OBJECTIVE

To compare clinical and laboratory data obtained from patients with primary Antiphospholipid Syndrome (PAPS) with and without limb ischemia (LI).

METHODS

A transverse study with 66 (83.3% female) PAPS patients was performed. All data were evaluated. Patients were subdivided into one of two groups: PAPS with LI and PAPS without LI and compared.

RESULTS

Sixty-six primary APS were selected. PAPS with LI group exhibited a longer disease duration (p = .012) and more arterial events (p = .002). A lower frequency of venous events was observed in PAPS with LI (p = .007), and deep venous thrombosis (p = .016). Furthermore, PAPS with LI patients had more deficiency of protein C of coagulation (p = .015) than the others.

CONCLUSION

PAPS and LI have a distinct clinical and laboratory spectra from those without LI and it is characterized by an increased frequency of protein C deficiency, and a lower frequency of venous events, deep venous thrombosis and IgM anticardiolipin.

Research trends and frontiers on antiphospholipid syndrome: A 10-year bibliometric analysis (2012-2021)

Objectives: A growing body of studies related to antiphospholipid syndrome (APS) have been published in recent years. Nevertheless, there is a lack of visualized and systematic analysis in the literature on APS. Hence, this study sought to conduct a bibliometric analysis to identify research status and discover frontiers in the field. Methods: Articles and reviews concerning APS were acquired from the Web of Science Core Collection (WoSCC) database. CiteSpace, VOSviewer and a bibliometric online analysis platform were employed to conduct a visualization and knowledge-map analysis. Results: A total of 1,390 publications regarding APS were identified. Globally, Italy contributed the most publications. The University of Padua was the most productive institution. Lupus ranked first in both the most published and most co-cited journals. Savino Sciascia and Spiros Miyakis were the most prolific and most co-cited authors, respectively. "Vitamin K antagonists (VKA)" and "immunoglobulin A (IgA)" were current research foci. Burst analysis of keywords suggested that "neutrophil extracellular trap (NET)," "direct oral anticoagulant (DOAC)," "open label," "outcome," "hydroxychloroquine (HCQ)," and "arterial thrombosis (AT)" were significant future research frontiers. Conclusion: The scientific literature on APS has increased steadily in the past 10 years. The clinical studies on the treatment and mechanism research of APS are recognized as promising research hotspots in the domain of APS. The research status and trends of APS publications from the bibliometric perspective can provide a practical guide and important reference for subsequent studies by researchers and physicians in the domain.

Heterogeneity of Stroke in Patients with Systemic Lupus Erythematosus

Objective The underlying pathophysiology varies according to stroke subtype. However, stroke heterogeneity among patients with systemic lupus erythematosus (SLE) remains unstudied. We hypothesized that the contribution of SLE to stroke might vary according to its subtype and investigated the associations of SLE and various stroke subtypes. Methods Diagnostic codes and electronic medical records were used to identify 70 patients with SLE who developed acute cerebral infarction or intracerebral hemorrhaging at four tertiary referral hospitals between 2008 and 2018. Intracerebral hemorrhaging was classified as lobar or deep, while cerebral infarction was classified according to the SSS-TOAST criteria. Physician notes were used to identify SLE activity, and their prevalences were compared among stroke subtypes. Outcomes were collected from the patients' medical records. Results The most common stroke subtype in patients with SLE was that of undetermined causes (31%), followed by small artery occlusion (16%), cardioaortic embolism (13%), other causes (11%), lobar hemorrhaging (10%), deep hemorrhaging (10%), and large artery atherosclerosis (9%). Stroke onset occurred during a period of high SLE activity in 21 patients (30%). The proportion of patients with high SLE activity varied according to stroke subtype (p=0.039) and was highest for cerebral infarction with undetermined causes. Stroke recurrence or death was observed in 40% of patients within 5 years after the initial stroke onset. Conclusion The contributions of SLE to stroke varied significantly according to the stroke subtype. Given the unfavorable prognosis, close stroke subtype-specific observation by rheumatologists and stroke specialists is recommended after stroke events.