The role of the intestinal microbiome in antiphospholipid syndrome

An Intestinal Microbiome Intervention Affects Biochemical Disease Activity in Patients with Antiphospholipid Syndrome

Background  The origin of autoantibodies in patients with antiphospholipid syndrome (APS) is unknown. The gut microbiome contributes to autoimmunity and contains peptide homologues to the main APS autoantigen, which affect disease activity in animal models. Alteration of the gut microbiota with vancomycin diminishes disease activity in mice but no data on the effect of gut microbiota alteration in APS patients are available to date. Objective  To evaluate whether the gut microbiome affects disease activity in human APS. Methods  This was a pre-post design intervention study in APS patients with stable disease and no gastrointestinal comorbidity. Subjects received oral vancomycin, 500 mg four times daily for 7 days, previously shown to alter gut microbiota composition without systemic effects. Disease activity was assessed at four time points by measuring a panel of clinical phenotype-related biomarkers: antiphospholipid antibodies (APLAs), complement and inflammation markers, and hemostatic parameters. The primary outcome was the composite of the biomarker panel determined by multilevel principal component analysis. Results  A total of 15 subjects completed the study. The primary outcome, the first principal component of the biomarker panel data, was significantly different after 7 days of vancomycin treatment ( p  = 0.03), but not at day 42. APLA titers were unaffected. Unexpectedly, 4 out of 15 patients were negative for APLAs at baseline. In a post-hoc analysis, there was a prolonged effect for subjects with positive antibodies at baseline ( p  = 0.03). In subjects with negative APLAs at baseline, the intervention showed no effect. Conclusion  The intestinal microbiome affects the biochemical disease activity in APS patients. The mechanism is yet unknown but appears to be APS-specific.

Antiphospholipid Antibodies Associated with Native Arteriovenous Fistula Complications in Hemodialysis Patients: A Comprehensive Review of the Literature

Antiphospholipid antibody (aPL)-persistent positivity is frequent in hemodialysis (HD) patients. Native arteriovenous fistula (AVF) complications such as stenosis and thrombosis are among the most important causes of morbidity and mortality in hemodialysis patients. The association between aPL positivity and AVF thrombosis seems to now be well established. However, whether aPL positivity is associated with other AVF complications, such as maturation failure or stenosis, is not well known. Given the significant impact of AVF failure on patient's prognosis, it is of interest to further investigate this particular point in order to improve prevention, surveillance and treatment, and, ultimately, the patient's outcome. This literature review aims to report the recent literature on aPL-associated native AVF complications.

Anti-Phosphatidylserine, Anti-Prothrombin, and Anti-Annexin V Autoantibodies in Antiphospholipid Syndrome: A Real-Life Study

The antiphospholipid antibodies (aPL) increase the risk of developing thrombotic events and may coexist with a variety of autoimmune diseases. They can be detected chronically or temporarily in patients with infectious diseases, during drug therapy, or in cases of cancer. A thrombotic event with aPL detection is known as antiphospholipid syndrome (APS) and the diagnostic criteria include the presence of lupus anticoagulant (LA), anticardiolipin (aCL) and β2-glycoprotein-1(aβ2GPI) antibodies. Other autoantigens recognized in APS are phosphatidylserine (aPS), prothrombin (aPT) and Annexin-5 (aA5). This real life study aimed to explore the connections between laboratory criteria and the prevalence of "non-criteria aPL" in APS. This study followed 300 patients with thrombosis and employed two phospholipid sensitivity assays for LA detection, chemiluminescence assays for aCL and aβ2GPI and enzyme-linked immunoassays for aPS, aPT and aA5. A significant association was found between aPS and aCL (r = 0.76) as well as aβ2GPI (r = 0.77), while the association with LA was less significant (r = 0.33). The results of the aPT and aA5 test did not correlate with criteria-antiphospholipid antibodies (r < 0.30). Since the risk of thrombotic complications increases with the intensity and the number of positive autoantibodies, measuring aPT and aA5 autoantibodies may be useful, particularly in aCL/aβ2GPI-negative patients or in cases of isolated LA positivity.

[Systemic lupus erythematosus and antiphospholipid syndrome: past, present, future]

Immune-inflammatory (autoimmune and autoinflammatory) rheumatic diseases are widespread severe chronic inflammatory diseases and also "models" for studying the fundamental mechanisms of pathogenesis and approach to pharmacotherapy of other diseases associated with autoimmunity and/or autoinflammation. Uncontrolled inflammation leading to hypercoagulation forms the basis of "thromboinflammation", which is considered a universal pathogenetic mechanism of organ involvement in immune-inflammatory rheumatic diseases, as well as in COVID-19 and atherosclerotic vascular lesions (atherothrombosis). Thrombo-inflammatory mechanisms play a crucial role in systemic lupus erythematosus and antiphospholipid syndrome. Russian rheumatology, under the leadership of academician Valentina Alexandrovna Nasonova, greatly contributed to the research of these disorders. This article addresses the current view about the overlapping pathogenetic mechanisms of thrombosis in systemic lupus erythematosus and antiphospholipid syndrome, the relevance of these studies during the COVID-19 pandemic, and the prospects for antithrombotic and anti-inflammatory therapy.