Association between interferon-I producing plasmacytoid dendritic cells and thrombotic antiphospholipid syndrome

Risk Factors for Antiphospholipid Antibodies and Antiphospholipid Syndrome

Persistence of serum antiphospholipid antibodies (aPL) is associated with a high thrombotic risk, both arterial and venous, and with pregnancy complications. Due to the potential morbidity and mortality associated with the presence of aPL, identifying and recognizing risk factors for the development of aPL and thrombosis in aPL carriers may help to prevent and reduce the burden of disease. Multiple elements are involved in the pathomechanism of aPL development and aPL-related thrombosis such as genetics, malignancy, and infections. This review will address the role of both well-known risk factors and their evolution, and of emerging risk factors, including COVID-19, in the development of aPL and thrombosis in aPL carriers.

Should we be targeting type 1 interferons in antiphospholipid syndrome?

Systemic autoimmune diseases are characterized by increased production of type I interferon (IFN-1) and upregulation of IFN-1-inducible genes, suggesting an important role of the IFN-1 pathway in their pathogenesis. Recent studies have demonstrated increased IFN-1 expression in both primary and secondary antiphospholipid syndrome (APS), along with increased toll-like receptor type 9 activity and plasmacytoid dendritic cell function. The increasing knowledge of the association between IFN-1 and APS pathology may provide a rationale for conducting clinical trials to assess the efficacy of IFN-1-targeting drugs in reducing APS-related complications. In this narrative review, we summarize the current knowledge on the role of IFN-1 in APS pathogenesis, explore its clinical implications, and examine the existing evidence regarding therapeutic options that have been investigated to date.

Interferons and systemic lupus erythematosus: Pathogenesis, clinical features, and treatments in interferon-driven disease

Type I interferons (IFNs) have recently received a lot of attention with the elucidation of the pathogenesis of systemic lupus erythematosus (SLE). Type I IFNs are associated with many SLE symptoms and play a role in the pathogenesis of autoimmune diseases that may occur concurrently with SLE, such as Sjögren's syndrome, antiphospholipid syndrome, myositis, scleroderma, and interferonopathy. Type I IFNs could be the link between these diseases. However, direct measurement of type I IFN levels and the IFN gene signature is currently unavailable in clinical practice. This review discusses type I IFN signalling in SLE, investigates the role of type I IFN in the clinical manifestations and symptoms associated with SLE and other IFN-related diseases, and discusses the clinical tests that can be used to diagnose SLE and measure disease activity. In addition, the role of type I IFN-blocking therapies as potential treatments for SLE is discussed.

Evaluation of a gene signature related to thrombotic manifestations in antiphospholipid syndrome

Thrombotic primary antiphospholipid syndrome (t-PAPS) is an acquired condition characterized by heterogeneous thrombotic manifestations, which is intriguing since venous and arterial thrombosis appear to have distinct pathogenesis. Gene expression analysis may constitute a new approach to evaluate potential similarities or differences between the clinical manifestations of t-PAPS. Recently, dysregulation of the ANXA3, TNFAIP6, TXK, BACH2, and SERPINB2 genes has been associated with both arterial and venous thrombosis in the general population. Therefore, the aim of this study was to examine whether ANXA3, TNFAIP6, TXK, BACH2, and SERPINB2 expression was associated with t-PAPS. Gene expression was quantified by qPCR of total leukocyte mRNA. In this case-control study, 102 t-PAPS patients, 17 asymptomatic antiphospholipid (aPL) carriers and 100 controls were evaluated. Increased expression of ANXA3 (P = 0.008) and TNFAIP6 (P = 0.001) and decreased expression of the TXK gene (P = 0.0001) were associated with an increased risk of t-PAPS compared to the control. ANXA3 upregulation was more evident in cases of arterial thrombosis and multiple thrombotic events. There was no difference in the expression of these genes between triple and non-triple aPL positivity. ANXA3, TNFAIP6, TXK, BACH2, and SERPINB2 expression levels were also similar between aPL carriers and controls (P = 0.77; P = 0.48; P = 0.08; P = 0.73, and P = 0.13, respectively). In conclusion, our results showed that genes related to hemostasis (ANXA3) and immunity (TNFAIP6, TXK) are dysregulated in t-PAPS compared to controls. Gene dysregulation was not detected in aPL carriers and was not related to the aPL profile, suggesting that this gene signature is related to thrombotic manifestations rather than to aPL burden. Our results suggest that innate immunity and hemostasis pathways are associated with t-PAPS at a molecular level and may play a role in disease severity.