Circulating microRNAs as biomarkers of disease and typification of the atherothrombotic status in antiphospholipid syndrome

We aimed to identify the plasma miRNA profile of antiphospholipid syndrome (APS) patients and to investigate the potential role of specific circulating miRNAs as non-invasive disease biomarkers. Ninety APS patients and 42 healthy donors were recruited. Profiling of miRNAs by PCR-array in plasma of APS patients identified a set of miRNAs differentially expressed and collectively involved in clinical features. Logistic regression and ROC analysis identified a signature of 10 miRNA ratios as biomarkers of disease. In addition, miRNA signature was related to fetal loss, atherosclerosis, and type of thrombosis, and correlated with parameters linked to inflammation, thrombosis, and autoimmunity. Hard clustering analysis differentiated 3 clusters rep-resenting different thrombotic risk profile groups. Significant differences between groups for several miRNA ratios were found. Moreover, miRNA signature remained stable over time, demonstrated by their analysis three months after the first sample collection. Parallel analysis in two additional cohorts of patients, including thrombosis without autoimmune disease, and systemic lupus erythematosus without antiphospholipid antibodies, each displayed specific miRNA profiles that were distinct from those of APS patients. In vitro, antiphospholipid antibodies of IgG isotype promoted deregulation in selected miRNAs and their potential atherothrombotic protein targets in monocytes and endothelial cells. Taken together, differentially expressed circulating miRNAs in APS patients, modulated at least partially by antiphospholipid antibodies of IgG isotype, might have the potential to serve as novel biomarkers of disease features and to typify patients' atherothrombotic status, thus constituting a useful tool in the management of the disease.