Establishment of activated platelet–monocyte complex detection method by whole-blood flow cytometry and clinical application

Abstract

In collagen diseases such as systemic lupus erythematosus (SLE), arterial thromboembolism occurs frequently regardless of the conventional risk factors for arteriosclerosis. Measurement of activated platelet–monocyte complexes (aPMCs) involved in the formation of arteriosclerotic lesions is very important, but its clinical utility has not been investigated. In this study, we investigated whether the measurement of aPMCs by flow cytometry analysis is useful as a clinical laboratory tool to predict the risk of arterial thromboembolism in prospective clinical studies of collagen disease patients. We measured the positivity rate of aPMCs in patients with various autoimmune diseases such as SLE, rheumatoid arthritis (RA), polyarteritis nodosa (PN), and mixed connective tissue disease (MCTD). The positivity rate of aPMCs was significantly higher in SLE patients than in other autoimmune disease patients. Furthermore, the SLE patients were classified into the antiphospholipid syndrome (APS)-complicated group and noncomplicated group, and both were compared. The positivity rate of aPMCs was obviously higher in the APS-complicated group. In addition, we divided SLE patients into the following 5 groups according to their complications: cerebral infarction (n = 9), myocardial infarction (n = 3), deep vein thrombosis (n = 5), pulmonary embolism (n = 2), and nonthrombosis (n = 17). The positivity rate of aPMCs was significantly higher in SLE patients with cerebral infarction and myocardial infarction than in those with deep vein thrombosis, pulmonary embolism, and nonthrombosis. The present study showed that the positivity rate of aPMCs determined by flow cytometry analysis could serve as a marker to predict the risk of arterial thromboembolism in SLE patients.