Increased risk of pulmonary embolism in patients with dermatomyositis/polymyositis, a retrospective cohort study from Israel

Background: Despite the well-established association between chronic inflammatory conditions and pulmonary embolism(PE), previous investigations of the relationship between Dermatomyositis(DM) and Polymyositis(PM) with PE were scarce and have been subject to significant limitations, including small sample sizes and failure to account for potential confounders. Objectives: To investigate the correlation between DM/PM and PE, as well as assessing the impact of serologic status, myonecrosis, and inflammation markers on this relationship. Methods: In this large, nationwide population-based study, we used the Clalit Health Services medical database and extracted all DM/PM patients who were first diagnosed between 1 January 2002 to 31 December 2018 and compared them with age and gender matched controls in a ratio of 1:5. Serological and laboratory values were obtained for each patient. Rates of PE were compared between groups using multivariate models. Results: The study included 1557 DM patients with 7633 controls, and 528 PM patients with 2560 controls. Compared with matched controls, the rates of PE were significantly higher in the DM/PM group, PM patients(2.8 % vs 0.5 % in controls, OR = 5.73, p < 0.001), DM patients(1.2 % vs 0.3 % in controls, OR = 3.42, p < 0.001). APLA seropositivity was significantly more prevalent in DM/PM patients compared with their matched controls, PM patients(10.8 % vs 2.7 % in controls, p < 0.001), DM patients(7.9 % vs 1.6 % in controls, p < 0.001). APLA seropositivity had a synergistic effect for PE in the DM/PM(OR = 23.18, p < 0.001). Conclusions: DM and PM are associated with higher rates of PE. Furthermore, patients with DM/PM demonstrate a significantly higher prevalence APLA which act as a potentiator of thrombosis in these patients.