AB0025 Pregnancy results in the selective modulation of platelet tissue factor expression independently of the presence of antiphospholipid antibodies or of other autoimmune features. (15th June 2017)

• Record Type: Journal Article
• Authors: Canti, V; Castiglioni, MT; A, M Angelo; Rovere-Querini, P; Maugeri, N
• Is Part Of: Annals of the rheumatic diseases. Volume 76(2017)Supplement 2
• Page Start: 1055
• Page End: 1055
• Publication Date: 2017-06-15
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2017-eular.6429
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Neutrophils and platelets are key innate immune cells that productively interact upon activation, generating/releasing moieties that can damage the bystander tissue and prompt vasculogenesis. Successful pregnancy critically depends on a tight regulation of the latter events. Conversely pregnancy complications are associated with alteration/damage of the vasculature associated to the placenta. Blood-born tissue factor (TF) due to the expression of the moiety by platelets and leukocytes has been involved in the pro-thrombotic diathesis associated with sustained human autoimmunity, including that associated with anti-phospholipid syndrome (APS). Objectives: To test the modulation of parameters related to blood-born TF during normal and pathological pregnancy Methods: The expression of TF by platelets, monocytes and neutrophils has been studied in 40 women at the 12th week of gestation (wg) including twelve healthy women, 14 patients with insulin-dependent diabetes mellitus (IDDM) and 14 patients with a previous history of pregnancy complications, six of them with APS. 30 healthy age-matched non-pregnant women served as controls. When possible, patients were studied again at least one year after the pregnancy completion. Blood samples were collected and processed as described 1, 2 . Other features reflecting cell activation were assessed in parallel 1, 2 . Results: The expression of platelet TF was significantly higher in pregnant women compared with age-matched controls. Platelet P-selectin was as well significantly up-regulated. Neutrophils circulating in all pregnant women were mildly degranulated. The content of the neutrophil secondary granules was depleted in particular in subiects with previous pregnancy complications sine causa . Conclusions: Our data support the contention that the activation of the innate immune system is a key feature of pregnancy, regardless of the presence of features of systemic or organ-specific autoimmunity. This implies an important modulation of the machinery involved in the reciprocal activation of platelets and neutrophils and in the pro-thrombotic phenotype of circulating cells. The analysis of the potential modulation of these parameters by ongoing treatment is currently being carried out. References: Manfredi A & al. Ann Rheum Dis. 2016;75(8):1511–20. doi: 10.1136/annrheumdis-2015-208442. Maugeri N et al. Blood. 2011 Sep 22;118(12):3359–66. doi: 10.1182/blood-2011-02-337337. Disclosure of Interest: None declared