AB1287 A population-based study on the prevalence and incidence of vascular primary antiphospholipid syndrome: a new rare disease

• Published in: Annals of the rheumatic diseases Vol. 77; no. Suppl 2; p. 1736
• Main Authors: Nalli, C., Andreoli, L., Pascariello, G., Zentilin, A., Raffetti, E., Martini, G., Kumar, R., Gasparotti, C., Magoni, M., Scarcella, C., Donato, F., Tincani, A.
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01.06.2018
• Subjects: Antiphospholipid antibodies; Antiphospholipid syndrome; Autoimmune diseases; Cerebral infarction; Embolism; Epidemiology; Health risk assessment; Heart attacks; Myocardial infarction; Population; Population studies; Population-based studies; Rare diseases; Rheumatology; Thrombosis
• ISSN: 0003-4967; 1468-2060
• DOI: 10.1136/annrheumdis-2018-eular.5676

BackgroundAntiphospholipid Syndrome (APS) is a systemic autoimmune disease characterised by the presence of thrombotic and/or obstetrical manifestations and antiphospholipid antibodies (aPL). In 2006 the updated Sapporo criteria for APS were published but by now no epidemiological study on this disease were performed. Incidence and prevalence of primary APS (PAPS) in the general population are still unknown.ObjectivesThe aim of this study was to evaluate the prevalence during the year 2013 and incidence for the period 2011–2015 of vascular PAPS in the adult population of a defined area, Valtrompia valley, using multiple sources. Valtrompia is a 40 kilometers-long prealpine valley in northern Italy. The population in 2013 was 101.477 inhabitants. The only easy access to the valley is from Brescia, the main city of the province. This valley is a cul-de-sac area without any other comfortable and practicable access. Therefore, this valley is ideal for epidemiological studies. In addition, the only Rheumatology referral tertiary Centre of the province is located in Brescia. This project was approved by the local Ethical Committee.MethodsWe identified adult subjects of 18–50 years old living in Valtrompia. Patients with thrombotic events were identified by two sources: 1) hospital discharge code using keywords (deep vein thrombosis, pulmonary embolism, myocardial infarction, ischaemic stroke); 2) patients with defined diagnosis of vascular PAPS already followed by the Rheumatology tertiary Centre in Brescia.ResultsThe prevalence of PAPS in 2013 was calculated to be 35.4 (CI 95% 20.6–59.6) per 100.000 inhabitants. Table 1 shows the incidence rates of vascular PAPS. We identified 47 patients with venous events during 2011–2015. 27/47 (57%) were tested for aPL, 4/27 (15%) positive. Regarding arterial events, 36 patients had stroke and 33/36 (92%) were tested for aPL, 4/33 (12%) positive. Finally, 64 patients with myocardial infarction (IMA): only 14/64 (22%) were tested for aPL, 2/14 (14%) positive.Table 1 Incidence rates of antiphospholipid antibody syndrome per 100.000 inhabitants in Valtrompia in adult population (18–49 years) between 2011 and 2015. The 95% confidence intervals (CIs) are reported in parenthesis.Abstract AB1287 – Figure 1ConclusionsPreliminary results of this population-based study showed that PAPS is a rare disease. A critical point emerged from this study is that aPL were not routinely tested in young subjects with vascular events, especially in patients with myocardial infarction. The study will be implemented by contacting patients who never tested for aPL during the hospital admission.Disclosure of InterestNone declared