Primary Antiphospholipid Syndrome with Vascular Manifestations Is a Rare Disease: A Population-Based, Multi-Source Study Assessing the Prevalence and Incidence in Adults

Cecilia Nalli¹, Greta Pascariello¹, Arianna Zentilin¹, Elena Raffetti², Laura Andreoli¹, Rajesh Kumar¹, Giuliana Martini³, Roberta Ottaviani¹, Cinzia Gasparotti⁴, Michele Magoni⁴, Carmelo Scarcella⁴, Francesco Donato⁵ and Angela Tincani¹, ¹Rheumatology and Clinical Immunology, Spedali Civili and University of Brescia, Brescia, Italy, ²Epidemiology and Public Health Intervention Research group (EPHIR), Department of Public Health Sciences, Karolinska Institutet, Solna, Sweden, ³Hemostasis and Thrombosis Center, Spedali Civili of Brescia, Brescia, Italy, ⁴ATS Brescia (Brescia Health Protection Agency), Brescia, Italy, ⁵Department of Medical and Surgical Specialties Radiological Sciences and Public Health, Unit of Hygiene, Epidemiology, and Public Health, University of Brescia, Italy., Brescia, Italy

Meeting: 2018 ACR/ARHP Annual Meeting

Keywords: antiphospholipid syndrome, epidemiologic methods and thrombosis

Session Information

Date: Tuesday, October 23, 2018

Title: Epidemiology and Public Health Poster III: SLE, SSc, APS, PsA, and Other Rheumatic Diseases

Session Type: ACR Poster Session C

Session Time: 9:00AM-11:00AM

Background/Purpose:

Antiphospholipid Syndrome (APS) is a systemic autoimmune disease characterized by thrombotic and/or obstetrical manifestations mediated by antiphospholipid antibodies (aPL). By now, no population-based study was performed to assess the epidemiology of APS. Incidence and prevalence of primary APS (PAPS) are therefore unknown. The 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 in a 40 kilometers long prealpine valley in northern Italy. The population was 101.477 inhabitants in 2013. The only easy access to the valley is from the main city of the area, where the only Rheumatology referral tertiary Cente is located. Therefore, this valley is ideal for epidemiological studies by matching different sources for patients’ identification. The search for PAPS cases was restricted to adults below the age of 50, since this is supposed to be the age period for the onset of “true” vascular PAPS.

Methods:

We identified adult individuals of 18-50 years of age living in the study area. Patients with thrombotic events were identified by three sources: 1) hospital discharge codes using keywords (deep vein thrombosis, pulmonary embolism, myocardial infarction, ischemic stroke); 2) General Practitioners working in the study area; 3) patients with definite diagnosis of vascular PAPS already followed-up in the tertiary Rheumatology Center. Patients were classified as PAPS if aPL positivity was confirmed overtime.

Results:

We identified 47 patients with venous events during the period 2011-2015. Twenty-seven out of 47 (57%) were tested for aPL, 5/27 (19%) resulted to be positive. Regarding arterial events, 36 patients had stroke and 33/36 (92%) were tested for aPL, 4/33 (12%) were positive. Sixty-four patients with myocardial infarction (MI) were observed: 14/64 (22%) were tested for aPL, 2/14 (14%) were positive. Prevalence was estimated to be 22,9 (CI 95% 11,4-41,0) per 100.000 inhabitants in 2013. Table 1 shows the incidence figures of vascular PAPS. We also calculated the “historical” incidence of APS in the 10 years before our study period (2001-2010), yielding a value of 1,2 (CI 95% 0,4-2,6) per 100.000 inhabitants. By comparing the two incidence values (1,2 vs 3,7), we can assume a better diagnostic sensitivity over the years and increasing awareness of PAPS as a cause of thrombosis in younger patients.

Conclusion:

This is the first population-based epidemiological study assessing the prevalence and incidence of PAPS in adult population below the age of 50. According to the prevalence estimates, PAPS can classified as a “rare disease”. This study identified a gap in the diagnostic work-up, as nearly 50% and 80% of patients with venous thrombosis and MI were not tested for aPL. We are currently contacting patients who were tested for aPL in order to refine the epidemiological evaluation.

Disclosure: C. Nalli, None; G. Pascariello, None; A. Zentilin, None; E. Raffetti, None; L. Andreoli, None; R. Kumar, None; G. Martini, None; R. Ottaviani, None; C. Gasparotti, None; M. Magoni, None; C. Scarcella, None; F. Donato, None; A. Tincani, Bristol-Myers Squibb, 2,UCB, Inc., 5.

To cite this abstract in AMA style:

Nalli C, Pascariello G, Zentilin A, Raffetti E, Andreoli L, Kumar R, Martini G, Ottaviani R, Gasparotti C, Magoni M, Scarcella C, Donato F, Tincani A. Primary Antiphospholipid Syndrome with Vascular Manifestations Is a Rare Disease: A Population-Based, Multi-Source Study Assessing the Prevalence and Incidence in Adults [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/primary-antiphospholipid-syndrome-with-vascular-manifestations-is-a-rare-disease-a-population-based-multi-source-study-assessing-the-prevalence-and-incidence-in-adults/. Accessed .

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