Catarina Favas

Evaluation of phosphatidylserine-dependent antiprothrombin antibody testing for the diagnosis of antiphospholipid syndrome: results of an international multicentre study.

Objective A task force of scientists at the International Congress on Antiphospholipid Antibodies recognized that phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) might contribute to a better identification of antiphospholipid syndrome (APS). Accordingly, initial and replication retrospective, cross-sectional multicentre studies were conducted to ascertain the value of aPS/PT for APS diagnosis. Methods In the initial study (eight centres, seven countries), clinical/laboratory data were retrospectively collected. Serum/plasma samples were tested for IgG aPS/PT at Inova Diagnostics (Inova) using two ELISA kits. A replication study (five centres, five countries) was carried out afterwards. Results In the initial study (n = 247), a moderate agreement between the IgG aPS/PT Inova and MBL ELISA kits was observed (k = 0.598). IgG aPS/PT were more prevalent in APS patients (51%) than in those without (9%), OR 10.8, 95% CI (4.0–29.3), p < 0.0001. Sensitivity, specificity, positive (LR+) and negative (LR–) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 91%, 5.9 and 0.5, respectively. In the replication study (n = 214), a moderate/substantial agreement between the IgG aPS/PT results obtained with both ELISA kits was observed (k = 0.630). IgG aPS/PT were more prevalent in APS patients (47%) than in those without (12%), OR 6.4, 95% CI (2.6–16), p < 0.0001. Sensitivity, specificity, LR + and LR– for APS diagnosis were 47%, 88%, 3.9 and 0.6, respectively. Conclusions IgG aPS/PT detection is an easily performed laboratory parameter that might contribute to a better and more complete identification of patients with APS.

Stress-related mucosal disease: incidence of bleeding and the role of omeprazole in its prophylaxis.

BACKGROUND Upper gastrointestinal bleeding is the severe complication of stress-related mucosal disease in hospitalized patients. In intensive care units (ICU), risk factors are well defined and only mechanical ventilation and coagulopathy proved to be relevant for significant bleeding. On the contrary, in non-ICU settings there is no consensus about this issue. Nevertheless, omeprazole is still widely used in prophylaxis of bleeding. The objective of our study was to evaluate the relevance of stress-related mucosal disease bleeding in patients admitted to an internal medicine ward, and the role of omeprazole in its prophylaxis. METHODS We conducted a retrospective study in which we analysed consecutive patients who were admitted to our ward over a year. We recorded demographic characteristics of the patients, potential risk factors for stress-related mucosal disease (clinical data, laboratory, and medication), administration of prophylactic omeprazole, and total cost of this prophylaxis. Patients with active gastrointestinal bleeding on the admission were excluded. We recorded every upper gastrointestinal bleeding event with clinical relevance. RESULTS Five hundred and thirty-five patients, mean age 70 years, mean length of stay 9.6+/-7.7 days; 140 (26.2%) patients were treated with 40 mg of omeprazole intravenously, 193 (36.1%) with 20mg of omeprazole orally, and 202 (37.8%) patients had no prophylaxis. There was only one episode (0.2%) of clinically relevant bleeding. CONCLUSION In patients admitted to an internal medicine ward, incidence of upper gastrointestinal bleeding as a complication of stress-related mucosal disease is low. We found that there is no advantage in prophylaxis with omeprazole.

Extended‐release niacin increases anti‐apolipoprotein A‐I antibodies that block the antioxidant effect of high‐density lipoprotein–cholesterol: the EXPLORE clinical trial

Aims Extended‐release niacin (ERN) is the most effective agent for increasing high‐density lipoprotein–cholesterol (HDL‐C). Having previously identified anti‐HDL antibodies, we investigated whether ERN affected the antioxidant capacity of HDL and whether ERN was associated with the production of antibodies against HDL (aHDL) and apolipoprotein A‐I (aApoA‐I). Methods Twenty‐one patients older than 18 years, with HDL‐C ≤40 mg dl–1 (men) or ≤50 mg dl–1 (women) were randomly assigned to receive daily ERN (n = 10) or placebo (n = 11) for two sequential 12‐week periods, with 4 weeks of wash‐out before cross‐over. Primary outcome was change of paraoxonase‐1 (PON1) activity and secondary outcomes were changes in aHDL and aApoA‐I antibodies. Clinical Trial Unique Identifier: EudraCT 2006–006889‐42. Results The effect of ERN on PON1 activity was nonsignificant (coefficient estimate 20.83 U l–1, 95% confidence interval [CI] –9.88 to 51.53; P = 0.184). ERN was associated with an increase in HDL‐C levels (coefficient estimate 5.21 mg dl–1, 95% CI 1.16 to 9.25; P = 0.012) and its subclasses HDL2 (coefficient estimate 2.46 mg dl–1, 95% CI 0.57 to 4.34; P = 0.011) and HDL3 (coefficient estimate 2.73 mg dl–1, 95% CI 0.47 to 4.98; P = 0.018). ERN was significantly associated with the production of aApoA‐I antibodies (coefficient estimate 0.25 &mgr;g ml–1, 95% CI 0.09–0.40; P = 0.001). aApoA‐I titres at baseline were correlated with decreased PON activity. Conclusions The rise in HDL‐C achieved with ERN was not matched by improved antioxidant capacity, eventually hampered by the emergence of aApoA‐I antibodies. These results may explain why Niacin and other lipid lowering agents fail to reduce cardiovascular risk.

Persistency of low levels of anticardiolipin and anti-beta2 glycoprotein1 in thrombosis.

BACKGROUND Antiphospholipid antibodies, the hallmark of the antiphospholipid syndrome, are associated with both venous and arterial thrombosis. Despite some reports stating that this association may be present in patients with low titres of anticardiolipin antibodies, a clear association has only been established in the presence of a moderate to high concentrations (above 40 GPL or MPL). METHODS In order to study whether low antibody titres could be associated with thrombosis, we reviewed the files of 196 patients, 94 with and 102 without thrombotic events, for a period of 4.4 and 5.1 years respectively. Files from patients with persistent low titres of antiphospholipid antibodies recorded in the unit database were selected, independently of the associated clinical history or diagnosis. Epidemiology, clinical and treatment information were collected and the serum variability of the antibody titres was analysed in relation to the presence of thrombotic events. RESULTS Thrombotic events were classified as venous 81.9% and arterial 18.1%. 23/94 (24.5%) patients with thrombosis had miscarriages. There were no significant differences between serum concentrations of antiphospholipid antibodies in the thrombotic and non-thrombotic groups. However, there was a higher consistency of the antibody concentrations in patients with thrombosis, as seen by the significantly lower variability of IgG aCL and abeta2GP1 titres in patients with thrombosis when compared to non-thrombotic controls (p=0.0025 and p<0.0001, respectively). CONCLUSION Consistency of low titres of antiphospholipid antibody levels may be associated with a higher risk of thrombotic events overall.

OP0223 Significance of IGG Phosphatidylserine-Dependent Antiprothrombin Antibody Testing for the Diagnosis of Antiphospholipid Syndrome: Results from the Initial and Validation International Multi-Centre Studies

Background Phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) are strongly correlated with lupus anticoagulant. A Task Force of scientists at the International Congress on Antiphospholipid Antibodies (APLA 2010) accepted that aPS/PT would potentially contribute for a better identification of antiphospholipid syndrome (APS). Accordingly,we carried out an Initial and a Validation retrospective, cross-sectional multi-centre study on aPS/PT. Objectives To ascertain the value of aPS/PT for APS diagnosis. Methods We conducted an initial study involving 8 centres from 7 countries.Demographics and clinical/laboratory data were retrospectively collected.A sample from the subjects was prepared at each institution.Specimens were blinded and determination of IgG aPS/PT performed at Inova Diagnostics, Inc.USA (Inova) using ELISA kits from two manufacturers:Medical and Biological Laboratories Co Ltd, Japan (MBL) and Inova.After completing the initial study, a Validation study with a new sample of subjects (5 different centres from 5 countries) was carried out using the same methodology. Results The Initial study comprised 247 subjects.Statistically significant correlation in the IgG aPS/PT values was obtained with both ELISA kits (r=0.827, p<0.001). amples with concordant IgG aPS/PT results in both ELISAs (n=204) were subsequently analyzed (99 APS,58 non-APS and 47 healthy). IgG aPS/PT was more prevalent in APS patients (51%) than in those without (9%), OR: 10.8 [95%CI 4-29], p<0.0001. Sensitivity, specificity, positive (LR+) and negative (LR-) likelihood ratio of IgG aPS/PT for APS diagnosis were 51%, 94%, 8.9 and 0.5 respectively.The diagnostic accuracy of IgG aPS/PT for APS diagnosis was assessed by ROC curves showing AUC values of 0.782 and 0.777 for MBL and Inova assays, respectively. In the Validation study (n=214) a statistically significant correlation was found in the IgG aPS/PT titers with both ELISAs (r=0.827, p<0.001). IgG aPS/PT concordant samples were analyzed (n=182;76 APS,57 non-APS and 49 healthy). IgG aPS/PT was more frequent in APS patients (47%) than in those without (12%), OR: 6.4 [95%CI 2.6-16], p<0.0001. Sensitivity, specificity, LR+ and LR- for APS diagnosis were 47%, 93%, 7.2 and 0.6, respectively.AUC values were 0.757 and 0.759 for MBL and Inova assays, respectively. Conclusions The performance of IgG aPS/PT using Inova and MBL ELISA kits is reliable. IgG aPS/PT detection is an easily performed laboratory parameter that may help in the diagnosis of APS. Acknowledgements The authors want to acknowledge the contributions of the late Prof. Silvia Pierangeli, University of Texas Medical Branch, Galveston, TX, USA Disclosure of Interest O. Amengual: None declared, R. Forastiero: None declared, M. Sugiura-Ogasawara: None declared, K. Otomo: None declared, O. Kenji: None declared, C. Favas: None declared, J. Delgado Alves: None declared, P. Žigon: None declared, A. Ambrožič: None declared, M. Tomšič: None declared, I. Ruiz Arruza: None declared, G. Ruiz Irastorza: None declared, M. Bertolaccini: None declared, G. Norman Employee of: Inova Diagnostics, Inc, San Diego, CA USA, Z. Shums: None declared, A. Jiro Employee of: Medical and Biological Laboratories, Co. Ltd, A. Murashima: None declared, A. Tebo: None declared, M. Gerosa: None declared, P. Meroni: None declared, I. Rodriguez-Pintό: None declared, R. Cervera: None declared, J. Swadzba: None declared, J. Musial: None declared, T. Atsumi Grant/research support from: Chugai Pharmaceutical Co., Ltd., Eisai Co., Ltd., Bristol-Myers Squibb Co., Astellas Pharma Inc., Daiichi Sankyo Co., Ltd. and Mitsubishi Tanabe Pharma Co., Speakers bureau: Astellas Pharma Inc. and Mitsubishi Tanabe Pharma Co.

Antibodies against HDL Components in Ischaemic Stroke and Coronary Artery Disease

Quantitative and qualitative defects of high-density lipoprotein (HDL) are important in atherogenesis. In this study, we investigated whether antibodies against HDL components had additional value to conventional cardiovascular risk factors for the diagnosis of ischaemic stroke (IS) and coronary artery disease (CAD). Cross-sectional study was conducted on 53 patients with IS, 51 with CAD and 55 healthy controls, and in vitro studies to validate findings of the clinical study. We determined serum immunoglobulin G (IgG) antibodies against HDL (aHDL), apolipoproteins (aApoA-I, aApoA-II and aApoC-I) and paraoxonase-1 (aPON1) as well as PON1 activity (PON1a), total antioxidant capacity and biomarkers of endothelial activation (serum nitric oxide metabolites, 3-nitrotyrosine, VCAM-1 and ICAM-1); in vitro assays tested the capacity of IgG aHDL purified from high titer patients to inhibit PON1a and to reverse protective effect of HDL on endothelial cells. IgG aHDL, aApoA-I and aPON1 were higher in IS and CAD than controls (p < 0.001), predicted negatively PON1a and positively VCAM-1 and ICAM-1. By adding IgG aHDL and aApoA-I to a traditional cardiovascular risk factors model for IS and by adding IgG aHDL in a similar model for CAD, we obtained better discrimination of IS and CAD from healthy controls. IgG aHDL purified from IS and CAD inhibited PON1a by 38% (p < 0.01) and abrogated the protective effect of HDL on VCAM-1 expression by 126% compared with non-specific human IgG (p < 0.001). IgG against HDL components interfere with the antioxidant and anti-inflammatory properties of HDL and may represent novel biomarkers for vascular disease that need to be investigated in prospective studies.

PS1:13 Systemic lupus erithematosus with positive anticentromere antibodies – a different clinical subgroup?

Introduction Anticentromere antibodies (ACA) are one of the most specific systemic sclerosis (SSc)-related antibodies. The presence of ACA has also been identified in other autoimmune diseases, mainly in SSc overlap syndromes with Sjogren syndrome (SjS), primary biliary cirrhosis and rarely in patients with systemic lupus erythematosus (SLE). Purpose To evaluate the prevalence and clinical significance of ACA in a cohort of SLE patients. Methods Retrospective analysis of all ACA positive SLE patients (ACA +SLE), from a cohort of 270 consecutive SLE patients fulfilling the 2012 SLICC Criteria and/or 1997 ACR Criteria, of a single referral centre, between 2010–2016. Comparative analysis was made with a representative group of 63 consecutive SLE patients without ACA (ACA-veSLE). Data were obtained by medical records review. Results From 270 SLE patients, 10 (3.7%) were ACA+. All ACA +SLE patients were female. The age at the time of diagnosis was not different between the groups (40.9±16.6 years ACA +SLE vs 37.8±16.2 years ACA-veSLE), but ACA +SLE patients had longer disease duration (15.2±17.3 years vs 9.5±8.8 years, p=0.002, respectively). ACA +SLE patients had significantly more Raynaud’s phenomenon (RP) (p=0.028), but none had a capillaroscopy SSc pattern. Sicca symptoms were also more frequent in ACA +SLE (p=0.013), with only 1 patient with a positive anti-SSA antibody. None of these patients fulfilled criteria for SjS. Prevalence of arthritis, oral ulcers, alopecia, cutaneous lupus, serositis, neurologic, renal and hematologic involvement was not significantly different between the two groups. Hypocomplementemia at any time of the disease course was more frequent in ACA-veSLE (p=0.016). Antiphospholipid antibodies were less frequently positive in ACA+SLE patients (20% vs 46%, p=0.1), and none fulfilled criteria for antiphospholipid syndrome (APS) (21% of ACA-veSLE patients with APS). Apart from RP, SSc-associated clinical characteristics (skin thickening, digital ulcers, telangiectasia, pulmonary arterial hypertension, interstitial lung disease, gastroesophageal reflux and calcinosis) were not present in any of the ACA+SLE patients. Conclusions ACA +SLE patients do not constitute a different clinical subgroup regarding organ involvement, but can associate with a lower probability of concomitant APS. Moreover, although highly specific of SSc, ACA can be identified in SLE patients without SSc overlap, and should not hamper the diagnosis of SLE.

157 Antibodies towards atp-binding cassette transporter abca1: a new mechanism for atherosclerosis in sle?

Background and aims Systemic Lupus Erythematosus (SLE) is considered an independent risk factor for cardiovascular disease. ATP-binding cassette transporter ABCA1, also known as the cholesterol efflux regulator protein, is a ubiquitous cholesterol transporter that is highly expressed in macrophages. Its main function is to donate cholesterol to apolipoproteinA-I in lipid-poor HDL particles. As such, ABCA1 closely influences HDL levels and its role in atherosclerosis has been increasingly studied. This study was undertaken to determine if antibodies against ABCA1 can be detected in patients with SLE. Methods Serum from 48 patients were compared with an age and sex-matched control group. Patients were divided in groups A (13 patients) and B (35 patients), respectively with up to 3 and at least 4 SLICC classification criteria (2012). IgG anti-ABCA1 and anti-HDL antibodies were assessed by home-made ELISAs. Plasma lipid profile was determined by standard enzymatic techniques. Results Group A did not differ from control group. Group B had higher titers of anti-ABCA1 antibodies (p=0.004), with 4 patients showing positive anti-ABCA1 titers (11.4%). In group B, anti-ABCA1 antibodies titers tend to negatively correlate with HDL (p=0.06) and apoliporoteinA-I levels (p=0.04). In both groups, anti-HDL antibodies did not correlate with anti-ABCA1 titers. Conclusions This is the first report of naturally occurring antibodies against ABCA1. These antibodies are increased in patients with SLE with at least 4 SLICC classification criteria. Future studies will determine their pathogenic role. This work was supported by the Portuguese Foundation for Science and Technology via the post-doctoral SFRH/BPD/112411/2015 and Fundação Oriente.