T. Del Ross

Risk factors for a first thrombotic event in antiphospholipid antibody carriers. A multicentre, retrospective follow-up study

Objectives: To asses risk factors for a first thrombotic event in antiphospholipid antibody (aPL) positive carriers and evaluate the efficacy of prophylactic treatments. Methods: Recruitment criteria were age 18–65 years, no history of thrombosis, positivity for lupus anticoagulant and/or IgG/IgM anticardiolipin antibody (aCL) on ⩾2 occasions at least 6 weeks apart. Demographic, laboratory and clinical parameters were collected at enrolment and at the time of the thrombotic event. Results: 370 patients/subjects (mean (SD) age 34 (9.9) years) were analysed retrospectively for a mean (SD) follow-up of 59.3 (45.5) months. Thirty patients (8.1%) developed a first thrombotic event during follow-up. Hypertension and medium/high levels of IgG aCL were identified by multivariate logistic regression analysis as independent risk factors for thrombosis. Thromboprophylaxis during high-risk and long-term periods was significantly protective. Conclusions: Hypertension or medium/high titres of IgG aCL are risk factors for a first thrombotic event in asymptomatic aPL carriers and primary prophylaxis is protective.

Confirmation of initial antiphospholipid antibody positivity depends on the antiphospholipid antibody profile

The revised classification criteria for the antiphospholipid syndrome state that antiphospholipid (aPL) antibodies (lupus anticoagulant [LAC] and/or anticardiolipin [aCL] and/or anti‐β2‐glycoprotein I [aβ2GPI] antibodies) should be detected on two or more occasions at least 12 weeks apart. Consequently, classification of patient risk and adequacy of treatment may be deferred by 3 months.

Anti-double-stranded DNA antibodies in the healthy elderly: Prevalence and characteristics

UsingCrithidia luciliae fluorescent assay a significant prevalence (7.6%;P<0.006) of anti-double-stranded DNA antibodies was found in a healthy old population. A negative enzyme-linked immunosorbent assay for anti-total histone antibodies excluded a false-positive reaction. Anti-double-stranded DNA antibodies in the aged differed from those found in patients with systemic lupus erythematosus and were characterized by a low titer (95.6% of cases), belonging to the IgA class alone (95.6%), no complement-fixing ability (100%), and negativity to Farr assay (100%). It is concluded that, in elderly subjects without signs and symptoms of disease, including systemic lupus erythematosus, such a peculiar anti-double-stranded DNA antibody may be detected.

A catastrophic antiphospholipid syndrome: the importance of high levels of warfarin anticoagulation.

Abstract. We report the clinical observation of a 23‐year‐old woman affected by the so‐called ‘catastrophic antiphospholipid syndrome’. Within a 3‐month period she suffered a number of thrombotic events and haemolytic anaemia with thrombocytopenia and had high levels of immunoglobulins G and M and anticardiolipin antibodies associated with lupus anticoagulant activity. The severity of the clinical and laboratory changes is described and diagnostic and therapeutic difficulties are discussed. The apparent control of thrombotic events only with high levels of warfarin anticoagulation is stressed.

Antiphospholipid antibodies in mixed connective tissue disease

SummaryWe studied the prevalence and clinical significance of antiphospholipid antibodies (ab) in 28 patients affected with well-defined mixed connective tissue disease (MCTD). Forty-two patients affected with systemic lupus erythematosus (SLE) and 60 healthy subjects were also evaluated, as controls. In MCTD the prevalence of anticardiolipin (aCL) ab was: IgG high level 17.8% (p<0.01 versus healthy controls), IgG low level 7.1% and IgM high level 7.1%. No patients had low level of aCL IgM, lupus anticoagulant or false positive VDRL. The aCL profile was similar to that found in SLE patients, but in SLE all prevalences were higher than in MCTD. Furthermore, in MCTD patients the aCL ab were correlated with thrombocytopenia but not with recurrent thrombosis and/or abortions.

AB0371 Clinical Significance of Anti-Adalimumab Antibodies in Rheumatoid Arthritis, Ankylosing Spondilitis and Psoriasic Arthritis

Background The generation of antidrug antibody (ADAb) is increasingly recognised as a mechanism explaining the failure of anti-TNF drugs in chronic inflammatory diseases. Objectives We designed a prospective, multicentre study on antibodies against adalimumab (anti-ADA) in a cohort of patients treated with adalimumab and affected with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriasic arthritis (PsA), to evaluate their clinical significance. Methods Fifty-eight consecutive patients were enrolled from four Italian Rheumatology Centres. Twenty-one (36.2%) were affected by RA, 22 (37.9%) by AS and 15 (25.9%) by PsA respectively. Anti-ADA antibodies were tested using ELISA commercial kits, kindly provided by Technogenetics, Italy, following the manufacters instructions. Moreover, anti-nuclear antibodies (ANA), anti-dsDNA antibodies, anti-estraible nuclear antigen (anti-ENA) and anti-phospholipid antibodies (aPL) were determined. Detection was made at baseline, 4, 12 and 24 weeks of therapy, respectively. Also, clinimetric (DAS28, BASDAI, BASFI, ASAS20) and serological (rheumathoid factor [RF], anti citrullinated cyclic peptides [ACPA] data were collected at the same intervals. Results The prevalence of anti-ADA, was 6/21 (28.6%) in RA, 4/22 (18.2%) in AS and 1/15 (6.7%) in PsA patients. Ten of the eleven anti-ADA (90.9%) occurred within the first month of therapy. There was a significant association between anti-ADA and lack of response and/or loss of drug efficacy in RA (OR 2.7, 95% CI: 1.5 - 4.9, p=0.0009), in AS (OR: 2.03, 95% CI 1.1 - 3.6; p=0.02), and in PsA (OR: 743.2, 95% CI 44.30 – 12.468; p<0.0001), respectively. Also, was a significant association between the presence of anti-ADA and the development of adverse events (p<0.0001). Surprisingly, was found a significant association between the positivity of RF and/or ACPA antibodies and the absence of anti-ADA, OR: 0.25, 95% CI: 0.1-0.5, p<0.0001 and OR: 0.3, 95% CI: 0.1-0.6, p=0.0008, respectively. The presence of ANA or anti-ENA was significantly associated with the development of anti-ADA (OR: 2.56, 95% CI 1.42-4.63, p=0.002 and OR: 4.56, 95% CI 2.39-8.67 p<0.0001). While, there was no significantly association between the presence of aPL antibodies and the presence of anti-ADA. No patient developed signs and/or symptoms of connective tissue disease or thrombosis during treatment with ADA. Conclusions Our study suggests that anti-ADA antibodies may be considered a predictor of the clinical response to ADA and the occurrence of adverse events. It would therefore justified to incorporate the determination of anti-ADA in the monitoring of patients with RA, AS and PsA treated with ADA. In the course of therapy with ADA may also be helpful the determination of ANA and anti-ENA in view of their association with anti-ADA. It remains to confirm whether patients positive for ACPA, because of the association with the absence of anti-ADA, may have a better response to treatment with ADA. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.5938

Clinical value of anti-domain I-β2Glycoprotein 1 antibodies in antiphospholipid antibody carriers. A single centre, prospective observational follow-up study

BACKGROUND There seems to be a clear correlation between antibodies against domain I (anti-DI) of β2Glycoprotein I and severe clinical profiles in antiphospholipid syndrome (APS) patients. We investigated the clinical significance of anti-DI antibodies in a cohort of aPL carriers. METHODS One hundred and five carriers persistently positive for IgG anti-β2Glycoprotein 1 antibodies (a-β2GPI) and/or IgG anticardiolipin (aCL) and/or lupus anticoagulants (LAC) were tested for the presence of anti-DI antibodies using the QUANTA Flash® Beta2GPI-Domain I chemiluminescence immunoassay. RESULTS Anti-DI antibodies were detected in 44 aPL carriers (41.9%) and they were significantly associated to triple aPL positivity (LAC plus IgG a-β2GPI plus IgG aCL antibodies). Isolated LAC and a-β2GPI antibodies were significantly associated to anti-DI negative aPL carriers. During a 82.2 month mean follow-up, ten aPL carriers (9.5%) developed a first thrombotic event so becoming APS patients. Anti-DI antibodies, triple aPL positivity, thromboembolic risk factors and autoimmune disorders significantly prevailed in carriers becoming APS. Logistic regression analysis showed that anti-DI positivity was an independent risk factor for thrombosis. CONCLUSIONS Anti-DI antibody positivity can be considered a new risk factor predictive of the first thrombotic event in aPL carriers, instead, negative anti-DI may be useful to identify low-risk aPL carriers.

AB0410 Pregnancy and Anti-TNFα Drugs: Experience of Four Centres

Background The introduction of biologic therapies has significantly improved the outcome of inflammatory rheumatic diseases. As most of these diseases affect women and men in childbearing age there is concern about safety of biologic drugs during reproduction and pregnancy. Objectives To evaluate the effects of anti-TNFα agents on pregnancy and foetal outcome. Methods We conducted a retrospective multicentre study of 24 women and 2 men with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA), respectively. They were treated with anti-TNFα agents prior to conception or until conception/during pregnancy. Data were collected from four Centres (Belluno, Padua, Trento and Udine). A 28-question chart abstraction form was filled by the treating rheumatologist. The primary outcome was the occurrence of congenital malformations. Secondary outcomes were the rate of premature birth (defined as <37 weeks of gestation), small for gestational age (defined as <10th percentile) and the occurrence of vaccine complications. Results Until to 31st December 2014, a total of 32 pregnancies were registered, including one twin pregnancy; 5 women had multiple pregnancies. Twenty-four/32 (75%) pregnancies were exposed to anti-TNFα agents at conception or during pregnancy; 21 of these (87.5%) pregnancies occurred following maternal exposure and 3 (12.5%) following paternal exposure. While 8/32 (25%) pregnancies, following leaflet recommendations, had suspended the therapy before conception. An overview of pregnancies following maternal exposure is reported in table 1. One infant was diagnosed with congenital diaphragmatic hernia and obstructive megaureter; the mother was exposed to adalimumab (ADA) at conception and developed preeclampsia at 33 week of gestation (WG). One infant was diagnosed with cystic fibrosis at 3 months of age; the mother was exposed to etanercept (ETN) at conception. One mother exposed to certolizumab (CZP) at conception underwent caesarean section at 35 WG due to preterm premature rupture of membranes. Two mothers exposed to ETN at conception developed a vanishing syndrome and a post-partum infection, respectively. There was no significant difference concerning gestational age and birth weight, both between the group exposed to anti-TNF-alpha at conception and that exposed before conception and, between the groups exposed to different anti-TNFα agents. Seventeen out of 21 infants (80.9%) underwent vaccinations according to national schedule. None of them have any vaccine complications. The pregnancies following paternal exposure were all in ETN. All pregnancies ended in live births. There was one infant with intrauterine growth restriction. The baby was admitted for 14 days to the neonatal intensive care unit for respiratory distress. Conclusions Maternal exposure to anti-TNFα at conception was not associated with an increased risk of congenital malformation and/or with other adverse outcomes. Also the exposure to anti-TNFα in men at time of conception was not associated with any adverse outcome in their partners or newborns. Disclosure of Interest None declared

THU0386 Aphaeretic Procedures and Intravenous Immunoglobulins in Addition to Conventional Therapy to Treat Pregnant Women with High-Risk Antiphospholipid Antibody Syndrome. A Prospective Cohort Study

Background Conventional treatments based on the use of low molecular weight heparin (LMWH) and/or low dose aspirin (LDA) fail in about 20-30% of pregnant women affected with antiphospholipid antibody syndrome (APS). Several risk factors predictive of pregnancy failure during conventionally treated pregnancies have been identified. It has recently been reported that APS women with thrombosis and triple aPL positivity have significantly higher live birth rates when they are prescribed an additional second-line therapy (1). There are as yet no guidelines on the optimal additional treatment strategy for APS women at high risk of pregnancy failure. Objectives This prospective cohort study was undertaken to investigate the efficacy and safety of a second-line treatment protocol administered in addition to conventional therapy to pregnant women with high-risk APS. Methods Seventeen pregnancies in 13 women, all diagnosed with primary APS on the basis of the Sydney International Consensus Statement classification criteria, were assessed perspectively. The studys inclusion criteria were: presence of triple aPL positivity (IgG/IgM anticardiolipin plus IgG/IgM anti-β2Glycoprotein I antibodies plus lupus anticoagulant) along with a history of thrombosis and/or of one or more severe pregnancy complications (preeclampsia, HELLP syndrome, placental insufficiency). The treatment protocol included weekly aphaeretic procedures i.e. plasmapheresis or immunoadsorption and fortnightly 1g/kg intravenous immunoglobulins (IVIG) in addition to daily LDA and twice daily LMWH throughout pregnancy. Results Seventeen consecutive pregnancies occurring between 2002 and 2014 in 13 primary APS patients were assessed. All had triple aPL positivity. Seven (53.8%) had a history of thrombosis, 2 (15.4%) reported one or more severe pregnancy complications and 4 (30.8%) had both. Prior to the study none of the 13 women had experienced a normal pregnancy; nine (69.2%) reported one or more unsuccessful pregnancies while treated with conventional therapy. Of the 17 pregnancies treated conventionally together with the second-line therapy, 16 (94.1%) had favorable outcomes producing 16 live infants, all born between the 26th and 37th week (mean 33.4±2.7 SD). Three (23.1%) women had multiple pregnancies. The infants (8 males and 8 females) had a mean birth weight of 41.9 percentiles ±23.3 SD (range 10-97). The mean Apgar score at 5 min was 8.4±1.0 SD (range 6-10). Due to severe preeclampsia one pregnancy (5.9%) ended at the 24th week; the premature neonate died during the perinatal period. Maternal complications were noted in 4 cases (25%) and foetal complications in 4 (25%). No side-effects linked to the various types of therapy included in the treatment protocol were registered. Conclusions In view of the high live birth rate and the safety of the treatment noted in these women, we can conclude that additional aphaeretic procedures and IVIG should be considered when high-risk pregnancies are being evaluated for treatment. References Ruffatti A, et al. Thromb Haemost 2014; 112: 727-735. Disclosure of Interest None declared

OP0084 Cardiopathogenic Role of Human RO/SSA and LA/SSA Antibodies Demonstrated in a Novel Animal Model of Congenital Heart Block

Background Congenital atrioventricular block (CHB) depend on Ro/SSA and/or La/SSB-autoantibody mediated inflammation and subsequent fibrosis of the atrioventricular node. Despite the association of maternal Ro/SSA and La/SSB autoantibodes with congenital heart block, the mechanisms involved remain unclear. Objectives To study the effect on cardiac conduction of purified human IgG antibodies from a CHB patient mother in an animal model. Methods Female Dark Agouti rats (Charles-Rivers, Germany), 15 weeks old, were injected intra peritoneally with different doses (4 and 2 mg) of IgG purified from a CHB mother tested positive for anti-Ro52-p200 antibodies, a healthy control or with vehicle only on day 7 post mating. The assessment of fetal cardiac function during pregnancy was performed by fetal echocardiography/Doppler recordings at approximately 14 days of pregnancy, and neonatal cardiac function after birth was assessed by ECG recordings within 24 h of birth. Results Performing echocardiography/Doppler we observed significant bradycardia and AV time prolongation in the group injected with 4 mg patient IgG compared to pups injected with 4 mg control IgG or PBS (p=0.0004 and p=0.001, respectively) as well as a significant prolongation of isovolumetric contraction time (ICT) and ejection time (ET) time (p=0.01 and p=0.007). Furthermore, pups in the group injected with 4 mg patient IgG had a significantly higher myocardial performance index (MPI) (p=0.002) than the group injected with 4 mg control IgG. We did not observe bradycardia and/or prolongation of AV time in the group injected with 2 mg patient IgG. However, a significant prolongation of ICT, isovolumetric relaxation time (IRT) and ET time was observed also in the group injected with 2 mg patient IgG compared to 2 mg control IgG (p=0.0003, p=0.001 and p=0.03, respectively). Further, there was a significant increase of MPI (p=0.002) between groups injected with 2 mg patient and control IgG. The ECGs recordings showed that the pups from the group injected with 4 mg patient IgG present a significant reduction of mean heart rate compared to the group injected with 4 mg control IgG (p<0.0001). Moreover, the pups from the 4 mg patient IgG group present a significant prolongation of the PR and RR intervals compared to the group injected with 4 mg IgG control sera (p<0.0001). There was no bradycardia and/or prolongation of PR and RR interval in the group injected with 2 mg patient IgG. Conclusions Our data suggest that high levels (4 mg) of Ro/SSA and La/SSA autoantibodies induce bradycardia, AV time prolongation and decrease cardiac performance, accurately mimicking features of the human disease and confirming a role for the autoantibodies in disease pathogenesis. Even at low levels (2 mg) these antibodies cause a decrease in cardiac performance. The data also suggest that an animal model for CHB can be established by a simple technique of passive transfer of human IgG from a patient with a child with CHB. This model will be useful and highly relevant for investigating the pathogenesis of CHB induced by human Ro/La antibodies, and for evaluating novel therapeutic approaches and drugs. Disclosure of Interest None Declared