Low complement levels are related to poor obstetric outcomes in women with obstetric antiphospholipid syndrome. The EUROAPS Registry Study Group

INTRODUCTION

Obstetric antiphospholipid syndrome (OAPS) is an autoimmune disease related to antiphospholipid antibodies (aPL) with primaryinflammatory injury followed by clot cascade activation and thrombus formation. Complement system activation and their participation in aPL-related thrombosis is unclosed.

METHODS

We haveanalysed adverse pregnancy outcomes (APO) related to low complement (LC) levels in a cohort of 1048 women fulfilling classification criteria for OAPS.

RESULTS

Overall, 223 (21.3%) women presented LC values, during pregnancy. The length of pregnancy was shorter in OAPS women with LC compared to those with normal complement (NC) (median: 33 weeks, interquartile range: [24-38] vs. 35 weeks [27-38]; p = 0.022). Life new-born incidence was higher in patients with NC levels than in those with LC levels (74.4% vs. 67.7%; p = 0.045). Foetal losses were more related to women with triple or double aPL positivity carrying LC than NC values (16.3% vs. 8.0% NC; p = 0.027). Finally, some placental vasculopathies were affected in OAPS patients with LC as late Foetal Growth Restriction (FGR >34 weeks) rise to 7.2% in women with LC vs. 3.2% with NC (p = 0.007).

DISCUSSION

Data from our registry indicate that incidence of APO was higher in OAPS women with LC levels and some could be reverted by the correct treatment.

Comparative study of obstetric antiphospholipid syndrome (OAPS) and non-criteria obstetric APS (NC-OAPS): report of 1640 cases from the EUROAPS registry

OBJECTIVES

To compare clinical features, laboratory data and fetal-maternal outcomes between 1000 women with obstetric APS (OAPS) and 640 with aPL-related obstetric complications not fulfilling Sydney criteria (non-criteria OAPS, NC-OAPS).

METHODS

This was a retrospective and prospective multicentre study from the European Registry on Obstetric Antiphospholipid Syndrome.

RESULTS

A total of 1650 women with 5251 episodes, 3601 of which were historical and 1650 latest episodes, were included. Altogether, 1000 cases (OAPS group) fulfilled the Sydney classification criteria and 650 (NC-OAPS group) did not. Ten NC-OAPS cases were excluded for presenting thrombosis during follow-up. All cases were classified as category I (triple positivity or double positivity for aPL) or category II (simple positivity). Overall, aPL laboratory categories showed significant differences: 29.20% in OAPS vs 17.96% in NC-OAPS (P < 0.0001) for category I, and 70.8% in OAPS vs 82% in NC-OAPS (P < 0.0001) for category II. Significant differences were observed when current obstetric complications were compared (P < 0.001). However, major differences between groups were not observed in treatment rates, livebirths and thrombotic complications. In the NC-OAPS group, 176/640 (27.5%) did not fulfil Sydney clinical criteria (subgroup A), 175/640 (27.34%) had a low titre and/or non-persistent aPL positivity but did meet the clinical criteria (subgroup B) and 289/640 (45.15%) had a high aPL titre but did not fulfil Sydney clinical criteria (subgroup C).

CONCLUSION

Significant clinical and laboratory differences were found between groups. Fetal-maternal outcomes were similar in both groups when treated. These results suggest that we could improve our clinical practice with better understanding of NC-OAPS patients.

FRI0154 SHOULD BE OLDER PATIENTS TESTED FOR ANTIPHOSPHOLIPID ANTIBODIES? 695 CASES FROM THE RETROSPECTIVE SERIES HIBISCUS

Background:

Although guidelines do not recommend antiphospholipid antibodies testing after 60 yo, recent data reported late onset antiphospholipid syndrome (APS).

Objectives:

To comparatively analyse the clinical, laboratory features and outcomes in 695 cases with primary APS between patients older and younger than 70 yo.

Methods:

we have performed an international study within the framework of the International Registry of primary APS patients treated with Hydroxychloroquine, HIBISCUS (an ongoing retrospective and prospective register launched in 2016). 28 centres from 17 countries participate. Data about late onset APS were analysed in 695 patients and were obtained from a standardized form registered in the database containing 66 items with respect to demographics, clinical and biological features.

Results:

Arterial events and especially stroke represented the main initial and recurrent clinical manifestation in 40 primary APS patients older than 70 yo. There were not statistically significant differences with respect to cardiovascular risk factors between the two groups of patients. A significant male predominance, a familial APS history, a higher prevalence of triple positivity, lower complement levels, and anticardiolipin antibodies (aCL) IgA isotype were found in older patients. Low anticoagulation regimens were safe and efficient, with a low relapse rate in older patients.

Conclusion:

we suggest that the detection of aPL antibodies should be included into the initial screening panel tests in elderly with thrombotic events, especially arterial, in particular those with recurrent stroke and familial APS.

Our study further suggests that lower intensity anticoagulation regimens could be a therapeutic option in older APS patients, as no differences in outcomes and relapse rate were found between patients with high and low intensity anticoagulation regimens.

References:

[1]Grimaud F et al. Rheumatology. 2019;58:1006-10.

[2]Goldman-Mazur S et al. Thromb Res. 2019;176:67-73.

[3]Hirmerova J et al. 2017;36:167-73.

Disclosure of Interests:

Cristina Belizna: None declared, Omar Latino: None declared, Ljudmila Stojanovich: None declared, Patrick Saulnier: None declared, Katrien Devreese: None declared, Sebastien Udry: None declared, Natasa Stanisavljevic: None declared, Aleksandra Djokovic Speakers bureau: KRKA, Astra Zeneca, Actavis, Jaume Alijotas-Reig: None declared, Enrique Esteve-Valverde: None declared, Raquel Ferrer-Oliveras: None declared, Angela Tincani: None declared, Laura Andreoli: None declared, Francesca Regola: None declared, Maarten Limper: None declared, Alexander Makatsariya: None declared, Jamilya Khizroeva: None declared, Viktoria Bitsadze: None declared, Cecilia Chighizola: None declared, Francesca Pregnolato: None declared, Maria Orietta Borghi: None declared, Pier Luigi Meroni: None declared

[Annexins and recurrent pregnancy loss]

Recurrent Pregnancy Loss (RPL) affects public health and directly compromises the quality of life of hundreds of women, with a detrimental effect on their physical and mental health. Approximately 50% of RPL are not associated to any of the currently known etiology and will be considered idiopathic. Recently, it has been demonstrated that the expression of annexin 5 (ANXA5), a protein found on the trophoblastic surface, plays a fundamental role in the development of pregnancy due to its immunomodulator and anticoagulant function at the placentary level. Some genetic haplotypes of ANXA5 are associated to alterations in the expression of this gene, such as haplotype M2 which is associated to a decrease in the expression of ANXA5. The presence of this haplotype is related to the following conditions occurring during pregnancy: RPL, foetal intrauterine growth restriction, low child weight at birth, preeclampsia and maternal pulmonary thromboembolism. This review describes the structure, function and genetic expression of ANXA5, as well as its possible implication in RPL.