Obstetrical outcome and treatments in seronegative primary APS: data from European retrospective study

Abstract

Objective: To compare characteristics, pregnancies and treatments during pregnancies of seronegative and seropositive antiphospholipid syndrome (APS), to analyse factors associated with obstetrical outcome.

Patients and methods: Inclusion criteria were: (1) thrombotic and/or obstetrical APS (Sydney criteria); (2) absence of conventional antiphospholipid antibodies (APL); (3) at least one persistent non-conventional APL among IgA anticardiolipin antibodies, IgA anti-B2GPI, anti-vimentin G/M, anti-annexin V G/M, anti-phosphatidylethanolamine G/M and anti-phosphatidylserine/prothrombin G/M antibodies. The exclusion criteria were: (1) systemic lupus erythematosus ( SLE) or SLE-like disease; and (2) other connective tissue disease.

Results: A total of 187 women (mean 33±5 years) with seronegative APS were included from 14 centres in Austria, Spain, Italy, Slovenia and France and compared with 285 patients with seropositive APS. Seronegative APS has more obstetrical rather than thrombotic phenotypes, with only 6% of venous thrombosis in comparison to seropositive APS. Cumulative incidence of adverse obstetrical events was similar in seronegative and seropositive APS patients, although higher rates of intrauterine deaths (15% vs 5%; p=0.03), of preeclampsia (7% vs 16%, p=0.048) and lower live birth term (36±3 vs 38±3 weeks of gestation; p=0.04) were noted in seropositive APS. The cumulative incidence of adverse obstetrical events was significantly improved in treated versus untreated seronegative APS (log rank<0.05), whereas there was no difference between patients who received aspirin or aspirin-low-molecular weighted heparin combination.

Conclusion: Several non-criteria APL can be detected in patients with clinical APS features without any conventional APL, with various rates. The detection of non-criteria APL and thus the diagnosis of seronegative APS could discuss the therapeutic management similar to seropositive APS, but well-designed controlled studies are necessary.

Keywords: Antibodies; Antiphospholipid; Antiphospholipid Syndrome; Health Care; Outcome and Process Assessment.

Figure 1

Adverse obstetrical events (fetal loss and/or premature birth before the 34 weeks of gestation because of eclampsia or severe preeclampsia or placental insufficiency) in 109 pregnancies of seronegative APS depending on treatment during the pregnancy and the type (aspirin or aspirin/LMWH combination). APS, antiphospholipid syndrome; LMWH, low-molecular weighted heparin.

Figure 2

Adverse obstetrical events (fetal loss and/or premature birth before the 34 weeks of gestation because of eclampsia or severe preeclampsia or placental insufficiency) among 183 pregnancies depending on APS seropositive and seronegative status. APS, antiphospholipid syndrome.