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.

Comparative study between obstetric antiphospholipid syndrome and obstetric morbidity related with antiphospholipid antibodies

BACKGROUND AND OBJECTIVES

To compare clinical, laboratory, treatment and live birth rate data between women with aPL-related obstetric complications (OMAPS) not fulfilling the Sydney criteria and women fulfilling them (OAPS).

MATERIALS AND METHODS

Retrospective and prospective multicentre study. Data comparison between groups from The European Registry on Antiphospholipid Syndrome included within the framework of the European Forum on Antiphospholipid Antibody projects.

RESULTS

338 women were analysed: 247 fulfilled the Sydney criteria (OAPS group) and 91 did not (OMAPS group). In the OMAPS group, 24/91 (26.37%) fulfilled laboratory Sydney criteria (subgroup A) and 67/91 (74.63%) had a low titre and/or non-persistent aPL-positivity (subgroup B). Overall, aPL laboratory categories in OAPS vs. OMAPS showed significant differences: 34% vs. 11% (p<0.0001) for category I, 66% vs. 89% (p<0.0001) for category II. No differences were observed when current obstetric complications were compared (p=0.481). 86.20% of OAPS women were treated vs. 75.82% of OMAPS (p=0.0224), particularly regarding the LDA+LMWH schedule (p=0.006). No differences between groups were observed in live births, gestational, puerperal arterial and/or venous thrombosis.

CONCLUSIONS

Significant differences were found among aPL categories between groups. Treatment rates were higher in OAPS. Both OAPS and OMAPS groups had similarly good foetal-maternal outcomes when treated. The proposal to modify OAPS classification criteria, mostly laboratory requirements, is reinforced by these results.