Differences in the clinical profile between isolated lupus anticoagulant and triplepositive antiphospholipid antibody profiles in primary antiphospholipid syndrome.
Azevedo B, Signorelli F, Balbi G, Andrade D • Einstein (Sao Paulo, Brazil) • 2026
No more severe phenotype was observed in patients with triple positivity compared with those with isolated lupus anticoagulant positivity in primary antiphospholipid syndrome in this Brazilian cross-sectional study.
Key Findings
Methods
Among 313 patients screened from two Brazilian tertiary centers, 135 with primary antiphospholipid syndrome were selected: 99 with isolated lupus anticoagulant (LA) positivity and 36 with triple positivity.
Cross-sectional study using two cohorts from two tertiary centers in Brazil.
Patients were divided into two groups by antiphospholipid antibody profile.
Most participants were female (58.5%) and White (61.5%).
Mean age was 50.1±12.0 years and median disease duration was 16 (12-22) years.
Results
Thrombosis rates were similar between the isolated LA and triple-positive groups.
Thrombosis occurred in 93.9% of the LA group versus 100% of the triple-positive group (p=0.131).
The difference was not statistically significant.
Results
Obstetric event rates were similar between the two groups.
Obstetric events occurred in 55.8% of the isolated LA group versus 60.0% of the triple-positive group (p=0.754).
Results
Microthrombotic and non-thrombotic event rates were comparable between the groups.
The abstract reports these rates as comparable without giving specific values.
Results
Hydroxychloroquine use was significantly higher in the triple-positive group than in the isolated LA group.
Hydroxychloroquine use was 36.1% in the triple-positive group versus 15.2% in the LA group (p=0.008).
Conclusions
Triple-positive patients did not show a more severe clinical phenotype than patients with isolated LA positivity.
No more severe phenotype was observed in triple-positive patients compared with isolated LA patients.
This contrasts with expectations from some other populations, where triple positivity is considered higher risk.
Discussion
The authors suggest that the mixed ancestry and demographic composition of the Brazilian population may explain differences compared with more homogeneous populations.
This is offered as a possible explanation for the divergent findings, not as a tested result.
What This Means
This study compared two groups of people with primary antiphospholipid syndrome, an autoimmune condition that raises the risk of blood clots and pregnancy complications. One group tested positive only for lupus anticoagulant, one type of antibody. The other group tested positive for all three main antibodies, known as triple positivity. The researchers looked at 135 patients from two specialized hospitals in Brazil: 99 with lupus anticoagulant alone and 36 with triple positivity.
Triple positivity is often thought to signal a more severe disease, but this study did not find that. Rates of blood clots (93.9% versus 100%) and pregnancy-related complications (55.8% versus 60.0%) were not significantly different between the groups. Rates of small-vessel clotting and non-clotting features were also similar. The one clear difference was that hydroxychloroquine, a medication sometimes used in this condition, was prescribed more often to the triple-positive group (36.1% versus 15.2%).
This research suggests that, in this Brazilian group, the antibody profile did not separate patients into milder and more severe disease. The authors propose that Brazil's mixed ancestry might explain why results differ from studies in more uniform populations. Because this was a cross-sectional study of a relatively small number of patients at specialist centers, the findings may not apply to all patients, and the explanation about ancestry was not directly tested.
Azevedo B, Signorelli F, Balbi G, Andrade D. (2026). Differences in the clinical profile between isolated lupus anticoagulant and triplepositive antiphospholipid antibody profiles in primary antiphospholipid syndrome.. Einstein (Sao Paulo, Brazil). https://doi.org/10.31744/einstein_journal/2026AO1654