Extended persistence of antiphospholipid antibodies beyond the 12‐week time interval: Association with baseline antiphospholipid antibodies titres

Abstract

Introduction The confirmation time interval for the presence of antiphospholipid antibodies (aPL) has been extended to 12 weeks as epiphenomenal antibodies may disappear after 6 weeks. Our aim was to analyse extended persistence of aPL positivity beyond the 12‐week interval. Methods We retrospectively analysed our database of 23 856 aPL test samples collected between 2005 and 2017 from 17 367 consecutive patients. Two groups of patients were identified among aPL‐positive patients, confirmed at 12 weeks: with or without extended persistence beyond confirmatory testing. Percentages of extended persistence are given according to the initial aPL positivity profiles, and baseline laboratory variables are compared between the two groups. Results Three hundred and twenty‐seven patients confirmed aPL‐positive had subsequent testing. The vast majority of them displayed extended persistence in the long term: 89.6% and up to 97.9% for patients with initial triple positivity. In extended persistent positive patients, there were more LA‐positive initial samples, and baseline LA test values and IgG aCL titres were higher than in nonpersistent positive patients. Conclusion Data from a large database of an aPL referral laboratory showed that the time interval of 12 weeks defining persistence of aPL positivity was appropriate for the majority of patients. Furthermore, we found baseline features associated with extended persistence.

Guidance from the Scientific and Standardization Committee for lupus anticoagulant/antiphospholipid antibodies of the International Society on Thrombosis and Haemostasis

“…80 These results support the choice of extending the retest interval beyond 12 weeks, which would identify patients who remain persistently positive even beyond this period. 80 Confirmation of triple-positive patients (same isotype 81 or independent of isotype of aCL and aβ2GPI 80 ) seems to be predictable without the need to retest after 12 weeks because triplepositivity persists in the majority of patients. 80,81 A confirmatory positive test after 12 weeks renders the initial test result more reliable and increases assurance of a test result in the context of poor standardization and interferences affecting the test result.…”

“…A recent long‐term follow‐up study reported persistence of aPL over time to be associated with the highest risk of thrombosis in triple‐positive patients 79 . A retrospective study evaluated extended persistence and demonstrated persistence in 96% in a median follow‐up of 56 weeks, with no significant lower persistence in the single positive patients compared with the double and triple positives 80 . These results support the choice of extending the retest interval beyond 12 weeks, which would identify patients who remain persistently positive even beyond this period 80 .…”

“…80 Confirmation of triple-positive patients (same isotype 81 or independent of isotype of aCL and aβ2GPI 80 ) seems to be predictable without the need to retest after 12 weeks because triplepositivity persists in the majority of patients. 80,81 A confirmatory positive test after 12 weeks renders the initial test result more reliable and increases assurance of a test result in the context of poor standardization and interferences affecting the test result. 2,3 We conclude that retesting for confirmation after 12 weeks is still recommended.…”

“…A retrospective study evaluated extended persistence and demonstrated persistence in 96% in a median follow‐up of 56 weeks, with no significant lower persistence in the single positive patients compared with the double and triple positives 80 . These results support the choice of extending the retest interval beyond 12 weeks, which would identify patients who remain persistently positive even beyond this period 80 . Confirmation of triple‐positive patients (same isotype 81 or independent of isotype of aCL and aβ2GPI 80 ) seems to be predictable without the need to retest after 12 weeks because triple‐positivity persists in the majority of patients 80,81 …”

Antiphospholipid syndrome and direct oral anticoagulants: to the future and back again?

“…Recent data from a prospective cohort (Kearon et al, ) confirm previous work showing that multiple positivity of tests and persistence over time increase the risk of recurrent thrombosis after anticoagulant cessation. It has also been shown recently that confirmation of aPL positivity on two or more occasions at least 12 weeks apart was usually associated with persistent positivity over time (Devignes et al , ).…”