eLetters

2 e-Letters

published between 2019 and 2022

  • Persistence of aPL, looking for the holy grail

    To the editor,

    We have read with interest the study from Khawaja et al. entitled ''Loss of antiphospholipid antibody (aPL) positivity post-thrombosis in systemic lupus erythematosus (SLE)''(1). The authors described 31 patients with antiphospholipid syndrome (APS) associated with systemic lupus erythematosus who presented loss of antiphospholipid antibodies (aPL) positivity after thrombotic events.

    They measured four types of aPL: IgM, IgG and IgA isotypes of anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC). Complete disappearance after thrombosis was observed in 41% of APS patients for IgG aCL, 51% for those with IgM aCL, 50% for IgA aCL, and 20% for LAC. However, 60% of those who at the same time lost IgG aCL and 76% of those who became negative for LAC, reacquired the antibodies within five years. In contrast, only 37% and 17% of those who lost IgM or IgA aCL, reacquired the antibodies within five years, respectively. Finally, 14 (45%) patients never turned back positive during the follow-up period. They concluded that recurrence of aPL positivity is frequent in APS associated with SLE, after their disappearance in post-thrombotic states.

    Until now, long term oral anticoagulation (OAC) is the cornerstone of treatment for thrombotic primary and SLE-associated APS (2). The decision to withdraw OAC in APS patients when aPL become "persistently" negative remains a matter of debate. In the light of results fro...

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  • Overcoming the challenges in new lupus diagnostics

    Dr Olsen and Karp have summarised data from several important papers on the use of novel diagnostic tests for earlier diagnosis of SLE. I agree in the importance of this problem, for the early exclusion of SLE in people with benign ANA positivity, and early intervention in people destined to develop SLE or related disease.

    I also agree with the key challenges in such research. Previous studies have been limited by a retrospective design. Inclusion of patients with variable symptom duration or patient populations that were selected for certain clinical characteristics may bias findings by conditioning on the outcome. Also, putative biomarker results need to be appraised alongside routine diagnostic tests, not in isolation.

    These challenges were met in our previous study into these questions[1]. We invited all ANA-positive referrals to our centre with an onset of the symptoms that triggered referral within the past 12 months to participate, ensuring an unbiased sample appropriate to the clinical question. We collected detailed data on clinical presentation, routine immunology assessments, patient and physician reported severity, and family history, and integrated these data into our biomarker evaluation. Our patients were recruited and followed up prospectively in a standardised schedule of visits with strict assessment of criteria and a "flare hotline" in case new symptoms developed.

    By doing so, we were able to reliably demonstrate the value...

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