Additional laboratory tests to improve on the diagnosis of antiphospholipid syndrome: Response from Pengo

Abstract

With great interest, we read the work of Meyer et al, who used a mock neonatal extracorporeal membrane oxygenation (ECMO) circuit to investigate the impact of varying flow rates on platelet activation, leukocytes, extracellular vesicles, and thrombin generation in vitro. 1 We appreciate the authors' efforts toward refining treatment to prevent device-related thrombosis as a major cause of morbidity and mortality in this particular group of patients. Indeed, we have previously discovered massive clotting activation in term newborns under ECMO support. Prothrombin fragments 1 + 2, thrombin-antithrombin complex, and D-dimer were substantially increased after 1 hour with a progression that fits the pattern of consumptive coagulopathy. 2 We very much appreciate the comments given by Guzzetta and Downey, who emphasize the developmental peculiarities in neonatal hemostasis that need to be taken into account for a

Lupus anticoagulant testing during anticoagulation, including direct oral anticoagulants

“…As an alternative to LA testing while on anticoagulant therapy, some authors instead advocate for performance of anti–phosphatidyl‐serine/prothrombin (aPS/PT) antibodies, which can be used as a surrogate test for LA and is not affected by anticoagulants. 66 , 67 , 68 The premise for such use is that most patients with APS and triple positivity are also positive in aPS/PT (tetra‐positive aPL), 67 and that aPS/PT more than aβ2GPI is responsible for LA activity in these patients. 68 Figure 4 provides an algorithm that summarises the sentiments expressed in this review, representing a potential approach to the investigation of LA when a patient is on anticoagulant therapy.…”

“…However, should this be unavoidable, there are several strategies available to mitigate anticoagulant interferences, including the use of various anticoagulant neutralizers. As an alternative to LA testing while on anticoagulant therapy, some authors instead advocate for performance of anti–phosphatidyl‐serine/prothrombin (aPS/PT) antibodies, which can be used as a surrogate test for LA and is not affected by anticoagulants 66‐68 67 and that aPS/PT more than aβ2GPI is responsible for LA activity in these patients 68 .…”

Solid Phase Assays for Antiphospholipid Antibodies

“…Testing for aDI in these patients could confirm or exclude the association of pathogenic aβ2GPI autoantibodies. 58…”

“…aPS/PT antibodies might be a surrogate for LA because of their strong correlation with LA, 61 65 66 particular in conditions where LA assays show methodological shortcomings as in anticoagulated patients, this might be helpful. 58 67 However, not all single LA positive patients are aPS/PT positive. 63 65 To replace LA with a suitable and similarly predictive marker that can be measured with an immunological method needs further investigation.…”

“…When the aPL profile shows double positivity, positive aPS/PT may suggest a false negative LA, and when aDI and aPS/PT are negative, this indicates a lower risk for thromboembolic events. 58…”