The antiphospholipid syndrome: a large elephant with many parts or an elusive chameleon disguised by many colours?

Abstract

by the protean clinical manifestations of APS; (2) current nomenclature and recent proposals for revision of the 2006 international classification criteria; (3) an overview of some key issues related to aPL testing; (4) potential pitfalls of applying the APS classification criteria as diagnostic criteria; and (5) the controversial subgroups of seronegative APS and non-APS aPL positivity.

Clinical audit of antiphospholipid antibody testing in tertiary practice: towards improved relevance in thrombophilia investigations

“…From a total of 557 requests for investigation of LA and 1006 requests for aPL testing, we identified 268 internal requests where LA and aCL testing was applied over the study period. The assessed patient samples derived from both inpatients and outpatients, and were referred by a wide variety of specialists (neurologists, obstetrician, rheumatologists, vascular surgeons, cardiologists and haematologists), in line with prior expectations from the literature 3,6 . From the pathology request form, 243/268 (90.6%) requests were for LA testing (or similar (e.g.…”

“…The antiphospholipid syndrome (APS) is an autoimmune condition classically characterised by vascular thromboses and/or pregnancy morbidity, and its diagnosis typically requires laboratory evidence for the presence of antiphospholipid antibodies (aPL) 1–6 . APS actually crosses into many different clinical specialties because of the wide variety of clinical presentations with which it is associated 2,3,6 . aPL are identified using a large number of laboratory procedures based on one of two distinct test processes, namely ‘solid‐phase’ assays and ‘liquid‐phase’ assays 1–6 .…”

“…The former includes several assays, but primarily anticardiolipin antibodies (aCL) and anti‐beta‐2‐glycoprotein‐I antibodies (aβ2GPI), whereas the latter are centred on clot‐based tests that are used to identify the ‘lupus anticoagulant’ (LA). Nevertheless, each of the available laboratory test systems has differing clinical utility and may be differentially applied to identify aPL and diagnose APS 3,6–9 …”

Trials and tribulations in lupus anticoagulant testing

“…This is an important component of the laboratory evaluation of the antiphospholipid syndrome (APS) [2,3] , in turn having significant implications for patient management [2 -4] . In brief, patients identified clinically to have APS, as diagnostically aided using laboratory assessment by LA, can be subjected to long-term anticoagulant therapy, which has significant implications for both lifestyle changes as well as bleeding and thrombosis risk.…”

“…When results are expressed as a ratio, such as a normalised dRVVT ratio, the resultant inter-laboratory coefficients of variation (CVs) range from approximately 5 % -20 % (see Figure 1D for examples from the RCPA QAP). Interestingly, comparative data for solid phase antiphospholipid antibody (aPL) testing, which represents another facet of testing in APS [2,3,7] , shows substantially worse inter-laboratory CVs ranging from approximately 30 % to over 200 % (see Figure 1E for examples from the RCPA QAP; [11] ).…”