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Poster Networking

Arterial Thromboembolism

PB0059 - Clinical utility of laboratory tests used at the Royal Hospital to diagnose patients suspected with antiphospholipid syndrome.

Sunday, June 23, 2024
13:45 – 14:45 ICT
Room: Exhibition Hall
Background: The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the presence of antiphospholipid antibodies(aPLs) leading to a hypercoagulable state associated with vascular thrombosis and pregnancy loss. Diagnosis of APS is made by demonstrating the presence of antibody again phospholipid using lupus anticoagulant and anticardiolipin antibodies. However, two positive tests at >12 weeks apart are required to confirm APS.

Aims: We aimed to investigate the epidemiology of APS among 4621 patients referred to the Royal Hospital for a 3 years period.

Methods: Data files of 4621 patients (823 male and 3798 female, median age 38±13) were analysed for the following parameters: ACL antibody, Anti-B2GP1 antibody, APTT and DRVVT. The ACL and Anti-B2GP1 were investigated using AcuStar analyser whereas lupus anticoagulant was performed using CS-5100 analyser. Abnormal results were repeated with a fresh sample at least 12 weeks apart.

Results: Overall, only 106/4621(2.3%) patients were found to be positive for APS. Positive results were confirmed in two separate occasions. All 106 patients were presented with underlined disorders including SLE, Thrombotic events or pregnancy morbidity. Fifteen patients had triple positive, sixteen patients had double positive and remaining seventy five patients had single positivity. All positive cases were correlated with their clinical history. In contrast, APS was not detected in 4515 patients, 4081 of which were negative where as43474 patients had their initial results positive, however the repeated results were either negative(n=30) or were not tested(n=404 ). The overall levels of antibodiesfor ACL and B2GPI varied considerable ranging from 2 to 7762 and 6.2 to 23143 respectively.

Conclusion(s): Our current study revealed that high proportion of patients investigated in this cohort was found to be negative for APS. One of the possible reasons is that the initial patient’s selection criteria were not strictly followed and so need to be addressed.