- antibodies that block phospholipids surfaces important for coagulation
- increase APTT
- prolonged APTT does not correct with a 1:1 mix of normal platelet-free plasma
- correction of clotting time after addition of excess phospholipids confirms the presence of LA
-> result in acquired hypercoagulability due to poorly understood actions ? alteration of the regulation of haemostasis and endothelial cell injury
- recurrent venous and arterial thromboembolism
- repeated miscarriages
- bleeding in conjunction with thrombocytopenia
- autoimmune disease (SLE, IBD, tumours)
- infections – e.g. mycoplasma, EBV, syphilis, and hepatitis C (may be transient, with lupus anticoagulant resolving after treatment of infection)
- drugs (phenothiazines, phenytoin, hydralazine, quinine, amoxicillin)
- anticoagulation and DVT prophylaxis important
- thrombosis/emboli may be a reason for admission or complication during stay (PE, venous sinus thrombosis, MI, CVA)
- as no single test can detect all antiphospholipid antibodies, consensus guidelines recommend screening for LA with 2 or more phospholipis-dependent coagulation tests that work using different principles:
(2) dilute Russell viper venom time
(3) silica clotting time
(4) kaolin clotting time
(5) dilute PT
(6) textarin time
(7) taipan time
References and Links
- LITFL CCC — Antiphospholipid syndrome
- PracticalHaemostasis.com — Antiphospholipid antibodies: introduction
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.