Editor–I read with great interest the above case by Perry and colleagues (Clin Med June 2011 pp 268–70). To assess lupus anticoagulant the assay that is widely available is the Russell's viper venom test. Unfortunately, as pointed out by Perry et al, this test cannot be used when patients are on warfarin. Recently, I was educated about the presence of another assay called the Taipan viper venom test. This assay can be used to detect the presence of lupus anticoagulant even if patients have been commenced on warfarin. With respect to this particular patient maybe the doctors would like to explore this option? It would help them exclude or confirm the diagnosis of secondary aPL syndrome and hence decide the duration of anticoagulation accordingly. The pitfall is that this assay is available only in London and Manchester as far as I am aware.
letter . 2011 Oct;11(5):507–508. doi: 10.7861/clinmedicine.11-5-507b
Clinical Medicine. 2011 Oct;11(5):507–508.
We thank Garg et al for their feedback. Cardiac involvement in SLE is indeed important. In our case with a history consistent with pulmonary embolus, the absence of marked cardiovascular compromise on clinical examination, CTPA confirming pulmonary embolus and showing no evidence of pericardial effusion. Echocardiography was performed as a later investigation rather than as an immediate investigation in the acute setting.
We would also like to thank Madan for the guidance, and we will look into the possibility of checking Taipan venom time in this patient.