Lupus Anticoagulant

October 2026 QQ: Anti-Phospholipid Antibody Summary

Our October 2026 quiz, with 32 respondents, asked, “Which is NOT an antiphospholipid antibody?” The answers reveal participants’ wisdom: Anti beta-2 glycoprotein 1: 1 (3%) Alpha-2 antiplasmin: 23 (72%) Lupus anticoagulant: 1 (3%) Antiprothrombin: 7 (22%) Anticardiolipin: 0 The only mislead that attracted respondents was antiprothrombin, a relatively rare APL that is associated with bleeding. […]

Quick Question Archive

What is CAPS?

Here is an illustrated Hemostasis Today description by Dr. Abdul Mannan, Consultant Haematologist at Betsi Cadwaladr University Health Board, of catastrophic antiphospholipid syndrome (CAPS), which accounts for 1% of antiphospholipid syndrome (APS) diagnoses. As Dr. Mannan reports, the APL assay is a vital diagnostic consideration of this acute condition.

Lupus Anticoagulant

Analysis of Antiphospholipid Antibody Testing

Select an open-access article, Thirunavukarasu C, PasalicL, Favaloro EJ. A contemporary analysis of solid-phase antiphospholipid antibody testing: implications for classification or diagnosis of antiphospholipid syndrome, Pathology, https://doi.org/10.1016/j.pathol.2025.07.003 for a look at current ACL and anti β-2 glycoprotein 1 assays and their efficacy in diagnosing APS. Abstract Antiphospholipid antibody (aPL) testing is required for diagnosis of […]

Plasma Collection for IVD

Thanks to Mr. Darcy Shannon of Drumlin Plasma, Inc. for the attached SOP, which distinguishes between plasma collected for IVD applications, such as coagulation calibrators, controls, and reagents, and plasma collected to produce therapeutic plasma fractions.

Bleeding Disorders

April 2025 Quick Question: How to Measure Warfarin in a LAC Patient

Our April 2025 Quick Question is a poll that asks, “How do you measure warfarin in a patient with lupus anticoagulant (LAC)?” This question is a sequel to our March 2025 question, “How do you test for lupus anticoagulant?” that references the ISTH‘s most recent LAC guidelines, Devreese KMJ, Bertolaccini ML, Branch DW, et al. […]

Lupus Anticoagulant

March 2025 Quick Question: LAC Testing Outcome

Our March 2025 Quick Question asked, “How do you test for lupus anticoagulant?” The question drew 38 responses. DRVVT Screen/Confirm only: 4 (11%) PTT Screen/Confirm only: 2 (5%) First DRVVT S/C then PTT S/C if pos: 1 (3%) First PTT S/C then DRVVT S/C if pos: 3 (7%) Both DRVVT S/C & PTT S/C: 27 […]

Lupus Anticoagulant

Lupus Anticoagulant Testing

Anfal Helu asked: I have a question regarding the screening and confirmatory testing for the lupus anticoagulant (LA). Recently, a young female pt was clotting everywhere after a hospital visit for a status epilepticus attack during which she was intubated and placed on mechanical ventilation. She had 2 pulmonary emboli, 2 MI, ischemic colitis, renal […]

Prolonged DRVVT Screen

Soha Abuelela asked how to report a DRVVT screen above 120 seconds and how to report the ratio. I [Geo] consulted with my colleague Dave McGlasson. We began by assuming that 120 seconds represents your instrument’s limit and that the actual clotting time was unrecorded. It could be that your specimen has an undetected clot […]

Anticoagulant Therapy

Is DRVVT Normalization Necessary?

The clot-based dilute Russell viper venom test (DRVVT) reagent activates the coagulation mechanism’s common pathway at the factor X (10) level, relying only on factor V, prothrombin, and fibrinogen for clot formation. The DRVVT test complements the PTT-based assay for lupus anticoagulant (LAC) detection. Because LAC is phospholipid (PL)-dependent, both assays use a minimal-phospholipid (PL) […]

Testing for the Lupus Anticoagulant: The Good, the Bad, and the Ugly

Click here for a “State of the Art Review,” Favaloro EJ, Pasalic L, Selby R. Testing for the lupus anticoagulant: The good, the bad, and the ugly. Research and Practice in Thrombosis and Haemostasis 2024; 8: DOI:https://doi.org/10.1016/j.rpth.2024.102385.

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George Fritsma is a medical laboratory scientist, educator, and author. George is a member of the International Society on Thrombosis and Hemostasis, the International Society for Laboratory Hematology, and the American Society for Clinical Laboratory Science.

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