Rare diseases · Sign or symptom
Lupus anticoagulant
HP:0025343
What it means
Presence of lupus anticoagulant (LA) autoantibodies. LA represent a heterogeneous group of autoantibodies, IgG, IgM, or a mixture of both classes, that interfere with standard phospholipid-based coagulant tests (this is only an in vitro phenomenon, LA do not cause reduction of coagulation in vivo). The antibodies are directed against plasma proteins which also bind to phospholipid surfaces.
Most individuals with lupus anticoagulant do not have lupus erythematosus or other systemic autoimmune disorders. One of the tests for lupus anticoagulant is the dilute Russell's viper venom time (dRVVT).
Rare diseases that can present with this7
Sometimes5–29%
4The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
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Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.