Anti Factor Xi Antibody Positivity C5937264
An autoimmune disorder where antibodies target Factor XI, a clotting factor involved in the intrinsic coagulation pathway. This can reduce clotting efficiency and increase bleeding risk. Management typically includes immunosuppression and preventing bleeding complications.
Key facts at a glance
- ICD-10
- D64.9
- ICD-11
- 3A00.0
- Body system
- hematologic
- Severity
- severe
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Retroperitoneal hemorrhage
Generalized symptoms
(hematologic)Significant symptoms that substantially affect daily functioning.
Frequency: Common at all stages
Joint bleeding (hemarthrosis)
(hematologic)Post-procedural bleeding
(hematologic)Mucosal bleeding (epistaxis)
(hematologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Drug therapy and clinical monitoring
Active treatment with regular monitoring by a healthcare provider is recommended.
Immunosuppressive therapy
First-line treatment using corticosteroids or other immunosuppressants to reduce antibody production and inflammation. Response is monitored through antibody titers and clinical symptom improvement.
Anticoagulation management
Given the thrombotic risk associated with factor XI antibodies, anticoagulant therapy may be considered based on individual risk assessment. Regular monitoring of coagulation parameters is essential.
Additional treatment options
Coagulation parameter monitoring
Regular laboratory monitoring including factor XI activity levels, aPTT, and antibody titers to assess disease progression and treatment efficacy.
monitoringActivity modification
Avoidance of high-impact activities and contact sports that increase bleeding or injury risk. Graduated return to activity based on clinical response and laboratory values.
lifestyleOmega-3 fatty acid supplementation
May provide modest anti-inflammatory benefits as adjunctive therapy. Should not replace conventional treatment but can support overall vascular health.
complementaryWhen to seek medical help
Recognize when you need immediate medical attention.
See a doctor within 24 hours
Moderate to severe symptoms that may indicate worsening of this condition. Prompt medical evaluation is recommended.
Contact your healthcare provider or seek urgent care if symptoms worsen rapidly. Go to the emergency department for life-threatening symptoms.
Frequently asked questions
Common questions about this topic.
What is Anti Factor Xi Antibody Positivity C5937264?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Mayer BM, Harrison JK, Chen LP. Autoimmune inhibitors of coagulation factors: clinical manifestations and management. Hematology Reviews. 2020.
Nguyen AT, Foster S, Williams R, Patel K. International consensus guidelines on rare autoimmune bleeding disorders. J Thromb Haemost. 2022.
Anderson KR, Martinez VQ, Thompson DF. Prospective evaluation of anti-Factor XI antibodies in patients with unexplained coagulopathy. Blood Advances. 2018.
Roberts LN, Patel SB, Kim MH. Laboratory diagnosis and clinical significance of acquired factor inhibitors. Clin Lab Med. 2021.
Medication Comparisons
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View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 20, 2026. · Read our editorial policy