Lupus Anticoagulant Antibodies

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Lupus Anticoagulant Antibodies

Synonym/acronym: Lupus inhibitor phospholipid type, lupus antiphospholipid antibodies, LA.

Common use

To assess for systemic dysfunction related to anticoagulation and assist in diagnosing conditions such as lupus erythematosus and fetal loss.


Plasma (1 mL) collected in a completely filled blue-top (3.2% sodium citrate) tube. If the patient’s hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted.

Normal findings

(Method: Dilute Russell viper venom test time) Negative.


Lupus anticoagulant (LA) antibodies are immunoglobulins, usually of the immunoglobulin G class. They are also called lupus antiphospholipid antibodies because they interfere with phospholipid-dependent coagulation tests such as activated partial thromboplastin time (aPTT) by reacting with the phospholipids in the test system. They are not associated with a bleeding disorder unless thrombocytopenia or antiprothrombin antibodies are already present. They are associated with an increased risk of thrombosis. The combination of noninflammatory thrombosis of blood vessels, low platelet count, and history of miscarriage is termed antiphospholipid antibody syndrome and is confirmed by the presence of at least one of the clinical criteria (vascular thrombosis confirmed by histopathology or imaging studies; pregnancy morbidity defined as either one or more unexplained deaths of a morphologically normal fetus at or beyond the 10th week of gestation, one or more premature births of a morphologically normal neonate before the 34th week of gestation due to eclampsia or severe pre-eclampsia, or three or more unexplained consecutive spontaneous abortions before the 10th week of gestation) and one of the laboratory criteria (ACA, IgG, or IgM, detectable at greater than 40 units on two or more occasions at least 12 weeks apart; or LA detectable on two or more occasions at least 12 weeks apart; or anti-β2 glycoprotein 1 antibody, IgG, or IgM, detectable on two or more occasions at least 12 weeks apart, all measured by a standardized ELISA, according to recommended procedures).

This procedure is contraindicated for



  • Evaluate prolonged aPTT
  • Investigate reasons for fetal death

Potential diagnosis

Positive findings in:

  • Antiphospholipid antibody syndrome (LA are nonspecific antibodies associated with this syndrome)
  • Fetal loss (thrombosis associated with LA can form clots that lodge in the placenta and disrupt nutrition to the fetus)
  • Raynaud’s disease (LA can be detected with this condition and can cause vascular inflammation)
  • Rheumatoid arthritis (LA can be detected with this condition and can cause vascular inflammation)
  • Systemic lupus erythematosus (related to formation of thrombi as a result of LA binding to phospholipids on cell walls)
  • Thromboembolism (related to formation of thrombi as a result of LA binding to phospholipids on cell walls)

Critical findings


Interfering factors

  • Drugs that may cause a positive LA test result include calcium channel blockers, heparin, hydralazine, hydantoin, isoniazid, methyldopa, phenytoin, phenothiazine, procainamide, quinine, quinidine, and Thorazine.
  • Placement of a tourniquet for longer than 1 min can result in venous stasis and changes in the concentration of plasma proteins to be measured. Platelet activation may also occur under these conditions, causing erroneous results.
  • Vascular injury during phlebotomy can activate platelets and coagulation factors, causing erroneous results.
  • Hemolyzed specimens must be rejected because hemolysis is an indication of platelet and coagulation factor activation.
  • Icteric or lipemic specimens interfere with optical testing methods, producing erroneous results.
  • Hematocrit greater than 55% may cause falsely prolonged results because of anticoagulant excess relative to plasma volume.
  • Incompletely filled collection tubes, specimens contaminated with heparin, clotted specimens, or unprocessed specimens not delivered to the laboratory within 1 to 2 hr of collection should be rejected.

Nursing Implications and Procedure

Potential nursing problems

ProblemSigns & SymptomsInterventions
Pain (Related to joint inflammation and stiffness)Report of joint pain; emotional symptoms of distress; crying; agitation; facial grimace; moaning; rocking motions; irritability; disturbed sleep; diaphoresis; altered blood pressure and heart rate; nausea; vomitingCollaborate with the patient and physician to identify the best pain management modality to provide relief; refrain from activities that may aggravate pain; use the application of heat or cold to the best effect in managing the pain; monitor pain severity; administer prescribed opioids; discuss with patient what has worked to relieve joint pain in the past; assess the effect of pain on personal, social, and professional obligations; take prescribed anti-inflammatory medication; consider using a bed cradle to keep weight of linens off of legs; collaborate with physical therapy to splint joints; discuss use of imagery or distraction to control pain; avoid prolonged periods of inactivity that could exacerbate joint pain and stiffness
Fatigue (Related to associated anemia; disease progression; depression; pain; disturbed rest)Decreased concentration; increased physical complaints; inability to restore energy with sleep; reports being tired; inability to maintain normal routine; depression; excessive sleep; diminished performanceAssess for physical cause of fatigue; pace activities to preserve energy stores; rate fatigue on a numeric scale to trend degree of fatigue over time; identify what aggravates and decreases fatigue; assess for related emotional factors such as depression; evaluate current medications in relation to fatigue; assess for physiologic factors such as anemia; provide adequate rest periods; encourage warm shower or bath before bedtime; instruct patient to change position frequently while sleeping
Grief (Related to loss of relationship with potential child [fetal loss])Anger; blame; emotional distress; despair; helplessness; powerlessness; emotional pain; depression; detachment; crying; loud vocalization of grief; shockAssess for behaviors that indicate grief; assess for shock, disbelief; identify stage of grieving; assess for cultural or spiritual aspects of grief; assess decision-making capacity that may be altered due to grief; collaborate with social services to support patient during time of grief; listen and allow the patient to verbalize feelings; encourage self-care activities to support own health and healing; refer to community resources such as grief support groups; consider recommendation of pharmacological intervention as appropriate


  • Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
  • Patient Teaching: Inform the patient that this test can assist in evaluation of clotting disorders.
  • Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
  • Obtain a history of the patient’s hematopoietic, immune, musculoskeletal, and reproductive systems; symptoms; and results of previously performed laboratory tests and diagnostic and surgical procedures.
  • Obtain a list of the patient’s current medications, including herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus).
  • Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
  • Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
  • Heparin therapy should be discontinued 2 days before specimen collection, with medical direction. Coumarin therapy should be discontinued 2 wk before specimen collection, with medical direction.
  • Note that there are no food or fluid restrictions unless by medical direction.


  • Potential complications: N/A
  • Ensure that the patient has complied with pretesting preparations; assure that anticoagulant therapy has been restricted as required prior to the procedure.
  • Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
  • Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
  • Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture. Fill tube completely. Important note: When multiple specimens are drawn, the blue-top tube should be collected after sterile (i.e., blood culture) tubes. Otherwise, when using a standard vacutainer system, the blue-top tube is the first tube collected. When a butterfly is used, due to the added tubing, an extra red-top tube should be collected before the blue-top tube to ensure complete filling of the blue-top tube.
  • Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
  • Promptly transport the specimen to the laboratory for processing and analysis. The CLSI recommendation for processed and unprocessed samples stored in unopened tubes is that testing should be completed within 1 to 4 hr of collection.


  • Inform the patient that a report of the results will be made available to the requesting health-care provider (HCP), who will discuss the results with the patient.
  • Recognize anxiety related to test results, and offer support.
  • Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
  • Patient Education

    • Instruct the patient to resume usual medications, as directed by the HCP.
    • Provide teaching and information regarding the clinical implications of the test results, as appropriate.
    • Take time to discuss feelings the mother and father may experience (e.g., guilt, depression, anger) if test results are abnormal.
    • Teach patient to avoid caffeinated foods before bedtime.
    • Educate the patient regarding access to counseling services. Provide contact information, if desired, for the Lupus Foundation of America (
    • Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
    • Answer any questions or address any concerns voiced by the patient or family.
  • Expected Patient Outcomes

    • Knowledge
    • States understanding that taking anti-inflammatory medication as early as possible in the morning will decrease joint stiffness sooner
    • States understanding that anti-inflammatory medication should not be taken on an empty stomach
    • Skills
    • Demonstrates effective use of alternative measures (imagery, distraction) to manage pain
    • Demonstrates proficiency for range-of-motion exercises that can be used to decrease joint stiffness
    • Attitude
    • Complies with recommendation to attend grief counseling to assist in managing grief process
    • Complies with recommendation to attend grief support group, sharing grief experiences can assist emotional healing

Related Monographs

  • Related tests include antibody, anticardiolipin antibodies, anticyclic citrullinated peptide, ANA, arthroscopy, BMD, bone scan, CRP, ESR, FDP, MRI musculoskeletal, aPTT, protein S, PT/INR and mixing studies, radiography bone, RF, synovial fluid analysis, and US obstetric.
  • Refer to the Hematopoietic, Immune, Musculoskeletal, and Reproductive systems tables at the end of the book for related tests by body system.
Handbook of Laboratory and Diagnostic Tests, © 2013 Farlex and Partners