Antiphospholipid syndrome

Review the puzzling pathophysiology and learn what you can do to help your patient ward off complications. By Richard L. Pullen, Jr., RN, EDD; Jan Cannon, RN, MSN; and Jill Rushing, RN, MSN

Fighting fat isn't always a good thing, especially when phospholipid, a fat molecule in cell membranes, is under attack. Antiphospholipid syndrome (APS) is an autoimmune disorder that occurs when the immune system recognizes phospholipid as foreign and produces abnormal antibodies that react with it. Someone with APS can develop life-threatening complications in any organ.

The diagnosis of APS is based on clinical signs and the presence of antiphospholipid antibodies in the patient's blood. The mnemonic CLOT summarizes the most common signs:

C: recurrent arterial or venous clots

L: livedo reticularis, a lacelike rash over the extremities and trunk caused by sluggish cutaneous blood flow and exaggerated by cold

O: obstetric losses-recurrent miscarriage

T: thrombocytopenia.

The aim of this article is to help you understand the disorder so you can educate a patient with APS about her disease, assess her for complications, and encourage her to maintain a lifestyle that helps prevent related problems.

Clotting process gone awry

Phospholipids affect the clotting process at the platelet and clotting factor levels. When antibodies interfere with phospholipid activity, the risk of thrombosis and ischemia increases, making the patient more susceptible to stroke, myocardial infarction, miscarriage, and gangrene. Her risk of bleeding may increase too, causing her to bruise easily and bleed from the skin, nose, gums, or intestines. She may develop cutaneous ulcerations due to skin thrombosis, renal insufficiency due to renal artery or vein thrombosis, or blindness from thrombosis of the retina. Atherosclerotic heart disease may accelerate, or deep vein thrombosis of the legs may lead to pulmonary emboli.

A definitive diagnosis is made when blood work on someone with a history of thrombosis, thrombocytopenia, recurrent miscarriage, or cutaneous manifestations shows the presence of one or more antiphospholipid antibodies on two separate occasions at least 6 weeks apart. Several antibodies may be responsible, but anticardiolipin antibody, anti-beta 2 glycoprotein I (anti-beta 2 GPI) antibody, and lupus anticoagulant are the most common. Someone who has all three may have thrombosis and bleeding tendencies at the same time. Infection or inflammation can trigger transient anticardiolipin antibodies, but they aren't associated with thrombosis.

Many classes of anti-cardiolipin and anti-beta 2 GPI antibodies exist, such as the immunoglobulins IgG, IgM, and IgA, with IgG commonly associated with thrombosis. Lupus anticoagulant triggers thrombocytopenia, interfering with clotting at the platelet level. Although it can prolong coagulation results, it also increases the risk of blood clots. When someone has a clot and her activated partial thromboplastin time (aPTT) is normal, special coagulation tests can help pinpoint clotting problems associated with lupus anticoagulant.

Tests for APS include the following:

* enzyme-linked immunosorbent assay (ELISA) for anticardiolipin or anti-beta 2 GPI antibody

* modified Russell viper venom clotting time, platelet neutralization procedure, and kaolin clotting time for lupus anticoagulant.

Primary or secondary disease

When APS occurs without another disease process, it's known as primary APS. When it affects someone with another autoimmune disease, such as systemic lupus erythematosus (SLE), it's considered a secondary disorder.

Antiphospholipid antibodies are present in 20% of women with recurrent pregnancy losses. Microscopic thrombi in the blood vessels of the placenta lead to infarction that interrupts delivery of nourishment to the fetus. A woman with a history of pregnancy losses, poor fetal growth, or early onset of severe preeclampsia should be tested for APS.

Approximately 30% of people with SLE develop APS, and secondary thrombosis is a major cause of death in these patients. Closely monitor any patient with SLE for signs and symptoms of APS.

Catastrophic APS is a rare disorder of rapidly progressing multisystem thromboses of small and large vessels. Generally correlating with high antibody titers, catastrophic APS has a 50% mortality rate. Clinical manifestations may include thrombotic thrombocytopenic purpura, disseminated intravascular coagulation, and signs and symptoms of active SLE. Life-threatening complications include gangrene, central nervous system deterioration, massive cardiopulmonary thrombosis, progressive renal failure, and infarction of the bowel, adrenal glands, and liver.

To treat or not to treat

A patient with APS who's never had a blood clot may not require treatment. However, someone who's had clotting problems requires anticoagulation therapy with low-dose aspirin, warfarin, or heparin to prevent future clots. She may also receive prednisone to suppress immune activity and reduce inflammation. Careful assessment is key in someone who's receiving prednisone because corticosteroids can predispose her to thrombosis.

Catastrophic APS always requires treatment with one or more of the following:

* anticoagulation with heparin or warfarin

* plasmapheresis to remove anticardiolipin antibody from the blood

* intravenous immune globulin.

Assess, respond, and teach

When you care for a patient with APS, keep in mind that she may be trying to cope with another condition such as SLE. Encourage her to tell her story during the health history and listen actively as she does. If she wishes, include her family in care planning.

Assess her from head to toe, emphasizing the central nervous system, heart, lungs, and skin. Discolored or bruised skin, diminished capillary refill, or the patient's report of pain may indicate ischemia and thrombocytopenia. Assess her skin for rashes and lesions, which may indicate cutaneous vasculitis and livedo reticularis. Assess her gums for bleeding and test her stool for occult blood.

Anticardiolipin and anti-beta 2 GPI antibodies can cause thickening of the cardiac valves and development of vegetations. Fragments can break off, embolize, and obstruct blood flow to the brain, heart, lungs, blood vessels, or kidneys. Auscultate your patient's heart for murmurs. If she has chest pain or pressure, change in mental status, or decreased or absent peripheral pulses, promptly notify her health care provider; these are signs and symptoms of vascular occlusion and she needs immediate treatment.

Someone with APS may have breathing difficulty, most commonly caused by recurrent pulmonary embolism or pulmonary hypertension. Monitor the rate, depth, and quality of your patient's respirations and auscultate her breath sounds. Correlate your findings with her level of consciousness and her SpO^sub 2^ level, arterial blood gases, and the results of chest X-rays and other imaging studies. Elevate the head of her bed to promote lung expansion. Be on the lookout for the development of anxiety, unexplained tachycardia, shortness of breath, chest pain, and a decrease in SpO^sub 2^, which signal pulmonary emboli.

Behavior changes may indicate hypoxia from pulmonary involvement or thromboembolism of the brain. Assess your patient's mental status and the strength and sensation of her arms and legs. A change may indicate transient ischemic attack or stroke. Monitor her speech patterns. Impaired speaking may be an early sign of neurologic involvement.

Teach your patient and her family about APS. By understanding the importance of a healthy lifestyle, she can decrease her risk of thrombus formation. (See Reducing the Risk of Complications for steps she can follow.) Also share your knowledge of APS with other health care providers, emphasizing the possibility of APS when a patient has few or no risk factors yet experiences thrombosis.

Monitoring and teaching

Once you understand what APS is and how it can affect your patient, you can monitor for complications and teach her to maintain a healthy lifestyle to help ward off future problems.

SELECTED WEB SITES

Lupus Foundation of America: http://www.lupus.org

American College of Rheumatology: http://www.rheumatology.org

Last accessed on February 3, 2004.

SELECTED REFERENCES

Hansen, K.: "Antiphospholipid Antibody Syndrome," in Rheumatology Secrets, 2nd edition. Philadelphia, Pa., Hanley & Belfus, 2002.

Lockshin, M., and Erkan, D.: "Treatment of the Antiphospholipid Syndrome," The New England Journal of Medicine. 349(12):1177-1179, September 18, 2003.

Williams, F., et al.: "Critical Illness in Systemic Lupus Erythematosus and the Antiphospholipid Syndrome," Annals of the Rheumatic Diseases. 61(5):414-421, May 2002.

Wilson, W., et al.: "International Consensus Statement on Preliminary Classification Criteria for Definite Antiphospholipid Syndrome: Report of an International Workshop," Arthritis and Rheumatism. 42(7):1309-1311, July 1999.

By Richard L. Pullen, Jr., RN, EDD; Jan Cannon, RN, MSN; and Jill Rushing, RN, MSN

Richard L. Pullen, Jr., is a professor of nursing and Jan Cannon and Jill Rushing are instructors of nursing at Amarillo (Tex.) College.

Copyright Springhouse Corporation Mar 2004
Provided by ProQuest Information and Learning Company. All rights Reserved