SLE is an inflammatory autoimmune disorder that affects nearly every organ in the body (Systemic). The overall incidence is estimated to be 1.8 to 7.6 per 100,000 people, occurring 4 to 12 times more in women than men. It is more common in African Americans, Hispanics/Latino Americans, Asians, and American Indians/Alaska Natives, compared to White Americans. Other forms of lupus also exist, including subacute cutaneous or discoid lupus erythematous, and drug-induced lupus.
Pathophysiology
The exact cause of SLE is unknown. The immunoregulatory disturbance is thought to be brought about by some combination of four distinct factors: genetic, immunologic, hormonal, and environmental. Research suggests multiple genes that are likely implicated in the development of SLE. Despite this, the majority of SLE cases remain sporadic and unrelated to family history. Hormones (estrogen) have been hypothesized to play a role because of the high number of women with SLE compared to men.
It begins with the immune system inaccurately recognizing one or more components of the cell’s nucleus as foreign, and treats it as an antigen, which prompts the immune cells to begin to develop antibodies for the nuclear antigen.
- In particular, B cells begin to produce antibodies with the help of multiple cytokines such as B-lymphocyte stimulator (BLyS), which is overexpressed in SLE.
- The antibodies and antigens produce antigen-antibody complexes and have the propensity to get trapped in the capillaries of visceral structures. The antibodies also act to destroy host cells. It is thought that these two mechanisms produce the majority of clinical manifestations of this disease process.
Clinical Manifestations
SLE is an autoimmune, systemic disease that can affect any body system. Chronic states where symptoms are minimal or absent, then acute flares where symptoms and lab results are elevated occur.
- Symptoms most often include: fever, fatigue, skin rashes, as well as joint pain and swelling. The mucocutaneous, musculoskeletal, renal, nervous, cardiovascular, and respiratory systems are most commonly involved. The GIT, liver, and ocular systems are less commonly affected.
- 85% of patients experience some type of cutaneous system manifestation, including subacute cutaneous lupus erythematosus, which involves papulosquamous or annular polycyclic lesions, and a discoid rash, which is a chronic rash with erythematous papules or plaques and scaling, and can cause scarring and pigmentation changes. In some cases, the only skin manifestation may be a discoid rash. Skin involvement is a precursor to more systemic involvement. These lesions often worsen during flares of the systemic disease and possibly are provoked by sunlight or artificial ultraviolet light. This may also be accompanied by oral ulcers, splinter hemorrhages, alopecia, and Raynaud’s phenomenon.
- Joint pain and swelling occur in more than 90% of patients with SLE. The same with tenderness is commonly produced by movement. These are also accompanied by morning stiffness.
- The cardiac system is also commonly affected in SLE. Pericarditis is the most common cardiac manifestations. Patients may present with with substernal chest pain that worsens with movement or inspiration. These symptoms can be acute or last weeks at a time. Other manifestations include myocarditis, hypertension, cardiac arrhythmias, and valvular incompetence.
- Nephritis as a result of SLE, also referred to as lupus nephritis occurs from a buildup of antibodies and immune complexes that damage the nephrons. Serum creatinine levels and urinalysis are used for screening for renal involvement. Early detection allows for prevention of renal damage. Renal damage may also result in hypertension.
- CNS Involvement is widespread, encompassing the entire range of neurologic disease. The varies and frequent neuropsychiatric presentations of SLE include psychosis, cognitive impairment, seizures, peripheral and cranial neuropathies, transverse myelitis, and strokes. These are generally demonstrated by subtle changes in behavior patterns or cognitive ability.
Diagnostic Examination
Diagnosis is based on complete history, physical examination, and blood tests. Assessment for known or suspected SLE has special features:
- (Skin) Erythematous rashes, plaques, hyperpigmentation or depigmentation, and other skin changes. Question the patient about sensitivity to sunlight or artificial ultraviolet light.
- (Cardiovascular) Auscultate for pericardial friction rub, possible associated with myocarditis and accompanying pleural effusions, reflecting respiratory insufficiency. These manifest as abnormal lung sounds. Papular, erythematous, and purpuric lesions on the fingertips, elbows, toes, and extensor surfaces of the forearms or lateral sides of the hand that may become necrotic suggest vascular involvement.
- Joint swelling, tenderness, warmth, pain on movement, stiffness, and edema may be detected on physical examination. These are often symmetric and are similar to RA.
- (Neurologic) Identify and describe any CNS changes: behavioral changes, including manifestations of neurosis or psychosis. Signs of depression are noted, as are reports of seizures, chorea, or other CNS manifestations.
- The ANA test is positive in more than 95% of patients with SLE, indicating exceptional specificity. Other tests include anti-DNA (antibody against the patient’s own DNA), anti-ds DNA (anti-DNA specific to SLE), and anti-Sm (antibody against protein in nucleus).
- CBC reveals anemia, thrombocytopenia, leukocytosis, and leukopenia.
Medical Management
Acute diseases require interventions directed at controlling increased disease activity or exacerbations that may affect any organ system. Disease activity is a composite of clinical and laboratory features that reflect active inflammation secondary to SLE. Management of the chronic condition involves periodic monitoring and recognition of harmful clinical changes requiring adjustments in therapy.
Pharmacologic Therapy
The mainstay of treatment is based on pain management and nonspecific immunosuppression. These include monoclonal antibodies, corticosteroids, antimalarial agents, NSAIDs, and immunosuppressive agents. Each of these medications have potentially serious side effects, including organ damage.
- Belimumab is a monoclonal antibody that specifically recognizes and binds to BLyS (B-Lymphocyte Stimulants) that promote antibody production against the body’s nuclei. This action halts the production of unnecessary antibodies and decreases disease activity in SLE. Live vaccines are contraindicated 30 days before taking the medication.
- Rituximaub is an additional monoclonal antibody with immune modulating effects used in treatment.
- Corticosteroids are used (1) topically for cutaneous manifestations, (2) in low doses for minor disease activity, and (3) in high doses (or IV corticosteroids) for major disease activity. Use of corticosteroids in a chronic disease like SLE runs the risk of osteoporosis and fractures. The NSAIDs used for minor clinical manifestations are often used in conjunction with corticosteroids in an effort to minimize corticosteroid requirements.
- Hydroxycholoroquine, an antimalarial agent, is effective in managing cutaneous, musculoskeletal, and mild systemic features of SLE.
- Immunosuppressive agents (alkylating agents and purine analogues) are used because of their effect on overall immune function. These are reserved for serious forms of SLE that are unresponsive to conservative therapies. Examples include cyclophosphamide, azathioprine, mycophenolic acid, and methotrexate, which are contraindicated in pregnancy and have been used most frequently in SLE nephritis.
Nursing Management
The most common nursing diagnoses include fatigue, impaired skin integrity, body image disturbance, and lack of knowledge for self-management decisions.
- Fatigue: facilitate development of appropriate activity/rest schedule, encourage adherence, refer to a conditioning program, and encourage adequate nutrition.
- Body Image Disturbance: dramatic changes in appearance may occur as a result of the cutaneous manifestations of SLE. Participation in support groups that may provide disease information, daily management tips, and social support.
- Avoid exposure to sunlight and ultraviolet light that can increase disease activity. Utilize sunscreen and appropriate clothing.
- Emphasize the need for periodic screenings and health promotional activities. A dietary consultation can fight against the risk of cardiovascular disease, including hypertension and atherosclerosis.
- Stop smoking or using any electronic nicotine delivery systems (ENDS), as these increase risk for respiratory infections, lung cancer, risk of CAD, increased hypertension, worsen kidney function, inhibit liver function, increase risk for skin diseases, and osteoporosis. Refer to and encourage smokers to participate in a smoking cessation program.
- Immunosuppression creates a risk for infection. Monitor the patient for all signs and symptoms of infection, especially in acutely ill patients.
- Screen patients on long-term corticosteroid therapy for osteoporosis. A BMD test is performed at the beginning of therapy as a baseline value. Encourage intake of calcium and vit. D, and weight-bearing exercise.
- Educate the patient in medications, their effects, side effects, and what to monitor and report to the physician.