– A chronic, multisystem, inflammatory connective tissue disorder.
Causes and Incidence
The cause of systemic lupus erythematosus (SLE) is unknown, but it is thought to be an autoimmune disease with interrelated environmental, hormonal, viral, and genetic factors. More than 500,000 individuals in the United States have diagnosed cases of SLE. Nine times as many women as men are affected, and three times as many blacks as whites.
After the etiologic agent or agents are introduced, the body forms antibodies directed against iselfi tissues, cells, and serum proteins. The regulatory components of the immune system are severely compromised by these autoantibodies. The number and activity of T-suppressor cells is diminished, allowing unrestrained proliferation of B cells and resultant hypergammaglobulinemia. Combinations of autoantibodies and autoantigens form, circulate, and are deposited within capillary complexes, renal glomeruli, renal interstitia, serosal membranes, and the choroid plexus and in the pleural vasculature. The formation of these immune complexes triggers an inflammatory response, leading to chronic destruction of host tissue.
Signs and symptoms vary with the acuteness of the disease and the distribution of the immune complexes in body tissues. There is no characteristic clinical pattern, but the following manifestations may be seen: skin: malar or discoid rash (butterfly rash) with scaling, plugging of hair follicles and scarring, painless ulcerations of nasal and oral mucosa, photosensitivity-induced rash; joints: tenderness, swelling, arthritis-like pain; lungs: pleuritis, pleuritic pain, dyspnea, cyanosis; kidneys: oliguria, bladder spasms, edema, proteinuria; neurologic effects: seizure activity, depression, psychoses; blood: anemia, thrombocytopenia; cardiac effects: pericarditis, murmurs, electrocardiographic changes; general: fatigue, headache, fever, malaise, nausea, vomiting, anorexia, weight loss, abdominal pain.
SLE is a chronic and relapsing disease often marked by long periods of remission. If acute episodes can be successfully controlled, the long-term prognosis is good. The 10-year survival rate approaches 95% in the United States. Concomitant infections and renal failure are the leading causes of death.
Antinuclear antibody (ANA) tests are positive in 98% of SLE cases. A positive ANA test should lead to use of a test for anti-DNA antibodies. A high titer in this test is almost specific for SLE.
Joint replacement for chronic synovitis.
Nonsteroidal antiinflammatory drugs for mild disease; steroids and immunosuppressives for severe disease; antiinfective drugs for secondary infections; antimalarials for skin rash.
Plasmapheresis to reduce circulating immune complexes; aggressive management of intercurrent infection; long-term medical monitoring; balanced diet; careful monitoring if pregnant; keeping a disease-related log to trace conditions that trigger flareups; early treatment of flareups; counseling to adapt to long-term disease.