Lupus is notoriously variable in its presentation, course, and outcome (Table 59-2). Findings may be conined initially to one organ system, and others become involved later. Or, the disease may irst be multisystem. Frequent findings are malaise, fever, arthritis, rash, pleuropericarditis, photosensitivity, anemia, and cognitive dysfunction. At least half of patients have renal involvement. SLE is also associated with declines in attention, memory, and reasoning (Hahn, 2015; Kozora, 2008).
Identification of antinuclear antibodies (ANA) is the best screening test, however, a positive result is not speciic for SLE. For example, low titers are found in normal individuals, other autoimmune diseases, acute viral infections, and chronic inlammatory processes. Several drugs can also cause a positive reaction. Antibodies to double-stranded DNA (dsDNA) and to Smith (Sm) antigens are relatively speciic for SLE, whereas other antibodies are not (see Table 59-1). Although hundreds of autoantibodies have been described in SLE, only a few have been shown to participate in tissue injury (Sherer, 2004; Tsokos, 2011). Currently, micro array proiles are being developed for more accurate SLE diagnosis (Putterman, 2016).
TABLE 59-1. Some Autoantibodies Produced in Patients with Systemic Lupus Erythematosus (SLE)
Best screening test, multiple antibodies; a second negative test makes SLE unlikely High titers SLE-specific; may correlate with disease activity, nephritis, and vasculitis Specific for SLE
Not SLE-specific, high titers associated with rheumatic syndromes
Not SLE-specific; associated with sicca syndrome, predisposes to cutaneous lupus, neonatal lupus with heart block, reduced risk of nephritis Associated with anti-Ro Common in drug-induced lupus
Lupus anticoagulant and anticardiolipin antibodies associated with thrombosis, fetal loss, thrombocytopenia, valvular heart disease; false-positive test for syphilis Direct Coombs test, may develop hemolysis
Thrombocytopenia in 15%; poor clinical test dsDNA = double-stranded DNA; RNP = ribonucleoprotein. Data from Arbuckle, 2003; Hahn, 2015.
TABLE 59-2. Some Clinical Manifestations of Systemic Lupus Erythematosus
Modified from Kasper, 201r5.
Anemia develops frequently, and there may be leukopenia and thrombocytopenia. Proteinuria and casts are found in the half of patients with glomerular lesions. Lupus nephritis can also cause renal insuiciency, which is more common if there are anti phospholipid antibodies (Moroni, 2004). Other laboratory indings include false-positive syphilis serology, prolonged partial thromboplastin time, and higher RF levels. Elevated serum D-dimer concentrations often follow a lare or infection, but unexplained persistent elevations are associated with a high risk for thrombosis (Wu, 2008).
The diagnostic criteria for SLE are listed in Table 59-3. If any four or more of these 11 criteria are present, serially or
TABLE 59-3. Clinical Criteria for Classification of Systemic Lupus Erythematosus
Renal: proteinuria, casts, biopsy
Neurological: seizures, psychosis, myelitis, neuropathies,
ANA = antinuclear antibodies; dsDNA = double-stranded DNA; Sm = Smith.
Data from Hahn, 201r5; Hochberg, 1997.