b. Systemic Lupus Erythematosus (SLE). SLE is a chronic inflammatory
disease of connective tissue that affects the skin, joints, kidneys, nervous system, and
mucous membranes. A characteristic light-induced butterfly rash or erythema may be
present across the nose. The disease may begin acutely with fever, joint pain, and
malaise or smolder over a period of years with intermittent fever and malaise.
Symptoms from any organ system may be present. The disease occurs most often in
c. Sjogren's Syndrome (SS). This is a benign chronic disease characterized
by a lack of tears and dryness of the eyes and mouth with little or no saliva. It often
occurs secondary to RA or one of the other connective tissue disorders. The disease
occurs most often in women.
d. Progressive Systemic Sclerosis (PSS). PSS is a chronic illness
characterized by a fibrous thickening of the skin (scleroderma) and several internal
organs (gastrointestinal tract, heart, kidney, and lungs). Two-thirds of the patients are
e. Mixed Connective Tissue Disease (MCTD). This is a relatively newly
defined syndrome whose designation is reserved for patients with combined clinical
features of RA, SLE, and PSS.
a. Anti-Native (Double-Stranded) DNA. High levels of this antibody are
associated with SLE and a positive correlation exists with associated nephritis.
b. Anti-Deoxyribonucleoprotein (DNP). A significant number of SLE patients
demonstrate high levels of anti-DNP. Persons with other connective tissue diseases
may display low levels of this antibody.
c. Anti-Sm (Smith). 30% of all patients with SLE are positive, but this is highly
specific for SLE. Greater than 75% of patients with clinically active SLE are anti-Sm
positive. It is absent in other autoimmune conditions.
d. Anti-Ribonucleoprotein (RNP). High titer found in all patients with MCTD.
Low titers may be seen in SLE.
e. Antinucleolar. High titers are highly indicative of PSS.