Amanda Chenoweth, 21 years of age, returned from a summer job as a pianist on a cruise ship where she was exposed daily to excessive sun; she developed a rash on her cheeks

Question

She complained that her finger joints were stiff and painful, which made it difficult to play the piano, and that her hips became painful after sitting at the piano for long periods. Her blood sample tested positive for anti-nuclear antibodies and had decreased serum C3 levels. A urine albumin test showed elevated protein levels. A course of prednisone (an anti-inflammatory steroid) in combination with naprosyn (a nonsteroidal anti-inflammatory agent) was begun and her condition improved rapidly. What is the most likely cause and clinical name of her condition?

What will be an ideal response?
a. deterioration of the central nervous system; multiple sclerosis
b. cartilage destruction by bone-cell enzymes; rheumatoid arthritis
c. immune complexes fixing complement in kidney, joints, and blood vessels; systemic lupus erythematosus
d. autoantibodies against acetylcholine receptor at the neuromuscular junction; myasthenia gravis
e. consumption of seafood to which she was allergic; acute systemic anaphy

Answer 1

Rationale: The answer is c. This is a case of systemic lupus erythematosus (SLE). The vascular rash on the face, and the painful finger joints and hips, suggest that Amanda has developed a systemic inflammatory condition. The decreased levels of C3 are consistent with increased complement fixation by the classical pathway mediated by the anti-nuclear antibodies typical of SLE. Elevated levels of protein in the urine are suggestive of glomerulonephritis, another common complication of SLE. When immune complexes of antibody, complement, and antigen are deposited in the synovia of joints, in blood vessel walls, and in kidney glomeruli rather than being cleared from the circulation, inflammation results.