NEW YORK (Reuters Health) Feb 15 - In a report in the February 16th issue of The Lancet, researchers from Rush Medical College, Chicago, describe four cases of etanercept-induced systemic lupus erythematosus in arthritis patients.

The first case, reported by lead author Dr. Najia Shakoor and colleagues, involved a 72-year-old woman with a history of inadequately controlled rheumatoid arthritis. Fourteen months after starting etanercept, she complained of malaise, fever, and polysynovitis.

Tests revealed an "antinuclear antibody titer of 1:160, antibodies against double-stranded DNA 33 IU/mL and antihistone antibodies of 2.2." Four weeks after etanercept was discontinued these symptoms resolved.

The second patient, a 47-year-old woman with a history of rheumatoid arthritis, developed a discoid lupus rash 3 months after starting etanercept therapy. This patient too had abnormal antinuclear antibody titer and antibodies against double-stranded DNA. After etanercept was halted, the rash cleared in 6 weeks, the researchers report.

A 39-year-old woman with a 5-year history of rheumatoid arthritis was the third patient. Six weeks after starting etanercept, she developed hypertension, edema, erythematous facial rash, and symmetric polyarthralgia of the hand and wrists. Tests showed that she was positive for antihistone antibodies. Her symptoms resolved 2 weeks after etanercept was stopped.

The last patient, a woman 50 years of age, with a 1-year history of polyarthritis and morning stiffness, developed pleuritic chest pain, malar rash and diffuse skin erythema 5 months after starting etanercept. She had an abnormal antinuclear antibody titer and antibodies against double-stranded DNA, smith antigen, and ribonucleoprotein. Within 2 weeks after etanercept was discontinued, her symptoms resolved, Dr. Shakoor's team notes. "Anti-tumor necrosis factor-alpha is a powerful addition to out therapeutic armamentarium and is generally well tolerated," the investigators write.

"Although the occasional development of antinuclear antibodies is insignificant, these cases suggest that etanercept might be associated with true drug-induced systemic lupus erythematosus; further investigation is necessary to clarify its prevalence and pathogenesis," Dr. Shakoor and colleagues conclude.

Lancet 2002;359:579-580.