Legionnaires' disease diagnosed by bronchoalveolar lavage.

A 51-year-old woman who had been on steroid therapy for systemic lupus erythematosus (SLE) developed a high fever 3 days after visiting a hot spring resort. Chest X-ray films revealed an interstitial, pneumonia-like shadow in the left lung field, which increased rapidly with a worsening of her symptoms. She died of multiple organ failure one week after the onset of the pneumonia. Although the serum antibody titer was negative, Legionella pneumophila was recovered from her bronchoalveolar lavage (BAL) fluid. BAL seems to be a useful method to diagnose Legionnaires' disease.