Eosinophilic pleural effusion with high anti-DNA activity as a manifestation of systemic lupus erythematosus

A patient, known to have systemic lupus erythematosus (SLE), presented with an eosinophilic pleural effusion. It is believed that SLE was the cause of her pleural effusion as increased levels of anti-DNA activity were found in the pleural fluid. Eosinophilic pleural effusion is a previously unreported observation in SLE patients (so far as the authors are aware), and the existence of increased anti-DNA activity in the pleural fluid may have value as an additional aid in the diagnosis of this disease.