A young woman with cough and chest pain.

A 27 year old woman was admitted to our hospital with a history of a nonproductive cough and breathingdependent chest pain. The symptoms were manifested after a common cold a few weeks earlier. No fever or loss of body weight was noted. The patient’s medical history was remarkable for insulin-dependent diabetes mellitus of 6 yrs duration. She had never smoked. On physical examination, the patient had a normal heart rate and blood pressure. Chest examination revealed normal breathing sounds, and findings on cardiac examination were normal. In fact, no abnormalities were found. Laboratory evaluation, including kidney function and different serological tests, was within normal limits: angiotensin-converting enzyme (ACE) 11.6 nmol·min-1 (normal level 7–20 nmol·min-1), rheumatoid arthritis haemagglutination (RAHA) <40 (0–40), L-antistreptolysine titre (AST) 40 IE·ml-1 (normal level 0–299 IE·ml-1), negative values of antinuclear factors (ANF), anti-double-