Bucillamine [N-(2-mercapto-2-methylpropionyl)-
L-cysteine] is an
anti-rheumatic drug which was developed in Japan.
Interstitial pneumonia induced by
bucillamine has been reported in two patients with
rheumatoid arthritis. In this report, we describe another patient who developed
bucillamine-induced
interstitial pneumonia. In August 1990, a 53-year-old man was admitted because of
fever, dry
cough and
dyspnea on exertion (DOE). Five months previously, he had noted
polyarthritis, and treatment with
bucillamine was started in May 1990. His
polyarthritis improved about 2.5 months after starting
bucillamine, but he developed
fever, dry
cough, and DOE in August 1990. Chest X-ray on admission showed diffuse acinar and interstitial shadows predominantly in the bilateral upper lung fields. Pulmonary function tests revealed decreased vital capacity and diffusing capacity. Arterial blood gas (ABG) analysis revealed moderate
hypoxemia with PaO2 67 Torr. After stopping
bucillamine, the
fever, dry
cough, and DOE improved gradually, and the abnormal shadows on chest X-ray and ABG analysis showed moderate improvements. Bronchoalveolar lavage studies showed that total cell counts and proportion of lymphocytes were increased, and CD4+/CD8+ ratio of T cell subsets was decreased to 0.56. Transbronchial lung biopsy specimen revealed lymphocytic alveolitis and mild interstitial thickening. Lymphocyte stimulation test to
bucillamine was negative, but patch test with
bucillamine was positive. From the patient's
clinical course, laboratory data, and pathologic findings, we concluded that this is a case of
bucillamine-induced
interstitial pneumonia.
After treatment with
corticosteroid, his chest X-ray and pulmonary function test showed marked improvements.(ABSTRACT TRUNCATED AT 250 WORDS)