[A case of rheumatoid arthritis associated with agranulocytosis during bucillamine treatment]

Bucillamine has been reported to have beneficial effects in rheumatoid arthritis. This report concerns a case of RA in which agranulocytosis developed while on a course of bucillamine. A 52-year-old female with RA developed a rapid fall in white blood cell count after 4 weeks of bucillamine treatment at daily dose of 50 mg. Agranulocytosis was diagnosed (WBC 1300/mm3, granulocytes 5%). The administration of bucillamine was halted and she was treated with only prophylactic antibiotic regime. The peripheral granulocyte count result rapidly reversed within 3 days after discontinuation of the bucilamine treatment. Anti-leukocyte antibody was detected by the leukocyte lysis phenomenon method during the period of agranulocytosis. And high intrinsic G-CSF activities were detected in the patient serum before the recovery period of agranulocytosis. Agranulocytosis is a rare side effect of bucillamine but it is potentially more harmful than other side effects. In treatment with bucillamine, therefore, the drug should be carefully administered and regular blood examinations carried out to prevent the occurrence of this side effect.