Chloroquine treatment and bone changes in rheumatoid arthritis.

The effect of chloroquine on bone and articular cartilage was studied in 28 rheumatoid arthritis patients. After the administration of chloroquine for a minimum of 6 months, a metatarsal bone specimen was taken at operation. The control material consisted of 24 operated patients treated in the same way, except that they had not received chloroquine. Histological investigation, in which pairs of slides were compared in a blind test, revealed that the changes in the articular cartilage in those given chloroquine were less marked. Moreover, a diminished tendency to pannus formation and a more vigorous bone regeneration were observed in this group. Chloroquine seems thus to have a prophylactic effect on the articular cartilage changes in case of rheumatoid arthritis.