Three cases of arthritis after BCG therapy for bladder cancer.

The authors report three cases of arthritis occurring after treatment with BCG immunotherapy for bladder disease. This complication is observed in 0.5 to 1% of treated patients and affects the small joints of the first BCG injection. The clinical outcome is favourable with non-steroidal antiinflammatory drugs. This form of arthritis may be attributable to a cross-reaction between antigenic components of cartilaginous proteoglycan and BCG, influenced by a particular HLA-DR pattern, and with the intervention of a heat shock protein