[Local immunotherapy with streptococcal preparation, OK-432 in superficial bladder tumors, and common antigens between OK-432 and the tumor].

In 38 patients with superficial bladder, local immunotherapy with streptococcal preparation OK-432 has been performed. We investigated whether OK-432 was an effective biological response modifier (BRM) against bladder tumors or not, and the relationship between the common antigens which OK-432 shared with the tumors, and antitumor effects of OK-432. In six out of 28 patients treated by intravesical instillation, and three out of 10 cases treated by intratumor injection, tumors were eliminated endoscopically. In the other patients, the tumors did not change. The PAP study using an anti-OK-432 antibody, showed a positive reaction in 66.7% of the instillation cases and in 40.0% in the injection cases. In 66.7% of the patients with the common antigens treated by the instillation and in 75.0% of patients with the antigens treated by the injection, tumors were eliminated. However, the PAP study showed a positive reaction in 9.1% of the no-change cases treated by the instillation and in 14.3% out of the no-change cases treated by the injection. We concluded that OK-432 was a favorable BRM for topical immunotherapy against bladder tumor and the presence of the common antigens between OK-432 and tumor may enhance the immune response of patients and promote tumor regression.