Combination of standard cytology and immunocytology with BL2-10D1 monoclonal antibody for monitoring-treated bladder cancer patients.

Monoclonal antibody BL2-10D1 directed against a tumor-associated antigen of bladder carcinoma was used for monitoring 11 intravesically treated patients. Thirty-three bladder washout specimens were used for standard cytology and immunological staining. Prior to treatment, 9 of 11 cytologic specimens examined with standard cytology were found to be positive. Using BL2-10D1 alone, only 6 were positive but 1 patient negative with standard cytology was positive with the antibody and corresponded to a positive histological control. Thus, before treatment, an increase in positive rate was observed using the combination of the 2 methods from 82 to 91%. At the end of treatment, 9 washout specimens remained positive with standard cytology, whereas 1 case negative in standard cytology was positive in immunocytology. Thus, the positive rate increased from 82 to 91%. One month after the end of treatment, of 11 washout specimens tested, 3 false-negative standard cytologies and 4 false-negative immunocytologies were shown. However, used in combination, the two methods lead to an increase in positive rate from 67 to 89%. In view of these results, BL2-10D1 may be considered as a useful reagent in combination with the standard cytology for the confirmation of the presence of tumor cells before and after immunotherapy.