A monoclonal antibody (Bl2‐10D1) reacting with a bladder‐cancer‐associated antigen

Abstract

A hybridoma cell line secreting an IgM monoclonal antibody (MAb) was produced after immunizing a mouse with RT4 cells and a crude suspension of human bladder carcinoma cells (WHO grades II and III TCC). This MAb reacted with RT4 target cells derived from a human transitional bladder cancer but failed to react with a majority of non-bladder cancer cell lines. Immunohistological studies indicate that this MAb reacts inconstantly with normal bladder: in positive cases only a few superficial cells (5% to 10% umbrella cells) are stained but not intermediate or basal cells of the urothelium. This MAb was evaluated on 118 tumors: it reacted with tumor tissue in a majority of grade I (79.5%) and grade II papillary TCC (77.3%), less with grade III papillary TCC (45%) and very rarely with invasive non-papillary TCC (14%). In cases of flat lesions a strong reactivity of superficial, intermediate and/or basal layer cells was observed in 50% of moderate and severe dysplasia and in all cell layers of carcinomas in situ (CIS)(9/9).

Combination of Standard Cytology and Immunocytology with BL2-10D1 Monoclonal Antibody for Monitoring-Treated Bladder Cancer Patients

“…Six of 11 cytologic specimens were positive with BL2-10D1: 2 CIS, 2 grade 2 TCC and 2 grade 3 TCC. As already described, BL2-10D1 was positive in CIS [9], In addition, positive cells were detected in 1 specimen nega tive with standard cytology. Thus, the use of BL2-10D1 MAb improved the cytologic diagnosis from 82 to 91%.…”

“…There was a discrepancy between standard cytology and immunocytology in 5 cases (patients No. 2,6,7,8,9). Among these 5 cytologic specimens, BL2-10D1 failed to react in 4 cases (2,6,7,8) which were positive with standard cytology.…”

Monoclonal antibodies in bladder cancer cytology

“…Using this criterion, 36 of the 40 TCC patients showed positive staining (90%). In all, 55 patients were monitored after transurethral resection (TUR) of stage Ta and TI TCCs [14]. Immunocytology was performed every 4 weeks for a mean period of 2 years.…”

“…All of these antibodies cross-react to some extent with the same non-TCC cells, such as umbrella cells, granulocytes, goblet cells, and proximal renal tubules. In addition, G4/E7 inhibits binding of 10DI to a target cell line [14]. G4/E7 and 486 P3/12 recognize glycoproteins with similar molecular weights, suggesting that they may recognize closely related antigenic determinants, e.g.…”

“…Antibody BL2-10D1 was obtained by immunizing BALB/c mice with a mixture of the RT4 human bladdercancer cell line and a crude extract of grade II and III bladder cancers and is of the IgM subclass [14]. It also reacts with frozen and deparaffinized sections.…”