Colocalization of immunoglobulin binding factor and prostate specific antigen in human prostate gland

Immunoglobulin binding factor (IgBF) produced in the prostate is a useful marker for the diagnosis of prostatic tumor. IgBF was localized in the majority of epithelial cells of benign prostatic hypertrophy by an immunohistochemical technique. Prostate specific antigen (PSA), a known marker for prostatic cancer, was localized to all epithelial cells. Double immunolabeling of IgBF and PSA using fluorescent methods revealed that all epithelial cells producing IgBF were also immunopositive for PSA and some cells were positive only for PSA. The present findings suggest that the prostatic glands consist of two types of epithelial cells, one producing both IgBF and PSA and the other producing PSA alone.