Clinical utility of the interaction between lectin and serum prostate specific antigen in prostate cancer

The present investigation was a lectin-based diagnosis of malignant prostate cancer (PC) by the interaction of phytohemagglutinin (PHA lectin) from Phaseolus vulgaris with the glycan part of serum prostate specific antigen (PSA) of patients with prostatic disorder. This was confirmed by the interaction between PHA and purified PSA obtained from serum by electrophoretic separation and finally by HPLC chromatography. The precipitate of carbohydrate content after binding of PHA with purified PSA of PC was significantly higher than that of benign prostate hyperplasia (BPH) and/or normal serum PSA. The results suggest that there may be a striking difference in glycosylation pattern of PSA between BPH and PC. The cut off value > or = 10 microg/ml of the carbohydrate content of PHA-PSA precipitate indicates strong suspicion for PC irrespective of total serum PSA cut off level > or = 4.0 ng/ml by conventional immunoassay method and this may be taken as a guideline in differentiating PC and BPH. Key words: prostate cancer, BPH, PSA, lectin.