Immunochemical Identification of an Epithelial Membrane Antigen in Patients With Bladder Cancer

Abstract

An epithelial membrane antigen (EMA) has been analyzed with Western blot at 130-kDa. ELISA was used for screening and diagnosis of EMA in urine samples of bladder cancer patients. EMA was detected in 43 out of 51 bladder cancer patients with detection rate 84%, while it was detected in 22 out of 28 suspicious patients with detection rate 78.5%. In addition, EMA was detected in 21 out of 51 bladder cancer-free patients with detection rate 41%. Moreover EMA was detected in 1 out of 32 urine samples from healthy individuals with detection rate 3.1%. The performance characteristics of ELISA as a rapid diagnostic assay of bladder carcinoma based on EMA detection in urine samples revealed that the sensitivity was 84%, while the specificity was 96.9% among normal individuals. There was an extremely significant (P<0.0001) evaluation of urinary EMA level in patients with bladder cancer compared to the level of healthy subjects. Also the levels of urinary EMA of suspicious patients and bladder cancer-free patients were highly significantly elevated compared to its level in healthy subjects. Furthermore, urinary EMA level of bladder cancer was significantly El-Wseef AM et al. 2 (P<0.0001) higher than its level in bladder cancer-free patients. EMA levels were progressively increased with grades and stages of bladder cancer. It is concluded that, EMA detected at 130 kDa using Western blot and assayed using ELISA for screening and diagnosis of bladder cancer can be used with high sensitivity compared to cystoscopy and high specificity among healthy individuals. Also quantitative estimation of EMA level in the urine of bladder cancer patients can differentiate them from other bladder affections. Therefore, it is concluded that urine EMA assay may serve as a marker for bladder cancer assessment.