Purpose: This study aimed to assess the impact of hemodialysis treatment and different dialysis membranes with varying surface areas on serum levels of total prostate-specific antigen (tPSA), free prostate-specific antigen (fPSA), and the fPSA/tPSA ratio in patients undergoing hemodialysis treatment.
Material and Methods: The study was conducted at the Central Laboratory of....Hospital in May, June, and July 2020. tPSA, fPSA, and fPSA/tPSA ratios measured in pre-dialysis and post-dialysis samples were determined. Correlation between pre-dialysis and post-dialysis of fPSA and tPSA levels and patients' ultrafiltrates were evaluated. The fPSA, tPSA, and fPSA/tPSA measured in pre-dialysis and post-dialysis samples grouped according to membrane type were compared.
Results: The fPSA levels and fPSA/tPSA ratios of pre-dialysis samples were significantly lower than post-dialysis samples. tPSA values were not significantly different in pre-dialysis and post-dialysis samples. According to membrane types, it was found that pre-dialysis and post-dialysis tPSA, fPSA, and fPSA/tPSA were not significantly different. There was a positive correlation between difference in fPSA concentrations measured in pre-dialysis and post-dialysis samples and ultrafiltrate (rho=0.380). A positive correlation was found between difference in tPSA concentrations measured in pre-dialysis and post-dialysis samples and ultrafiltrate (rho=0.562).
Conclusion: Post-dialysis fPSA values and fPSA/tPSA ratios were found to be elevated in patients receiving hemodialysis treatment due to hemoconcentration and other potential effects of dialysis. Therefore, interpreting fPSA values and fPSA/tPSA ratios in patients undergoing hemodialysis treatment according to current clinical decision limits may lead to misinterpretation. In this group of patients, the use of tPSA testing is safe as it remains unaffected by dialysis treatment.