Project description

Serum prostate‐specific antigen complexed to alpha2‐macroglobulin is occult and is not detected by conventional immunoassays. Conditions affecting alpha2‐macroglobulin levels may alter the specificity of prostate‐specific antigen free/total ratio in predicting prostate cancer. A group of patients (n = 24) undergoing surgical stress due to a coronary artery bypass grafting was followed pre‐ and postoperatively up to 6 days. Total and free prostate‐specific antigen, alpha2‐macroglobulin, and C‐reactive protein were measured by electrochemiluminescence, immunonephelometry, and immunoturbidimetry, respectively. Total prostate‐specific antigen and C‐reactive protein increased significantly postsurgery and remained elevated. Free/total ratio correlated negatively with C‐reactive protein only (p = 0.000) using xtgee panel data analysis, after correction for plasma volume changes using albumin. Increased C‐reactive protein may reflect falsely decreased free/total ratio. Therefore, prostate‐specific antigen free/total ratio would be more reliable if interpreted in combination with information about CRP. However, it is recommended to defer the measurement of free/total ratio if CRP is highly elevated.

Researchers

Keywords

Clinical immunology Oncology