What Is Prostate Specific Antigen?

Prostate-specific antigen, also known as gamma-seminoprotein or kallikrein-3, P-30 antigen, is a glycoprotein enzyme encoded in humans by the KLK3 gene. PSA is a member of the kallikrein-related peptidase family and is secreted by the epithelial cells of the prostate gland.

What is the purpose of prostate-specific antigen?

Prostate-specific antigen (PSA) is a protein produced by normal prostate cells. This enzyme participates in the dissolution of the seminal fluid coagulum and plays an important role in fertility. The highest amounts of PSA are found in the seminal fluid; some PSA escapes the prostate and can be found in the serum.

What does a high prostate-specific antigen mean?

Elevated prostate-specific antigen (PSA) levels can be a sign of prostate cancer. It can also indicate noncancerous problems such as prostate enlargement and inflammation. Your healthcare provider will work with you to figure out the next steps if you have a high PSA level.