Prostate specific antigen (PSA) exists in the serum in several molecular forms that can be measured by immunodetectable assays: free PSA, PSA complexed to alpha 1-antichymotrypsin (complexed PSA) and total PSA, which represents the sum of the free and complexed forms. Introduction: Prostatic tumor tissue produces a more complex form of PSA (cPSA) than free PSA (fPSA). For the early detection of prostate cancer, cPSA is supposed to be more sensitive than the ratio of fPSA and tPSA. The aim of the study was to evaluate the diagnostic value of cPSA in the early detection of malignant prostatic tumor. Complexed PSA: This test directly measures the amount of PSA that is attached to other proteins (the portion of PSA that is not "free"). This test could be done instead of checking the total and free PSA, and it could give the same amount of information, but it is not widely used. In addition, previous attempts to measure complexed PSA (PSA±ACT: PSA bound to a-1-antichymotrypsin) have been limited to the high cross reactivity of the monoclonal antibodies to other ACT An additional portion of PSA that is complexed with α 2-macroglobulin can be measured only if the complex is opened and the PSA epitopes become accessible. Of the total PSA (tPSA) in serum, 10-30% is not bound to serum proteins and is called free PSA (fPSA). .

complexed psa vs free psa