Pre- and post-centrifugation stability of total and free prostate specific antigen samples at room temperature storage conditions

Objectives: Considering the recommendations of literature, it was important to note the potential for differences in pre-and post-analytical storage conditions at room temperature between total and free prostate-specific antigen.The aim of our study was to establish whether it would be appropriate to align the pre-and post-analytical times for the determination of free prostate-specific antigen (fPSA) with those for total prostate-specific antigen (tPSA).Methods: Two blood samples were taken from 48 male patients aged 60 to 84.One specimen was centrifuged within one hour of collection.Each sample was tested immediately for total and free PSA.The second blood sample was kept at room temperature for 12 hours before being tested and then reanalyzed 24 hours after blood sampling.Serum specimens were analyzed on the Roche Cobas E801.Results: There were no notable alterations in any PSA forms (p=0.866 and 0.971) or calculated ratios (Kappa=1) for the blood sample that was stored at room temperature for 12 hours prior to processing.Furthermore, all forms of PSA demonstrated stability (p=0.956 and 0.901), and fPSA/tPSA ratios showed good agreement in serum for up to 24 hours at room temperature (Kappa=1).Conclusion: It would be beneficial to extend the pre-and post-analysis times of fPSA to align them with those of tPSA.Following the elevated tPSA discovery, investigating fPSA could be more streamlined, offering an improved patient management solution.