Same here. My initial post RP PSA test was 0.050 on a Siemens Centaur, and all subsequent tests on that machine have yielded 0.029-0.059. ALL tests on other machines - Labcorp's Roche, Quests' Beckman Coulter etc etc have been undetectable.
I believe that it is due to hetrophile antibodies I have that react uniquely with the reagent used by Siemens. I started a thread on this. www.healingwell.com/community/default.aspx?f=35&m=3879066
I'm still in the process of arranging a PSA test on the Siemens assay that uses my blood treated to remove heterophiles antibodies.
Heterophile anitibody interference is supposed to be rare. But with the ultra sensitive PSA tests, they seem far more common than from research which uses higher tolerances for PSA, judging from the many posters with this problem
Dx Age 55 Dec '16, PSA 4.313
MP MRI Jan '17: PR 5, Bn Scan -ve
Jan '17 MRI Fs BX 4 of 12 +ve G7 (3+4)
RALP Feb 2, 2017
Path: tumor 1.75x1.8x1.8 G7 (3+4), PT2c ECE, Margins, LN, SV all -ve
Mar-May 2017(SG): 0.029-0.059(Siemens); <0.008(Inn); <0.03(NSCC); < 0.01(Bck Coulter)
Jun-Jul 2017(USA): <0.02(Bck Coulter, Quest); <0.006(Roche, Labcorp); 0.04(Siemens)
Post Edited (WeightLoss) : 8/22/2017 4:51:04 AM (GMT-6)