Serum and urinary prostate-specific antigen and urinary human glandular kallikrein concentrations are significantly increased after testosterone administration in female-to-male transsexuals

Background: The genes that encode prostate-specific antigen (PSA) and human glandular kallikrein (hK2) are up-regulated by androgens and progestins in cultured cells, but no published studies have described the effect of andr ogen administration in women on serum and urinary PSA or hK2. Methods: We measured serum and urinary PSA and hK2 before, and 4 and 12 mon ths post testosterone treatment by immunofluorometric methods in 32 female- to-male transsexuals. Results: Mean serum PSA increased from 1.1 ng/L to 11.1 ng/L and then to 22 ng/L by 4 and 12 months post treatment, respectively; the corresponding me an values in urine were 17, 1420, and 18130 ng/L, respectively. Serum hK2, another kallikrein closely related to PSA, remained undetectable at the thr ee time points. However, urinary hK2 concentration rose from below the dete ction limit (<6 ng/L) before treatment to 18 and 179 ng/L, by the 4th and t he 12th month of treatment, respectively. All changes were statistically si gnificant (P <0.001) at 4 months. Conclusions: Testosterone administration increases serum and urinary PSA an d urinary hK2 in women. These measurements may be useful as indicators of a ndrogenic stimulation in women. (C) 2000 American Association for Clinical Chemistry.