Toxic masculinity in red blood cell units? Testosterone therapy in blood donors revisited.

BACKGROUND: FDA guidelines limit the use of blood from donors taking testosterone replacement therapy (TRT) to red blood cell (RBC) concentrates, whereas plasma and platelets are discarded. The purpose of this study is to bring awareness to above-average free testosterone concentrations in RBC units from TRT donors. STUDY DESIGN: We quantified the concentrations of free (bioavailable; pg/ml) and total (protein bound and free; ng/dl) testosterone in plasma (frozen within 24 h) and supernatants from 42-day stored leukocyte-reduced RBC units from 17 TRT male donors and 17 matched controls (no TRT). Total testosterone concentrations were determined by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Free testosterone concentrations were quantified in the same samples using equilibrium dialysis/LC-MS/MS. RESULTS: Plasma free and total testosterone concentrations in TRT donors were 2.9 and 1.8 times higher than that of controls. Total testosterone concentrations in RBC supernatants were about 30% of that of plasma. In contrast, free testosterone concentrations in RBC supernatants were 80%-100% of that of plasma and were significantly (p = .005) higher in TRT compared with controls (252.3 ± 245.3 vs. 103.4 ± 88.2 pg/ml). Supraphysiological free testosterone concentrations (>244 pg/ml) in RBC supernatants were observed in five TRT donors and two control donors. CONCLUSIONS: RBC units from TRT donors may contain supraphysiological concentrations of free testosterone. This may be resolved by avoiding blood collections soon after testosterone dosing and by enhanced screening of TRT donors. These data establish a rationale for new studies and reexamination of the current guidelines concerning the utilization of blood components from TRT donors.