Increasing hCG concentrations during storage at +4°C with the Bayer Centaur Total hCG method

Abstract

Total hCG concentrations in serum specimens collected during early pregnancy increase significantly during storage when measured by the Bayer Centaur Total hCG method, possibly due to a conformational change in hyperglycosylated hCG. When this method is used for monitoring early pregnancy, specimens should ideally be analysed on the day of collection.

False‐positive pregnancy test after passive transfusion of β‐human chorionic gonadotropin from donor red blood cells during erythrocytapheresis

“…Although some degradation of the bHCG was possible during this unit's blood storage con-ditions (19 days at 4°C), a recent study suggests that there was little change over 4 weeks in the level of the hormone in samples from pregnant women with an initial bHCG level of more than 1000 mIU per mL. 6 The bHCG concentration (3826 mIU/mL) was further decreased, by a factor of 34, to 114 mIU per mL ( Table 3, line 6), due to dilution during erythrocytapheresis, into three compartments: 1) the recipient's plasma volume, 2) the extracorporeal volume in the circuit, and 3) waste bag (Table 3). Finally, we applied the upper and lower range of in vivo t1/2 of the bHCG hormone 7 to determine that the expected bHCG level (14-57 mIU/mL) was comparable to that observed in the patient (9 mIU/mL; Table 1).…”

“…The estimated bHCG concentration in the supernatant of the transfused RBC unit would be lower, 3826 mIU per mL (Table 3, line 5), because 100 mL of additive solution (AS) is added to the unit after the FFP is separated from the donor bag. Although some degradation of the bHCG was possible during this unit's blood storage conditions (19 days at 4°C), a recent study suggests that there was little change over 4 weeks in the level of the hormone in samples from pregnant women with an initial bHCG level of more than 1000 mIU per mL 6 . The bHCG concentration (3826 mIU/mL) was further decreased, by a factor of 34, to 114 mIU per mL (Table 3, line 6), due to dilution during erythrocytapheresis, into three compartments: 1) the recipient's plasma volume, 2) the extracorporeal volume in the circuit, and 3) waste bag (Table 3).…”