Quantification of tissue factor pathway inhibitor (TFPI) in human seminal plasma and in human ovarian follicular fluid

Abstract number: P0564

Thyzel^* E., Siegling^* S., Götting^* C., Tinneberg† H. R., Brinkmann^* T., Kleesiek^* K.

†Frauenklinik, Justus-Liebig-Universität Giessen, Germany ^*Institut für Laboratoriums- u. Transfusionsmedizin, Germany;

Tissue factor pathway inhibitor (TFPI) is a multivalent serine protease inhibitor which plays a central role in the extrinsic pathway of blood coagulation. It consists of three repetitive tandem Kunitz-type domains. TFPI inhibits factor Xa directly and factor VIIa/tissue factor via a quaternary complex. For further elucidation of the known hypocoagulable state of human ovarian follicular fluid and the suggested correlation between subfertility and coagulum formation after ejaculation, we have investigated TFPI levels in liquor folliculi and for the first time in seminal plasma. Total TFPI concentrations were measured in seminal plasma samples of 28 healthy ejaculate donors and 23 infertile patients with oligo-, astheno- or teratozoospermia. TFPI levels were also determined in ovarian follicular fluid gained from the punctured follicles of superovulated women (n = 70) undergoing in vitro fertilization (IVF) and intra cytoplasmatic sperm injection (ICSI). Mean TFPI concentrations in seminal plasma of healthy men were determined as 3.75 ± 2.42 ng mL^-1 and as 2.70 ± 2.03 ng mL^-1 in seminal fluid samples of infertile patients. Thus in seminal fluid of infertile patients TFPI levels were significantly lower (P < 0.07) than in the control group. In follicular fluid mean TFPI concentrations of 330 ± 158 ng mL^-1 were measured, which is about four times higher than the levels found in human blood. The decreased TFPI concentrations in seminal plasma of infertile men support the possible correlation between the coagulum liquefication properties of ejaculated semen and the semen quality which is in concordance with the findings of other groups. Our findings draw attention to coagulation and fibrinolysis markers in the evaluation of patients with fertility problems. However, the significance of this protein for male fertility is not known in detail and remains to be further elucidated. The high TFPI levels measured in liquor folliculi underline the physiological importance of the hypocoaguable state of human ovarian follicular fluid.