Seminal tissue factor revisited

Area of Science:

• Reproductive Biology
• Hemostasis
• Andrology

Background:

• Previous studies suggested seminal tissue factor (TF) might not be involved in seminal coagulum formation due to a reported lack of factor X.
• Recent discoveries of hemostatic factors in semen necessitate a re-evaluation of TF's role.

Purpose of the Study:

• To investigate the presence and concentration of functional and antigenic TF in semen.
• To correlate seminal TF levels with fertility parameters and sperm characteristics.

Main Methods:

• Semen specimens were collected from sub-fertile, normally fertile, semen donors, and vasectomized subjects.
• Semen was fractionated into sperm, prostasome-rich fraction, and seminal plasma.
• Functional and antigenic TF levels were quantified and analyzed in relation to fertility parameters.

Main Results:

• Semen contains high concentrations of both functional and antigenic TF, primarily in seminal plasma and prostasomal fractions.
• TF antigen levels were significantly higher in vasectomized subjects compared to fertile groups.
• Seminal TF antigen levels correlated with sperm agglutination and abnormal morphology, and were elevated in subjects with anti-sperm antibodies.

Conclusions:

• Semen harbors substantial amounts of functional and antigenic TF, suggesting a potential pro-coagulant role.
• The presence of a full complement of clotting factors in semen supports TF's involvement in coagulation.
• Reduced seminal TF levels are associated with improved male fertility parameters.