Correlation of seminal plasma transferrin concentration and hypoosmotic swelling of the sperm

To investigate whether there is a relationship between seminal plasma transferrin concentration and hypoosmotic swelling of the sperm, semen samples from 46 infertile patients were examined. Seminal plasma transferrin concentration in oligozoospermic subjects (sperm concentration < 20 x 10(6)/mL) was significantly lower than that in normozoospermic subjects (sperm concentration > or = 20 x 10(6)/mL) (p < .05). Patients with > or = 50% swollen sperm showed significantly higher transferrin concentration in seminal plasma than those with < 50% swollen sperm (p < .05), while in oligozoospermic patients no difference was observed between seminal plasma transferrin concentration and hypoosmotic swelling. No relationship between seminal plasma transferrin concentration and serum gonadotropin levels was demonstrated. The results indicate that transferrin synthesis is important to sperm membrane integrity and functional competence. However, subsequent fertility must be examined to determine whether seminal plasma transferrin levels are predictive of fertilizing capacity.