IDENTIFYING THE CAUSES OF MALE INFERTILITY
Nancy L. Brackett, Ph.D. • Charles M. Lynne, M.D.

Most spinal cord injuries happen to young men, and often result in the inability to father children without medical intervention. The main reason for this infertility is poor sperm motility. While technological advances in assisted reproduction have provided the means to overcome infertility, the underlying cause of poor sperm motility following SCI is still unknown.

The male fertility laboratory at the Miami Project continues to delve into studies to uncover the reasons for the poor sperm motility. A series of studies by Drs. Brackett and Lynne show that the most pronounced loss of sperm motility occurs after the sperm cells contact seminal plasma during ejaculation. They have also found biochemical abnormalities in semen of men with SCI.

One biochemical abnormality is a higher than normal concentration of leukocytes. Leukocytes (immune system cells) normally act to combat infection. In this most recent study, Drs. Brackett and Lynne used flow cytometry to determine the types of leukocytes present. They found that the most common type of leukocyte present was activated T-cells. Activated T-cells can secrete substances harmful to sperm. Further investigations will determine if these harmful substances are present in the semen of men with spinal cord injury. The results of this study provide a significant step in solving the mystery of decreased sperm motility seen in men with SCI.