OHSU Researchers Develop Infertility Test for Men
01/30/01 Portland, Ore.
Test Might Quickly Be Developed for Use in Fertility Clinics and Could Result in New Fertility Treatments
Scientists at Oregon Health Sciences University are pleased to announce the development of a new test that may soon aid fertility clinics in diagnosing male infertility. Until now, there have been few objective methods for infertility diagnosis in men. The new test also could offer explanations for infertility while current testing methods offer inconclusive results. Additionally, the test could prevent women from having to undergo unnecessary fertility treatment when male infertility is the cause of the inability to conceive. The research was conducted by Peter Sutovsky, Ph.D., staff scientist at the Oregon Regional Primate Research Center (ORPRC), and Gerald Schatten, Ph.D., a senior scientist at the ORPRC; research director of the Center for Women's Health; and professor of obstetrics and gynecology, and cell and developmental biology, in OHSU's School of Medicine. Colleagues at the Tohoku University School of Medicine were involved in the investigation. Results are printed in the February issue of Human Reproduction.
The new test, called Sperm-Ubiquitin Tag Immunoassay (SUTI), is linked to the cell's natural ability to break down and recycle obsolete proteins internally. The process, called ubiquitation, results in the presence of ubiquitin on the cell surface. Past research has shown that a high level of ubiquitin on the surface of sperm cells is evidence of damage or defect to the sperm. During this study, researchers used immunoflourescence and flow cyclometry to identify sperm cells with high levels of ubiquitin on the surface and detect defective sperm levels in study participants.
To assess the effectiveness of this test, scientists analyzed the sperm of 17 patients from infertility clinics. A total of 13 of the 17 donors displayed high levels of ubiquitin on the sperm cell surface. In the remaining four cases, the test confirmed female-only infertility in three patients. In the final case, the test showed that the male was unlikely to be the cause of unexplained infertility.
"Not only could this research be used to develop an objective method for male infertility testing, it could also provide answers that have not been obtainable in the past," explained Sutovsky. "In addition to confirming infertility, this test also can help physicians detect the reasons for infertility. These reasons may include head and tail defects in the sperm cell, the presence of residual matter that can interfere with fertility, and underdeveloped sperm. Currently about a fifth of infertility cases cannot be explained. Hopefully this test can provide answers in at least a portion of these cases."
According to the American Society for Reproductive Medicine, about 6.1 million people in the United States have trouble conceiving a child. Approximately 40 to 50 percent of these cases are caused by male infertility.
Scientists are hopeful that in the future this research also might result in improved fertilization methods in fertility clinics. "By removing the potentially unhealthy sperm, physicians would be able to use only the best for infertility treatments," explains Schatten. "For those couples who are having trouble conceiving, this would be very good news."
The research was funded by the National Institute of Occupational Safety and Health, and the National Institute of Child and Human Development, two institutes of the National Institutes of Health. The United States Department of Agriculture provided additional funding.