A preliminary report of fetal spinal cord tissue transplantation in two patients suggests that the procedure is both feasible and safe in humans, setting the stage for future research seeking better treatments for spinal cord injuries. The results, part of a four-year study, are included in two papers in the September issue of the Journal of Neurotrauma.
The clinical study was based on a long history of laboratory research showing that transplants of embryonic nerve tissue in laboratory animals could achieve partial anatomical and functional repair following spinal cord injury (SCI). To determine whether this strategy could be successfully translated to humans, a pilot safety and feasibility study was initiated in 1997 in a group of eight patients with progressive posttraumatic syringomyelia.
The study was conducted by a team of neuroscientists and clinical investigators from the University of Florida's College of Medicine, College of Health Professionals, and Evelyn F. & William L. McKnight Brain Institute, and the Malcom Randall Veterans Administration Medical Center, all in Gainesville. One of the team members, Dr. Richard G. Fessler, moved to Rush-Presbyterian-St. Luke's Medical Center in Chicago in July 2000, and is professor of neurological surgery. He is also director of the Institute for Spine Care at the Chicago Institute of Neurosurgery and Neuroresearch (CINN). Another author, Dr. Edward D. Wirth, III, will join the faculty at Rush as assistant professor, neurological surgery, this month.
Syringomyelia, a painful and troublesome complication of SCI characterized by the formation of long cysts in the spinal cord, leads to further tissue damage and neurological problems. The reports present findings for the first two patients in the study, men aged 44 and 51. For 18 months following transplantation surgery, both patients were stable neurologically, and magnetic resonance imaging showed evidence suggesting solid tissue at the graft sites without indications of donor tissue overgrowth.
The study's primary goal is to evaluate the safety of the transplantation procedure with respect to possible early complications and long-term consequences. Although data from the study authored by Wirth and others suggest that transplantation of fetal spinal cord tissue into syringomyelia cavities is logistically feasible and procedurally safe, the long-term consequences of graft survival are still uncertain, say the authors. A secondary goal, addressed in the paper by Thompson and others, is to establish a more comprehensive diagnostic protocol, ranging from neurophysiological tests that monitor subclinical function to standardized questionnaires that measure patients' quality of life.
"We didn't set out to find a cure," said Dr. Douglas K. Anderson, a co-author of the paper. "We wanted to prove that fetal spinal cord transplantation was feasible and procedurally safe, and I think we've done that. We have also provided a template for future studies, which is extremely important. We now have a better idea of how to put these studies together, how to evaluate these patients, and what kinds of outcome measurements to include."
"Before this, there wasn't a lot going on translationally in spinal cord injury," said Dr. Wirth. "Sometimes it takes a study like this to break the ice. We're hoping it will show that with the proper preliminary data these kinds of studies are possible."
"Studies such as these are also important because they take us from the lab bench to the bedside and put us on an important learning curve about human spinal cord injury," added co-author Paul J. Reier, PhD. "They help us identify practical issues in the development of new and safe treatments. In that sense, this experience is already helping us design future laboratory studies that are more in line with real clinical conditions."
"Spinal cord injuries have been documented over the last 5,000 years, yet over that period of time, very little progress has been made in treating them. Transplantation offers us hope for the treatment of spinal cord injury that we had never had before," Dr. Fessler noted.
Donor tissue for the study was human fetal spinal cord tissue of six to nine weeks gestational age, procured following elective abortions in accordance with federal and state laws and ethical guidelines, with informed consent for donation. Reier pointed out that although such fetal cells are very unlikely to be the tissue source of choice for future treatments involving cell grafting in the spinal cord, "they still represent an important research tool in the study of spinal cord injuries and a benchmark for many other types of transplant material now being studied."
"Many questions regarding graft sources, long-term graft survival, growth, and safety still must be addressed," said Journal of Neurotrauma editor in chief John T. Povlishock, PhD, of the Medical College of Virginia of Virginia Commonwealth University. "Yet these early results are encouraging because they illustrate the potential of tissue transplantation for the stabilization and possible repair of central nervous system damage in humans."
"As a first step in this process, these studies have demonstrated that we can do this research safely. The next steps involve learning how to make transplantation achieve the results in patients that we would like to see," said Dr. Fessler.
At the time when the funded research study was conducted, stem cells were not available. Future research work will use stem cells from the 60 existing stem cell pools following the guidelines recently outlined by the Bush administration.
Stem cells are derived from embryonic or adult tissues, cultured and grown in test tubes for later use in transplantation. Embryonic cells are harvested from embryos, maintained for a very short period of time in culture, and transplanted almost immediately.
"President Bush's approval of stem cell research is really important for our ongoing research on spinal tissue transplantation," said Dr. Fessler.
"Feasibility and Safety of Neural Tissue Transplantation in Patients with Syringomyelia" was authored by Edward D. Wirth III, MD, PhD.; Paul J. Reier, PhD; Richard G. Fessler, MD; Floyd J. Thompson, PhD; Basim Uthman, MD; Andrea Behrman, PhD, Joella Beard, MD; Charles J. Vierck, PhD; and Douglas K. Anderson, PhD.
"Neurophysiological Assessment of the Feasibility and Safety of Neural Tissue Transplantation in Patients with Syringomyelia" was authored by Thompson, Reier, Uthman, Susan Mott, MD, Fessler, Behrman, Mark Trimble, PhD, Anderson, and Wirth.
The Chicago Institute of Neurosurgery and Neuroresearch (CINN) is the region's most active neurosurgery practice. Its founder and medical director, Dr. Leonard Cerullo, is the chairman of the department of neurological surgery and co-director of the Rush Neuroscience Institute at Rush-Presbyterian-St. Luke's Medical Center, Chicago. All of the neurosurgeons of CINN have faculty appointments in the Rush Medical College.
Rush-Presbyterian-St. Luke's Medical Center includes the 824-bed Presbyterian-St. Luke's Hospital; 110-bed Johnston R. Bowman Health Center for the Elderly; Rush University (Rush Medical College, College of Nursing, College of Health Sciences and Graduate College); and seven Rush Institutes providing diagnosis, treatment and research into leading health problems. The medical center is the tertiary hub of the Rush System for Health, a comprehensive healthcare system capable of serving about two million people through its outpatient facilities and five member hospitals.
The above story is based on materials provided by Rush Presbyterian St. Luke's Medical Center. Note: Materials may be edited for content and length.
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