Stem cell treatments being promised in mainland China are "21st century snake oil" scam., according to two pediatric eye surgeons at Washington University School of Medicine in St. Louis .
Recent newspaper stories - including several from Missouri -- have reported parents flying their children to main land China for umbilical cord stem cell (CSC) infusions. The cost of these treatments, paid for entirely out-of-pocket by the parents, can be $50,000 or more. CSCs are extracted from the umbilical cords of Chinese mothers and their newborns and injected into the fluid around the spinal cord of the American children. The parents are led to believe by Chinese doctors that these CSCs are an effective treatment for optic nerve hypoplasia (ONH), a disease causing partial blindness at birth.
AdvertisementONH is growth failure of one or both optic nerves during the first trimesters of pregnancy. The nerve is the "cable" connecting the eye to the brain and each nerve should have one million fibers; in ONH the number of fibers ranges from 200,000-800,000. ONH, which affects about 1 in 5,000 newborns, is not hereditary and the exact cause is unknown.
Lawrence Tychsen, M.D., and Gregg Lueder, M.D., professors of ophthalmology and visual sciences at Washington University School of Medicine and pediatric ophthalmologists at St Louis Children's Hospital, diagnose and treat dozens of children each year with ONH. They are concerned that the CSC reports will mislead many parents of children with ONH, who may bankrupt savings, go deeply into debt or organize fundraisers to pay for sham treatment.
Although some parents claim improvement in their child's vision after returning from China, Tychsen and Lueder caution that no objective visual gains after CSC treatment have been demonstrated in any child with ONH. They can measure visual improvements objectively in infants and toddlers using non-invasive nerve and brain imaging and electronic measures of visual brain activity. They add that one would expect "a powerful placebo effect after these purported treatments.
The temptation to believe vision had improved, after the expenditure of so much time and money, would be difficult to resist." Aside from grave ethical concerns, they say that the injections could be dangerous, introducing infection or toxic matter into the brain fluids.
Tychsen, who is also a neurobiologist studying visual brain development in infant monkeys, listed a number of reasons to disbelieve reports of improvement. First, CSCs placed in human spinal fluid would not be transported into the fibers of the optic nerve. Second, CSCs have never been shown to transform into optic fibers, even in fish or rodent experiments. In a monkey or human, the task would be "several orders of magnitude more complex," Tychsen said. Third, to improve vision, 100,000 or so fibers would need to grow, not just a few, and each of the fibers would need to connect precisely in the brain.
"CSCs are used legitimately throughout the United States to treat blood diseases (such as leukemia) when the donor and recipient are genetically matched," Tychsen said. "But CSCs from an unrelated person are rejected and destroyed. Even if an unmatched CSC survived, found its way inside the optic nerve and transformed itself into a new fiber, the fiber would need to find the correct connection among more than 500,000 connections in the visual brain.
Such a series of events would be so improbable as to qualify as miraculous, the equivalent of a chimpanzee typing the five acts of King Lear at one sitting," Tychsen said. He said he believes that experiments by neuroscientists devoted to the discovery of nerve growth molecules may hold the best hope for future cures.
Lueder pointed out that parents of ONH children should not despair.
"Many babies born with ONH will have some improvement as they mature, because they learn to exploit more effectively the optic fibers that remain," he said. Children with ONH can also achieve some improvements with surgery for eye crossing and nystagmus (roving movements of the eyes). He added that many ONH children function reasonably well in school using enlarged print, magnifiers and other aids for the visually impaired.