Treating ALD

There are currently only two available treatments for childhood cerebral ALD: Lorenzo's oil and stem cell transplantation, using either umbilical cord stem cells or bone marrow stem cells. Both treatment approaches have shown promise, and been effective for some boys with ALD, but they also both have drawbacks. While research indicates that these treatments may be able to arrest the progress of the disease, neither can dramatically repair the damage done by ALD once it has already begun. To do that, a treatment would have to actually restore the lost myelin.

Both Lorenzo's oil and stem cell transplantation are considered treatments only for boys with childhood cerebral ALD; the options for treating men with adrenomyeloneuropathy (AMN), the adult form of the disease, are more limited. Currently, doctors will not perform stem cell transplantation on adults with the disease, generally because the risks of the treatment are considered to outweigh the potential benefits. But as transplantation technology improves and becomes safer, it is possible that stem cell transplantation will be available for men with AMN.

Lorenzo's Oil

Lorenzo's oil is a combination of two fats extracted from olive oil and rapeseed oil. It was developed by Augusto and Michaela Odone to treat their son, Lorenzo, after he was diagnosed with ALD in 1982. The mixture of fatty acids in Lorenzo's oil works to reduce the levels of very long chain fatty acids, which are known to cause ALD.

Recent studies indicate that Lorenzo's oil may be effective in staving off the onset of symptoms in boys with the disease who have not yet become symptomatic. A study published in theArchives of Neurology in July 2005 followed 89 boys with ALD who took Lorenzo's oil and ate a low-fat diet. The boys had normal MRIs and no symptoms of ALD, but had been screened for the disease because they had an affected relative. After an average follow-up of seven years, 74% of the boys still had normal MRIs and no neurological symptoms.

This study does not definitively prove that Lorenzo's oil is what kept the boys from developing symptoms. It is possible that the boys who did not develop symptoms would not have developed the disease in childhood anyway, and they all could still develop adrenomyeloneuropathy (the later-onset form of the disease) when they reach adulthood.

Nonetheless, the study's results are encouraging. Parents with a child who may be at risk for ALD can inquire about enrolling in a clinical trial at the Kennedy Krieger Institute, 800-873-3377. That is presently the only way to obtain Lorenzo's oil in the U.S. Since it is not approved by the Food and Drug Administration and still considered an experimental drug, not all insurance companies will provide coverage for the oil, which costs over $400 for a month's treatment.       

Stem Cell Transplantation

Boys with ALD who have a Loes score lower than 8 or 9 (an MRI measure of the severity of the disease) are generally considered candidates for stem cell transplantation. There are currently two sources for transplanted stem cells: umbilical cord blood (UCBT) or bone marrow (BMT). In both cases, the goal is to provide the patient with healthy stem cells that produce a functioning ALD protein -- the protein that is lacking in people with ALD. Scientists believe that this works as some portion of the donated cells, which are not genetically defective, find their way into the brain, express the missing or nonfunctioning ALD protein, and halt or even reverse the brain damage.

Although much of this theory remains to be scientifically proven, these transplants have been successful; among the small number of patients who have had transplants, some have had their condition stabilize, and a few even made slight improvements. But there is a very narrow window in which stem cell transplantation appears to be effective -- the time between when the brain lesions appear on an MRI, and when the boy first starts showing symptoms.

This treatment also has serious risks. Both types of transplantation require that the patient's immune system essentially be wiped out by high-dose chemotherapy and/or radiation, so that their bodies do not reject the foreign donor cells. This leaves patients vulnerable to almost any kind of infection, and these procedures have a mortality rate that is as high as 40%. It can also be difficult to find a well-matched donor, and sometimes the donor cell graft does not "take."

Unfortunately, there also appears to be a period of about six to eighteen months following transplant when the disease progression continues. This means that, even in a best case scenario, the child emerging from this medical procedure will have more advanced brain damage than he had going in. If the downward slide is then arrested by the transplant, this may be a trade-off worth making. But in boys suffering from a late diagnosis, often a BMT will only rapidly advance their condition into a completely vegetative state.

Clearly, the decision to pursue a bone marrow transplant is not an easy one and cannot be made lightly.