麻豆传媒

A woman with multiple sclerosis (MS) who had intrathecal injections of umbilical cord stem cells in Mexico ended up with a severe Mycobacterium abscessus infection that took weeks to identify and treat, according to a case study.

In October 2022, the woman in her 30s traveled to Baja California, Mexico, and received two lumbar punctures of the stem cell product as a "treatment" for MS after researching the clinic online, Daniel Pastula, MD, of the University of Colorado and the Colorado School of Public Health, and colleagues reported in .

Her diagnostic odyssey started the day after her second injection, when she went to an emergency department in the U.S. for a headache and received an epidural blood patch for presumed postlumbar puncture cerebrospinal fluid (CSF) leak.

After two more outpatient blood patches and persistent fevers, she was admitted to a hospital with a fever of 101.3ºF but otherwise normal vital signs and complete blood counts, and nothing remarkable in CSF. A 10-day course of antibiotics helped, but as soon as she stopped them, she had a worsening headache and her fever came back -- which was when she ended up with Pastula's team.

Pastula and colleagues ultimately discovered a rapidly growing nontuberculous mycobacterium after 7 days of incubation.

They started one intensive antibiotic regimen that was intolerable due to gastrointestinal side effects; but once they homed in on M. abscessus, they were able to adjust the regimen to azithromycin (500 mg IV 1x/d), ceftaroline (600 mg IV 3x/d), eravacycline (80 mg IV 1x/d), imipenem (500 mg IV 4x/d), and tedizolid (200 mg orally 1x/d). They had to stop ciprofloxacin and trimethoprim/sulfamethoxazole, which are resistant to M. abscessus.

Pastula and team reported that the regimen resolved the patient's headaches and fevers, and she's now completed 3 months of treatment without recurrent symptoms. It's not clear how long she will have to remain on the regimen, as the infection can be indolent and antibiotic treatment may be needed for many months, Pastula said.

They noted that it took "8 weeks of evaluations after her initial visit to the outside emergency department to identify and treat M. abscessus."

Pastula said the case is particularly dangerous not only because of the procedure itself, but also the severity of the infection, the challenge in treating it, and potential longterm effects on the patient.

In addition, drugs to treat MS are immunosuppressive, and should not be used during an active chronic infection, Pastula pointed out.

"Not only did the clinic give her something that wasn't effective against MS and cause an infection; now, we have to delay, for some unknown period of time, the treatments that work best for MS," he said. The patient had not previously been on disease-modifying or immunosuppressive drugs for MS.

The case also highlights the problematic nature of medical tourism, particularly when it comes to stem cell therapies, the researchers said.

"Right now, stem cell therapy for various chronic neurologic conditions, chronic progressive [ones], is not proven," Pastula told 麻豆传媒. "It has not proven to be ... safe, and it is not proven to be effective."

According to the National Multiple Sclerosis Society, stem cell therapy for MS "should only be provided at that meet specific criteria to perform stem cell procedures or within a ." The organization also notes that there is currently "no evidence that injection of cells in the spine or brain has any benefit in MS." (Hematopoietic stem cell transplant for MS is a different procedure, and while investigational, has been used in severe cases of disease with promising effects.)

Stem cell experts say this case is yet another example of clinics both abroad and in the U.S. using misleading marketing to lure the most desperate patients -- often with chronic progressive diseases -- into risky and unproven treatments. A recent investigation by 麻豆传媒 found a number of patients whose vision was harmed after treatment at a Florida clinic claiming to be able to treat chronic diseases with autologous bone marrow-derived stem cells.

Pastula said the clinic in Mexico claimed in marketing materials that the umbilical cord stem cells were "programmed to treat MS."

Paul Knoepfler, PhD, of the University of California Davis, who tracks dubious stem cell treatments, wrote to 麻豆传媒 in an email, "How were the cells programmed and could such changes put people at risk? A worry is that, especially in immunocompromised individuals, receiving donor cells in the brain could pose a tumor risk long-term. Any kind of changes to stem cells such as by some kind of 'programming' could increase that risk."

It's also difficult to quantify the extent of damage from stem cell medical tourism. "There is not some sort of systematic data collection going on," Leigh Turner, PhD, executive director of the bioethics program at the University of California Irvine, who also studies stem cell companies, told 麻豆传媒. "We don't know exactly how many people are entering this global marketplace. You don't know how many procedures are being done."

It is also impossible to know the source of the bacterial contamination itself, Pastula said. Inadequate infection control with non-sterile needles or water could pose a different public health threat than contamination of an injected product. Pastula said the CDC and the Colorado Department of Public Health and Environment were alerted to the case, but have only limited authority to investigate.

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