Bacterial Infections Linked with Unapproved Stem Cell Treatments

Unproven products marketed as stem cell therapies could be risky, according to a new study from the Centers for Disease Control and Prevention, which analyzed bacterial infections from unapproved products derived from umbilical cord blood.

The case series study, published in JAMA Network Open, examined 20 bacterial infections in eight states. It involved reviewing medical records, sterility testing of products and whole-genome sequences of patient and product isolates for participants who developed bacterial infections after receiving stem cell treatments between August 2017 and September 2018.

“The findings of this investigation show that stem cell therapies that are not FDA-approved or that are not used for the approved medical conditions can pose serious health risks to patients with no benefit,” Kiran Mayi Perkins, MD, lead investigator with the CDC’s Outbreak and Response Team, told Contagion. “Currently, the only stem cell products derived from umbilical cord blood that are FDA-approved for use in the United States are approved for use in patients with disorders that affect the production of blood, but they are not approved for other uses. However, these products are often illegally marketed by clinics as being safe and effective for treating a wide range of diseases or conditions. Therefore, patients should be aware of the unproven benefits and the potential risks to their health when using unapproved and unproven stem cell products for conditions that they have not been shown to effectively treat.”

All but one of the patients in the study required hospitalization after receiving stem cell treatment for conditions including osteoarthritis, rheumatoid arthritis and injury. The CDC performed sterility testing on vials of product and compared bacterial isolates with those from the patients.

“We were surprised by the magnitude of bacterial contamination found in the vials that we tested; over half of the vials of the stem cell product that we tested were contaminated with bacteria, and many of these vials had very high bacterial counts,” Perkins said.

Unapproved stem cell products have been marketed for conditions such as joint diseases, sports injuries and chronic pain and have become more prevalent as people seek products to prevent and treat COVID-19, the study noted. However, these uses are not approved by the US Food and Drug Administration (FDA).

ReGen Series products processed by Genetech and distributed by Liveyon were recalled after bacterial infections were reported in Texas and Florida in 2018, and a national investigation was launched. Information was gathered about patients, product administration, infection control practices and product manufacturing and distribution.

“The bottom line is that many stem cell clinics are offering unproven products that have the potential to be dangerous,” Perkins said. “There is good research that is being done on stem cell therapies, but there are also a lot of clinics that are selling stem cells for unproven uses. To date, the only stem cell treatments approved by the FDA are products made from a donor’s umbilical cord blood that are used to treat certain cancers and disorders of the blood and immune system. If the cells are being used to treat other conditions such as pain, orthopedic conditions, autism, anti-aging, or COVID-19, they are not approved and may not be safe. We urge all patients and health care practitioners considering stem cell therapies to ensure that the stem cell product is being used for the approved indication or under an Investigational New Drug Application (IND) and is on FDA’s list of approved products.”

The states in which confirmed bacterial infections were identified as of March 2021 are Texas, Florida, California, Arizona, Kansas, Maine, Colorado and Massachusetts.

The treatments were injected into the patients’ knees, shoulders, spine or digits or administered through intravenous infusion or as a nasal spray. Infections included 10 at the injection site, five bloodstream infections and five with both injection site and bloodstream infections. Most common bacteria were Escherichia coli and Enterobacter cloacae.

“CDC will continue to investigate any reports that it receives that are concerning for infectious risks to patients associated with the receipt of stem cell products and will report these to FDA, the agency that has regulatory oversight for these types of therapies,” Perkins said.