Stem cell treatments for lung diseases may have taken a big step forward according to a pair of studies published earlier this month.
In one animal study, researchers did transbronchial biopsies, sending miniscule tweezers down the throats of rats in order to obtain lung cells.
The researchers were able to culture tens of millions of cells and inject them into rats that had a condition similar to idiopathic pulmonary fibrosis.
Rats that received the injected cells showed less lung inflammation and overall healthier lung cells than those that didn’t receive the cells.
Both studies, published in the journals Respiratory Research and Stem Cells Translational Medicine, built upon research into stem cell therapies for heart diseases, and less successful work on lung diseases like emphysema.
Both offer new hope for fibrosis patients, whose current treatment options are medications to reduce symptoms, or a lung transplant.
Research could create new treatments
The new research raises the possibility of reversing the impacts of fibrosis and similar diseases that cause lung inflammation, which gradually damages lung tissue and makes internal organs less able to transfer oxygen to the blood.
It’s also the first time stem cells have been gathered and reproduced using the minimally invasive biopsy method, researchers said.
Lung stem cells are most often obtained surgically.
That requires putting the patient on a ventilator and cutting out a small piece of lung, said Dr. Jason Lobo, an assistant professor at the University of North Carolina School of Medicine, and co-author of the new papers.
Using the method employed by the researchers, Lobo told Healthline, medical professionals can tweeze out a few cells and send patients home the same day.
However, “minimally invasive” may be a relative term.
“It’s not as invasive as opening up your chest, but if you’ve ever had a tube stuck down your throat, you wouldn’t call it noninvasive,” Dr. Norman Edelman, senior scientific advisor to the American Lung Association, told Healthline.
But Edelman calls the new research “exceedingly interesting.”
“Stem cells are hot,” he said. “People are doing a lot of interesting things with stem cells, and I expect eventually they’ll hit on something, and maybe this it.”
Some cautionary words
Edelman cautions, however, that “there’s been a long history of stem therapy for lung diseases, most of it not very satisfactory.”
He points specifically to work using stem cells to fight emphysema. He said the therapies haven’t been proven to be successful, but have led to a number of clinics outside the United States providing Americans with stem cell treatments not yet approved by the U.S. Food and Drug Administration (FDA).
The American Lung Association has cautioned against these unregulated stem cell therapies.
“Lots of interesting things in rats and mice don’t turn out,” said Edelman, who wasn’t involved in the latest studies.
But he expects the University of North Carolina researchers would go through “all the necessary safeguards when they start testing in humans and not offer it as something more than experimental.”
Looking toward the future
Lobo said they hope to have FDA approval to begin human trials by the end of the year. Those would start within six months after the approval.
“We might have to do more mouse trials, but the last time we met with the FDA, we got the feeling they weren’t leaning that way,” Lobo said.
They would join about a dozen other clinical trials looking into the use of various types of stem cells to combat pulmonary fibrosis.
Stem cells are young enough that they can still “grow up” to become any number of specialized cells, potentially including mature lung tissue cells.
Other research into stem cell therapies has largely focused on mesenchymal stromal cells, which have immunosuppressive qualities but aren’t necessarily obtained from lungs.
Lobo and his co-authors focused on “resident” lung cells, which they figured would more easily graft to the lungs and survive — a hypothesis backed up in a 2015 paper.
While their current research is focused on idiopathic pulmonary fibrosis, they hope the therapies, if successful, may eventually help people with related diseases, including chronic obstructive pulmonary disease (COPD), cystic fibrosis. and fibro-cavernous pulmonary tuberculosis.
Asked whether a cure for lung cancer could be on the horizon, Lobo said probably not, due to the different nature of the disease.
“But hopefully we will be able to extend into other diseases... any chronic lung disease,” he said.