MRI

Study shows reduction in brain injury after stroke patients were treated with their own stem cells

/ Yimy Villa / 3 Comments
Illustration showing the mechanism of an ischemic stroke. In an ischemic stroke, blood supply to part of the brain is decreased, leading to dysfunction of that area of the brain. Here, a blood clot is the reason for restricted blood flow.

Stroke is the third leading cause of death and serious long-term disability and affects nearly 800,000 Americans a year, with someone in the U.S. suffering a stroke every 40 seconds. Roughly 87% of all strokes are ischemic strokes, meaning that a clot blocks blood flow to the brain. Unfortunately 90% of those who suffer an ischemic stroke also end up suffering from weakness or paralysis to one side of the body.

A study conducted by Muhammad Haque, Ph.D. and Sean Savitz, M.D. at The University of Texas Health Science Center at Houston (UTHealth) found that treating patients with stem cells from their own bone marrow could lead to a reduction in brain injury after a stroke caused by a blood clot.

For this study, there were 37 patients from ages 18 to 80. While all received the standard stroke treatment and rehabilitation follow-up, 17 patients whose strokes were the most severe received a bone marrow stem cell therapy. To measure any improvement, the UTHealth team used 3D brain imaging of the patients obtained from MRI scans. They used these images to compare changes in white matter of those treated with their own bone marrow stem cells to those who were not treated.

White matter is a specific type of tissue in the brain that is critical for motor function because it is responsible for carrying movement-related information to the spinal cord.

Three months after the stroke, the MRI scans of each patient showed the expected decrease after a stroke. However, scans taken 12 months after the stroke occurred showed an improvement on average in the 17 patients who received bone marrow cell therapy.

In a press release from UTHealth, Dr. Haque elaborates on what these results could mean for developing treamtents for stroke patients.

“We envision that future clinical trials might be directed toward identifying white matter protection or repair as an important mechanistic target of efficacy studies and potency assays for bone marrow cell therapies.”

The full results to this study were published in STEM CELLS Translational Medicine.

Positively good news from Asterias for CIRM-funded stem cell clinical trial for spinal cord injury

/ Kevin McCormack / 3 Comments

AsteriasWhenever I give a talk on stem cells one of the questions I invariably get asked is “how do you know the cells are going where you want them to and doing what you want them to?”

The answer is pretty simple: you look. That’s what Asterias Biotherapeutics did in their clinical trial to treat people with spinal cord injuries. They used magnetic resonance imaging (MRI) scans to see what was happening at the injury site; and what they saw was very encouraging.

Asterias is transplanting what they call AST-OPC1 cells into patients who have suffered recent injuries that have left them paralyzed from the neck down.  AST-OPC1 are oligodendrocyte progenitor cells, which develop into cells that support and protect nerve cells in the central nervous system, the area damaged in spinal cord injury. It’s hoped the treatment will restore connections at the injury site, allowing patients to regain some movement and feeling.

Taking a closer look

Early results suggest the therapy is doing just that, and now follow-up studies, using MRIs, are adding weight to those findings.

The MRIs – taken six months after treatment – show that the five patients given a dose of 10 million AST-OPC1 cells had no evidence of lesion cavities in their spines. That’s important because often, after a spinal cord injury, the injury site expands and forms a cavity, caused by the death of nerve and support cells in the spine, that results in permanent loss of movement and function below the site, and additional neurological damage to the patient.

Another group of patients, treated in an earlier phase of the clinical trial, showed no signs of lesion cavities 12 months after their treatment.

Positively encouraging

In a news release, Dr. Edward Wirth, the Chief Medical Officer at Asterias, says this is very positive:

“These new follow-up results based on MRI scans are very encouraging, and strongly suggest that AST-OPC1 cells have engrafted in these patients post-implantation and have the potential to prevent lesion cavity formation, possibly reducing long-term spinal cord tissue deterioration after spinal cord injury.”

Because the safety data is also encouraging Asterias is now doubling the dose of cells that will be transplanted into patients to 20 million, in a separate arm of the trial. They are hopeful this dose will be even more effective in helping restore movement and function in patients.

We can’t wait to see what they find.

New Cellular Tracking Device Tests Ability of Cell-Based Therapies to Reach Intended Destination

/ cirmweb / 2 Comments

Therapies aimed at replacing damaged cells with a fresh, healthy batch hold immense promise—but there remains one major sticking point: once you have injected new, healthy cells into the patient, how do you track them and how do you ensure they do the job for which they were designed?

New tracking technique could improve researchers' ability to test potential cell therapies.

New tracking technique could improve researchers’ ability to test potential cell therapies.

Unfortunately, there’s no easy solution. The problem of tracking the movement of cells during cell therapy is that it’s hard to stay on their trail they enter the body. They can get mixed up with other, native cells, and in order to test whether the therapy is working, doctors often have to rely on taking tissue samples.

But now, scientists at the University of California, San Diego School of Medicine and the University of Pittsburgh have devised an ingenious way to keep tabs on where cells go post injection. Their findings, reported last week in the journal Magnetic Resonance in Medicine, stand to help researchers identify whether cells are arriving at the correct destination.

The research team, lead by UCSD Radiology Professor Dr. Eric Ahrens, developed something called a periflourocarbon (PFC) tracer in conjunction with MRI technology. Testing this new technology in patients receiving immune cell therapy for colorectal cancer, the team found that they were better able to track the movement of the cells than with traditional methods.

“This is the first human PFC cell tracking agent, which is a new way to do MRI cell tracking,” said Ahrens in a news release. “It’s the first example of a clinical MRI agent designed specifically for cell tracking.”

They tagged these cells with atoms of fluorine, a compound that normally occurs at extremely low levels. After tagging the immune cells, the researchers could then see where they went after being injected. Importantly, the team found that more than one-half of the implanted cells left the injection site and headed towards the colon. This finding marks the first time this process had been so readily visible.

Ahrens explained the technology’s potential implications:

“The imaging agent technology has been shown to be able to tag any cell type that is of interest. It is a platform imaging technology for a wide range of diseases and applications.”

A non-invasive cell tracking solution could serve as not only as an attractive alternative to the current method of tissue sampling, it could even help fast-track through regulatory hurdles new stem cell-based therapies. According to Ahrens:

“For example, new stem cell therapies can be slow to obtain regulatory approvals in part because it is difficult, if not impossible, with current approaches to verify survival and location of transplanted cells…. Tools that allow the investigator to gain a ‘richer’ data set from individual patients mean it may be possible to reduce patient numbers enrolled in a trial, thus reducing total trial cost.”

What are the ways scientists see stem cells in the body? Check out our Spotlight Video on Magnetic Particle Imaging.