Hongkui Deng, who has been working on a trial involving iPSC transplants, is observed by students.
By the age of 25, Mingyu, a pseudonym being used to protect her privacy, had already undergone two liver transplants and a pancreas transplant in an effort to treat her type 1 diabetes. In her ten years living with the condition, she had also experienced three life-threatening periods of severe hypoglycaemia (low blood sugar), despite intensive insulin therapy. So, when her doctor suggested she enrol in a clinical trial at her local hospital in Beijing, it felt like a rare chance to regain her health.
In type 1 diabetes, the immune system attacks and destroys the β-cells in the pancreas that produce insulin, the hormone that regulates the body’s blood-sugar levels. People with this form of diabetes require lifelong insulin therapy to survive.
Researchers at Peking University in Beijing have been exploring an alternative treatment, using stem-cell technology to generate insulin-producing cells that can be transplanted into the patient, restoring their ability to produce the hormone. As part of Mingyu’s clinical trial, the team first took a small sample of fat cells from her and reprogrammed them to be induced pluripotent stem cells (iPSCs) — cells in an embryonic-like state that can become any other cell type in the body. They then guided these cells to develop into pancreatic islets — clusters of hormone-producing cells that include β-cells. Mingyu was then given an injection of these freshly grown islet cells.
Nature Index 2026 Regenerative medicine
The results were resoundingly positive: within a couple of months, Mingyu’s blood-sugar levels remained healthy and consistent, without the need for insulin injections. Nearly three years later, she is doing well, says immunologist Hongkui Deng, leader of the Peking University team and co-author of the 2024 study that describes the clinical trial1. “This has had a huge positive impact on her quality of life and overall physical, mental and emotional wellbeing,” says Deng.
Type 1 diabetes is one of more than 100 autoimmune diseases that span from organ-specific afflictions such as Graves’ disease — which mainly affects the thyroid — to systemic conditions that affect multiple sites and organs, such as rheumatoid arthritis and lupus. They all share a common underlying problem: the immune system’s failure to distinguish between something potentially harmful and the healthy self. Almost none of them have a cure.
Up to 10% of the global population has at least one autoimmune disease, and for reasons scientists do not understand, these diseases are becoming more common2. The prevalence of type 1 diabetes worldwide, for example, has nearly doubled in the past 40 years3. This makes the need to find safe and effective therapies and preventative approaches increasingly urgent, says Frederick Miller, an emeritus immunologist and rheumatologist at the US National Institutes of Health in Bethesda, Maryland.
For decades, the most that doctors could do was to manage autoimmune diseases indirectly, by suppressing the immune system to blunt the inflammation it causes, or by replacing what the body is unable to produce on its own. More recently, momentum has been building around the potential for regenerative medicine to be an effective, long-term solution, with scientists exploring a variety of methods to reset dysfunctional components of the immune system and restore lost function.
Stem cells are one of the most promising tools for making that possible, says Holger Russ, a stem-cell biologist at the University of Florida in Gainesville. “Ten years ago, this was science fiction,” he says. “Now it’s actually happening as we speak.”
A lot of work is needed, however, to fine-tune treatments, reduce risks and ensure accessibility, Miller says. “All of these approaches are promising, but there needs to be a lot of tedious, meticulous therapeutic trials done on each disease.”
First-generation approaches
Stem-cell technology was first used to tackle autoimmune diseases around three decades ago. This involved haematopoietic stem cells (HSCs), which are found primarily in bone marrow. Unlike iPSCs, which can become almost any cell type, HSCs can differentiate into only blood and immune cells. As a result, rather than replacing damaged tissues, HSCs are used to rebuild or ‘reset’ the immune system in the hope of eliminating the autoimmune response.
The first step of the process is to harvest HSCs by using drugs to coax them out of the bone marrow and into the blood stream for collection — usually from the patient themselves, but sometimes from a donor who is a close genetic match. Next, the patient is given chemotherapy to wipe out their existing autoreactive immune system. Finally, the HSCs are transplanted back into the blood stream, where they naturally differentiate into blood and immune cells, rebuilding the immune system.
Fibroblasts are used to produce iPSCs.Credit: Vshivkova/iStock /Getty Images Plus
Worldwide, some 70,000 HSC transfers are performed each year, with autoimmune cases representing an estimated 4% of those, or about 3,000 patients4. One of the most common uses of HSCs is to treat systemic scleroderma — a chronic and painful condition that hardens the skin and connective tissue and can lead to fatal organ failure.
There are some serious risks associated with HSC transplants, including severe infection, potential for relapse and in rare cases, treatment-related mortality. But they are often considered a first-line treatment for scleroderma because of the disease’s high toll on patients, and the feeling among doctors that there is little else they can do, says Keith Sullivan, who studies stem-cell transplants at Duke University in Durham, North Carolina.
“The key point is that this is a one-time procedure,” says Giorgio Orofino, a haematologist at San Raffaele Hospital and Vita-Salute San Raffaele University in Milan, Italy. More than 15 years ago, his colleague, Raffaella Greco, was part of a team that performed the first HSC transplants for two patients with neuromyelitis optica, a rare autoimmune disease that causes blindness and paralysis5.
In June this year, Orofino, Greco and colleagues published a follow-up study6 showing long-term remission in the two patients they treated. One of the patients regained the ability to walk without aid, Orofino says. The second patient remained wheelchair-bound, but experienced significant neurological improvement. “It gives an immune reset that is really profound,” says Greco.
The treatment is not without drawbacks, however. Over the months it takes for a patient’s new immune system to develop, they are highly susceptible to infection and vulnerable to excess bleeding and arrhythmias (changes in heartbeat). These risks necessitate careful patient selection and monitoring, Orofino says.
Relapse is another risk. Elizabeth Volkmann, a rheumatologist at the University of California, Los Angeles, has cared for a number of patients who received HSC transplants years ago at other clinics, but redeveloped their autoimmune diseases. One woman required a lung transplant after her scleroderma came back. “It’s not a perfect cure for all patients,” Volkmann says.
HSCs are also only one part of the solution. Although they can reset the immune system and halt the attack, they cannot rebuild what has already been lost. A person with type 1 diabetes, for example, would still need replacement β-cells in order to produce insulin. For that, researchers are turning to pluripotent stem cells — a complementary but different branch of regenerative medicine.
The next frontier
Human pluripotent stem cells were first derived from early-stage embryos in 1998 by a team at the University of Wisconsin-Madison. This was followed by the discovery in 2006 by a team from Kyoto University in Japan that adult cells could be reprogrammed to create induced pluripotent stem cells — ‘induced’ being a nod to the fact that they came from adult cells rather than embryonic ones.
As of 2025, more than 600 studies have been published related to iPSCs and diabetes. Many of these focused on using the cells as a model for learning more about the biology of the disease and for screening potential drugs, but increasingly researchers have been pursuing them as the basis of new therapies.
A laboratory technician holds a bag of frozen haematopoietic stem cells at a facility in a cell therapy unit in Clamart, France. Credit: Phanie – Sipa Press/Alamy Stock Photo
Type 1 diabetes is especially suited to this approach “because the disease involves the loss of a clearly defined cell population”, says Xiaojun Lance Lian, a biomedical engineer at Pennsylvania State University in State College, Pennsylvania, referring to the insulin-producing β-cells within the pancreatic islets. Transplantation of islet clusters from deceased donors has proved effective, but there is a limited availability of these organs. Pluripotent stem cells could provide a more scalable solution than relying on donor tissue, Lian says.
Deng and his colleagues were among the first to transplant iPSC-derived islets into patients. The case of Mingyu is the only one that they have published, but two other patients had clinical outcomes that were also “highly consistent”, Deng says. Building on these results, he adds, the team is nearing completion of a larger clinical trial.
Last year, another team published the first early-stage clinical trial of islets derived from human pluripotent stem cells for type 1 diabetes, involving a group of 14 participants with a history of severe hypoglycaemic events7. Rather than harvest cells from each individual participant as the Peking University team did, this group used standardized ‘off-the-shelf’ islets. The cells, made by Vertex Pharmaceuticals, a company headquartered in Boston, Massachusetts, were derived from a human embryonic stem-cell line established from a donated IVF embryo. Because such cells divide indefinitely, Vertex can create an effectively unlimited quantity in the lab and then coax them into becoming islets.
Within six months of undergoing treatment, 10 of the 12 participants who received a full dose of treatment regained the ability to produce insulin and no longer needed injections. Trevor Reichman, a surgeon-scientist at the University of Toronto in Canada and lead author of the study, says the results amounted to a “functional cure”.
Lian, who was not involved in the study, says that although this assertion is valid, there are careful qualifications that need to be made. For most participants, “the therapy functionally replaced the pancreatic β-cells that had been lost to type 1 diabetes”, says Lian, which he describes as “remarkably encouraging”.
But the study was relatively small, and how long the positive effects will last is still unknown. This makes it a “compelling proof of concept” for some patients, Lian says, but “it is too early to consider this an established cure”.
There is also an inherent shortcoming to the treatment: patients who are given an off-the-shelf islet product must spend the rest of their lives taking daily doses of immunosuppressants, so their bodies do not reject the foreign cells. These drugs — which are given for dozens of conditions, not just pluripotent stem-cell therapies — do not make patients so immunosuppressed that they cannot fight off any illness, but they do leave them more vulnerable to infections and diseases such as cancer.
“Immunosuppression comes with significant risks that limit who is a good candidate for these therapies,” says Audrey Parent, a stem-cell scientist at the University of California, San Francisco.
Beyond immunosuppression
The ultimate goal for researchers who are trying to treat autoimmune diseases is to get around the need for immunosuppression altogether. “Many people could benefit from this if we solve the immune-suppressive puzzle,” Russ says.
