Interesting news story on stem cell transplants for Type 1 diabetes

Note:
I am not medically trained and it is 13 years since I worked in this area. 
Single words below in bold italics are explained in the Jargon Buster at the end.

The news story
London [as in Ontario, Canada] woman off insulin for Type 1 diabetes after a single dose of experimental manufactured stem cells (21 June 2025) CTV News
- read to the end for a cracking typo / correction :D

It's really exciting news and hopefully can be expanded to more people with Type 1 diabetes but, as is almost always the case, it's not a simple fix.

When I worked at Diabetes UK a question that came up frequently at any research talk I gave, or through our question and answering service, was along the lines of "Can't people with Type 1 diabetes just have their beta cells replaced with stem cells?"

Yes.... but...

Type 1 diabetes is an autoimmune condition
A person with Type 1 diabetes has an autoimmune condition in which their immune system selectively goes after and destroys the insulin-producing beta cells in the islets of their pancreas. Destruction is a gradual process but at some point there won't be enough beta cells to produce enough insulin (an essential hormone) and the person will start to show unavoidable symptoms of Type 1 diabetes, requiring daily insulin injections or use of an insulin pump. 

Their immune system has attacked their own insulin-producing cells. 

Using your own stem cells, or other cells, as a source of potential replacement cells
If a person with Type 1 had stem cells taken from their own body, the cells tweaked in some way to convert them to insulin-producing beta cells and then returned to the person's body I think there's a high chance that the immune system would attack these genetically-identical-to-the-last-lot-of-beta-cells in the exact same way. Possibly the cells would survive for a period of time before the autoimmune system got round to munching through all of them, but I'm fairly certain it would happen. 

Using cells from elsewhere
If you were to take or make beta cells, derived from stem cells or another source, from any other person you'd also have the problem of tissue rejection or organ rejection that happens whenever your immune system meets something 'foreign' (after all that is what it has evolved to do). 

For the autoimmune side of things I don't know if it's because the immune system has some objection to (or at least is triggered by) -

(a) beta cells in particular - perhaps there is some marker on the surface of the cell, e.g. a glycoprotein in the cell membrane to which the immune system 'takes offence' and so will attack any beta cell. An analogy to this might be a computer virus that attacks any PDF file.
or
(b) any cell that secretes insulin (so perhaps tweaking other types of cells to be able to produce insulin wouldn't solve the problem). An analogy to this might be a computer virus that attacks any file that has the word 'insulin' in it, whether it's in a doc, spreadsheet, PDF or reminder note to collect a prescription.

The need to suppress the immune system
The 'solution', such as it is, when giving anyone a donor organ (pancreas) or cell transplant (islets) is to accompany that with immune suppressing medication that stops the immune system from attacking the newly transplanted tissue. That's good but having your immune system suppressed is not an easy way to go through life (for example think back to the groups of people needing the most protection from Covid).

The news story about a stem cell trial
The news article above reports on an encouraging development in using an external ('allogeneic') source of stem cell-derived insulin-producing cells* to help people with Type 1 diabetes in Canada (Canadian scientists have been doing amazing work in Type 1 diabetes and transplantation research), where their diabetes was difficult to manage. This was a small trial with 14 patients.

The woman interviewed has been able to come off insulin for now (I don't know if that will be permanent) but she does have to take immune suppressing medicine for life (or for the length of time that the transplanted cells survive). The article also notes the death of two of the trial participants, one was possibly linked to immune suppression but the person died from infection following an unrelated surgery. The other death seems entirely unrelated to the trial as they died from dementia.

•••••••••••••••••••• 

*the stem cells were used to make more than just the insulin-producing beta cells, so the end result was slightly more similar to the grouping of cells (called 'islets') naturally found in the pancreas.

Anyway let's all enjoy the news site's correction - "The Edmonton Protocol involves cells from deceased organ donors, not diseased organ donors." 

Further reading

The news article (also linked above): London [as in Ontario, Canada] woman off insulin for Type 1 diabetes after a single dose of experimental manufactured stem cells (21 June 2025) CTV News

which is about the study reported here: Stem Cell–Derived, Fully Differentiated Islets for Type 1 Diabetes (20 June 2025) New England Journal of Medicine, DOI: 10.1056/NEJMoa2506549

and this paper has also been reviewed here: Can Stem Cells Cure Type 1 Diabetes? (10 July 2025) NEJM Journal Watch
"Phase 2 trial results look promising... Although the treatment potentially obviates some issues with pancreatic transplants (e.g., organ availability and surgical complexity), it still requires immunosuppression."

See also the section headed "Promising results from beta cell therapy trials in type 1 diabetes" in Diabetes UK's research news roundup for 3 July 2025.

Jargon buster
allogeneic / allotransplantation: 'allo' here means 'other' and refers to cells or organs being transplanted from someone else. Allogeneic just means 'contains material from someone that isn't you'.

glycoprotein - a molecule that contains a sugar element and a protein element. All sorts of molecules are found inside, within and outside the cell membrane. Some are used as a sort of 'flag' to say 'this is the type of cell I am'.

islets - 'islets of Langerhans' - groups of hormone-secreting cells scattered within the pancreas. Islets include beta cells which release insulin, and alpha cells that release another hormone glucagon. Both help to control the level of glucose in the blood.