"The study, published in Cell today, follows results from a separate group in Shanghai, China, who reported in April that they had successfully transplanted insulin-producing islets into the liver of a 59-year-old man with type 2 diabetes2. The islets were also derived from reprogrammed stem cells taken from the man’s own body and he has since stopped taking insulin."

The idea is that because the stem cells come from the patient, there is less risk of graft vs host attack.

One patient has been living 1 year with the transplant and has see no drop off in insulin production.

"Two-and-a-half months later, the woman was producing enough insulin to live without needing top-ups, and she has sustained that level of production for more than a year. By that time, the woman had stopped experiencing the dangerous spikes and drops in blood glucose levels, which remained within a target range for more than 98% of the day. “That’s remarkable,” says Daisuke Yabe, a diabetes researcher at Kyoto University. “If this is applicable to other patients, it’s going to be wonderful.”"

However, this woman was receiving immunosupressive drugs:
"Because the woman was already receiving immunosuppressants for a previous liver transplant, the researchers could not assess whether the iPS cells reduced the risk of rejection of the graft.

Even if the body doesn’t reject the transplant because it doesn’t consider the cells to be ‘foreign’, in people with type 1 diabetes, because they have an autoimmune condition, there is still a risk that the body could attack the islets. Deng says they didn’t see this in the woman because of the immunosuppressants, but they are trying to develop cells that can evade this autoimmune response."

https://www.nature.com/articles/d41586-024-03129-3