Category: stem cells

Stem cells and Type 2 diabetes

Tuesday 1 December 2009

I wrote this, as part of my work, in response to someone enquiring about paying for stem cell treatments for Type 2 diabetes. I think there is an awful lot of work to be done in this area before that’s doable, but am aware that there is research into bone marrow stem cells and Type 2 diabetes (ie it’s a bit early, but it’s not actually a crazy idea).

This should not be taken as gospel (I might be wrong) nor as medical advice (I’m not medically trained) but I hope will be useful nonetheless 🙂

I’ve tweaked my response for this blog.

All views expressed are mine alone and do not necessarily reflect the views of my employer.

Dear ________

The research into stem cells and diabetes is not yet at the stage where it would be appropriate to start putting such cells into people with the intention of using this as a therapy (ie in the hope of improving symptoms).

There have been some small trials where people have received stem cell transplants, under very particular conditions, to ‘see what happens’ and to get an idea of the safety (or not) of doing this.

Companies offering stem cell transplants are, to the best of my knowledge, not involved in clinical trials but are instead claiming this as a therapy, and charging for it. Without sufficient evidence from clinical trials that show that stem cells can actually help people with Type 2 diabetes and that the transplants are safe in the long run then this sort of intervention is rather speculative.

There is nothing wrong with a clinical trial to see if transplanting stem cells can help but prospective patients are not usually asked to pay. Also there are very strict regulations for clinical trials in place to protect participants. People travelling abroad for stem cell transplants do not have this protection if anything goes wrong. The science journal Nature has an interesting blog post on charging people for unproven stem cell treatments http://blogs.nature.com/reports/theniche/2008/03/patients_paying_for_stem_cells.html

At this stage it is not exactly clear how a stem cell transplant would help someone with Type 2 diabetes. As insulin resistance is generally the major problem (that is, insulin can still be produced by the cells of the pancreas but the body becomes less able to respond to it) then adding in more insulin-producing cells would not necessarily be an appropriate way to treat that problem.

It is certainly true that Type 2 diabetes is a progressive condition (which effectively means that the way in which the condition is treated changes over time) and the insulin-producing cells may well begin to fail after a while, meaning that less insulin can be produced. Of course it makes sense, theoretically, that someone in this situation could benefit from replacement insulin-producing cells – however we do not yet have the evidence that stem cell transplants can help.

The cells used in these transplants are generally the patient’s own bone marrow stem cells. These cells have the capacity to form a limited number of blood cells (including cells of the immune system) and they do not naturally form insulin-producing cells. While it is possible to modify cells in a laboratory to persuade them to secrete insulin the modified cells may not be very safe for transplantation.

I do want to stress that scientists are not discounting the possibility that transplanting bone marrow stem cells into people with Type 2 diabetes could help – it is possible that the presence of these blood-type cells could help to ‘rescue’ in some way the pancreatic cells from further damage and so improve blood glucose levels. It’s less likely that the cells would spontaneously form insulin-producing cells, but it’s not impossible.

A report of a recent trial (with 25 patients) suggested that this might be a possibility (http://www.physorg.com/news157534107.html) – but this research is at an early stage and it would be unlikely for patients to have to pay for this.

We do not know what the long-term effects of giving stem cell transplants are and one particular case study has caused concern among researchers and doctors http://news.bbc.co.uk/1/hi/health/7894486.stm

Interestingly several case studies have suggested that bone marrow transplants (given to children suffering from leukaemia) may actually be linked with a subsequent worsening of glucose metabolism and insulin resistance http://www.ncbi.nlm.nih.gov/pubmed/11041401

I would recommend this brief (eight pages) patients’ guide to stem cell treatments http://www.isscr.org/clinical_trans/pdfs/ISSCRPatientHandbook.pdf and seek advice from your own doctor before committing any money to unproven treatments.

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Stem cells and diabetes (i)

Lots to say on this topic, so will have to break it up into manageable pieces using multiple posts!

Something I’ve been getting an increasing number of enquiries about is stem cell transplants for diabetes as there are a number of companies making the claim that they can cure the condition. I’m not aware of any evidence for this (beyond the company’s own claims, based on patient testimony – which is no guarantee of truth or accuracy) so am inclined to be very wary.

It seems that bone marrow cells are removed from the patient and purified (or otherwise modified in some way) before being returned to the patient in the hope of improving their blood glucose levels.

Bone marrow stem cells are able to form a fairly limited number of blood type cells – I’m not convinced how easy it is for them to transdifferentiate into insulin-producing cells once replaced in the body. If they’re modified before transplantation then I’d want to know a bit more about the safety of the modification procedure. The sort of laboratory tweaking that can be done to cells is generally performed only for research purposes and could preclude the cells from being suitable for transplantation.

It’s often claimed that because the stem cells are the person’s own cells there will be no issue of tissue rejection. This may not be true.

Type 1 diabetes is caused by an underlying autoimmune disorder which seeks out, and destroys, the insulin-producing beta cells in the pancreas and de. If new insulin-producing cells are transplanted then there’s every reason to suspect that the autoimmune attack will recur and these will be destroyed too. I don’t think the immune system cares too much where insulin-producing cells come from, if they’re producing insulin then it seems that this is sufficient for them to be destroyed.

Sometimes it’s claimed that the transplanted cells ‘support’ the pancreas in some way, to help it to regenerate its own insulin-producing cells. Maybe, but this would surely just mean that that the cells the pancreas generates itself will be destroyed (which is exactly what happened during the development of Type 1 diabetes in the first place).

Companies are also claiming that transplanted cells can help people with Type 2 diabetes – but for these people it’s more likely that insulin resistance is the problem driving their diabetes rather than a lack of insulin. It’s not clear how adding in more insulin-producing cells would help.

It’s something I expect to come back to in this blog as the pace of research is pretty speedy – but just because research in an area is fast-moving it doesn’t mean that it’s appropriate to bend the research too quickly into a treatment.

Monya Baker of nature.com’s stem cell blog “The Niche” has written a post highlighting that “Patients paying for stem cells are probably getting bad science
http://blogs.nature.com/reports/theniche/2008/03/patients_paying_for_stem_cells.html

Good places to find out about the status of research is to see what clinical trials are being done at ClinicalTrials.gov and Current Controlled Trials.

Clinical Trialsdiabetes and stem cells results page.
Current Controlled Trialshttp://www.controlled-trials.com/mrct/ – type in diabetes and stem cells into the ‘search for’ box and put a tick by ‘all registers’ to search all of them or choose individual registers.

Note that the results may contain trials that are not specifically about the use of stem cells in the treatment OF diabetes, merely that diabetes might be mentioned somewhere as a keyword.

Jo

Disclaimer – all posts are my opinion and not necessarily those of my employer.