Haematopoietic stem cell transplantation (HSCT) is an intense chemotherapy treatment for MS. It aims to stop the damage MS causes by wiping out and then regrowing your immune system, using your stem cells.
The big question is – what actually happens after the stem cells are put back? We take a closer look.
Rebuilding the immune system
After HSCT, haematopoietic stem cells help to repopulate the immune system. As our immune system is made up of lots of different types of cell, this happens in stages. Most immune cells develop within weeks or months of treatment, but others can take up to two years.
While the immune system is developing, people having HSCT are at an increased risk of developing infections.
How much does the immune system change?
The theory is that the new immune cells will no longer attack myelin, and may even protect against further damage. But how? We funded Dr Paolo Muraro and his team at Imperial College London to investigate how HSCT affects the immune system in a bit more detail.
Using blood samples taken from people before and after HSCT, they found that the treatment can change the balance of different immune cells in the body.
There is an increase in cells that regulate the immune system after the treatment, which could begin to explain how HSCT helps to stop immune attacks in MS.
It’s all in the gene (expression)
To really get under the hood of HSCT, scientists looked a bit closer at the stem cells – and the immune cells they become.
They found that haematopoietic stem cells from people with MS look very similar to those taken from people without the condition. This suggests that haematopoietic stem cells in people with MS aren’t pre-programmed to be inflammatory. Great news!
But does it translate to the new immune cells? Research suggests it does. T cells (a type of immune cell) examined after HSCT were more similar to T cells from people without MS than they were to the T cells found before the treatment.
Specific stem cells
Haematopoetic stem cells are incredible at rebuilding your immune system, but they can’t do everything. They can't repair myelin or regenerate permanently damaged nerves.
For myelin repair we need to turn our attention to other stem cells.