Stromal cells suppress immune response symptoms

A new therapy for the serious Graft-versus-Host disease

Researchers at LUMC have developed a new therapy for Graft-versus-Host disease, a serious condition, based on mesenchymal stromal cells. Research into the effectiveness of this therapy is already in its final phase. To achieve a therapy that is generally available to patients, effectiveness is being tested on a large group of patients in a so-called phase III study.

Graft-versus-Host

Stem cell transplantation is a commonplace treatment, such as for patients with leukaemia. Unhealthy stem cells in the bone marrow are replaced with healthy stem cells, which usually come from a donor. Unfortunately, this sort of transplant procedure always carries the risk of an immune response. The patient’s body may reject the donor’s stem cells, but conversely, the donor’s stem cells can also exhibit an immune response to the patient’s body. The latter situation can lead to Graft-versus-Host disease, a serious condition that is fatal for many patients.

The surprising effects of stromal cells

Over the last few years, researchers in Leiden have developed a new treatment for this Graft-versus-Host disease, based on mesenchymal stromal cells (MSCs). MSCs are special cells that can be extracted from bone marrow, fat tissue or the umbilical cord. They can grow to become bone, cartilage or fat tissue. One of these cells’ special properties is that they do not trigger an immune response, and in fact they can even suppress such a response. The immune-suppressing properties of these cells were first demonstrated in Graft-versus-Host disease.

Professor Wim Fibbe and his colleagues achieved promising results with MSCs extracted from donor bone marrow. In a clinical study with a group of fifty-five patients, 70 to 80 per cent of them were cured of Graft-versus-Host disease after receiving these MSCs. The results for children were even slightly better than for adults. Doctors who collaborated on the study were completely surprised by what they saw.

From the lab table to the patient

Before a new method of treatment becomes generally available for patients, it must first go through a long clinical test phase. Tests are conducted to determine whether it is feasible to give the cells to patients (phase I), whether it is safe (phase II) and finally whether the treatment is actually effective (phase III). The effectiveness is shown in a large randomised study: a study in which patients are arbitrary divided into test groups. One of the test groups is given the therapy, and the other group is given a placebo. In order to identify a sufficient number of patients with Graft-versus-Host disease for the study, LUMC is collaborating with hospitals throughout the Netherlands and with colleagues in six other countries in the European Union. This study, sponsored by the EU under the name RETHRIM, began in 2015 and will continue for about five years.

See the RETHRIM-website for more information on this research.