The exact process by which ECP alters the body’s immune system is not yet know. Current research suggests that lymphocyte cells treated with UVADEX and then exposed to UVA light undergo apoptosis (cell death). The presence of these apoptotic cells in the body then leads to changes in other immune cells that result in the benefits seen with the treatment.

We will collect blood samples from patients at different time points during the trial. These samples will then be analysed to try and understand further the immunological changes that occur from ECP.  We will also look for markers in the blood that may help predict which patients are most likely to respond to ECP treatment.