People who have received a lung transplantation may experience a drop in their lung function months or years following their transplant. In some cases, this drop in lung function is because they have developed a conditional called chronic lung allograft dysfunction (CLAD for short). CLAD happens when some of the white blood cells that make up a person’s own immune system change their behaviour and attack and damage the transplanted lungs, reducing how well they work.
One treatment currently used to treat a variety of different conditions affecting the immune system is called extracorporeal photopheresis (ECP). Extracorporeal photopheresis (ECP) is a treatment where part of a patient’s blood is taken from a vein and circulated through an ECP machine (THERAKOS CELLEX System®). This machine separates the red and white blood cells, with the red blood cells being returned immediately back to the body.
Within the machine, the remaining white blood cells are combined with a drug called Methoxsalen (also called UVADEX), which makes them sensitive to the effects of ultraviolet light. They are then exposed to ultraviolet A (UVA) light inside the machine, causing them to shut down before being returned back into the bloodstream. UVA light is found naturally in sunlight.
Some of the white blood cells called lymphocytes play an important part in regulating the immune system. The ultraviolet light modifies the function of the lymphocytes to stop the immune system from inflicting damage which may help to slow down the progression of CLAD.
A few studies have used ECP to treat CLAD and these have shown promise at slowing the progression of CLAD. However, these studies were carried out in single hospitals in very selected patients and without careful comparison to those patients not getting ECP. This means there is currently not enough high-quality evidence to show that ECP is effective in treating CLAD for the NHS to use it routinely.
The E-CLAD trial will assess if ECP can be successfully used to stop, or slow, the damage caused by CLAD and prevent the further deterioration of lung function. It will also help us to understand specifically how ECP works in the treatment of CLAD, which patients are most likely to benefit and ultimately help the NHS decide whether ECP should be routinely used to treat CLAD.