Extracorporeal Photopheresis

Apollo Doctors Talk

Our Patient was a 7 year old boy filled with an enthusiasm for life that only children can bring on. On one fateful day, he gets diagnosed to have acute myeloid leukaemia. In view of persistent disease despite chemotherapy, he is referred for haematopoietic stem cell transplantation (HSCT). He undergoes the HSCT from his fully matched brother and is declared cured of disease. Two years later, he comes back with inability to walk and completely sclerosed and hide-bound skin. He has had terrible losses on the personal front and has completely lost his will to live and laugh. He is declared to have severe chronic skin and joint graft versus host disease (GvHD). Several lines of medications have been tried resulting in more toxicity and less efficacy on improving his condition. He has severe joint contractures; his skin is very tight and sclerodermatous and he is wheelchair bound. Where do we go from here? Have we really cured him or have we replaced one disease with another? Is there nothing in the vast armamentarium of modern medicine that can get this innocent and cherubic child back to life?

Haemtopoeitic stem cell transplantation (HSCT) is curative for several blood and stem cell disorders. With better outcomes, research is focused on decreasing morbidity and ensuring intact survival with improved quality of life.

Acute graft versus host disease (GvHD) is known to affect as many as 10-60% of all HSCTs. Chronic GvHD is associated with significant impairment in quality of life. Steroids are the first line of treatment for GvHD. Several second line agents are available which have improved outcomes in GvHD namely etanercept, rituximab and mycophenolate mofetil. All of these medications have associated adverse effects on immunity and have a propensity to increase susceptibility to infections.

EXTRACORPOREAL PHOTOPHERESIS

Extracorporeal photopheresis (ECP) is a significant advance in the treatment of GvHD which has the potential to be steroid sparing thus decreasing long term toxicity.

PROCESS OF ECP

The process involves the following steps:

Mononuclear cells (MNCs) are collected from the patient through apheresis. These cells are T lymphocytes which are the responsible for effecting GvHD.
The collected MNCs are transferred into an illumination bag which is the injected with 8-methoxypsoralen (8MOP) at a dose of 20mcg/ml. The 8MOP gets attached to the collected MNCs which are then exposed to Ultraviolet A light (UVA).
The treated product is then reinfused into the patient.

MECHANISM OF ACTION OF ECP

The UVA light while targeting the 8MOP tagged lymphocytes results in covalent DNA linkages and apoptosis of the T lymphocytes. These apoptotic lymphocytes result in further immunomodulatory effects in the patient through activation of dentritic cells and regulatory T cells (Tregs). Certain immunosuppressive cytokines are also released.

ADVERSE EFFECTS

No significant adverse effects have been noted in any of the patients so far.

SCOPE OF ECP

ECP was initially developed for treating patients with cutaneous T cell leukaemia. Along with acute and chronic GvHD, it has also been found to be of benefit to prevent graft rejection and treatment of GvHD in solid organ transplants namely liver, kidney and heart and lung transplants.

WHAT HAVE WE DONE SO FAR?

The first ECP in India has been performed at Apollo Cancer Centres, Chennai in April 2016. We have a team of trained pediatric hemato-oncologist, haematologist, apheresis technicians and nurses to perform the ECP

The Patients underwent 8 sessions of ECP, all of which he tolerated well. Gradually, with each session, there was improvement in his skin and joints. His contractures improved, skin became suppler and less hide-bound and range of movements improved. His emotional milieu and his self-esteem showed an exponential improvement and from being wheel-chair bound, he walked home. He is on the way to gradual recovery and will need physiotherapy and occupational therapy to improve muscle functions.