The effect of extracorporeal photopheresis on T cell response in chronic graft-versus-host disease

Abstract

Extracorporeal photopheresis (ECP) is a safe and effective immunoregulatory therapy for steroid-refractory chronic graft-versus-host disease (cGVHD) but its mechanism of action is poorly understood. In this study, we evaluated the effect of ECP in a sample of cGVHD patients. Our data showed that ECP-treated patients had lower CD4 T and B cells, and substantially higher NK cells than untreated patients. T regulatory (Treg) cells were similar between the two groups of patients. Interestingly, Treg cells were higher in ECP-treated patients and ECP-responders who had no history of aGVHD or sclerosis, than in those who had one of them or both. These findings suggest that at least one of the mechanisms of immunomodulation by ECP targets the Treg cell population and that an increase in Treg cells may be associated with response in patients with cGVHD. Together, the results of ECP are different depending on the patients’ clinical condition.

Keywords::

• Extracorporeal photopheresis treatment
• chronic graft-versus host disease

Acknowledgements

We thank Maggie Kennel and Bryan Fiema for patient's sample collections and the data management, respectively.

This work was supported in part by Michigan Institute for Clinical and Health Research and MCubed both of which were funded by the University of Michigan to Drs Couriel and Chang, and also in part by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR000433 to Dr Chang.

Potential conflict of interest

Disclosure forms provided by the authors are available with the full text of this article at www.informahealthcare.com/lal