Extracorporeal photopheresis in refractory chronic graft-versus-host
disease: The influence on peripheral blood T cell subpopulations. A
study by the Hellenic Association of Hematology
Extracorporeal photopheresis (ECP) has been established as an effective
treatment modality for patients with chronic extensive graft-versus host
disease (GVHD). In the present study, we evaluated the influence of ECP
on the numbers of CD4(+), CD8(+), CD20(+), CD56(+) cells, and on
T-regulatory (Tregs), as well as on the numbers of naive, central memory
(CM), and effector memory (EM) T-cells in patients treated for
refractory chronic GVHD. Flow cytometric analysis of peripheral blood
lymphocytes was performed for the calculation of the different T-cell
subsets. Patients with GVHD had a higher percentage of EM-CD4(+) cells
in comparison with healthy donors (p = 0.046). The percentages of
naive-CD8(+), naive-CD4(+), CM-CD8(+), CM-CD4(+), EM-CD8(+), and Tregs
were not different between patients with GVHD and healthy donors.
Similarly there was no statistical difference in the percentages of
naive, CM, and EM CD4(+) and CD8(+) cells before and after 3 months of
treatment with ECP. However, in the subset of Tregs a statistically
significant increase was observed after 3 months of treatment with ECP
(p = 0.015). Responders to ECP had statistically significantly higher
absolute numbers of CD4(+), and CD8(+) cells, in comparison with
non-responders. These data further support the concept that ECP does not
cause immune-suppression, but should be better considered as an
immune-modulating treatment. (C) 2011 Elsevier Ltd. All rights reserved
