title: Whole-body UVB irradiation during allogeneic hematopoietic cell transplantation is safe and decreases acute graft-versus-host disease.
abstract: Depletion of host Langerhans cells (LCs) prevents cutaneous graft-versus-host disease (GvHD) in mice. We analyzed whether UVB irradiation is tolerated during the course of human allogeneic hematopoietic cell transplantation and whether depletion of LCs by broadband UVB could improve GvHD outcome. A total of 17 patients received six whole-body UVB irradiations with 75% of the individually determined minimal erythemal dose after conditioning with a reduced intensity protocol. LCs, dermal dendritic cells (DCs), and macrophages were analyzed before and after UVB irradiation by immunohistochemical analysis. Circulating blood cells and serum factors were analyzed in parallel. In striking contrast to previous data, our irradiation protocol was well tolerated in all patients. UVB treatment decreased the number of LCs and also affected dermal DCs. UVB-treated patients also had significantly higher 25-hydroxyvitamin D3 serum levels and higher numbers of circulating CD4+ FoxP3+ regulatory T cells. Strikingly, nine out of nine patients with complete LC depletion (<1 LC per field) developed only grade I GvHD or no GvHD up to day 100. Our results strongly suggest that prophylactic UVB irradiation post transplant is safe and should be further explored as a clinical strategy to prevent acute (skin) GvHD.
authors.affiliation: Department of Hematology and Oncology, University of Regensburg, Regensburg, Germany. marina.kreutz@klinik.uni-regensburg.de
authors.forename: Marina
authors.initials: M
authors.lastname: Kreutz
authors.forename: Sigrid
authors.initials: S
authors.lastname: Karrer
authors.forename: Petra
authors.initials: P
authors.lastname: Hoffmann
authors.forename: Eva
authors.initials: E
authors.lastname: Gottfried
authors.forename: Rolf-Markus
authors.initials: RM
authors.lastname: Szeimies
authors.forename: Joachim
authors.initials: J
authors.lastname: Hahn
authors.forename: Matthias
authors.initials: M
authors.lastname: Edinger
authors.forename: Michael
authors.initials: M
authors.lastname: Landthaler
authors.forename: Reinhard
authors.initials: R
authors.lastname: Andreesen
authors.forename: Miriam
authors.initials: M
authors.lastname: Merad
authors.forename: Ernst
authors.initials: E
authors.lastname: Holler
mesh_terms: D000208:Acute Disease; D000328:Adult; D000818:Animals; D002908:Chronic Disease; D003131:Combined Modality Therapy; D005260:Female; D006086:Graft vs Host Disease / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D020544:Graft vs Leukemia Effect; D019337:Hematologic Neoplasms / Q000628:therapy*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects* / Q000379:methods*; D006801:Humans; D007801:Langerhans Cells / Q000276:immunology; D008297:Male; D051379:Mice; D008875:Middle Aged; D011829:Radiation Dosage; D013045:Species Specificity; D019172:Transplantation Conditioning / Q000379:methods; D014184:Transplantation, Homologous; D014916:Whole-Body Irradiation / Q000379:methods*