title: Ultraviolet-B irradiation of leukapheresis. Products: dose-response relationship with the mixed lymphocyte reaction.
abstract: Ultraviolet-B (UVB) irradiation of blood constituents intensifies their anti-rejection effect in pretransplant donor-specific transfusions. UVB-induced inhibition of the mixed lymphocyte reaction (MLR) between UVB-irradiated donor cells and prospective recipient cells is a predicator of this anti-rejection effect. In order to define the dose-response relationship between the incident UVB irradiation on leukocyte concentrates and subsequent inhibition of their MLR responses, we collected 4 +/- 2 x 10(9) leukocytes (93 +/- 7% lymphocytes) in 200 ml plasma from each of three volunteers by leukapheresis and exposed them to rapid, serial doses of UVB irradiation which was delivered by a blood product irradiator (4R4440 UVB Irradiator, Baxter, Inc) with aliquots removed between doses. Lymphocytes from each aliquot were placed in MLR with panel donors and studied in three groups: 1) the panel donor cells were gamma-irradiated (1,500 rads) (i.e., only the UVB-irradiated cells could proliferate), 2) the UVB-irradiated cells were gamma-irradiated (i.e., only the panel lymphocytes could proliferate), and 3) no gamma-irradiation (i.e., both cell populations could proliferate). Each group had a similar UVB dose-related diminution in the MLR (p = .79, ANOVA). A single dose of 6 J/cm2 extinguished the MLR to baseline in all groups. This dose should theoretically prevent transfused cells from producing either graft-versus-host disease or allosensitization, and might heighten their tolerogenic effect. This dose will be employed in our study of donor-specific leukocyte transfusion in clinical renal transplantation.
authors.affiliation: Department of General Surgery, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612, USA.
authors.forename: P F
authors.initials: PF
authors.lastname: Foster
authors.forename: H
authors.initials: H
authors.lastname: Gebel
authors.forename: B C
authors.initials: BC
authors.lastname: McLeod
authors.forename: N
authors.initials: N
authors.lastname: Ebert
authors.forename: S
authors.initials: S
authors.lastname: Jensik
authors.forename: H N
authors.initials: HN
authors.lastname: Sankary
authors.forename: A
authors.initials: A
authors.lastname: Tambur
authors.forename: J W
authors.initials: JW
authors.lastname: Williams
mesh_terms: D004307:Dose-Response Relationship, Radiation; D006801:Humans; D007108:Immune Tolerance; D007937:Leukapheresis; D017708:Leukocyte Transfusion; D007959:Lymphocyte Culture Test, Mixed; D008214:Lymphocytes / Q000276:immunology / Q000528:radiation effects*; D014466:Ultraviolet Rays