title: Effect of gamma irradiation of red blood cell units on T-cell inactivation as assessed by limiting dilution analysis: implications for preventing transfusion-associated graft-versus-host disease.
abstract: Transfusion-associated graft-versus-host disease can be prevented by treating cellular blood products with gamma irradiation. A wide range of gamma irradiation dose levels has been used in routine practice. We used limiting dilution analysis, which measures clonable T cells, to assess the influence of 500 to 3,000 cGy of gamma irradiation delivered from a 137Cs source on T cells when delivered in situ to ADSOL-preserved red blood cell (RBC) units in blood bags. In a series of experiments using RBC units irradiated within 24 hours after collection, 1,500 cGy inactivated > 4 log10 of T cells; however, viable T cells were detected in all experiments. With 2,000 cGy, a > or = 4.7 log10 decrement in T-cell growth occurred in 7 of 8 experiments. With 2,500 or 3,000 cGy, no T-cell growth (> 5 log10 depletion) was detected. Comparable effects were observed with ADSOL-preserved RBC units in the standard PL 146 plastic container and in the recently developed PL 2209 plastic container. T-cell inactivation, as a function of gamma irradiation dose, was similar when either a 137Cs or a linear accelerator source was used. T cells isolated from ADSOL-preserved RBC units after storage for 7 and 21 days, although reduced in number as compared with a fresh unit stored for 24 hours, were viable, capable of proliferation, and susceptible to inactivation by gamma irradiation. Using a sensitive in vitro assay for T-cell proliferation, we found that a gamma irradiation dose of 2,500 cGy may be required to completely inactivate T cells in RBC units.
authors.affiliation: Department of Hematology/Oncology, Children's National Medical Center, Washington, DC 20010.
authors.forename: M M
authors.initials: MM
authors.lastname: Pelszynski
authors.forename: G
authors.initials: G
authors.lastname: Moroff
authors.forename: N L
authors.initials: NL
authors.lastname: Luban
authors.forename: B J
authors.initials: BJ
authors.lastname: Taylor
authors.forename: R R
authors.initials: RR
authors.lastname: Quinones
mesh_terms: D000328:Adult; D001793:Blood Preservation; D004307:Dose-Response Relationship, Radiation; D004912:Erythrocytes / Q000528:radiation effects*; D005720:Gamma Rays; D006086:Graft vs Host Disease / Q000517:prevention & control*; D006801:Humans; D013601:T-Lymphocytes / Q000528:radiation effects*; D065227:Transfusion Reaction