1994 Volume 40 Issue 5 Pages 744-750
We tried to make an appropriate standard condition for UV-B irradiation of platelets concentrates (PC), which is useful for prophylaxis against post-transfusion graft versus host disease (PT-GVHD) as well as prevention against alloimmunization.
Agitation of PC bags during UV-B irradiation is necessary to irradiate evenly cells in the bag, becaue a lot of UV-B ray should be absorbed by bag membrane and plasma. Amounts of UV-B that each lymphocyte or platelet would actually receive on an average (UVavg) was calculated by the equation as below.
UV*avg=K1×(K2L-1)×UV/(logeK2×L), K1 and K2 are permiability index of bag membrane and that in plasma, respectively; while L and UV stands for depth of PC bag and emitting dose of UV-B, respectively. We irradiated PC bags with UV-B in a dose of 541-13, 525J/m2 of UV*avg, and examined lymphocytes in the bags about the responder and stimulator activities in mixed lymphocytes culutre (MLR), as well as platelet function in the bags. Irradiation more than 5, 000J/m2 of UV*avg is needed to suppress responder and stimulator activities, and platelet function is maintained up to 13, 525J/m2 of UV*avg.
In conclusion, UV-irradiation in a range of 6, 000-13, 000J/m2 of UV*avg is considered appropriate to prevent from PT-GVHD or alloimmunization.
