Fiebig E, Lane T A
Department of Pathology, School of Medicine, University of California, San Diego, La Jolla.
Transfusion. 1994 Oct;34(10):846-51. doi: 10.1046/j.1537-2995.1994.341095026968.x.
Ultraviolet B (UVB) irradiation of platelet concentrate (PCs) reduces platelet alloimmunization, but the mechanism of the effect is unclear. Evidence suggests that UVB may downregulate the expression of surface adhesion molecules on passenger antigen-presenting cells in PCs.
The effect of blood bank storage, platelet preparation from whole blood, and UVB irradiation on the quantitative expression of intercellular adhesion molecule-1 (ICAM-1, or CD54), HLA-DR, CD45, and CD11c on CD14-positive antigen-presenting cells (monocytes) was studied by using two-color flow cytometry.
Blood bank storage for 4 days resulted in upregulation of ICAM-1 and HLA-DR and downregulation of CD14 but left the expression of CD11c and CD45 unchanged. Preparation of PCs from fresh whole blood was associated with a rapid increase in CD11c without upregulation of ICAM-1 and HLA-DR. UVB irradiation before storage inhibited the upregulation of ICAM-1 and HLA-DR, resulted in accelerated downregulation of CD14, and was associated with increased loss of monocytes. Agitation of the PC bag during irradiation was of critical importance, since omission of agitation resulted in largely uninhibited upregulation of ICAM-1 but was still associated with significantly higher cell loss than that seen in unirradiated controls.
UVB exposure nonspecifically affects monocytes in PCs, resulting in downregulation of surface molecules that are important for antigen presentation, as well as in significant cell loss.
紫外线B（UVB）照射血小板浓缩物（PCs）可降低血小板同种免疫，但作用机制尚不清楚。有证据表明，UVB可能下调PCs中过客抗原呈递细胞表面黏附分子的表达。
采用双色流式细胞术研究血库储存、全血制备血小板以及UVB照射对CD14阳性抗原呈递细胞（单核细胞）上细胞间黏附分子-1（ICAM-1，即CD54）、HLA-DR、CD45和CD11c定量表达的影响。
血库储存4天导致ICAM-1和HLA-DR上调，CD14下调，但CD11c和CD45的表达无变化。用新鲜全血制备PCs与CD11c迅速增加相关，而ICAM-1和HLA-DR无上调。储存前进行UVB照射可抑制ICAM-1和HLA-DR的上调，导致CD14加速下调，并与单核细胞损失增加相关。照射期间摇动PC袋至关重要，因为不摇动会导致ICAM-1在很大程度上不受抑制地上调，但仍与比未照射对照组显著更高的细胞损失相关。
UVB暴露非特异性地影响PCs中的单核细胞，导致对抗原呈递重要的表面分子下调，以及显著的细胞损失。
