Fas, Fas ligand,and transfusion immunomodulation

dem-onstrated that soluble HLA class I (sHLA-I) moleculesupregulate FasL expression and sFasL secretion in activatedFas-positive CD8+ T-cells and trigger their apoptosis. Thelevel of sHLA-I molecules is significantly increased in theserum of patients with an activation of their immune sys-tem, such as occurs during acute rejection of organ al-lografts, acute GVHD after BMT, autoimmune disease, orviral infection.