title: Increased serum concentration of soluble HLA-DR antigens in HIV infection and following transplantation.
abstract: HLA class I and class II antigens circulate in serum as soluble molecules. Increased concentrations of soluble HLA class I molecules have been demonstrated in viral diseases, in rejection episodes following organ transplantation and in graft versus host disease. To explore the possibility of a variation of the serum concentrations of soluble HLA class II molecules in the same pathologic conditions we developed a double determinant immune assay that detects whole soluble HLA-DR molecules (sHLA-DR). The mean level of sHLA-DR antigens in sera from 23 healthy individuals was 0.64 +/- 0.72 microgram/ml. Elevated serum concentrations of sHLA-DR molecules were detected in sera from HIV infected patients in CDC2/3 and in CDC4 C1 stages (2.0 +/- 1.7 micrograms/ml and 4.6 +/- 1.7 micrograms/ml, respectively), in sera from patients affected by acute rejection after liver transplantation (5.3 +/- 3.7 micrograms/ml) and in sera from patients affected by severe acute graft versus host disease following bone marrow transplantation (8.8 +/- 3.1 micrograms/ml). The increase of sHLA-DR molecules in these sera significantly correlated with the elevation of soluble HLA class I antigens (P = 0.0004). The reported data suggest that both soluble HLA class I and class II molecules serum levels increase during viral infections and strong immune reactions and could suggest the involvement of these molecules in immunoregulation.
mesh_terms: D016026:Bone Marrow Transplantation / Q000276:immunology; D006084:Graft Rejection / Q000097:blood / Q000209:etiology; D006086:Graft vs Host Disease / Q000097:blood / Q000209:etiology; D015658:HIV Infections / Q000097:blood / Q000150:complications / Q000276:immunology*; D006684:HLA-DR Antigens / Q000097:blood*; D015395:Histocompatibility Antigens Class I / Q000097:blood; D000949:Histocompatibility Antigens Class II / Q000097:blood; D006801:Humans; D007118:Immunoassay / Q000592:standards; D018799:Intercellular Adhesion Molecule-1 / Q000097:blood; D016031:Liver Transplantation; D012680:Sensitivity and Specificity
chemical_list: D006684:HLA-DR Antigens; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D018799:Intercellular Adhesion Molecule-1