Oxidized LDL have been shown to be strongly atherogenic and immunogenic in experimental animals and in humans. Similarly, autoantibodies against ox-LDL and various epitopes of ox-LDL have been detected in sera and atherosclerotic lesions. Those autoantibodies are mainly directed against adducts of lipid peroxidation products (mainly highly reactive carbonyls) and apolipoproteins or aminolipids. Oxidation of LDL may also lead to generation of oxidized derivatives of cholesterol (i.e. 7-ketocholesterol - 7-ketoCh), which are characterized by high cytotoxicity, muta- and carcinogenicity as well as
immunosuppressive effect and probably immunogenic properties. The aim of this study was quantification of autoantibodies to 7-ketoCh in sera from  patients post OHT. Antibodies in IgG class were measured in sera from 81 patients post OHT and 73 healthy volunteers with the use of home-made ELISA method. As antigen we used 7-ketoCh hemisuccinate conjugated to bovine serum albumin. Anti-7-ketoCh antibodies were detected in all examined sera. Their concentration was significantly higher in OHT patients than in control groups (respectively 109.0±109.7 and 53.5±20.0 U/ml, p<0.005).  Also relationship between antibodies concentration and time between OHT and sampling was observed. The obtained results show that also low molecular products of LDL oxidation - 7-ketoCh are immunogenic and probably anti-7-ketoCh autoantibodies can play a role in progression of atherosclerosis in OHT patients.

Keywords: Heart Transplantation