Evidence exists that HD patients are exposed to enhanced oxidative stress that is initiated by the generation of oxygen free radicals, mainly in tissue and probably in the circulation. The most potent O2-generating proteins are oxidatively modified lipoproteins, mainly oxidized (oxLDL). OxLDL have been shown to trigger apoptosis of endothelial cells, macrophages, and lymphocytes. However, the pathophysiological relevance of oxLDL-induced CD4+ T cell apoptosis in HD patients remains uncertain.