Cytokines may also play a role in the pathophysiology of TA-TMA. Cytokines produced by donor T cells make endothelial cells more susceptible to apoptosis or cell lysis mediated by perforin, granzyme B, or TNF.35 Smaller studies have identified elevated levels of circulating cytokines, including IL-8, IL-12, and thrombomodulin, during TA-TMA.21,40,41 The variable antigenicity of endothelial cells m