Effect of therapeutic plasma exchange on plasma levels of oxidative biomarkers in a patient with thrombotic thrombocytopenic purpura.

BACKGROUND: The role of oxidative stress in the initiation and progression of endothelial damage in thrombotic thrombocytopenic purpura (TTP) syndrome has been the subject of much speculation in the recent past. OBJECTIVES: The aim of this study was to measure the concentration of plasma advanced oxidation protein products (AOPPs), advanced glycation end products (AGEs), and carbonyl groups (CG) as markers of oxidative stress in plasma of a patient with TTP during the course of the disease until recovery and to evaluate the effect of plasmapheresis (PE) on these biomarkers. MATERIALS AND METHODS: The study consisted of plasma analysis of the patient, and 23 healthy subjects served as controls. In the patient with TTP, AOPP, AGE, and CG analysis was performed before and after each PE at the days +1 (Tα), +2, +4, +6, +10, +9, and +17 after the last plasmapheresis (Tω). RESULTS: Plasma concentrations of AOPPs were increased in the acute phase of TTP, and at Tα, the patient had AOPPs levels higher than 99°‰ of controls. AOPPs decreased in the recovery phase, and at Tω, their values were between 84° and 85°‰ of controls. No significant difference was found in AOPP levels before and after each PE. No significant differences for AGEs or CG concentrations were found at Tα with respect to the control group, while only a trend was observed for reduction of plasma AGEs after each plasmapheresis. CONCLUSION: Our data seem to confirm the hypothesis that oxidative stress is a critical component of the pathogenesis of TTP.