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 ( AOPP s), advanced glycation end products ( AGE s), 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 ( T α), +2, +4, +6, +10, +9, and +17 after the last plasmapheresis ( T ω). Results Plasma concentrations of AOPP s were increased in the acute phase of TTP , and at T α, the patient had AOPP s levels higher than 99°‰ of controls. AOPP s decreased in the recovery phase, and at T ω, 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 AGE s or CG concentrations were found at T α with respect to the control group, while only a trend was observed for reduction of plasma AGE s after each plasmapheresis. Conclusion Our data seem to confirm the hypothesis that oxidative stress is a critical component of the pathogenesis of TTP .