Octaplas Adult TTP Trial

Inclusion Criteria: 1. Patient is a male or female at least 18 years of age or older. 2. Patient has a diagnosis of TTP or suspicion of TTP that is planned on being treated with TPE within 3 days of study entry. 3. Patient has thrombocytopenia (platelets \< 100 x 10P9P/L). 4. Patient is willing to give voluntary written informed consent before any study-related procedure is to be performed that is not part of standard medical care, with the understanding that consent may be withdrawn by the subject at any time without prejudice to future medical care. Exclusion Criteria: 1. Patient has a history of severe hypersensitivity reaction to plasma-derived products or to FFP. 2. Patient has an already known IgA deficiency with documented antibodies against IgA. 3. Patient is currently participating in an interventional clinical study or has participated during the past 1 month prior to study inclusion. 4. Patient has severe deficiencies of Protein S. 5. Patient received more than 1 treatment of plasma exchange or plasma infusion for current episode of TTP prior to randomization. 6. Patient is currently taking ACE-inhibitors; in case patient is under ACE-inhibitor treatment a wash-out period of at least 24 hours has to elapse prior the first plasma infusion.