Results of treatment of 13 patients fulfilling the criteria for TTP are presented. Thrombocytopenia was present in all patients (100%). Eleven of 13 patients (84.6%) had conciousness disorder, and seven of 13 patients (53.8%) had renal impairment. Immunosuppressive therapy with plasmapheresis and replacement of removed volume with fresh frozen plasma in a dosage of 25 ml/kg body weight resulted in statistically significant increase of platelet count (p = 0.0033), and significant improvement of consciousness as defined by increased Glasgow Coma Score (GCS) (p = 0.0524). In two patients, renal function recovered and, in one patient, hemodialysis was no longer needed. This improvement in a small patient group has no statistical significance.