Immune thrombotic thrombocytopenic purpura in Armenia: A case series highlighting the role of early empiric therapy and multidisciplinary management

Abstract Immune thrombotic thrombocytopenic purpura (iTTP) is a rare but potentially fatal thrombotic microangiopathy characterized by severe ADAMTS13 deficiency due to autoantibodies, leading to microangiopathic hemolytic anemia and thrombocytopenia. We report three adult iTTP cases treated at Yeolyan Hematology and Oncology Center in Armenia. The first patient, a 53-year-old male, presented with fatigue, confusion, anemia (Hb 55 g/L), thrombocytopenia (15×10⁹/L), reticulocytosis, elevated LDH (2778 U/L), undetectable haptoglobin, and a negative direct antiglobulin test (DAT). MRI showed basal ganglia edema. Treatment with Rituximab 375mg/kg once weekly, 4 doses, and dexamethasone pulse therapy was started before getting the results of the ADAMTS13 test. At that time, only ADAMST13 genetic testing was available, which came back negative. While hematologic parameters improved, he developed visual and auditory hallucinations that persisted for 2–3 weeks after platelet recovery. The patient received antipsychotic treatment prescribed by a psychiatrist leading to complete resolution of neuropsychiatric symptoms. The second patient, a 25-year-old male, presented withfatigue, mucosal bleeding, dark urine, and laboratory findings consistent with microangiopathic hemolytic anemia: hemoglobin 66 g/L, platelet count 9×10⁹/L, elevated lactate dehydrogenase (LDH) at 1235 U/L, undetectable haptoglobin, and a negative direct antiglobulin test (DAT). He rapidlydeteriorated into a coma, requiring intensive care unit (ICU) admission. ADAMTS13 activity was 2.5%, with detectable antibodies, confirming a diagnosis of immune TTP. Treatment with plasma exchange (PEX) (8 sessions), IV dexamethasone, and rituximab (4 doses on 1, 4, 8, 9 days) led to full hematologic recovery. Following recovery, the patient experienced visual and auditory hallucinations lasting about 2 weeks. He was started on antipsychotic therapy as per psychiatric consultation, resulting in full resolution of neuropsychiatric symptoms within a few days. The third patient, a 30-year-old male, presented with acute loss of speech lasting 9 hours. He had an Hb level of 60 g/L, platelet count of 9×10^9/L, LDH level of 2300 U/L, and undetectable haptoglobin. DAT was negative. ADAMTS13 activity was 0.03 IU/mL. He received immediate PEX, dexamethasone pulse therapy, and rituximab 375mg/m2 (1, 7, 11, 18 days). After two weeks (8 PEX, 3 doses of Rituximab), Hb improved to 85 g/L and platelets increased to 110×10⁹/L. However, he developed aggressive behavioral changes that persisted beyond hematologic recovery. Following the fourth infusion of Rituximab, hematologic parameters improved rapidly, and the neurologic symptoms fully resolved.