Persistent Remission of Angioimmunoblastic T-Cell Lymphoma and Associated Immune-Mediated Thrombotic Thrombocytopenic Purpura After Multimodal Therapy: A Case Report

Angioimmunoblastic T-cell lymphoma (AITL) is a rare subtype of peripheral T-cell lymphoma (PTCL) and is frequently associated with autoimmune phenomena. Clinically, AITL shows an aggressive disease course and poor prognosis with currently available treatment strategies. We here report the case of a 64-year-old female patient who was diagnosed with AITL and showed a complicated clinical course due to concurrent immune-mediated thrombotic thrombocytopenic purpura (iTTP). To our knowledge, the presented case highlights a previously unreported association of both conditions. Treatment, including chemotherapy and iTTP-directed treatments, resulted in rapid clinical improvement and sustained remission of both the AITL and the concurrent iTTP. In AITL, transformed T-follicular helper cells (TFHs) are particularly thought to mediate hypersecretion of cytokines and excessive autoantibody production. Immunological disturbances to large parts mediated through these transformed TFHs are thought to trigger autoimmune conditions, as seen with iTTP in this patient. At 36 months post-treatment, the patient remains in complete remission for both AITL and iTTP. This case highlights the complex immunopathological relationship between AITL and autoimmune disorders possibly impeding diagnosis and treatment in a timely manner.