Clinicopathological anaalysis of angioimmunoblastic T-cell lymphoma

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K15104
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49020:Human pathology-related
• Research Institution: Aichi Medical University
• Principal Investigator: Satou Akira 愛知医科大学, 医学部, 助教 (40732699)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 血管免疫芽球性T細胞リンパ腫 / Epstein-Barr virus / メトトレキセート関連リンパ増殖性疾患

Outline of Final Research Achievements

Angioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoma derived from follicular helper T cells. Epstein-Barr virus (EBV)-positive B cells have been detected in majority of patients with AITL. We evaluated the impact of EBV on the clinicopathological characteristics of AITL. We revealed that, among the younger group of AITL (<60 years old), EBV-positive status significantly improved prognosis compared to an EBV-negative status.
We also performed clicopathological study of AITL arising in patients treated with methotrecate (MTX-AITL). The study revealed that approximately 70% of patients with MTX-AITL presented with spontaneous regression (SR) after the cessation of MTX. We further compareted the microenvironment features of MTX-AITL and normal AITL by using nCounter sytem, and found that microenvironment of MTX-AITL is rich with plasmacytoid dendritic cells. This result suggests that plasmacytoid dendritic cells might be a key factor of SR after the MTX cessation.

Free Research Field

人体病理学

Academic Significance and Societal Importance of the Research Achievements

若年性AITLにおいて微小環境中のEBV陽性細胞の多寡が予後予測に有用であることを明らかにした。これにより予後不良と予測される症例では骨髄移植を考慮に入れて治療計画を立てるといった様に、治療選択の指標となることが期待される。
MTX-AITLではMTX中止による自然退縮が約7割で認めることから、通常のAITLの様に化学療法を治療の第一選択とするのではなく、MTX中止をまず試すべきであることが分かった。このことは必要でない化学療法を避けることにつながり、患者は化学療法による副作用を回避できる。結果として、患者の肉体的、精神的苦痛の軽減に寄与すると考えられる。