Differential diagnosis of Japanese patients with CLL and related disorders

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K08963
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Laboratory medicine
• Research Institution: Niigata University
• Principal Investigator: TAKIZAWA JUN 新潟大学, 医歯学系, 准教授 (70463990)
• Co-Investigator(Kenkyū-buntansha): 曽根 博仁 新潟大学, 医歯学系, 教授 (30312846) ; 青木 定夫 新潟薬科大学, 薬学部, 教授 (40242408) ; 鈴木 律朗 島根大学, 学術研究院医学・看護学系, 准教授 (20280810) ; 大島 孝一 久留米大学, 医学部, 教授 (50203766)
• Research Collaborator: Suzumiya Junji
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: CLL / CLLRSG-01 / LEF1 / Matutes' score / Typical CLL / Atypical CLL / IGHV / CLL-like LPD

Outline of Final Research Achievements

Chronic lymphocytic leukemia (CLL), the most frequent adult leukemia in Western countries, is rare in Japan. To clarify the characteristics of Japanese patients with CLL, we conducted a nationwide registry study (CLLRSG-01). The WHO classification was used to establish a central diagnosis in all cases. Analyses of flow cytometry, FISH, and the mutational status of IGHV were performed. Morphologically 162 cases were classified as CLL and 59 as other B-cell neoplasms. Immunophenotypically, 109 of the 162 cases were confirmed as CLL (classic CLL), but the other 53 patients could not be attributed to a diagnosis of CLL (CLL-like LPD). The frequency of morphologically atypical CLL in the CLL-like LPD group was higher than that in the classic CLL group. Our analyses indicate that the proportion of Japanese patients with classic CLL is much lower among those with small mature B-cell neoplasms.

Free Research Field

血液内科学

Academic Significance and Societal Importance of the Research Achievements

慢性リンパ性白血病(CLL)は本邦において希少疾患であり、欧米と形態評価の方法が異なっていたため(欧米は自然乾燥なのに対して本邦は強制乾燥を用いる)、正確な実態は明らかにされていなかった。今回、欧米と同じ手法を用いて、国内多施設共同研究を行うことにより、初めて本邦CLLの実態が多数例で評価された。典型的形態と免疫形質を有するCLLの頻度が低いことが初めて明らかになり、非典型例が多数存在することが示された。今後、典型例と非典型例の分子病態を比較することにより、本邦に特徴的な発症機序が明らかになれば新規治療に結びつく可能性が高く、学術的意義や社会的意義は大きいものと考えられる。