Pathological diagnosis of intravascular large B-cell lymphoma by multiple immunostainings focusing IMP3

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K15424
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 49020:Human pathology-related
• Research Institution: Kyoto University
• Principal Investigator: Fujimoto Masakazu 京都大学, 医学研究科, 准教授 (90573676)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: IMP3 / 血管内大細胞型B細胞リンパ腫 / 多重免疫染色

Outline of Final Research Achievements

We analyzed the utility of IMP3 immunohistochemistry for intravascular large B-cell lmyphoma (IVL) diagnosis in various organs. Overall, 152 pathological specimens(111 positive and 41 negative for IVL) obtained from 88 patients with a diagnosis of IVL were stained for IMP3 and IMP3/PAX5. As negative controls, 40 pathology specimens from 38 patients with no history of IVL or other B-cell lymphomas were stained for IMP3. All mononuclear cells with cytoplasmic staining were considered positive for IMP3 expression, but expression restricted to germinal center B cells was excluded from evaluation. All 111 IVL pathological specimens were positive for IMP3 and IMP3/PAX5. In addition,11 of the 41 specimens originally diagnosed as IVL-negative showed IMP3/PAX5 double-positive cells.However,of the 40 negative control samples,IMP3-positive nongerminal center B cells were detected in only 2 samples (P = 0.0131). IMP3 can be a helpful adjunct for IVLBCL diagnosis.

Free Research Field

病理診断

Academic Significance and Societal Importance of the Research Achievements

血管内大細胞型B細胞リンパ腫(intravascular large B-cell lymphoma; IVL)は生検組織
中の腫瘍細胞量が限られ、特異的な診断マーカーにも乏しい事から、しばしば診断が難しい高悪性度リンパ腫である。申請者は癌胎児蛋白の一種であるinsulin-like growth factorII mRNA-binding protein 3 (IMP3)がIVLの腫瘍細胞に高頻度に発現している事を見出し、多施設から集積した多くのIVL症例を用いた後ろ向き研究にて免疫組織化学的手法を用いてIMPの発現を解析し、IVLの病理診断におけるIMP3の有用性を証明した。