潰瘍性大腸炎における鋸歯状病変の分子生物学的特徴

Biological Characteristics of Serrated Polyps in Patients with Ulcerative Colitis

要旨●筆者らは潰瘍性大腸炎（UC）患者の鋸歯状病変36病変の臨床病理学的・分子生物学的特徴を解析した．有病率は1.8%であり，炎症範囲内の鋸歯状病変はUC罹病期間が長く，慢性持続型の男性に多い傾向であった．炎症範囲内のSSL-like dysplasiaは近位大腸に多く，BRAF変異主体であった．一方，TSA-like dysplasiaは遠位大腸に多く，KRAS変異主体であった．これらの特徴は非IBD患者のSSL・TSAと類似していたが，SSL-like dysplasiaは男性優位である点で差異が認められた．分類不能病変（SD NOS）はTSA-like dysplasiaと臨床・分子生物学的特徴が類似しており，両者の関連が示唆された．

　We analyzed the clinicopathological and biological characteristics of 36 serrated polyps in patients with ulcerative colitis（UC）. The prevalence of serrated polyps was 1.8%. Serrated polyps in the UC-affected segments were more frequently observed in male patients, with a longer disease duration and a chronic continuous type. Sessile serrated lesion（SSL）-like dysplasia in the UC-affected segments predominantly occurred in the proximal colon and was found to be primarily associated with BRAF mutations, whereas traditional serrated adenoma（TSA）-like dysplasia, also commonly found in the distal colon, was considered to be primarily associated with KRAS mutations. These characteristics closely resembled those of SSLs and TSAs, respectively, in patients with non-inflammatory bowel disease ; however, SSL-like dysplasia showed a notable male predominance. Additionally, serrated dysplasia not otherwise specified exhibited clinical and molecular characteristics similar to TSA-like dysplasia, suggesting a potential relationship between these entities.