炎症性腸疾患の内視鏡的重症度評価における病理組織学的所見の位置づけ─生検組織の炎症活動性評価の観点から

Assessment of Histologic Disease Activity in Evaluation of Endoscopic Severity of Ulcerative Colitis : From a Stand-point of Assessment of Biopsy Specimens

要旨●活動期内視鏡所見が高度の潰瘍性大腸炎症例を用いて，非難治例39例と難治例32例の生検粘膜の組織学的活動性を比較検討した．組織学的活動性の判定にはMattsの生検組織分類とRileyおよびGeboesの生検組織スコアをもとに作成した9項目から成る生検組織スコアを用いた．Mattsの生検組織分類では，難治例は非難治例に比べて活動性炎症の程度が高く，Grade 5の頻度が有意に高かった（84.4％ vs. 59.0％）．生検組織スコアの比較では，難治例は非難治例に比べてスコア合計の平均が有意に高かった（19.3±3.4 vs. 15.9±4.1）．個々の組織所見の比較では，難治例は非難治例に比べ好中球浸潤スコアと表層上皮破壊スコアが有意に高く，好中球浸潤スコアが好酸球浸潤スコアに比べて高いものが有意に多かった（40.6％ vs. 5.1％）．これらの結果から，内視鏡的所見が同質の粘膜であっても，その組織学的炎症活動性には違いがあること，炎症の活動性に関する組織所見の総和が難治化という臨床的重症化の指標としても有用であることが示唆された．

　HDAs（histologic disease activities）were assessed and compared between 39 cases of non-refractory and 32 cases of refractory ulcerative colitis with severe endoscopic findings. Matts histologic grading of biopsy specimen（Matts grade）and histologic activity score comprising 9 parameters, modified by Riley and Geboes histologic scores, were used for HDA assessment. Refractory cases showed higher Matts grade than non-refractory cases, and a frequency of Grade 5 of the former was significantly higher than that of the latter（84.4% vs. 59.0%）. Average HAS was significantly higher for refractory cases than non-refractory cases（19.3±3.4 vs. 15.9±4.1）. For each histologic parameter, neutrophil infiltration and surface epithelium integrity score were significantly higher for refractory cases than non-refractory cases. Furthermore, cases with the neutrophil infiltration score higher than eosinophilia score were more frequent for refractory cases than non-refractory cases. This finding indicates that even if the endoscopic findings are equal, HDA is not identical, and the assessment of HDA using biopsy specimens is useful to re-evaluate endoscopic severity.