Gastrointestinal and Liver Pathology Research Laboratory, Department of Pathology, Karolinska Institute and University Hospital, 17176, Stockholm, Sweden,
Virchows Arch. 2013 Nov;463(5):637-42. doi: 10.1007/s00428-013-1474-5. Epub 2013 Aug 25.
Under normal conditions, the colorectal mucosa exhibits small numbers of scattered lymphocytes and plasma cells in the lamina propria and only few mucosal lymphoid aggregates (MLAs). In Crohn's colitis, the number of lymphocytes and plasma cells in the lamina propria and of MLA is substantially increased. In addition, multiple lymphoid aggregates are newly formed in the submucosa (submucosal lymphoid aggregate (SLA)) and deeper. The aim of the present study was to investigate the cellular immune response in MLA, in SLA, and in the lamina propria in Crohn's colitis. Fifty-nine colorectal biopsies/surgical specimens with or without inflammatory diseases were challenged with multiple myeloma 1 (MUM1) that highlights activated T cells, committed B cells, and plasma cells (aT/cB/PC). The number of MUM1-positive aT/cB/PC per high-power field (HPF) in MLA and in SLA was significantly lower in Crohn's colitis than in controls (p < 0.05). In contrast, the number of MUM1-positive aT/cB/PC per HPF in the lamina propria was significantly higher in Crohn's colitis and in other forms of chronic colitis than in controls (p < 0.05). The paucity of MUM1-positive cells in MLA and in SLA in Crohn's colitis might be caused by an increased number of MUM1-negative precursors. These precursors would eventually migrate into the lamina propria to differentiate into aT/cB/PC, complying thereby with the immunological mucosal demands generated by the on-going chronic inflammation.
在正常情况下，结直肠黏膜固有层中可见少量散在的淋巴细胞和浆细胞，仅有少量黏膜淋巴集结（MLA）。在克罗恩病中，固有层和 MLA 中的淋巴细胞和浆细胞数量显著增加。此外，黏膜下（黏膜下淋巴集结（SLA））和更深层中还会形成多个淋巴集结。本研究旨在探讨克罗恩病中 MLA、SLA 和固有层中的细胞免疫反应。对 59 例伴有或不伴有炎症性疾病的结直肠活检/手术标本进行多发性骨髓瘤 1（MUM1）挑战，MUM1 突出显示活化的 T 细胞、定向 B 细胞和浆细胞（aT/cB/PC）。与对照组相比，克罗恩病中 MLA 和 SLA 中每高倍视野（HPF）的 MUM1 阳性 aT/cB/PC 数量显著减少（p<0.05）。相比之下，克罗恩病和其他类型慢性结肠炎中固有层中每 HPF 的 MUM1 阳性 aT/cB/PC 数量显著高于对照组（p<0.05）。克罗恩病中 MLA 和 SLA 中 MUM1 阳性细胞的缺乏可能是由于 MUM1 阴性前体数量增加所致。这些前体最终会迁移到固有层分化为 aT/cB/PC，从而满足持续慢性炎症产生的免疫性黏膜需求。
