Department of Pathology, Karolinska Institute and University Hospital, Stockholm, Sweden.
Anticancer Res. 2012 Sep;32(9):3723-6.
The number of round cells that should normally be present in the colonic mucosa remains disputed. Biopsies from patients with chronic diarrhoea, having a slightly increased number of round cells in the lamina propria mucosa (lpm) may be diagnosed as slight chronic colitis by some pathologists, while others may regard these biopsies as being normal.
The numbers of plasma cells/plasma cell precursors (PC-PCP) were assessed in colonic biopsies from 35 patients by the aid of MUM1 immunostaining. MUM1 (multiple myeloma oncogene 1) is a member of the interferon regulatory family of transcription factors (interferon regulatory factor 4 gene, IRF4).
Many of the round cells considered, as lymphocytes in H&E staining were in fact MUM1-positive PCP. In 6 patients having a priori, a slightly increased number of round cells, the mean number of MUM1-labelled cells was 40.8, in 5 patients with collagenous colitis, it was 81.4 and in 12 patients with Crohn's colitis, 87.6, whereas in 12 normal individuals it was 23.3 (MUM1-positive cells in collagenous-Crohn's colitis vs. normal mucosa, p<0.05).
MUM1 was of value in recording a significant increase of PC-PCP in collagenous colitis and Crohn's colitis. The subjective impression of increased cellularity in some colonic biopsies from patients with chronic diarrhoea was substantiated in mathematical terms, by demonstrating that the number of PC-PCP was increased.
结肠黏膜中正常应存在的圆形细胞数量仍存在争议。一些病理学家将慢性腹泻患者的活检标本中固有层黏膜（lpm）中略有增加的圆形细胞诊断为轻度慢性结肠炎，而另一些则可能认为这些活检标本正常。
通过 MUM1 免疫染色评估 35 例患者结肠活检标本中的浆细胞/浆细胞前体细胞（PC-PCP）数量。MUM1（多发性骨髓瘤癌基因 1）是干扰素调节家族转录因子（干扰素调节因子 4 基因，IRF4）的成员。
在 H&E 染色中被认为是淋巴细胞的许多圆形细胞实际上是 MUM1 阳性的 PCP。在 6 例先前认为圆形细胞略有增加的患者中，MUM1 标记细胞的平均数量为 40.8，在 5 例胶原性结肠炎患者中为 81.4，在 12 例克罗恩病结肠炎患者中为 87.6，而在 12 例正常个体中为 23.3（胶原性-克罗恩病结肠炎与正常黏膜中的 MUM1 阳性细胞，p<0.05）。
MUM1 在记录胶原性结肠炎和克罗恩病结肠炎中 PC-PCP 的显著增加方面具有价值。通过证明 PC-PCP 的数量增加，从慢性腹泻患者的一些结肠活检标本中观察到的细胞增多的主观印象在数学上得到了证实。
