Ferrara R M, Biancardi C, Cavalca V, Botta M, Bailo M, Bartorelli A
Cancer Detect Prev. 1987;10(1-2):101-8.
A factor that cross reacts with the carcinoembryonic antigen (CEA), which we call P factor, was isolated from normal human plasma. To demonstrate the difference between this P factor and the nonspecific cross-reacting antigen (NCA), the same anti-CEA serum was absorbed in an identical manner with both the antigens. Absorption was checked by immunohistochemistry by the beta-galactosidase procedure on sections of colonic adenocarcinoma and normal colonic mucosa. The unabsorbed antiserum recognizes both tissues; after absorption with NCA the staining becomes paler on both tissues, but maintains color on the normal colonic mucosa and granulocytes. Only absorption with the P factor will give an unstained field of normal colonic mucosa, thus revealing the tumor structure. Data obtained by us suggest that the NCA (tissue extract) is an antigen that is not suitable to the absorption of anti-CEA serum for immunocytochemistry techniques, whereas the P factor (plasma extract) appears to be utilizable with good results.
从正常人血浆中分离出一种与癌胚抗原（CEA）发生交叉反应的因子，我们称之为P因子。为了证明这种P因子与非特异性交叉反应抗原（NCA）之间的差异，用这两种抗原以相同方式吸收同一份抗CEA血清。通过免疫组织化学β-半乳糖苷酶法在结肠腺癌和正常结肠黏膜切片上检查吸收情况。未吸收的抗血清可识别这两种组织；用NCA吸收后，两种组织上的染色都变浅，但正常结肠黏膜和粒细胞上仍保持颜色。只有用P因子吸收才会使正常结肠黏膜出现无染色区域，从而显示出肿瘤结构。我们获得的数据表明，NCA（组织提取物）是一种不适用于免疫细胞化学技术中抗CEA血清吸收的抗原，而P因子（血浆提取物）似乎可产生良好效果。
