Corey E, Buhler K R, Vessella R L
Tumor Immunology Laboratory of the Urology Department, Medical School, University of Washington, Seattle 98195, USA.
Urology. 1997 Oct;50(4):567-71; discussion 571-2. doi: 10.1016/S0090-4295(97)00415-9.
Prostate-specific antigen (PSA) is commonly used as a marker for prostate disease. Prostate epithelium expresses both PSA and human glandular kallikrein (hK2) proteins, which share 80% sequence homology. The immunologic cross-reactivity of these two proteins could potentially interfere with determination of PSA levels in diagnoses of prostate cancer. We set out to determine the extent of this cross-reactivity for a panel of 10 anti-PSA monoclonal antibodies (mAbs).
Enzyme-linked immunosorbent assay (ELISA), sandwich assays, and western transfer techniques were used to assess the PSA/hK2 cross-reactivity of the anti-PSA mAbs.
We did not detect the hK2 protein with any of the 10 anti-PSA mAbs under western transfer conditions. In ELISA experiments, 8 of 10 mAbs exhibited hK2 cross-reactivity under certain conditions. However, no combination of mAbs tested in sandwich assays exhibited a signal in hK2 cross-reactivity experiments greater than 0.1% of the PSA signal.
We have evaluated 10 anti-PSA mAbs and determined that despite the 80% homology between PSA and hK2 proteins, cross-reactivity with hK2 by these antibodies would not significantly affect the determination of PSA levels by means of sandwich assays.
前列腺特异性抗原（PSA）常用于前列腺疾病的标志物。前列腺上皮细胞表达PSA和人腺激肽释放酶（hK2）蛋白，这两种蛋白的序列同源性为80%。这两种蛋白的免疫交叉反应性可能会干扰前列腺癌诊断中PSA水平的测定。我们着手确定一组10种抗PSA单克隆抗体（mAb）的这种交叉反应性程度。
采用酶联免疫吸附测定（ELISA）、夹心测定法和western印迹技术评估抗PSA mAb的PSA/hK2交叉反应性。
在western印迹条件下，我们用10种抗PSA mAb中的任何一种均未检测到hK2蛋白。在ELISA实验中，10种mAb中有8种在某些条件下表现出hK2交叉反应性。然而，在夹心测定法中测试的mAb组合在hK2交叉反应性实验中均未显示出大于PSA信号0.1%的信号。
我们评估了10种抗PSA mAb，并确定尽管PSA和hK2蛋白之间有80%的同源性，但这些抗体与hK2的交叉反应性不会显著影响通过夹心测定法测定PSA水平。
