Department of Molecular and Applied Biosciences, University of Westminster, London, UK.
Clin Chim Acta. 2010 Dec 14;411(23-24):1935-9. doi: 10.1016/j.cca.2010.08.009. Epub 2010 Aug 12.
Prostate specific antigen (PSA) measurement is used for the diagnosis of prostate cancer (PCa) but the test lacks specificity due to the number of false positive readings. The glycosylation of PSA is altered in PCa but studies in this area have been limited to few clinical samples and/or require advanced laboratory facilities. An assay to assess PSA glycosylation was established using equipment available in most routine biomedical testing laboratories.
Serum samples from patients with PCa or benign prostatic hyperplasia (BPH) were used. PSA (range 4-10 ng/ml) was affinity purified, separated and probed with the lectin Ulex europaeus (UEA-1; specific for α1,2 linked fucose). An enzyme-linked immunosorbent lectin assay (ELLA) with colorimetric detection was devised and PSA fucosylation assessed in a further independent set of 26 samples.
Free PSA (fPSA) from PCa patients showed a significant increase in fucosylation compared with fPSA from patients with BPH. The ELLA was 92% specific and 69% sensitive for PCa over BPH. In comparison, fPSA measurement was 70% specific and 56% sensitive (threshold set to 25% tPSA) for PCa over BPH.
Changes in glycosylation of PSA were identified using 50 μl of serum with PSA in the range of 4-10 ng/ml, this represents a more specific and sensitive test for PCa based on fucosylation changes of fPSA.
前列腺特异性抗原（PSA）检测用于诊断前列腺癌（PCa），但由于假阳性读数较多，该检测缺乏特异性。PCa 中 PSA 的糖基化发生改变，但该领域的研究仅限于少数临床样本，并且/或者需要先进的实验室设备。本研究建立了一种使用大多数常规生物医学检测实验室都具备的设备评估 PSA 糖基化的检测方法。
使用来自 PCa 或良性前列腺增生（BPH）患者的血清样本。PSA（范围 4-10ng/ml）经亲和纯化、分离后用荆豆凝集素（UEA-1；特异性识别α1,2 连接的岩藻糖）进行探测。设计了一种酶联免疫吸附凝集素检测法（ELLA），并采用比色法检测，进一步在 26 份独立样本中评估 PSA 岩藻糖基化。
与 BPH 患者的 fPSA 相比，PCa 患者的游离 PSA（fPSA）的岩藻糖基化显著增加。ELLA 对 PCa 与 BPH 的区分特异性为 92%，敏感性为 69%。相比之下，fPSA 检测法对 PCa 与 BPH 的区分特异性为 70%，敏感性为 56%（阈值设定为 25%总 PSA）。
使用 50μl 血清和 4-10ng/ml 范围内的 PSA 可鉴定 PSA 糖基化的改变，基于 fPSA 岩藻糖基化改变，该检测法对 PCa 具有更高的特异性和敏感性。
