血清PSA系列在前列腺疾病中的应用

Study on a series of prostate-specific antigen molecules for diagnosis of prostate cancer

目的探讨血清前列腺特异抗原(PSA)系列在前列腺疾病的诊断与鉴别中的价值.方法用磁微粒子免疫化学发光法测定210例良性前列腺增生(BHP)和138例前列腺癌(PCa)患者血清PSA系列:t-PSA、f-PSA、结合PSA(c-PSA),计算f-PSA/t-PSA、c-PSA/t-PSA、f-PSA/c-PSA的比值.结果 PSA各分子水平在BPH和PCa中变化幅度较大,各比值则较稳定(组内P＞0.05),尤其是c-PSA/t-PSA.t-PSA和c-PSA/t-PSA在BPH和pCa患者不同区段上分布差异有显著性(χ2=86.15,P＜0.005);在t-PSA诊断灰值区(t-PSA在4.0～10.0 ng/ml),以c-PSA/t-PSA=0.78为界值联合t-PSA可以更有效地区分BPH和PCa.以t-PSA≤10.0 ng/ml和c-PSA/t-PSA≥0.78为界值联合对BPH和PCa进行筛选,敏感性为95.8%,特异性为97.3%,阴性预测值为83.6%,阳性预测值为96.8%.结论 t-PSA与c-PSA/t-PSA的联合应用,对前列腺疾病的诊断具有重要临床意义,尤其是在t-PSA的诊断灰值区.

Objective To evaluate the series of prostate-specific antigen (PSA) molecules in serum,i.e.,total PSA (t-PSA),free-PSA (f-PSA) and complexed-PSA(c-PSA),for the diagnosis of prostate diseases.Methods Serum samples were obtained from 210 men with untreated benign prostatic hyperplasia (BPH) and 138 men with untreated prostate cancer (PCa).The levels of c-PSA,f-PSA,t-PSA in serum were determined by auto-immunochemical luminescence method,and the ratio of f-PSA/t-PSA,c-PSA/t-PSA and f-PSA/c-PSA were calculated.Results The range of c-PSA,f-PSA and t-PSA levels were significiantly changed in both BPH and Pca groups,but the ratio of f-PSA/t-PSA,f-PSA/c-PSA,especially c-PSA/t-PSA were relatively invariant ( P >0.05).There was a significant difference in the distribution of t-PSA and c-PSA/t-PSA ratio in both the patients with PCa and BPH (χ2=86.15, P <0.005).In the diagnostic gray zone of t-PSA (t-PSA values between 4.0 ng/ml and 10.0 ng/ml) the combination of t-PSA with c-PSA/t-PSA was helpful for effectively differentiation of PCa from BPH.When t-PSA≤10.0ng/ml and c-PSA/t-PSA≥0.78 was taken as the cut-off value for the screening of PCa,the sensitivity,specificity,negative predictive value and positive predictive value were 95.8%,97.3%,83.6% and 96.8% respectively.Conclusions The levels of the series of PSA molecules (c-PSA,f-PSA,t-PSA) in serum,especially c-PSA and c-PSA/t-PSA ratio hold important clinical significance for the early diagnosis of prostate diseases and the assessment for Pca,and it should be more sensitive and reliable especially within the diagnostic gray zone of t-PSA.