Clinical utility of the free prostate specific antigen (PSA), alpha 1-antichymotrypsin-complexed PSA, and free/total PSA ratio using the specific and sensitive enzyme-linked immunosorbent assay 'E-plate EIKEN PSA'

1)f-PSAとc-PSA測定系とも各抗原を特異的に測定し, t-PSA測定系はf-PSAとc-PSAを1:1の割合で測定していた. 2)f/t%とf/c%は共にPCaにおいてA1やB0のような早い病期からnon PCaと有意差が認められた. 3)t-PSAとc-PSA及びf/t%とf/c%のROC曲線における差は殆ど認められず, c-PSAの診断上の有用性はt-PSAと同等と思われた.f-PSA単独では有用性が認められなかった. 4)t-PSAが4～10ng/mlの検体においてはf/t%とf/c%がPSA-Dと同様に前立腺癌の診断に有効であった. 5)前立腺体積40ml以上でt-PSAが10ng/ml以下では癌でない確率が高い
We studied the clinical significance of serum prostate specific antigen (PSA) ratio: free-PSA/total-PSA and free-PSA/complex-PSA to discriminate between prostate cancer (PC) and prostate benign disease (non-PCa) by using total-PSA, alpha 1-antichymotrypsin complexed (complex)-PSA and free-PSA enzyme-linked immunosorbent assay (ELISA) kits newly developed at EIKEN Chemical Co, Ltd. Fre-PSA and complex-PSA ELISA kits demonstrated high sensitivity and specificity. Total-PSA ELISA kit also demonstrated equimolarity for free-PSA and complex-PSA. On the total-PSA range of 4-10 ng/ml, free-PSA/total-PSA% (f/t%) and free-PSA/complex-PSA% (f/c%) were very useful to discriminate between PCa and non-PCa by receiver operating characteristic curve analysis as well as PSA density (PSA-D) but not free-PSA level. F/t% and f/c% were even useful to discriminate early stage PCa (i.e. A1 or B0) from non-PCa by the Mann-Whitney U-test.