Jacobsen S J, Lilja H, Klee G G, Wright G L, Pettersson K, Oesterling J E
Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
Urology. 1994 Oct;44(4):512-8. doi: 10.1016/s0090-4295(94)80049-9.
To assess the comparability of the Tandem-R and IMx serum prostate-specific antigen (PSA) assays across levels of the ratio of free-to-total serum PSA found in a community-based population of healthy men.
Banked serum samples from the baseline component of the Olmsted County Study of Urinary Symptoms and Health Status Among Men were thawed and analyzed using the Tandem-R and IMx PSA assays. Serum levels also were determined for the free, noncomplexed form of PSA, PSA complexed to alpha-1 antichymotrypsin, and total PSA with a research-based immunofluorometric assay.
The results of the Tandem-R and IMx assays were strongly correlated at all levels of the ratio of free-to-total serum PSA. The Spearman correlation coefficients ranged from 0.87 to 0.98 (all p < 0.001). The relationship between the Tandem-R and IMx assays, however, differed at low levels of free-to-total serum PSA compared with high levels. In the lowest 10th percentile of the ratio of free-to-total serum PSA (0.04 to 0.18), the IMx assay read lower than the Tandem-R (slope +/- standard error = 0.92 +/- 0.04, intercept +/- standard error = 0.21 +/- 0.14); whereas in the upper 10th percentile of free-to-total ratio (0.46 to 0.65) the IMx assay yielded values higher than the Tandem-R assay (slope = 1.21 +/- 0.07, intercept = 0.14 +/- 0.05). In the middle 90%, the slope did not statistically differ from 1.0.
For the majority of men, results of the Tandem-R and IMx PSA assays were virtually identical. The small differences found would not be of clinical significance for most men but should be considered when comparing results of different assays in sequential determinations for a specific man.
评估在以社区为基础的健康男性人群中，Tandem-R和IMx血清前列腺特异性抗原（PSA）检测在不同游离PSA与总PSA比值水平下的可比性。
解冻来自奥尔姆斯特德县男性泌尿系统症状与健康状况研究基线部分的冻存血清样本，并用Tandem-R和IMx PSA检测进行分析。还使用基于研究的免疫荧光测定法测定了游离、非复合形式的PSA、与α-1抗糜蛋白酶复合的PSA以及总PSA的血清水平。
在游离PSA与总PSA比值的所有水平上，Tandem-R和IMx检测结果高度相关。Spearman相关系数范围为0.87至0.98（所有p<0.001）。然而，与高水平相比，在低水平的游离PSA与总PSA时，Tandem-R和IMx检测之间的关系有所不同。在游离PSA与总PSA比值的最低十分位数（0.04至0.18）中，IMx检测结果低于Tandem-R（斜率±标准误=0.92±0.04，截距±标准误=0.21±0.14）；而在游离与总比值的最高十分位数（0.46至0.65）中，IMx检测值高于Tandem-R检测（斜率=1.21±0.07，截距=0.14±0.05）。在中间的90%，斜率与1.0无统计学差异。
对于大多数男性，Tandem-R和IMx PSA检测结果几乎相同。发现的微小差异对大多数男性而言不具有临床意义，但在对特定男性进行连续检测并比较不同检测结果时应予以考虑。
