Preliminary clinical evaluation of free/total PSA ratio by the IMMULITE® system

M. Correale, A. Pagliarulo, G. Donatuti, F. Sturdà, A. M L Capobianco, V. Stigliani, M. Rizzello, S. Circhietta, F. Pignatelli, L. Leone, V. Frusciante, S. Modoni, F. Schittulli

Research output: Contribution to journalArticlepeer-review


The role of free (F) and complexed serum PSA is now under investigation. In the present study, we evaluated the clinical significance of F-PSA and F/Total (T) PSA ratio in a preliminary series of samples from 88 patients with prostate cancer (PC), 113 with benign prostatic disease (BPD); and 98 with non-prostatic disease (NP). We used the F-PSA and third generation T-PSA (DPC, Los Angeles, USA) chemiluminescent enzyme immunometric assays with the IMMULITE automated system. At the 10 ng/ml cutoff for T-PSA levels, we obtained a sensitivity of 83% with a specificity of 100% in NP and 80% in BPD. The addition of the F/T ratio - rather than F-PSA levels - was useful to better discriminate PC and BPD in the cases erroneously classified by T-PSA alone: 44/68 samples (65%) were correctly diagnosed. Moreover, the F/T ratio was particularly effective in the critical T-PSA range between 4.1-9.9 ng/ml; 26/40 cases (65%) were correctly evaluated. In conclusion, the F/T ratio seems to be an interesting auxiliary test to T-PSA, to be reserved for selected cases where additional diagnostic information is necessary.

Original languageEnglish
Pages (from-to)24-28
Number of pages5
JournalInternational Journal of Biological Markers
Issue number1
Publication statusPublished - Jan 1996


  • Benign prostatic hypertrophy
  • Free-PSA
  • Prostate cancer
  • PSA ratio

ASJC Scopus subject areas

  • Immunology
  • Biochemistry


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