BACKGROUND: Tumor-associated trypsin inhibitor (TATI) is mainly proposed as a tumor marker for ovarian cancer. However, recent discoveries of TATI in cancer and inflammatory diseases show that assay of TATI in biological samples is of increasing interest. METHODS: We validated a previously described TR-IFMA and a newly developed dual-monoclonal sandwich ELISA for TATI. These methods were compared with a commercial radioimmunoassay (RIA). We studied preanalytical factors affecting serum TATI concentrations and established age- and gender specific reference intervals using serum samples from 195 healthy volunteers. RESULTS: The assay range and precision were 0.8-45 μg/L and <9.1% for the ELISA, and 0.13 μg/L-150 μg/L and <12.5% for the TR-IFMA, respectively. Both assays correlated well with a RIA. Type of blood sample and nutritional status were not critical and TATI was stable in serum samples when stored at +4°C and -20°C for 4 weeks and at -80°C for 8 weeks. The 95% reference limits for serum TATI in adults were 5.2-15.3 μg/L in the age group 18-70 years and 7.5-21.3 μg/L in the age group >70 years. CONCLUSIONS: Significantly higher concentrations of serum TATI were observed in elderly women and in men. Both ELISA and TR-IFMA technologies can be employed to develop sensitive and robust immunoassays for TATI using monoclonal antibodies.
BACKGROUND:Tumor-associated trypsin inhibitor (TATI) is mainly proposed as a tumor marker for ovarian cancer. However, recent discoveries of TATI in cancer and inflammatory diseases show that assay of TATI in biological samples is of increasing interest. METHODS: We validated a previously described TR-IFMA and a newly developed dual-monoclonal sandwich ELISA for TATI. These methods were compared with a commercial radioimmunoassay (RIA). We studied preanalytical factors affecting serum TATI concentrations and established age- and gender specific reference intervals using serum samples from 195 healthy volunteers. RESULTS: The assay range and precision were 0.8-45 μg/L and <9.1% for the ELISA, and 0.13 μg/L-150 μg/L and <12.5% for the TR-IFMA, respectively. Both assays correlated well with a RIA. Type of blood sample and nutritional status were not critical and TATI was stable in serum samples when stored at +4°C and -20°C for 4 weeks and at -80°C for 8 weeks. The 95% reference limits for serum TATI in adults were 5.2-15.3 μg/L in the age group 18-70 years and 7.5-21.3 μg/L in the age group >70 years. CONCLUSIONS: Significantly higher concentrations of serum TATI were observed in elderly women and in men. Both ELISA and TR-IFMA technologies can be employed to develop sensitive and robust immunoassays for TATI using monoclonal antibodies.
Authors: Kati Räsänen; Kien X Dang; Harri Mustonen; Tho H Ho; Susanna Lintula; Hannu Koistinen; Ulf-Håkan Stenman; Caj Haglund; Jakob Stenman Journal: Mol Oncol Date: 2017-12-27 Impact factor: 6.603