Quantitation of TIMP-1 in plasma of healthy blood donors and patients withadvanced cancer

A kinetic enzyme-linked immunosorbent assay (ELISA) for plasma tissue inhib itor of metalloproteinase (TIMP)-1 was developed in order to examine the po tential diagnostic and prognostic value of TIMP-1 measurements in cancer pa tients. The ELISA enabled specific detection of total TIMP-1 in EDTA, citra te and heparin plasma. The assay was rigorously tested and requirements of sensitivity, specificity stability and good recovery were fulfilled, TIMP-1 levels measured in citrate plasma (mean 69.2 +/- 13.1 mu g l(-1)) correlat ed with TIMP-1 measured in EDTA plasma (mean 73.5 +/- 14.2 mu g l(-1)) from the same individuals in a set of 100 healthy blood donors (Spearman's rho = 0.62, P < 0.0001). The mean level of TIMP-1 in EDTA plasma from 143 patie nts with Dukes' stage D colorectal cancer was 240 +/- 145 mu g l(-1) and a Mann-Whitney test demonstrated a highly significant difference between TIMP -1 levels in healthy blood donors and colorectal cancer patients (P < 0.000 1). Similar findings were obtained for 19 patients with advanced breast can cer (mean 292 +/- 331 mu g l(-1)). The results show that TIMP-1 is readily measured in plasma samples by ELISA and that increased levels of TIMP-1 are found in patients with advanced cancer. it is proposed that plasma measure ments of TIMP-1 may have value in the management of cancer patients.