Radioimmunoassay of human tissue factor.

The apoprotein (AP) of tissue factor (TF) has been purified 72,000-fold to homogeneity from human placenta using acetone delipidation, sodium deoxycholate (DOC) extraction, Sephacryl S-300 column chromatography, preparative polyacrylamide-gel electrophoresis (PAGE) in DOC and tryptic digestion. The purified AP had an apparent molecular weight of 54,000 by sodium dodecyl sulfate/PAGE. A radioimmunoassay (RIA) for quantitation of the TF-AP using an antibody against this purified AP of TF was devised which was sensitive enough to measure as small a quantity as 100 pg/ml of TF-AP accurately with high reproducibility. In addition to TF clotting activity (TFA), the immunoreactive TF-AP (IR-TFR) in the homogenates of leukemic leukocytes from patients with acute non-lymphoid leukemia (ANLL) was determined using this RIA. In 30 patients with ANLL, the mean IR-TFR with standard deviation (SD) of 21 cases with DIC was 157.9 +/- 188.1 ng/10(8) cells, which was significantly higher than that (37.1 +/- 29.9 ng/10(8) cells) of 9 cases with no DIC during remission induction chemotherapy (p less than 0.01).