Radioimmunoassay of glandular kallikrein in human plasma after partial purification by immunoaffinity column.

Glandular kallikrein in human plasma was partially purified by immunoaffinity column (1.0 X 2.0 cm) and was measured by a radioimmunoassay (RIA). Plasma (5-10 ml) was diluted with an equal volume of 10 mmol/l sodium phosphate buffer, pH 7.4, containing 0.9% NaCl (PBS) and was applied to an immunoaffinity column from which glandular kallikrein was eluted with 3 mol/l NaSCN (20 ml). The enzymic fraction was concentrated with an Amicon PM 10 filter and dialyzed against PBS. The final recovery of the enzyme was 51.6 +/- 1.6% (mean +/- SD), determined by using [125I]kallikrein. The usable range of the standard curve covered 2.5-100 ng/tube. The coefficient of variation within the series was 5.9%, and the coefficient of variation between the series was 7.6%. In healthy controls (n = 25), the plasma content of glandular kallikrein was 1.36 +/- 0.39 ng/ml. In patients with acute pancreatitis (n = 6), the plasma concentration was 8.02 +/- 6.15 ng/ml, significantly different from the control group (p less than 0.01).