Determination of pregnancy zone protein in serum using an automated immunoprecipitin reaction method

Determination of pregnancy zone protein in serum by means of an automated immunoprecipitin reaction method and pretreatment with polyethylene glycol for reducing the serum blanks is described. Using this procedure the sensitivity of the method was greatly improved, from originally 100 mg/l to 1 mg/l. The precision "between days" was 9.9%. A positive and significant correlation to electroimmuno assay is demonstrated. In apparently healthy controls the median serum pregnancy zone protein in females was 38 mg/l (2--91 mg/l) and in males 2 mg/l (0--20 mg/l). No correlation between serum pregnancy zone protein and age could be demonstrated. In malignant diseases our results seem to confirm a relationship between increased pregnancy zone protein and spreading of the tumours. Serum pregnancy zone protein in disseminated malignancies are increased significantly compared to controls. In males 75% with disseminated tumours have elevated serum pregnancy zone protein.