In a set of human plasmas of apparently healthy donors (n=113), consis
ting of 48 males and 65 females aged from 19 to 66 years, a mean value
of 368 +/- 188 mu g/l PAP was observed. There is no correlation with
age and smoking. Females using oral contraceptives showed a non-signif
icant trend to higher PAP levels compared to non-using females. The En
zygnost(R) PAP showed a significant correlation with two other commerc
ially available test kits for PAP. There is a discrepancy in the measu
red absolute value of PAP. Blood sampling and handling for the assessm
ent of PAP allows working at both 4 degrees C and room temperature. Ex
tension of the time before centrifugation up to 2 hours did not affect
the results.