Protein Z - Does its analyzation make any clinical sense?

G. Kappert, M. Daoud, M. Siebert, H. Rott, S. Halimeh (Duisburg, Deutschland)

Laboratory tests
Date: 17.02.2017,
Time: 17:15 - 18:15

Objective: Protein Z (PZ) is a vitamin K-dependent (VKD) plasma glykoprotein belonging to different natural anticoagulant systems involved in the regulation of blood coagulation. The literature is mentioning an association between a low level of Protein Z and haemorrhage, thromboembolic events and miscarriage. But the role of PZ plasma level and PZ gene polymorphisms remains debated with conflicting results. For that reason, we decided to collect the data of patients in our centre, who got measured PZ.

Methods: PZ-concentration was measured by an ELISA. The datas of 707 patients (552 females and 155 males) were collected including age, sex, bleeding score, body mass index BMI, VWF-Activity, number of venous and of arterial thromboembolism, drug intake and number of miscarriages. Patients receiving Vit. K-Antagonists were excluded. The differences of medians of the PZ-level of different categories were examined with Mann-Whitney-U-Test or ANOVA.

Results: PZ does not differ between sexes but is raising with the age significantly (p=0.011). We did not see any difference in the PZ-level between the woman suffering from Hypermenorrhea or not. Also there was no difference between women suffering from miscarriage or not. No significant difference was also seen between patients suffering from venous thromboembolism or from arterial thromboembolism. We also get no significant difference between over- and underweight patients, so PZ does not seem to be BMI-dependent. Furthermore we could not see any association of PZ with the bleeding score of the patients or with the activity of the Von Willebrand factor. Women taking contraceptives with ethinyloestradiol had a 28% higher PZ-concentration than women not taking these contraceptives. (p=0.011)

Conclusion: In this overview over our patients, we did not find any evidence for a reasonable use of PZ in clinical routine.