Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>Abstract 2227</jats:p>
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<jats:title>Introduction:</jats:title>
<jats:p>Protein Z (PZ) is a vitamin K-dependent protein. In hemostasis PZ has two functions: together with Factor Xa it forms an inhibiting complex with the PZ- dependent protease-inhibitor and it enhances binding of Thrombin to phospholipid surfaces. Therefore, low PZ levels may induce thrombosis or bleeding.</jats:p>
<jats:p>The latter has been questioned by Vasse 2008 and in 1995 Kemkes-Matthes reported in 58% of patients (pts) with a bleeding history PZ deficiency as the only abnormality.</jats:p>
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<jats:title>Aim of the study:</jats:title>
<jats:p>To evaluate if low PZ levels are associated with a bleeding tendency, we reviewed data of pts referred to or laboratory. PZ determination is part of our diagnostic work up, including whole blood count, PT, PTT, VWF/FVIII-complex, FXIII and platelet function studies.</jats:p>
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<jats:title>Material and Methods:</jats:title>
<jats:p>Over a 1 year period we investigated PZ level in 173 pts. PZ concentration was determined by ELISA (Asserachrom Protein Z; Diagnostica Stago), a sandwich immunoassay using a mouse monoclonal antibody against PZ, normal range 1600 – 3300 μg/l, mean 2600 μg/l published by Miletich. Our normal range obtained by 62 donors 990–2490, mean 1740μg/l (+/− 2SD). PZ <1000μg/l is considered to be abnormal.</jats:p>
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<jats:title>Results:</jats:title>
<jats:p>In 75/173 (43%) pts with a bleeding history (e.g. postoperative hemorrhage, epistaxis, menorrhagia) no coagulation abnormality was detected. In 41/98 (42%) low PZ level was the only abnormality (mean PZ 642, range 195–994). 57/98 (58%) were diagnosed with vWD n=17; platelet function disorders n=10 or ASA/drugs causing platelet dysfunction n=20, others n=10. In 21/57 (37%) low PZ level was detected additionally (mean PZ 699μg/l; range 219–949) and in the remaining 36/57 (mean PZ 1689; range 1036–2842).</jats:p>
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<jats:title>Conclusion:</jats:title>
<jats:p>Surprisingly, in 24% of pts with a bleeding history the only abnormality was PZ deficiency. Therefore, we consider PZ determination a useful parameter in patients with a bleeding history after ruling out more common disorders. Low PZ levels may cause a coagulopathy in some pts.</jats:p>
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<jats:title>Disclosures:</jats:title>
<jats:p>No relevant conflicts of interest to declare.</jats:p>
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