ORIGINAL ARTICLESProtein Z is reduced in chronic kidney disease and not elevated in patients on haemodialysisBlyth, Emilya; Favaloro, Emmanuel Ja; Harris, Davidb; Kairaitis, LukasbAuthor Information aDepartment of Haematology, Institute of Clinical Pathology and Medical Research, Australia bDepartment of Renal Medicine, Westmead Hospital, Westmead, NSW, Australia Received 8 May, 2007 Revised 3 July, 2007 Accepted 11 July, 2007 Correspondence to Emily Blyth, Department of Haematology, Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW 2145, Australia Tel: +61 2 9845 6352; fax: +61 2 9845 5164; e-mail: email@example.com Blood Coagulation & Fibrinolysis: January 2008 - Volume 19 - Issue 1 - p 23-25 doi: 10.1097/MBC.0b013e3282f09df2 Buy Metrics Abstract Protein Z (PZ) is a vitamin K dependent serine protease inhibitor, which along with its cofactor Protein Z-dependant protease inhibitor (ZPI) has anti-Xa activity. PZ has previously been reported to be elevated in patients with end-stage chronic kidney disease (CKD) on haemodialysis but not in non-dialysed CKD patients raising the possibility that PZ may have a role in the bleeding diathesis of patients on haemodyalisis. PZ was measured in controls (n = 18), CKD on haemodialysis (n = 23) and CKD not on dialysis (n = 23). Patients on vitamin K antagonists, with acute inflammatory conditions (as measured by CRP) or liver dysfunction were excluded PZ levels were reduced in CKD patients when compared to levels in the control group (1.35 μg/mL vs 1.80 respectively, p = 0.022). Subgroup analysis revealed a trend toward reduction in mean PZ in the CKD subgroups (non-dialysed CKD group 1.37 (p = 0.08); haemodialysis 1.33 (p = 0.12)). There were no significant differences in the PZ levels for different stages of non-dialysed CKD patients when stratified by the level of glomerular filtration rate (GFR). These data show that PZ levels were reduced in patients with CKD, and not elevated in patients on haemodialysis, arguing against a role for PZ in the bleeding diathesis of renal failure. This finding is in contradiction to a previous report which found PZ to be elevated in patients on haemodialysis. © 2008 Lippincott Williams & Wilkins, Inc.