PAF-acetylhydrolase activity in plasma of patients with chronic kidney disease. Effect of long-term therapy with erythropoietin (EN)

Papavasiliou, E. C. (EN)

Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας (EL)

Papavasiliou, E. C. (EN)

Background. Platelet activating factor acetylhydrolase (PAF-AH) is a Ca2+-independent phospholipase A(2) that is secreted mainly from monocytes/macrophages. In human plasma, PAF-AH is associated primarily with low-density lipoprotein (LDL), while a small proportion of enzyme is associated with high-density lipoprotein (HDL). The ratio of HDL-PAF-AH to total plasma enzyme activity may represent a potential marker of atherogenicity. We evaluated possible alterations of lipoprotein-associated enzyme activity in Chronic Kidney Disease (CKD) patients, stages 3-4, and further investigated whether long-term therapy with recombinant human erythropoietin (epoetin) has any influence on the plasma PAF-AH activity in vivo or on the enzyme activity secreted from peripheral blood monocytes (PBMs), in vitro. Methods. Forty-eight patients, 28 men and 20 women, with CKD (stages 3-4) participated in the study. Patients were randomized into groups I and II. Patients of group I (n = 28) were administered subcutaneously epoetin, 50 units/kg once per week. The Hb target was 13 g/dl. In group II (n = 20), epoetin was initiated only when the Hb levels decreased during follow-up to less than 9 g/dl. All patients were seen on an outpatient basis at 2, 4 and 6 months. Twenty-two normolipidemic age- and sex-matched healthy volunteers also participated in the study and were used as controls. Results. The PAF-AH activity in plasma of both patient groups at baseline was higher compared to controls, whereas no difference in the HDL-PAF-AH activity was observed among the studied groups. Thus, the ratio of HDL-PAF-AH to the plasma enzyme activity was significantly lower in both patient groups compared to controls. Epoetin administration in the patients of group I was associated with a significant increase in the plasma PAF-AH and in HDL-PAF-AH activities 2 months after treatment, which remained stable for up to 6 months of therapy, a phenomenon not observed in untreated patients of group II. Thus, the ratio of HDL-PAF-AH to the plasma enzyme activity was significantly increased in patients of group I compared to the baseline values, a phenomenon not observed in patients of group II. In vitro treatment with epoetin of PBMs from patients of group I (undergoing therapy with epoetin) resulted in a dose-dependent increase in total and secreted enzyme activity, a phenomenon not observed in patients of group II who did not receive therapy with epoetin. This suggests that the in vivo increase in lipoprotein-associated PAF-AH observed in patients treated with epoetin may be attributed to the drug-induced enhanced secretion of PAF-AH from PBMs of these patients. Conclusions. CKD patients of stages 3-4 are characterized by an increase in plasma PAF-AH activity and a low ratio of HDL-PAF-AH to total plasma enzyme activity. Long-term therapy with epoetin may improve this atherogenic ratio thus this drug may play an important antiatherogenic role in CKD. (EN)

chronic kidney disease (EN)

Πανεπιστήμιο Ιωαννίνων

Ιδρυματικό Αποθετήριο Ολυμπιάς

Σχολή Θετικών Επιστημών

Άρθρα σε επιστημονικά περιοδικά ( Ανοικτά)

ΑΠΟΘΕΤΗΡΙΟ "ΟΛΥΜΠΙΑΣ"

Τμήμα Χημείας

Nephrology Dialysis Transplantation (EN)

Αγγλική γλώσσα

2006

http://olympias.lib.uoi.gr/jspui/handle/123456789/8744

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