A11518 Hemodialysis reduces levels of circulating microparticles in individuals with hypertension

Abstract

Objectives: Individuals with end stage kidney disease (ESKD) and hypertension are at increased risk of cardiovascular complications. Circulating microparticles (MPs) are putative biomarkers of vascular injury and circulating levels of MPs are increased in both hypertension and ESKD. The purpose of this study was to determine the effect of hemodialysis on circulating MPs in individuals with and without hypertension. Methods: 37 individuals with hypertension and 17 normotensive individuals on conventional 3 times weekly hemodialysis were studied (age 61 ± 2 years). Plasma samples from were collected in a non-fasting state immediately before and after hemodialysis at the mid-week hemodialysis session. An FX 800 hemodiafilter (Fresenius Medical Care) was used. Levels of endothelial (CD144 + ), platelet (CD41 + ), leukocyte (CD45 + ) and total (Annexin V + ) microparticles were assessed by flow cytometry. Results: Across all participants, significant reductions were seen in circulating annexin V + ve MPs (3x107vs1.6x107, P < 0.01), platelet MPs (1.8x107vs1.0x107, P < 0.001), leukocyte microparticles (2.4x106vs 1.8x106, P < 0.05), and endothelial MPs (8.4x105vs5.9x105, P < 0.01). There were no differences in pre-dialysis or post-dialysis MP levels (total, endothelial, leukocyte, or platelet) between hypertensive and non-hypertensive individuals and the inter-dialytic increases in MP levels were not significantly different between hypertensive and non-hypertensive individuals. Conclusion: Hemodialysis is associated with reductions in circulating platelet, leukocyte, and endothelial MPs. There may be significant interdialytic variation in MP levels and this should be an important consideration in studying MPs as biomarkers in ESKD. The presence of hypertension does not appear to alter inter-dialytic increases in circulating MPs.