Endothelial Protection

At the heart of atherosclerosis is an abnormal and dysfunctional endothelium.  Recent research has discovered a line of stem cells derived from the bone marrow that appear to be important to repair of damaged endothelium – the endothelial progenitor cells (EPC).  Several reports in recent literature describe qualitative and quantitative abnormalities of EPC in uremic and dialyzed patients.  Chan et al. isolated EPCs from 3 groups of subjects (normal control, n=10; conventional HD; n=12 and lNHD, n=10 patients1.  All subjects were matched for age and gender.  None had symptomatic cardiovascular disease.  EPC function was assessed by testing in vitro migratory response to 50ng/ml of vascular endothelial growth factor. LV mass index was derived using 2D echocardiography.  EPC number and function were markedly impaired in CHD patients despite higher doses of erythropoietin.  In contrast, lNHD patients had similar EPC biology to normal controls.  EPC number and function inversely correlated to pre-dialysis urea concentration and LVMI.

Endothelial precursor cell (EPC) number and migratory function in normal controls, conventional HD (CHD) and long nocturnal HD (lNHD). Based on reference 1.

While the exact function and relevance of EPC remains controversial and requires further exploration, that frequent dialysis remarkably restores EPC parameters is indicative that increasing frequency and time in this case of lNHD has profound effects on physiology and homeostasis that are lacking in conventional dialysis.

Reference:

  1. Chan CT, Li SH, Verma S.  Restoration of number and function of endothelial progenitor cells by nocturnal hemodialysis is associated with normal left ventricular geometry in dialysis patients. J Am Soc Nephrol 15:SU-P0370, 2004 (Abstract )