Supplementary Material for: Mononuclear Leukocyte Apoptosis and Inflammatory Markers in Patients with Chronic Kidney Disease

Background/Aim: Increased apoptosis along with enhanced inflammation has been reported in hemodialysis and pre-dialysis patients. However, there is limited information at which stage during the progression of chronic kidney disease (CKD) the balance between pro- and anti-apoptotic mechanisms is disturbed and inflammatory response is activated. The aim of this study was to investigate possible alterations in apoptotic and inflammatory markers during CKD (stages 1–4) progression and the probable interactions between them. Methods: In a cross-sectional study, 152 steady-state CKD outpatients (83 males, 55%) with mean estimated glomerular filtration rate 46 (29–76) ml/min/1.73 m2 were studied. Apoptosis was assessed in peripheral blood mononuclear cells by estimating Bcl-2 expression, annexin V-propidium iodine staining and serum soluble Fas (sFas) and Fas-ligand. Serum levels of C-reactive protein, tumor necrosis factor-α (TNF-α), interleukin-6 and plasma levels of fibrinogen were measured as markers of inflammation. Results: Bcl-2 expression was found to decrease significantly in both lymphocytes and monocytes from CKD stage 1 to 4. In contrast, the activity of sFas increased significantly and so did the levels of TNF-α and fibrinogen. The majority of these alterations occurred as soon as patients entered stage 3 of CKD. A multivariate regression analysis demonstrated that CKD remained a significant predictor of the aggregate of the assessed markers. Conclusions: Apoptosis appeared to increase across CKD stages 1–4, and this was associated with increased proinflammatory activity.