Eryptosis in Patients with Chronic Kidney Disease: A Possible Relationship with Oxidative Stress and Inflammatory Markers

Background. Eryptosis is the programmed death of red blood cells; it may contribute to worsening anemia in chronic kidney disease (CKD). In this clinical condition, different factors induce eryptosis, such as oxidative stress, energy depletion and uremic toxins. In our study, we investigated if the progression of CKD may influence erythrocyte death levels and its relationship with oxidative stress and inflammation. Methods. We evaluated eryptosis levels in 25 CKD patients (five for each stage), as well as markers of oxidative stress and inflammation: myeloperoxidase (MPO), copper/zinc superoxide dismutase (Cu/Zn SOD) and interleukin-6 (IL-6) were evaluated in plasma samples. Results. Higher cell death rate was reported in the highest CKD stages (p < 0.05). Furthermore, we divided CKD patients into two groups (eGFR< or ≥60 mL/min/1.73 m(2)). Patients with eGFR < 60 mL/min/1.73 m(2) had higher eryptosis levels (p < 0.001). MPO, CU/Zn SOD and IL-6 resulted significantly differently between groups (p < 0.001). Significant positive correlations were reported between eryptosis and MPO (Spearman’s rho = 0.77, p = 0.01) and IL-6 (Spearman’s rho = 0.52, p = 0.05) and Cu/Zn SOD. Spearman’s rho = 0.6, p = 0.03). Conclusions. In patients with CKD, different factors are involved in the pathogenesis of eryptosis, in particular uremic toxins and oxidative stress and inflammatory markers. The progressive impairment of renal function may be associated with the increase in eryptosis levels, probably due to the accumulation of oxidative stress factors, inflammatory cytokines and uremic toxins.